WO2025149757A1

WO2025149757A1 - Hair styling apparatus and method

Info

Publication number: WO2025149757A1
Application number: PCT/GB2025/050044
Authority: WO
Inventors: Ry CUTTER; Robert George Milner
Original assignee: Jemella Ltd
Current assignee: Jemella Ltd
Priority date: 2024-01-12
Filing date: 2025-01-10
Publication date: 2025-07-17
Anticipated expiration: 2026-07-12
Also published as: GB202400492D0; GB2637176A

Abstract

A hair drying and/or styling appliance is provided, comprising: a heater for providing heat for drying and/or styling hair, wherein the heater comprises independently operable heating zones; a processor; and an illumination display located adjacent to at least one side of the heater and comprising independently operable illumination portions; wherein the processor is configured to receive styler values and control illumination of the independently operable illumination portions in dependence on the styler values.

Description

HAIR STYLING APPARATUS AND METHOD

Field of the Invention

The present disclosure relates to a hair drying and/or styling appliance and/or apparatus for and method of operating the same for enhanced user interaction and operability. In some implementations, this includes outputting in real time feedback relating to styler values and/or a status of a styler or styler component, for example feedback relating to styling technique. In particular, aspects of the disclosure relate to: providing information relating to individual zones of a heater using an illumination display located adjacent to that heater; outputting feedback in relation to styling and styling time; providing further sensing capabilities and systems; providing improved systems for storage and retrieval of preferred user settings; providing further capabilities for ensuring systems remain up-to-date via communication with external databases; and providing architectures for connection of multiple users and hair drying and/or styling appliances.

Background to the Invention

Heated hair styling tools use heat to increase the temperature of hair to a desired styling temperature. For example, a hair straightener having a heated plate applies heat directly via conduction to heat the hair, which may be either wet or dry, to achieve the desired temperature for styling. The hair may be heated to a temperature that is particularly suitable for styling hair (for example, to or beyond a hair glass transition phase temperature). At lower temperatures, the user may have to make many passes with the hair straightener over the hair to achieve a desired styling effect, whereas at higher temperatures, there is a risk of causing permanent damage to the hair.

Similarly, a heated brush or hair dryer can also be used to style hair by heating air which in turn heats the hair to a temperature suitable for styling. The hair is typically styled from wet, for example after the user has washed their hair, although the hair could also be styled from dry.

Existing hair styling appliances typically use relatively thick heating plates or heating tubes that provide a certain amount of thermal mass to the hair styling appliance. These heating plates or tubes are heated by a heater that is mounted on an inner surface of the heating plate/tube. As a result of the thermal mass, the heating plates/tubes take time to heat up and, once heated, they can take quite a long time to cool down. This thermal mass makes it quite difficult to control the heating of the hair and over heating or under heating of the hair can result. There has been recent development by the applicant and other companies in developing hair styling appliances that use heaters having a lower thermal mass that can therefore heat up and cool down much more quickly. Such low thermal mass heaters are therefore more responsive and are easier to dynamically vary the temperature with time.

Such low thermal mass heaters are therefore more responsive, heat up faster, and have further capabilities. The inventors have realized that this means that users will be unaccustomed to the capabilities of such products and may misuse the product or at least not use the product to its full potential. The present disclosure seeks to provide improved hair styling devices, systems and parts therefor which enhance the user interaction with the devices and systems. By way of example, aspects of the present disclosure seek to provide feedback to a user as to the status of the device, including their usage of it, for example feedback on how to improve and enhance styling, and feedback reminders to ensure that the styler remains up-to-date on software and safety features. Furthermore, aspects seek to provide further data and information, for example via enhanced sensing capabilities. Additionally, aspects seek to provide further capability for connection of multiple users and stylers and for storing and retrieving user settings, and to provide further capability for communicating with external databases to ensure devices and systems remain up-to-date.

Summary of the Invention

The present invention is set out in the appended independent claims. Optional features are set out in the appended dependent claims. In the following, any examples and embodiments not falling within the scope of the claims do not form part of the invention and are provided for illustrative purposes only.

According to a first aspect, there is provided a hair drying and/or styling apparatus comprising: an elongate hair treatment portion comprising: a heater having a hair contacting surface for heating hair that comes into contact with the hair contacting surface, wherein the heater comprises a plurality of independently operable heating zones arranged sequentially along the length of the elongate hair treatment portion; and an illumination display comprising a plurality of independently operable illumination portions arranged sequentially along the length of the elongate hair treatment portion at a side of the heater so that each illumination portion is positionally aligned with at least one heating zone; and a controller for controlling the operation of the heater and the illumination display; wherein the controller is configured to receive styler values and to control illumination of the independently operable illumination portions in dependence on the styler values.

According to a further aspect, there is provided a hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, wherein the heater comprises independently operable heating zones; a processor (and/or controller); and an illumination display located adjacent to at least one side of the heater and comprising independently operable illumination portions; wherein the processor (and/or controller) is configured to receive styler values and control illumination of the independently operable illumination portions in dependence on the styler values.

The illumination display can advantageously provide real time and intuitive feedback to a user regarding the styler values.

Preferably, individual portions (i.e. the independently operable portions) of the illumination display are configured to portray information relating to at least one corresponding heating zone. In some preferable implementations, the processor (and/or controller) is configured to determine thermal load of the heating zones and/or temperature of hair loaded in the heating zones in dependence on the styler values and the individual portions (i.e. the independently operable portions) of the illumination display are configured to portray information relating to the thermal load of the at least one corresponding heating zone, preferably wherein thermal load comprises thermal load of hair applied to the heating zone and/or relating to the temperature of hair loaded in the at least one corresponding heating zone.

In preferable implementations, the processor (and/or controller) is configured to determine temperature of the heating zones in dependence on the styler values and the individual portions of the illumination display are configured to portray information relating to the temperature of the at least one corresponding heating zone.

In some implementations, the illumination display may comprise at least one illuminated strip comprising a series of the independently operable illumination portions arranged parallel and adjacent to the at least one side of the heater, preferably at least two sides of the heater, and/or preferably adjacent the length of the heater.

Preferably, each heating zone has an extent along the length of the hair treatment portion, wherein each illumination portion is positionally aligned with a respective heating zone and has an extent along the length of the hair treatment portion that is equal to or less than the extent of the corresponding heating zone. This means that there can be clear and direct communication of information relating to each heating zone by each illumination portion.

The portions of the display (i.e. the independently operable illumination portions) may be located adjacent to heating zones and configured to display information relating to those same heating zones. This can assist in displaying clear and intuitive information regarding the heating zones.

In some implementations, the styler values may relate to progression of a styler process, preferably wherein the styler process comprises: heating up; cooling down; loading firmware; styling; and/or loading firmware updates. The illumination display may typically be configured to display information relating to more than one of the styler values and/or styler processes (as appropriate).

Preferably, the control of illumination of the illumination display comprises control of colour and/or pattern and/or animation of the illumination. The illumination display may typically comprise a series of illumination sources (such as LEDs) which can be illuminated in different arrangements to form different colours and/or patterns. Different arrangements may be implemented in a sequence over time such that an animation of the illumination can be output. The appliance and/or apparatus may further comprise a light sensor, and the processor (and/or controller) may be configured to control illumination of the illumination display in dependence on detection of a light level below a threshold value.

The illumination of the illumination display may be asymmetric, for example different patterns may be displayed on different sides of the heater. This can assist with determination of the position of the styler.

Preferably, the illumination display comprises a plurality of LEDs, preferably a plurality of LEDs of different colours. The LEDs may typically comprise a series of RGB LEDs and/or white LEDs.

Preferably, the appliance and/or apparatus further comprises a control display, more preferably wherein the control display is configured to allow a user to control settings of the styler. The control display may typically be a separate component to the illumination display. The control display may also comprise illumination elements, such as an illumination display.

In some implementations, the appliance and/or apparatus may further comprise an inertial measurement unit (IMU), wherein the processor (and/or controller) may be further configured to receive styler values from the IMU and to control illumination of the illumination display (e.g. the independently operable illumination portions) in dependence on the orientation and/or speed of the styler.

In some implementations, the processor (and/or controller) may be configured to determine from the styler values from the IMU that the styler is idle and to control the illumination of the illumination display (e.g. the independently operable illumination portions) to portray that the styler is idle, preferably wherein the illumination comprises an alternative colour scheme.

In some implementations, the appliance and/or apparatus may be configured to operate in a styling mode and a training mode, wherein the heater is set to a higher temperature in the styling mode than in the training mode, and wherein illumination of the illumination display (e.g. the independently operable illumination portions) is controlled according to different colour schemes in the styling mode and the training mode.

The appliance and/or apparatus may further comprise a haptics unit for outputting haptic feedback and/or a speaker for outputting audio feedback.

In preferable implementations, the heater may have a heat up rate greater than 30 °C per second.

Preferably the appliance and/or apparatus comprises a handle portion to facilitate holding of the appliance.

In preferable implementations, the heating zones are arranged immediately adjacent each other along the length of the hair treatment portion. In preferable implementations, the illumination portions are arranged immediately adjacent each other along the length of the hair treatment portion.

In some preferable implementations, the heater may be a multilayer heater comprising a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance and/or apparatus so that during use of the appliance and/or apparatus by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating, wherein the multilayer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a conductive material that generates heat when a current is passed through the one or more heater electrodes; and at least one upper dielectric layer over the heater electrode layer to electrically isolate the heater electrode layer; wherein the multilayer heater has a thickness, as measured across all of the plurality of layers of the multilayer heater, which is between 30pm and 2mm. In some implementations, the average thermal conductivity of the layers forming the multilayer heater is less than 300 W/m.K (preferably less than 200 W/m.K) and greater than 80 W/m.K. The average thermal conductivity may be averaged through the thickness of the multilayer heater.

In some preferable implementations, the controller is configured to control illumination of the independently operable illumination portions in dependence on determining a styling release time in dependence on the styler values. The styling release time as used herein preferably refers to a preferable time for hair to be released from the styler. This may typically be a time at which a controller and/or processor has determined the hair has reached styling temperature (and/or the controller and/or processor has determined the hair is predicted to have reached styling temperature). The controller and/or processor may be configured to determine thermal load of the heating zones in dependence on the styler values, and to determine a styling release time in dependence on the timing of the thermal load.

According to a further aspect, there is provided a hair drying and/or styling apparatus comprising: a multilayer heater having a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating; a controller; and at least one feedback component comprising at least one of: an illumination display; a haptics unit; and a speaker; wherein the controller is configured to detect a thermal loading time of hair on the hair contacting surface of the heater based on styler values and to determine a styling release time relative to the thermal loading time, and wherein the controller is further configured to instruct the at least one feedback component to output feedback in dependence on the styling release time, preferably comprising outputting feedback at the styling release time. In this manner, the styler can output feedback in real time as to when a user should remove their hair from a hair drying and/or styling apparatus. This can facilitate the hair being heated sufficiently to style it effectively, while avoiding overheating the hair.

According to a further aspect, there is provided a hair drying and/or styling apparatus, comprising: a heater for providing heat for drying and/or styling hair; a temperature sensor and/or a power sensor; and a controller; wherein the controller is configured to receive signals from the temperature sensor and/or the power sensor to determine when hair is loaded onto the heater, and wherein the controller is further configured to determine when hair should be released from the heater and to cause feedback to be provided to a user.

A temperature sensor may typically be configured to measure the temperature of the heater, This may be determined by calculating the resistance of an electrode and then determining the temperature using a formula and/or look-up table relating resistance to temperature. A power sensor may typically be configured to measure the power delivered to the heater. The power delivered to each heater electrode can be calculated (and therefore tracked) using the values of current and/or current measured through the resistor and the voltage measured across each heater electrode.

According to a further aspect, there is provided a method of operating a hair drying and/or styling appliance and/or apparatus comprising a heater having independently operable heating zones and an illumination display located adjacent the heater and comprising independently operable illumination portions; wherein the method comprises: receiving styler values; processing the styler values to determine at least one styler status; and controlling illumination of the independently operable illumination portions to portray information relating to the styler status.

According to a further aspect, there is provided a method of operating a hair drying and/or styling appliance comprising an elongate hair treatment portion comprising: a heater comprising a plurality of independently operable heating zones and an illumination display located adjacent the heater; and comprising a plurality of independently operable illumination portions arranged sequentially along the length of the elongate hair treatment portion at a side of the heater so that each illumination portion is positionally aligned with at least one heating zone; wherein the method comprises: receiving styler values; processing the styler values to determine at least one styler and/or styling status; and controlling illumination of the independently operable illumination portions to portray information relating to the styler status.

This can provide a method of displaying information relating to the styler status in a real time and intuitive manner.

The at least one styler status may comprise a series of statuses of the independently operable heating zones and the controlling the illumination may comprise controlling illumination of individual portions (i.e. the independently operable portions) of the illuminated display to portray information relating to the status of at least one corresponding heating zone.

In some preferable implementations, the series of statuses may comprise thermal loads of the heating zones and controlling the illumination may comprise controlling illumination of individual portions (i.e. the independently operable portions) of the illuminated display to portray information relating to the thermal load of at least one corresponding heating zone, preferably wherein thermal load comprises thermal load of hair applied to the heating zone.

In some preferable implementations, the series of statuses may comprise temperatures of the heating zones and/or temperatures of hair loaded on the heating zones and controlling the illumination may comprise controlling illumination of individual portions (i.e. the independently operable portions) of the illuminated display to portray information relating to the temperature of at least one corresponding heating zone and/or the temperature of hair loaded on the at least one corresponding heating zone.

The status may comprise progress of a styler process, preferably wherein the styler process comprises: heating up; cooling down; loading firmware; and/or loading firmware updates.

In some implementations, the controlling of the illumination may be performed according to a different colour scheme in dependence on a mode of the styler, preferably wherein the mode may comprise at least one of: styling mode, training mode, low light mode and idle mode.

According to a further aspect, there is provided a method of operating a hair drying and/or styling appliance comprising a heater, the method comprising: receiving styler values; determining a thermal loading time in dependence on the styler values; and determining a styling release time relative to the thermal loading time.

The method may be implemented in the hair drying and/or styling appliance and/or apparatus as described above.

According to a further aspect, there is provided a hair drying and/or styling appliance and/or apparatus comprising: a heater for providing heat for drying and/or styling hair, wherein the heater comprises a plurality of independently controllable heating zones arranged along a length of the appliance and/or apparatus; a processor (and/or controller); and an illumination strip located adjacent to at least one side of the heater and comprising a plurality of independently controllable illumination portions corresponding to the plurality of heating zones; wherein the processor (and/or controller) is configured to control illumination of the independently controllable illumination portions and to control heating of the independently controllable heating zones.

Preferably, each independently controllable illumination portion is positioned adjacent to a corresponding one or more of the independently controllable heating zones. In some preferable implementations, each independently controllable illumination portion may be aligned with a corresponding one or more of the independently controllable heating zones.

In some implementations, the processor (and/or controller) may be configured, in a first mode, to control the plurality of independently controllable illumination portions in dependence upon a temperature or a loading of the corresponding independently controllable heating zones.

According to a further aspect, there is provided a computer program product comprising computer implementable instructions for causing a programmable device to carry out the method as described.

According to a further aspect, there is provided a hairbrush, comprising: a processor; at least one sensing component; and communications circuitry; wherein the at least one sensing component is configured to collect data relating to hair, motion and/or ambient conditions; and wherein the processor is configured to receive the data, and to communicate said data to external devices via the communications circuitry.

Such a hairbrush can provide further sensing components and capabilities. Such components and capabilities can provide further data, for example relating to user hair, technique and/or ambient conditions. Such data can be processed to provide improved feedback to be output to a user. Hair drying and/or styling components can only comprise a limited number of sensing components and capabilities, without becoming undesirably bulky, heavy and/or expensive. A sensing hairbrush in communication with such an appliance can therefore advantageously provide further data. Additionally, a hairbrush may typically make closer contact with the hair, by interacting with and touching it directly; as such, a hairbrush may be able to perform additional measurements, for example in respect of the hair itself.

According to a further aspect, there is provided a hair drying and/or styling system, comprising: a hairbrush, comprising: a processor; at least one sensing component; and communications circuitry; and a hair drying and/or styling apparatus, comprising: a heater for providing heat for drying and/or styling hair; a further processor; and further communications circuitry; wherein the hairbrush and the apparatus are external to one another and in communication via their respective communications circuitry; and wherein the hairbrush is configured to collect data relating to hair, motion and/or ambient conditions using the at least one sensing component; and the processor is configured to receive the measurements, and to communicate them to the appliance via the communications circuitry.

According to a yet further aspect, there is provided a method of controlling a hair drying and/or styling apparatus, comprising: receiving data from an external hairbrush; processing the data to determine hair characteristics and/or styling technique; and defining settings of the hair drying and/or styling apparatus in dependence on the hair characteristics and/or styling technique. According to a further aspect, there is provided a computer program product comprising computer implementable instructions for causing a programmable device to carry out the method as described.

According to a further aspect, there is provided a hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, a controller; and a memory; wherein the controller is configured to control settings of the appliance and wherein the memory is configured to store the settings as settings data in association with user data.

By storing preferred settings data on the appliance associated with user data, the settings data can be retrieved upon input of the user data. This means that a user can access (and typically implement) their preferred settings even if they connect an unknown device to the styler.

Preferably, the memory is configured to store multiple (for example, different) sets of settings data each associated with respective user data.

According to a further aspect, there is provided a system comprising: a hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, a processor; a memory; and communications circuitry; and a smart processing device external to the appliance, comprising: a further processor; a user interface; and further communications circuitry; wherein the communications circuitry and further communications circuitry are configured to communicate to effect connection of the appliance and the smart processing device; wherein the processor and/or the further processor are configured to control settings of the appliance; and wherein the memory is configured to store settings data in association with user data.

According to a yet further aspect, there is provided a method of operating a hair drying and/or styling appliance comprising a heater, comprising: adjusting settings of the appliance in dependence on user input; and storing to a memory within the appliance the settings of the appliance as settings data in association with user data.

According to a further aspect, there is provided a hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry for connecting to an external database; wherein the controller is configured to prevent user actuation of heating of the heater in dependence on data received from the database.

By preventing user actuation of heating of the heater in dependence on data received from the database, there is provided a safety check to ensure the user has fulfilled all obligations and the hair drying and/or styling apparatus is ‘up-to-date’, for example, on all safety software. This can facilitate a more interactive (for example, subscription-based) arrangement between a supplier and consumer.

According to a further aspect, there is provided a system comprising: a hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry; and a smart processing device external to the apparatus, comprising: a processor; and further communications circuitry; and a database comprising data; wherein the communications circuitry is configured to communicate with the further communications circuitry such that the apparatus and the smart processing device are connectable; and the further communications circuitry is further configured to communicate with the database to retrieve the data; and wherein the controller is configured to prevent user actuation of heating of the heater in dependence on the data received from the database.

According to a further aspect, there is provided a method of controlling a hair drying and/or styling apparatus, comprising: attempting connection of the apparatus to a database comprising data; and preventing user actuation of heating of the heater in dependence on: unsuccessful connection to the database or in dependence on data received from the database.

According to a yet further aspect, there is provided a method of controlling a hair drying and/or styling apparatus, comprising: connecting the apparatus to a central database or server; automatically sending an error report from the apparatus to the central database or server in the event of an error.

According to a further aspect, there is provided a hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry for communicating with smart processing devices; wherein the controller is configured to implement control instructions received from smart processing devices via the communications circuitry; and wherein the controller is configured to implement control instructions of one smart processing device at any one time.

This can facilitate effective control of a styler and can provide safer systems by which (only) one user can control a styler at any one time.

Preferably, the controller may be further configured to output to smart processing devices styler status, wherein the styler status comprises an indication whether a smart processing device is currently controlling the hair drying and/or styling apparatus. For example, in some implementations, the styler status may comprise identification of a smart processing device currently controlling the hair drying and/or styling apparatus. According to a further aspect, there is provided a system comprising: a hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry; and multiple smart processing devices external to the apparatus, each comprising: a processor; and further communications circuitry; wherein the communications circuitry and further communications circuitry are configured to communicate such that the processor of the smart processing devices can output control instructions to the controller; and wherein the controller is configured to implement control instructions received from one smart processing device at any time.

Preferably, the controller is further configured to output to smart processing devices styler status, wherein the styler status comprises an indication whether a smart processing device is currently controlling the hair drying and/or styling apparatus. In some preferable implementations, the styler status may comprise identification of a smart processing device currently controlling the hair drying and/or styling apparatus.

According to a further aspect, there is provided a method of operating a hair drying and/or styling apparatus comprising a heater, comprising: connecting simultaneously to multiple external smart processing devices; receiving from one of the smart processing devices control instructions for the hair drying and/or styling apparatus; and implementing control instructions received from one smart processing device at any one time.

The method may, in some implementations, further comprise outputting to the smart processing devices styler status, wherein the styler status comprises an indication whether a smart processing device is currently controlling the hair drying and/or styling apparatus, and preferably wherein the styler status comprises identification of a smart processing device currently controlling the hair drying and/or styling apparatus.

As used herein, a ‘controller’ may refer to a processor or a combination of processors (typically in communication with one another), which may be located on the same or on different components and/or devices.

The invention extends to methods and/or apparatus substantially as herein described with reference to the accompanying drawings.

Any apparatus feature as described herein may also be provided as a method feature, and vice versa.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

The terms ‘heating zone’ and ‘heater zone’ are used interchangeably.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, and with reference to the drawings in which:

Figure 1a shows an overview of an exemplary hair styling device;

Figure 1 b shows a hair styling device in use;

Figure 2 is a block diagram illustrating the main electronic components of the hair styling device shown in Figure 1 ;

Figure 3a is an exploded view of a heater forming part of the hair styling device shown in Figure 1 ;

Figure 3b is an assembled partially transparent view of the heater shown in Figure 3a;

Figure 4a schematically illustrates the heating zones on the heating surface of the heater shown in Figure 3;

Figure 4b schematically illustrates an alternative arrangement of heating zones;

Figure 5 schematically illustrates a further alternative arrangement of heating zones that are of different sizes and shapes;

Figure 6a illustrates the way in which the heating zones may be formed on a tubular substrate for use in a curling tong or the like;

Figure 6b illustrates the way in which the heating zones may be arranged on a curved substrate which may be used on a heated brush;

Figure 7 illustrates a tress of hair that partly overlaps with zones Z2 and Z4 of a heater;

Figure 8 illustrates a cross-sectional view of a further example of a low thermal mass heater that has curved edges and a supporting substrate onto which the heater is attached with an adhesive or via a diffusion bonding process (e.g. by melting them together);

Figure 9 is a partially exploded cross-sectional and perspective view of the different layers that form the heater shown in Figure 8;

Figure 10 is a plan view illustrating the form of a heat spreading layer forming part of the heater illustrated in Figure 8;

Figure 11 illustrates a main heating element layer forming part of the heater shown in Figure 8; Figure 12 is a simplified block diagram illustrating the way in which the heater electrodes of the heater shown in Figure 8 are used to heat the heater and to sense the temperature of the heating zones; Figure 13 is a partially exploded cross-sectional and perspective view of another heater assembly;

Figure 14a is an exploded view from above of a flexible heater, an adhesive layer and a heater support;

Figure 14b is an exploded view from below of the flexible heater, adhesive layer and heater support shown in Figure 14a;

Figure 15 illustrates a main heating electrode layer forming part of the heater shown in Figure 14;

Figure 16 illustrates a heat spreading a fuse layer forming part of the heater shown in Figure 14;

Figure 17a illustrates in more detail fuse circuitry shown in Figure 16;

Figure 17b illustrates in more detail fuse circuitry shown in Figure 16;

Figure 18a is a cross-sectional view of the heater assembly shown in Figure 14 illustrating a fuse when intact;

Figure 18b is a cross-sectional view of the heater assembly shown in Figure 14 illustrating when the fuse has melted due to overheating;

Figure 19 is a simplified schematic diagram of drive and control circuitry that can be used to control the heating of the heater shown in Figure 14;

Figure 20 illustrates a schematic side view of a hair styler comprising an illuminated display and illuminated strips;

Figure 21 illustrates a schematic top view of an arm of a hair styler comprising a heater with individual heating zones and illuminated strips either side of the heater;

Figure 22 illustrates a schematic top view of an alternative arrangement of an arm of a hair styler comprising a heater with individual heating zones and illuminated strips either side of the heater;

Figure 23 illustrates a schematic top view of a yet further alternative arrangement of an arm of a hair styler comprising a heater with individual heating zones and illuminated strips either side of the heater;

Figure 24 is a block diagram illustrating the main electronic components of the hair styling device shown in Figures 20 to 23;

Figure 25a illustrates a hair styler in heating mode;

Figure 25b illustrates a hair styler once heated;

Figure 26 illustrates a tress of hair across heating zones of a heater and the corresponding illumination if the illuminated strips;

Figure 27 illustrates a first method of indicating to a user when to remove hair from the heater;

Figure 28 illustrates a second method of indicating to a user when to remove hair from the heater;

Figure 29 illustrates a third method of indicating to a user when to remove hair from the heater;

Figure 30a illustrates a hair styler while firmware updates are loading;

Figure 30b illustrates a hair styler once firmware updates have been installed; Figure 31a illustrates a hair styler while firmware updates are loading according to an alternative implementation;

Figure 31 b illustrates a hair styler once firmware updates have been installed according to the alternative implementation;

Figure 32a illustrates a left side of the styler in a low light mode;

Figure 32b illustrates a right side of the styler of Figure 32a in a low light mode; and

Figure 33 shows a process flow illustrating how feedback is determined in dependence on styler values

Figure 34 shows an exemplary system in which hair stylers and smart brushes are in communication with one another, and with smart processing devices and a cloud-based processing unit;

Figure 35 shows a block diagram illustrating the main electronic components of a sensing brush;

Figure 36 shows an exemplary system comprising smart processing devices in communication with hair stylers;

Figure 37 shows an exemplary logic flow of a processor of a hair styler;

Figure 38 illustrates an exemplary data storage protocol of a hair styler;

Figure 39 illustrates an exemplary system comprising a hair styler, a smart processing device and a database;

Figure 40 shows an exemplary logic flow of a hair styler and system;

Figure 41 shows a further exemplary logic flow of a hair styler and system;

Figure 42 shows a yet further exemplary logic flow of a hair styler and system;

Figure 43 shows an exemplary multi-user system;

Figure 44 illustrates an exemplary user interface of a user smart processing device;

Figure 45 shows an exemplary multi-styler system;

Figure 46 illustrates a further exemplary user interface of a user smart processing device;

Figure 47 illustrates a further example of a multi-user system and network; and

Figure 48 illustrates an exemplary multi-user system and network comprising an administrator user.

Detailed Description of Preferred Embodiments

Overview of Hair Styling Device

Figure 1a illustrates a hand held (portable) hair styler 101. The hair styler 101 includes a first movable arm 104a and a second movable arm 104b, which are coupled at proximal ends thereof to a shoulder 102. The first arm 104a bears a first heater 106a at its distal end, and the second arm 104b bears a second heater 106b at its distal end. The first and second heaters 106a, 106b oppose one another and are brought together as the first and second arms 104a, 104b are moved from an open configuration to a closed configuration. As shown in Figure 1 b, during use, a tress of hair 140 is sandwiched between the two arms 104 so that the user’s hair is in contact with, and therefore heated by, outer heating surfaces of the heaters 106a, 106b. Therefore, as the user pulls the hair styler 101 along the tress of hair 140, the tress of hair 140 is heated by conductive heating to a suitable temperature to facilitate styling.

One or more user interfaces 111 are provided to allow the user to set user defined parameters and for the device to output information to the user. For example, a desired operating temperature may be set via the user interface 111. The user interface 111 may have a dial, button or touch display for allowing the user to input information to the device 101 and the user interface 111 may have an indicator light, display, sound generator or haptic feedback generator for outputting information to the user. In this embodiment, the user interface 111 also comprises a control button or switch 114 to enable the user to turn the device 101 on or off; and an indicator light 115 to show whether the power is on.

A printed circuit board assembly (not shown) may be provided at any suitable location within the housing of the device 101 and carries the control circuitry for controlling the operation of the device 101 and for controlling the interaction with the user via the user interface 111 . In this example, electrical power is provided to the device 101 by means of a power supply located at an end of the device, via a power supply cord 103. The power supply may be an AC mains power supply. However, in an alternative embodiment the power supply may comprise one or more DC batteries or cells (which may be rechargeable, e.g. from the mains or a DC supply via a charging lead), thereby enabling the device 101 to be a cordless product.

In use, the device 101 is turned on, energising the heaters 106 to cause them to heat up. The user then opens the first and second arms 104a, 104b and, normally starting from the roots of the hair (i.e. near the scalp), a length or tress of hair 140 (which may be clumped) is introduced between the arms 104a, 104b, transversely across the heaters 106a, 106b. The user then closes the arms 104a, 104b so that the length of hair 140 is held between the first and second arms 104a, 104b and then the user pulls the hair through the closed arms (as illustrated in Figure 1b). The outer (hair contacting) surface of the heaters 106 is flat in this embodiment and so the hair styler 101 can be used to straighten the user’s hair. The hair styling device 101 shown in Figure 1 can also be used to curl the hair by turning the device 101 through approximately 180 degrees or more after clamping the hair between the arms 104a, 104b and before moving the device 101 along the tress of hair 140.

Hair has a relatively high thermal mass and when in contact with the heating surface of the heater 106 the hair absorbs a significant amount of the heat energy. The heaters 106 must quickly supply the lost heat energy back to the heating surface otherwise the temperature of the heating surface will drop and potentially impact on the quality of the thermal styling. If the temperature of the heaters 106 falls below the glass transition temperature of the hair, the hair will not retain the styled shape. However, if the hair is heated to a temperature that is too high, the hair can undergo significant damage. As such, the device 101 must be able to control the temperature so that the heating surface of the heaters 106 remains within a particular temperature range. Furthermore, it must maintain the temperature range both when hair is frequently and quickly loaded and unloaded onto the heating surface, and when hair is held on the heating surface for a prolonged period of time.

Control Circuitry

Figure 2 is a simplified block diagram of control circuitry 215 that controls the operation of the hair styler device 101 shown in Figure 1. As shown, the control circuitry 215 comprises a power supply 221 that, in this embodiment, derives power from a battery power source (not shown). A mains power supply input may be provided to charge the battery via an AC to DC converter (not shown), which may be external or internal to the device 1. Alternatively, the power supply 221 may derive power from an AC mains supply input.

In this example, power is provided to the heaters 206 for heating the user’s hair. The power supplied to the heaters 206 is controlled by a controller 228 having a microprocessor 229. The power supplied to the heaters 206 is controlled by drive circuitry 223 (which may include one or more power semiconductor switching devices (triacs)) which controls the application of an AC mains voltage, or a DC voltage derived from the AC mains or from a battery, to the heaters 206 in accordance with instructions from the microprocessor 229. The microprocessor 229 is coupled to a memory 230 (which is typically a non-volatile memory) that stores processor control code for implementing one or more control methods that control the heating of the heaters 206 in accordance with a desired operating temperature of the heaters 206 and sensed temperatures of the heaters obtained from temperature measurement circuitry 225. The temperature measurement circuitry 225 may be temperature sensors such as thermistors or they may use circuitry that senses the resistance of heater electrodes that are used to heat the heaters 206, which resistance depends on the temperature of the heater electrode.

Figure 2 also shows that the user interface 211 is coupled to the microprocessor 229, for example to provide one or more user controls and/or output indications such as a visual indication or an audible or haptic alert. The output(s) may be used to indicate to the user, for example, if they have inserted too much hair between the heaters 206 or if they are moving the device 101 too quickly along the hair tress 140.

Finally, the control circuitry includes communications circuitry 227 to allow the device to communicate with a remote sensor, a remote server, or a remote application (e.g. on a mobile telephone). The communications circuitry 227 may use, for example, Bluetooth, Wi-Fi and/or 3GPP communication protocols to communicate with the remote device. Heaters

The heaters 306a, 306b are low thermal mass heaters and can therefore heat up and cool down quickly. Figures 3a and 3b show an exemplary embodiment of such heaters 306a, 306b, which comprise a stack of thin layers. Referring in particular to Figure 3a, the heaters 306a, 306b include an upper dielectric (electrically insulating) layer 362, an electrode layer 363 that has a plurality of separate heater electrodes 364, and a lower dielectric layer 366 which electrically insulates the heater electrodes 364 from other components mounted behind the heater 306a, 306b. The three layers 362, 363 and 366 are bonded together either through an adhesive layer (pressure set or thermoset) or through diffusion bonding of the contacting materials (e.g. melting them together) and define a heater 306 that is very thin (the three layers have an overall thickness of between 30 pm to 1000 pm (preferably between 75 pm and 300 pm) in the case of low voltage operation (less than about 40 Volts) and 0.8 mm to 2.0 mm in the case of AC operation) and with very low thermal mass. The upper surface of the layer 362 provides the hair contacting surface of the heater 306, although a non-stick coating may be applied to the upper surface of the layer 362 to facilitate the passage of the user’s hair over the heating surface. The bonded layers 362, 363 and 366 define a flexible heater 306 and rigidity of the heater is provided in the illustrated embodiment by mounting the heater layers 362, 363 and 366 into a rigid support 368 which forms a base. These layers may be mounted onto the rigid support after the layers themselves have been bonded together or they may be bonded one at a time (or multiple at a time) onto the rigid support 368. If a flexible heater is desired, then there is no need for the rigid support 368 or if a support is used, this may be a non-rigid support. Thus, in this embodiment, there is no heater plate or tube that is heated by the heaters 306, and instead, the heaters 306 directly heat the user’s hair. This provides a hair styler 101 having a very low thermal mass which can therefore heat up and cool down much more quickly than prior art stylers.

In the illustrated embodiment, there are ten heater electrodes 364 that each snake across and back across the width of the heater 306, folding twice such that they each cross the width three times. The ends of each of the heater electrodes 364 are electrically connected through the lower dielectric layer 366 to electrical connections within the rigid support 368, which connect to an electrical connector 370. Drive circuitry 223 that is mounted within one of the arms 104 connects to the heater electrodes 364 via the electrical connector 370 and applies electrical power to the individual heater electrodes 364 to control the heat generated by each heater electrode 364. The electrical connector 370 extends from a surface of the rigid support 368 facing away from the surface layer 362 (shown in Figures 3a and 3b as extending directly away from the upper layer 362, but it could also be provided as extending in a perpendicular direction).

Each of the heater electrodes 364 thus creates an individual heating zone 467 on the hair contacting surface of the heater 306, which spans the width (which we shall refer to as the x-direction) of the heater 306 and the heater electrodes 364 are arranged sequentially one after the other along the length (the y-direction) of the heater 306. Figures 4a and 4b show schematic views of different arrangements of such heating zones 467. Figure 4a shows an arrangement corresponding to that of Figures 3a and 3b, in which the heating zones 467-1 to 467-10 are arranged along the y-direction only. Figure 4b shows an alternative arrangement, in which heating zones 467-1 to 467-16 are arranged in both the x- and y-directions. Such an arrangement of heating zones 467 can be provided by arranging two sets of heater electrodes 364 like those shown in Figure 3a side by side in the width (x-) direction. The heaters 406 may be separated in this way into any number of heating zones 467 and may comprise any number of heating zones along the x- and y-directions. In particular, whilst Figure 4b shows two zones along the x-direction, a greater number of zones in the x-direction could also be provided. The heating zones 467 of the heaters 406a, 406b can be operated (heated) independently, which can help to reduce hot/cold spots when using very low thermal mass heaters 306 such as those shown in Figure 3.

The heating zones illustrated in Figure 4 are all the same size. Of course, different sized heating zones 467 may be provided, as illustrated in Figure 5, which shows a heater 506 having seven different sized heating zones (labelled 5Z1 to 5Z7). The way in which the heater electrodes 364 would be arranged to define these different sized zones would be understood by the skilled reader and will not be described in detail here.

The heating zones 467 described above form part of a heater having a flat hair contacting surface. The heater is not limited to flat hair contacting surfaces and can be configured for use in a tubular form, with heating zones labelled 6Z1 to 6Z4 (as illustrated in Figure 6a), for example for use in a hair curler device or in a curved form, with heating zones labelled 6Z1 to 6Z6 (as illustrated in Figure 6b), for example for use in a heated hair brush. The heater surface may have a corrugated or ribbed shape to provide a hair crimping device.

The temperature of each heating zone 467 is independently controllable. Each heating zone 467 can be set to a target temperature. The target temperature of each heating zone 467 may be different. A separate temperature sensor may be provided for sensing the temperature of each heating zone 467 which is fed back to the microprocessor 229 to allow the microprocessor 229 to control the delivery of power to the heater electrode 364 of the corresponding heating zone 467. Alternatively, if the heater electrodes 364 are formed of a material having a Positive Temperature Coefficient (PTC) or a Negative Temperature Coefficient (NTC) (such that its resistance varies with its temperature), then the temperature of each heating zone 467 can be determined by determining the resistance of the corresponding heater electrode 364. The microprocessor 228 controls the heating in order to reduce the difference between the actual temperature of the heating zone 467 and the target temperature for that heating zone 467. Heating Zone Sizing

One issue with low thermal mass heaters 306 is the regulation of hair contacting surface temperature in the locally hair loaded regions of the heater within desired temperature limits, without causing overheating of the unloaded regions at the same time. Specifically, when the user loads a tress of hair 140 onto the heaters 106, some parts of the heater will be loaded with hair whilst other parts will not be loaded with hair. Upon loading with hair, more power is supplied to the heater 306 to ensure that all regions on the hair contacting surface can be retained within and/or recovered back to the desired operating temperature limits. The low thermal mass heaters 306 described above are relatively thin and the dielectric layers are formed of materials with relatively low thermal diffusivities. If there was just a single heating zone, and hence a single continuous heater electrode 364 running across the whole length and whole width of the heater 306, then when more power is supplied to the heater 306 to recover the temperature drop in the locally hair loaded regions, the unloaded regions would undergo overheating, which could cause the heater materials to exceed their maximum operating temperatures, or cause the overheated regions to burn relatively small bundles/strands/tresses of hair that come into contact with them. This overheating can be prevented by using materials with higher thermal diffusivities in the layers that constitute the heater, and/or by increasing the thicknesses of the layers that constitute the heater and/or by dividing the heater 306 into multiple separately powered and controlled heating zones 367 across its length or its length and width. Increasing the thickness of the layers increases the thermal mass of the heater 306 which is undesired and there are limited materials that have the required dielectric strength and high thermal diffusivity (and which are available for use in mass produced consumer products). Therefore, the inventors have divided the heaters 306 up into plural heating zones. These heating zones can be equally and/or unequally sized and can be arranged regularly and/or irregularly across the width and length of the heater.

However, overheating can still occur within a single heating zone. For example, if half of the heating zone is loaded with hair (which is assumed to be the realistic worst case scenario during operation) and the other half is not loaded with hair, then the half that is loaded with hair will cause the temperature of that part of the heating zone to drop which will cause more power to be applied to that heating zone in its entirety. That applied power will bring the average temperature of the heating zone back up to the desired operating temperature, but the unloaded part of the heating zone will be above the average temperature of the heating zone. This temperature increase may be sufficient to cause the unloaded part to overheat. At the same time the loaded part of the heating zone will be below the average temperature causing a reduction in heat transfer and reduced styling performance. This situation is illustrated in Figure 7, which shows a tress of hair 740 overlying heating zones 7Z2, 7Z3 and 7Z4, with heating zone 7Z3 being fully loaded with hair and heating zones 7Z2 and 7Z4 being only partially loaded with hair. This problem can be reduced by making the heating zones very small - but that is costly due to all the connections needed to connect each heater electrode 364 for each heating zone back to the drive circuitry 223 as well as the number of control switches in the drive circuitry 223 needed to control the powering of each heater electrode 364. The inventors have found that for a given permitted maximum temperature within the heater, a maximum size of the heating zones can be defined which depends on the maximum power density to hair that can be extracted from the heating zone and the material characteristics and thicknesses of the layers forming the heating zone.

Specifically, if it is assumed that only one half of a heating zone 642 is loaded with hair, upon loading with hair, the maximum temperature that occurs in the unloaded half of a heating zone 642 can be defined with the equation below: q. W²

T ^l max — T'Tar

16t. k where,

T_Max ⁼ maximum temperature (°C) on the surface of the heater which would occur in the unloaded half (worst case) of an individual heating zone;

T_Tar = target operational temperature or average temperature (°C) of individual heating zones; q = power density (Wnr²) required to heat hair passing over the surface to the desired temperature for styling;

W = width of a heating zone measured perpendicular to the motion of hair over the surface; t = total thickness of the layers that constitute the heating zone; and k = the thickness averaged thermal conductivity of the thin layers that constitute the heating zone.

If it is assumed that the thickness averaged thermal conductivity of the constituent layers of a heating zone 467 and the total thickness of the layers that form the heating zone 467 are known and fixed (for any given device), then the above equation can be used to determine the required zone width (W) and hence a number of divisions along the length of the heater that will prevent overheating of the unloaded halves, when their other halves are loaded with hair, and more power is supplied to maintain and/or recover the hair contacting surface temperatures back to the desired operating limits. Consequently, for a given surface area that must be covered with the considered heater technology, the equation above can be used to determine the number of heating zones that should be positioned along the length of the given surface area, so that each heating zone 467 can be operated without exceeding the maximum operating temperature of the heater materials and without causing the temperature of the unloaded part of a heating zone 467 to exceed the maximum temperature (AT_mra) that could cause burning of relatively small bundles/strands/tresses of hair that come in contact with such overheated regions of the heating zone.

Specifically, the required divisions along the length can be determined from:

Where,

L = length of the heater plate (perpendicular to the direction that hair typically travels across the surface); n_L = number of zonal divisions along the length of the heater plate;

T_Max ⁼ maximum permitted temperature (°C) on the surface of the heater (which would occur in the unloaded half (worst case) of an individual heating zone) needed to avoid damage to hair or the heater;

T_Tar = target operational temperature or average temperature (°C) of individual heating zones; k = the thickness averaged thermal conductivity (Wm’¹°C’¹) of the layers that constitute the heating zone; t = total thickness of the layers that constitute the heating zone; and q = maximum power density (Wnr²) required to heat hair passing over the surface to the desired temperature for styling.

For a hair styling device, the inventors have found the following suitable ranges for these parameters:

Peak power density required for styling dry hair (q) is typically greater than 40,000 W/m² and less than 100,000 W/m².

The average thermal conductivity of the layers forming the heating zone (k) (averaged through the depth of the various layers) is between 80 and 200 W/m.K.

The maximum permitted temperature of a heating zone to manage (ideally avoid) hair damage is less than 250°C, more preferably less than 220°C and most preferably less than 200°C.

The total thickness of the layers (t) which make up the heater is less than 300pm but no less than 75pm due to manufacturing limitations. The target operational temperature of the heater (T_Tar) is between 150°C and

230°C.

Operating within these ranges, the inventors have found that the required number of heating zones per unit length (cm) along the length of the heater is between 0.6 and 2.5 per cm which is equivalent to a zone width (in the lengthwise direction of the heater) of between 0.4 cm and 1.7 cm.

Of course, this is for the case of there not being multiple zones in the width direction of the heater as well (e.g. this is for the single row case shown in Figure 4a). If multiple rows of heating zones 467 are provided along the length of the heater (such as is shown in Figure 4b), then each row of heating zones 467 should meet the limits defined above if the above-described overheating problem is to be avoided.

Alternative Heater Arrangement

An alternative flexible heater 806 is illustrated in Figure 8, which shows on the left hand side an exploded cross-sectional view of the heater 806 and substrate 868 and on the right hand side a perspective view of the heater 806 and substrate 868. As shown in Figure 8, the heater 806 has curved edges 872-1 and 872-2 that are shaped to match the shape of an upper surface 874 of the rigid support substrate 868 so that the flexible heater 806 can be bonded securely using an adhesive, or diffusion bonding (thermoforming) of the underlying materials to the upper surface of the rigid substrate 868, or by over-moulding in which the carrier is injection moulded over the back of the flexible heater within the mould. The curved edges of the heater 806 can be formed, for example, using a heat forming process. Figure 8 also illustrates that one or more surface mounted electronic components 876 may be attached to an underside of the heater 806. These components may be, for example, thermistors for sensing the temperature of the heating zones 867 of the heater 806 or fuses that can cut power to the heater electrode of each zone or all the zones in the case of a zone overheating. Figure 8 also shows a control printed circuit board (PCB) 878 that carries the drive and control electronics 215 illustrated in Figure 2 that controls the heating of the different heating zones 867 of the heater 806.

As before, the heater 806 is formed from a number of discrete layers that are mechanically or chemically bonded together. Each layer has a thickness between about 1 pm and 150 pm and preferably between 1 pm and 100 pm, more preferably between 10 pm and 70 pm or between 2 pm and 10 pm. The different layers forming part of the heater 806 are shown in exploded cross-sectional and perspective views in Figure 9. A description of each layer is given below. Low Friction Coating 981 (optional)

This is an optional layer and can be added to create a smooth, low friction surface to enhance the user experience by making the heater 806 feel less grippy against the hair. This layer would be as thin as possible (for example, between 1 and 3 pm) to reduce the thermal resistance from the heater 806 to the hair, whilst still being sufficiently durable and scratch resistant.

This layer would typically be applied last, possibly as a spray coating (e.g. Cerasol), after the rest of the heater 806 has been produced and assembled around the rigidifying substrate 868. This is needed because the coating is prone to cracking when flexed (e.g. inherently rigid), and once applied the coating will reduce the natural flexibility of the heater, and so it should be applied once the heater 806 has been formed into its final shape.

Alternatively, this coating may comprise multiple layers including, for example, a primer layer (of about 6pm), a base coat layer (of about 25pm) and a top coat layer (of about 10pm).

Heat Spreading Layer 982 (optional)

This is also an optional layer and, when provided, helps to spread the heat within each heating zone 467 to ensure that the temperature of individual heating zones 467 is able to maintain an acceptable degree of homogeneity during typical use. As discussed above, if a heating zone 467 was to be partially loaded with hair and was sufficiently large, the unloaded portion of the heating zone 467 could develop an unacceptably high temperature, whereas the loaded region would be too cold, as heat could not adequately flow from the hot region to the cold region. This problem is exacerbated by the anisotropic thermal characteristics of the serpentine like heater electrodes 364, and by the fact the control electronics 215 would typically work to maintain an “average” temperature within the heating zone 467 based on the overall resistance of the heater electrode that forms the heating zone 467 - from the perspective of the control electronics 215, the heating zone 467 would be at the “correct” temperature despite having hot and cold regions.

Each heating zone 467 would have its own heat spreader, which is thermally separated (there is a high thermal impedance/low thermal conductivity) from the heat spreaders for adjacent zones. This is desirable to prevent heating zones 467 from heating neighbouring heating zones 467 which might otherwise increase power consumption, reduce warm up time and complicate algorithms based on zonal power consumption by adding crosstalk. Figure 10 illustrates an example form of the heat spreader layer 1082. As shown, in this example there are 20 heat spreaders 1091-1 to 1091-20, each formed of a relatively high thermal conductivity material (such as copper). Each heat spreader 1091 is separated from its neighbouring heat spreaders 1091 and in effect forms an island of thermally conductive material over the corresponding heating zone. The heat spreaders 1091 may be separated from each other by a solid material having a thermal conductivity lower than 35 W/mK or they may be separated by air. The heat spreaders 1091 may be formed, for example, by taking a planar layer of metal (such as a layer of copper) that is bonded onto the layer below and then etching this layer of copper to physically separate the individual heat spreaders 1091 (so that they do not touch each other). Provided there is a break between neighbouring heat spreaders 1091 , it is difficult for heat from one heating zone 467 to pass into neighbouring heating zones 467. The solid material (dielectric and/or scratch resistant low friction material(s)) that is provided in the gap between adjacent heat spreaders 1091 may be provided by a PVD DLC, bond film, coating or a wash that is applied to the heat spreading layer 1082 after the etching process has formed the gaps between adjacent heat spreaders 1091 and may be the coating layer 1081 described above. Alternatively other suitable methods may be used to provide solid material in the gap between adjacent heat spreaders, such as masking and vapour deposition etc.

In some embodiments, it may be desirable to provide an electrical connection between neighbouring heat spreaders - for example to ground the heat spreading layer. In this case the individual heat spreaders may have some conducting material connecting them with at least some of their neighbouring heat spreaders. Even though an electrical connection is provided between adjacent heat spreading elements, as long as the connection is relatively small (for example less than 1/1 Oth of the length/width of the heat spreader), there will still be, in effect, a thermal break or thermal decoupling between immediately adjacent heat spreaders. In one possible implementation, each heat spreader may be electrically connected to the vias that couple to the common terminal of the heater electrodes. This will prevent the build-up of unwanted static in the heat spreading layer and may also obviate the need for a busbar as the connection to the electronics can then be made by connecting to the heat spreader(s) closest to the edge of the flexible heater. However, since there is minimal physical connection between adjacent heat spreaders, they can still perform the desired function of spreading the heat within the respective heating zones whilst minimizing the spread of heat from one zone to an adjacent zone or zones.

This layer 1082 can provide mechanical integrity to the overall heater 806, providing some protection from damage to the hair contacting surface that might otherwise expose the underlying heater electrodes 364, which in turn could lead to short circuits or loss of functionality.

Polyimide Separator layer 983

The polyimide separator layer 983 provides electrical insulation between the hair contacting surface of the heater 806 (which may be the upper surface of this layer 983 if the optional layers 981 and 982 are not provided) and the main heater electrode layer. This layer 983 would have as low thermal impedance as possible whilst still achieving the dielectric requirements of the layer. As the name suggests, this layer is formed of polyimide, although other dielectric materials could be used. Because this layer is relatively thin, the in-plane thermal diffusivity or thermal conductivity of this layer (in a plane perpendicular to its thickness) is quite low (less than 35 W/mK). This helps to prevent heat spreading from one heating zone 467 to an adjacent heating zone 467. Main Heater Electrode & Sensing Layer 984

This layer 984 is where heat is created by dissipating electric power from the power source (e.g. a power supply unit (PSU) or one or more batteries).

This layer 984 comprises a number of independently controllable heater electrodes 364 each defining a corresponding heating zone 467. Independently controllable means that each heating zone can be heated to any desired target temperature (or switched on/off) independently of the other heating zones. So, the set point temperature of a heating zone may, if desired, be different from the set point temperature of other heating zones. Figure 11 illustrates in more detail the form that this layer 984 takes in this example heater 806. As shown, in this example, there are twenty independently controllable heater electrodes 1164-1 to 1164-20 that each defines a corresponding heating zone 467. Each heater electrode 1164 is formed of a track of resistive material, whose geometry (track width, thickness, length) and material is specified in order to achieve the desired resistance and peak power requirements for the relevant power source.

Each heater electrode 1164 is formed into a serpentine pattern using, for example, chemical etching as a manufacturing process. In more detail, a solid layer of electrically conductive material is provided and then etched to form the different heater electrodes 1164. The straight lines shown in Figure 11 are the etched parts of the layer 984 and the white parts of the figure show the serpentine conductor paths that form the heater electrodes 1164. Other processes such as printing, thick film printing, physical vapour deposition and the like could be used to form the heater electrodes 1164. In this illustrated example, adjacent heater electrodes 1164 share a common positive terminal (although in other embodiments they may share a common ground terminal) to reduce the number of electrical connections needed to be made between the drive and control board 878 and the heater 806. This common positive terminal is connected to the different heater electrodes at suitable vias 1165-1 to 1165-5, which connect through to connection circuitry below (not shown) that connects to the drive and control board 878. The other end of each heater electrode connects through a respective switch (not shown) to the drive and control board 878 to allow independent control of current flow through each heater electrode 1164. As those skilled in the art will appreciate, it is not essential to have such a common positive (or ground) terminal, each heater electrode 1164 may be physically separate from all other heater electrodes 1164 in which case, each end of each heater electrode 1164 would be connected separately back to the drive and control board 878.

As schematically illustrated in Figure 11 , the end of each heater electrode 1164 that is connected to the switch is provided at the side of the heater and the direction of the serpentine tracks changes in this edge portion (which corresponds to the portion of the heater which is curved over the upper surface 874 of the rigid support substrate 868). The inventors have found that this arrangement helps heat generated in the heater electrodes 1164 in these edge portions to pass up to the top surface of the heater which is more likely to come into contact with the user’s hair. However, if the device is twisted in use such that the user’s hair comes into contact with the curved edge portion, then the hair will still be heated as this curved edge portion is heated.

The conductive material used in the layer 984 is preferably a PTC or an NTC material (such as stainless steel or copper) so that the resistance of the heater electrode 1164 depends upon its temperature - and so the temperature of the heating zone 467 can be determined by measuring a parameter that varies with the resistance of the corresponding heater electrode 1164. This removes the need for separate temperature sensors for each heating zone as a single sensor can be used to measure the temperature of each heating zone (as discussed below with reference to Figure 12).

Figure 12 is a schematic view of the way in which the heater electrodes 1264 may be connected together and to the drive circuitry 1223 and the power supply 1221. As shown in Figure 12, each heater electrode 1264 is connected at one end to the power supply 1221 and at the other end to a respective switch (in this case a MOSFET switch) 1295-1 to 1295-20. The switches 1295 are controlled by the microprocessor 1229. When a heater electrode 1264 is to provide heat, the corresponding switch 1295 is closed thereby connecting the heater electrode 1264 to ground through the resistor 12R. As a result, current flows from the power supply 1221 to ground causing the heater electrode 1264 to heat up. The microprocessor 1229 can control the position of each switch 1295 independently thereby allowing each heater electrode 1264 to be powered independently.

When the temperature of a selected heating zone 467 is to be determined, the switch 1295 of the corresponding heater electrode 1264 is closed and all other switches 1295 are opened. In this way, the selected heater electrode 1264 is provided in series with the resistor 12R. Since the heater electrodes 1264 are formed of a PTC or an NTC material whose resistance changes with the temperature of the heater electrode 1264, by measuring the voltage drop across the resistor 12R (using the operational amplifier 1297), the microprocessor 1229 can determine the resistance of the selected heater electrode 1264 and hence can determine the temperature of the corresponding heating zone 467. If the determined temperature is above the desired temperature for that heating zone 467, then the microprocessor 1229 can reduce the power applied to that heater electrode 1264; or if the heating zone 467 is at a lower temperature than that desired, then the microprocessor 1229 can increase the power applied to the corresponding heater electrode 1264. Any suitable ON/OFF control or PWM (pulse width modulation) control can be used to vary the power applied to the different heater electrodes 1264. The microprocessor 1229 can select each heater electrode 1264 in turn in order to determine the temperature of each heater electrode 1264/heating zone 467.

Polyimide Separator (Optional) 985

When an auxiliary heater electrode layer is provided, this layer is required to provide the required electrical separation (insulation) between that auxiliary heater electrode layer and the main heater electrode layer 984 described above. This polyimide layer 985 would have a low thermal resistance in the thickness direction whilst still achieving the dielectric requirements. Due to this layer being relatively thin, it will have a low thermal conductivity in the plane perpendicular to its thickness of less than about 35 W/mK. Other dielectric materials could be used instead of polyimide.

Auxiliary Heater Electrode Layer (Optional) 986

Some embodiments of the heater 806 may benefit from the presence of an additional heating element layer 986. This additional layer 986 could be used to dissipate power (create heat) from a secondary power source that operates at a different voltage to the main power source 221 , for example the main power source could be a power supply and the power source for the auxiliary heater electrode layer 986 could be one or more batteries or supercapacitors. In other embodiments the primary source could be one or more batteries and the auxiliary one or more supercapacitors. Alternatively still, the conductors on this auxiliary layer 986 could become the primary heaters, and those on the main heater electrode layer 984 would just be used for temperature sensing or vice versa.

The heater electrodes on the auxiliary layer 986 will typically have the same form as the heater electrodes 1164 used in the main heater electrode layer 984 - so that they will define the same heating zones 467 as the heating zones 467 defined by the heater electrodes 1164 on the main heater electrode layer 984. The path taken by the heater electrodes on the auxiliary layer 986 does not need to follow the same path as the corresponding heater electrodes 1164 formed on the main heater electrode layer 984. For example, whilst the main part of each heater electrode 1164 on the main heater electrode layer 984 (ignoring the edge part of each heater electrode 1164) serpentines in the longitudinal direction of the heater 806 in Figure 11 , the corresponding heater electrodes of the auxiliary heater electrode layer 986 could be arranged to serpentine in the width direction of the heater 806. Such an arrangement would reduce the anisotropic thermal conductivity caused by tracks mostly facing one direction, and may help to spread the heat flow within the heating zone 467 particularly if the heating zone 467 is only partially loaded with hair.

Polyimide backing 987

This layer encapsulates and electrically insulates the bottom heating layer (either the main or the auxiliary heating layer) so as not to allow its accidental exposure and to prevent moisture ingress. This backing layer 987 electrically separates the bottom heating layer from any surface mounted components that are present on the surface mounting layer 988 (discussed below) on the bottom of the heater 806. If desired, this dielectric layer 987 can be made thicker than the upper dielectric layers to provide enhanced structural integrity of the flexible part of the multilayer heater. As with the other dielectric layers, this backing layer 987 does not need to be a polyimide layer and other dielectric materials could be used. Rear Side Surface Mount Components (Optional) 988

This layer is used to mount components on to the rear of the flexible heater 306. These components may be temperature sensors (e.g. thermistors) or other components involved in providing fusing functionality for the heater (e.g. solder links).

This layer may be produced using standard chemical etching methods from the PCB manufacturing process. Additional surface mount components would be added later.

This layer may be treated during manufacturing to provide a rough copper surface (e.g. “Brown Oxide” or “Black Oxide”). This enables better bonding of the flexible heater 806 to the underlying support structure 868 when using an adhesive film 989.

High Temperature Adhesive / Bonding Layer 989 (Optional)

The function of this layer is to enable bonding of the flexible heater 806 to the rigid substrate 868 (shown in Figure 8) that forms the final shape of the overall heater. Various types of adhesive could be used such as a pressure activated adhesive (PAA), heat activated adhesive (HAA), thermosetting epoxy films (prepregs and B-stage films). It could also be a thermoplastic bonding film which sets after heat and pressure have been applied in a forming tool.

Another method of joining the flexible heater 806 to the support carrier 868 is to mount the heater in its final shape and overmould (a form of injection moulding) the carrier directly onto the back. In this case, layer 989 may be a material chosen for moulding compatibility, ensuring the plastic that the support carrier 868 is made from fuses to the adhesive/bonding layer 989 providing a strong bond between the heater and carrier.

Figure 13 shows an exploded cross-sectional and perspective view of another heater assembly which shows on the left hand side an exploded transverse cross-sectional view of the heater 1306 and substrate 1368 and on the right hand side a perspective view of the heater 1306 and substrate 1368. As before, the heater 1306 is formed from a number of discrete layers that are mechanically or chemically bonded together. These layers include:

Layer 1381 is a low friction coating that also provides electrical insulation. This layer may be formed, for example, from a ceramic coating or wash and is directly applied on to the heater electrode layer 1384. The layer 1381 is designed to give 500 volts of dielectric breakdown strength and have thermal impedance between 9.35 x 10-4 KW'¹cm² and to 0.8 KW'¹cm². This provides the required electrical insulation between the hair contacting surface of the heater (the upper surface of the layer 1381) and the heater electrodes whilst minimising the temperature drop that will occur through this coating layer 1381. Minimising the temperature drop through the layer 1381 is important when the heater electrodes are being used to sense temperature, as this will make the determined temperature closer to the actual temperature of the hair contacting surface. Ceramic based coatings, such as Cerasol with a thickness of about 30 to 45 pm, can provide this dielectric breakdown strength and have a thermal impedance of about 0.5 KW'¹cm² to 0.6 KW'¹cm². Other materials such as Aluminium Nitride can provide the required dielectric breakdown strength whilst providing even lower thermal impedances. For example, a 30 pm layer of Aluminium Nitride can provide the required dielectric breakdown strength of 500 volts and has a thermal impedance of just 9.35 x 10-4 KW'¹cm². However, for a mass-produced device such as a hair styler, the cost of an Aluminium Nitride layer may be too high in practice.

Layer 1384 is the heater electrode layer that carries the heater electrodes for heating the different heating zones of the heater. The electrodes may be formed from any suitable conducting material, although stainless steel is preferred.

Layer 1387 is an insulation layer (made for example from polyimide) that provides electrical insulation between the electrode layer 1384 and the heat spreading layer 1388 underneath. Polyimide is a good option for this insulation layer 1387.

Layer 1388 is the heat spreading layer that carries the heat spreaders and the fusing elements discussed above.

Layer 1392 is an adhesive layer that is used to bond the flexible heater 1306 (formed by layers 1381 , 1384, 1387 and 1388) to the rigid support 1368.

Figure 14a is a perspective view from above showing the flexible heater 1306 (with the layers 1381 , 1384, 1387 and 1388 bonded together), the adhesive layer 1392 and the rigid support 1368. Figure 14b is a view from below of the flexible heater 1306, adhesive layer 1392 and the rigid support 1368. As shown in Figure 14b, the rigid support 1368 has honeycomb struts 1453 to provide rigidity whilst keeping the weight down. The rigid support 1368 also includes eight vent holes 1455 (the ones at the two ends being obscured by the honeycomb struts 1453). These are positioned opposite eight thermal fuses that are mounted on layer 1388 of the heater 1306. In this embodiment, there are sixteen heating zones and each thermal fuse provides overheat protection for two neighbouring heating zones. Holes 1457 are provided in the adhesive layer 1392 around the vent holes 1455 to ensure that the vent holes 1455 are not blocked with adhesive.

Figure 15 is a plan view of the independently controllable heater electrodes 1564-1 to 1564- 16 on the heater electrode layer 1384 that define the sixteen heating zones 467 provided in this example. Each heater electrode 1564 is formed of a track of resistive material, whose geometry (track width, thickness, length) and material is specified in order to achieve the desired resistance for a specific power source voltage, therefore providing a desired peak power for a given heating zone. Each heater electrode 1564 may be formed into a serpentine pattern using chemical etching as a manufacturing process (although, as discussed above, other manufacturing processes can be used to form the heater electrodes 1564). In more detail, a solid layer of conductive material is provided and then etched to form the different heater electrodes 1564. The dark regions shown in Figure 15 are the boundaries between the etched parts of the electrode layer between the white serpentine parts of the figure that are the serpentine conductor paths that form the heater electrodes 1564. In this illustrated example, each heater electrode 1564 serpentines from an edge of the heater 1306 to a centre line of the heater 1306 before returning in a serpentine path back to the starting edge of the heater 1306.

Adjacent heater electrodes 1564 share a common positive terminal (although in other embodiments they may connect to a common ground terminal) to reduce the number of electrical connections needed to be made between the drive and control circuitry (not shown) and the heater 1306. The common positive terminal for pairs of adjacent heater electrodes 1564 are connected back from the edge of the heater 1306 to the drive and control circuitry (described in more detail below). Thus, in this example, no central vias 1165 or busbars are needed to connect to the positive tails of the heater electrodes 1564. The other end of each heater electrode 1564 connects to ground through a respective switch forming part of the drive and control circuit to allow for independent control of current flow through each heater electrode 1564. As those skilled in the art will appreciate, it is not essential to have such a common positive (or ground) terminal, each heater electrode 1564 may be physically separate from all other heater electrodes 1564 in which case, each end of each heater electrode 1564 would be connected separately back to the drive and control circuitry. As illustrated in Figure 15, both lengthways edges of this electrode layer 1384 have twelve tabs extending outward from it that bend round the upper surface of the rigid support substrate 1368 to connect to the drive and control circuitry. Sixteen of the twenty-four total tabs each contain the ground terminal for a heater electrode 1564 and eight contain the common positive terminal for a pair of adjacent heater electrodes 1564. As can be seen in Figure 15, in this example and unlike the example shown in Figure 11 , each heater electrode 1564 does not change direction of the serpentine path at the edge portion of the heater 1306.

The conductive material used in the layer 1384 (to form the heater electrodes 1564) is preferably a PTC or an NTC material (such as stainless steel or copper) so that the resistance of the heater electrode 1564 depends upon its temperature - and so the temperature of the heating zone 467 can be determined by measuring a parameter that varies with the resistance of the corresponding heater electrode 1564.

Figure 16 shows in more detail the form of the heat spreading layer 1388 used in this example (as viewed from below the heater 1306). As shown, this heat spreading layer 1388 includes sixteen heat spreaders 1691-1 to 1691-16 that are positionally aligned with the corresponding heater electrodes 1564-1 to 1564-16. The heat spreaders 1691 are formed of a thermally and electrically conducting material like copper. Each heat spreader 1691 (except for heat spreaders 1691-1 and 1691-16) is electrically connected to a neighbouring heat spreader at a corner portion thereof. Each heat spreader 1691 is also electrically connected to another neighbouring heat spreader 1691 by a fuse that sits between the neighbouring heat spreaders. A dashed circle 1634 shows one of the locations where a fuse is installed to electrically connect neighbouring heat spreaders 1691-3 and 1691-4. The heat spreaders 1691 are arranged so that when the fuses are in place, there is an electrical connection (and therefore a current path represented by the dashed arrows) from a positive fuse connection 1636 that is connected to heat spreader 1691-1 , through the heat spreaders 1691- 1 to 1691-16 and back to a negative fuse connection 1638 that is coupled to heat spreader 1691-16. If one of the heating zones overheats and the corresponding fuse connection breaks, then this current path breaks and the controller or control circuitry (to which the positive and negative fuse connections 1636, 1638 are coupled) can detect this break in the current path (for example by applying a voltage across the two fuse connections 1636 and 1638 and detecting the presence of a current (fuse circuit working correctly) or the absence of a current (meaning that one or more fuses have blown)) and can take the appropriate control action - such as stopping or preventing power being applied to the heater electrodes. The operation of preferred control circuitry to detect a fuse melting and to take a control action will be described in more detail later. The layer 1388 does not include a central busbar to which the positive tails of the heater electrodes 1564 connect through vias.

Figure 17a and 17b are zoomed perspective views of a fuse 1734 used in this example to connect adjacent heat spreaders 1691-3 and 1691-4. In this example, the fuse 1734 is formed of an electrically conductive solder material that electrically connects the adjacent heat spreaders 1691-3 and 1691-4. The fuse material sits on and electrically bridges across a layer of solder resist 1741. Figure 17a shows the fuse when intact, such that current can flow between adjacent heat spreaders 1691-3 and 1691-4; and Figure 17b shows what happens if a heating zone next to the fuse overheats and melts the solder material of the fuse 1734. In particular, when the solder material melts, it is repelled off the solder resist 1741 and beads up to the side where it will cool (once power is removed from the heaters) and solidify again. The solder resist 1741 is not electrically conductive, and so when the solder material melts and moves off the solder resist 1741 (as shown in Figure 17b), the adjacent heat spreaders 1691-3 and 1691-4 are electrically separated from one another thereby breaking the electrical connection between the two fuse connections 1636 and 1638. As discussed above, this break in the electrical connection is detected by the control circuitry and used to control (typically stop) the power delivery to the heater electrodes 1564.

Figure 18a and 18b are cross-sectional views through the heater 1306 (showing the electrode layer 1384, the insulation layer 1387 and the heat spreader and fuse layer 1388), the adhesive layer 1392 and the support 1368, showing the placement of a fuse 1734 and the corresponding vent hole 1455 discussed above. In particular, Figure 18a is a cross-sectional view when the fuse 1734 is intact and Figure 18b is a cross-sectional view when the fuse 1734 has melted and moved off the solder resist 1741. As those skilled in the art will appreciate from Figure 18, the vent hole 1455 prevents pressure build up due to the heated air. An air pocket 1844 is provided within the support 1368 to house the fuse 1734.

Drive & Control Circuitry

Figure 19 is a schematic diagram of the way in which the heater electrodes 1564 may be connected together and to the drive circuitry 1923 and the power supply 1921. As shown in Figure 19, each heater electrode 1564-1 to 1564-16 is connected at one end to the power supply 1921 through a master switch 1951 and at the other end to a respective switch (in this case a MOSFET switch) 1995-1 to 1995-16. The switches 1995 are controlled by the microprocessor 1929. When a heater electrode 1564 is to provide heat, the corresponding switch 1995 is closed thereby connecting the heater electrode 1564 to ground through the resistor 19R. As a result, current flows from the power supply 1921 to ground causing the heater electrode 1964 to heat up (provided the master switch 1951 is closed). The microprocessor 1929 can control the position of each switch 1995 independently thereby allowing each heater electrode 1964 to be powered independently to attain its own desired set point temperature. Typically, the set point temperatures for the different heater electrodes 1564 will be the same.

When the temperature of a selected heating zone 467 is to be determined, the switch 1995 of the corresponding heater electrode 1564 is closed and all other switches 1995 are opened. In this way, the selected heater electrode 1564 is provided in series with the resistor 19R. Since the heater electrodes 1564 are formed of a PTC or an NTC material whose resistance changes with the temperature of the heater electrode 1564, by measuring the voltage dropped across the resistor 19R (using the operational amplifier 1997), the microprocessor 1929 can determine the resistance of the selected heater electrode 1564 and hence can determine the temperature of the corresponding heating zone 467. If the determined temperature is above the desired temperature for that heating zone 467, then the microprocessor 1929 can reduce the power applied to that heater electrode 1564; or if the heating zone 467 is at a lower temperature than that desired, then the microprocessor 1929 can increase the power applied to the corresponding heater electrode 1564. Any suitable ON/OFF control or PWM (pulse width modulation) control can be used to vary the power applied to the different heater electrodes 1564. The microprocessor 1929 can select each heater electrode 1564 in turn in order to determine the temperature of each heater electrode 1564/heating zone 467. Figure 19 also shows that the voltage supplied to the heater electrodes 1564 may also be provided to the microprocessor 1929 (through suitable scaling or conversion circuitry (not shown) if at a voltage greater than can be accepted by the microprocessor 1929). This voltage input allows the microprocessor 1929 to adjust the driving of the heater electrodes 1564 in the event that, for example, the power is supplied by batteries and the batteries are becoming depleted. The voltage applied across the heater electrodes may drop for other reasons, including voltage drops along cables during high loads, tolerances in the outputs of the power supply etc. By measuring the applied voltage, the microprocessor 1929 can use this information to calculate more accurately the resistance of each heater electrode (and hence the temperature of that heater electrode) given the present circuit conditions. For example, the microprocessor 1929 can use the measured voltage across resistor 19R to work out the current flowing through the heater electrode 1564 (by dividing the measured voltage across resistor 19R by the known resistance of resistor 19R). The microprocessor 1929 can then determine the resistance of the heater electrode 1564 by subtracting the voltage across resistor 19R from the sensed voltage applied to the heater electrode 1564 and dividing that by the determined current. The calculated resistance can then be equated, if desired, to the temperature of the heater electrode 1564 through an appropriate look up table.

The inventors have found that sensing the temperatures of the heater electrodes in the above manner only requires about 5% of the overall time available - which does not therefore interfere with the powering of the heater electrodes.

Figure 19 also shows how the eight fuses 1734-1 to 1734-8 used in this example are connected to the control circuitry and can automatically remove power from the heater electrodes 1564. In particular, as shown in Figure 19, the gate of the master switch 1951 is connected to the power supply through a potential divider circuit 1956 that connects to ground through the fuses 1734 and an optional test switch 1958. In normal operation, when the fuses 1734 are intact, the voltage at the gate of the master switch 1951 will be at a lower voltage than at the source. This means that the switch is closed and current can flow from the power supply 1921 through the master switch 1951 to the heater electrodes 1564. However, in the event that one or more of the fuses 1734 melts and breaks the electrical connection between the potential divider circuit 1956 and ground, then the voltage on the gate of the master switch 1951 will become the same as the voltage on the source of the master switch 1951 , and this will cause the master switch 1951 to open, thereby isolating the heater electrodes 1564 from the power supply 1921.

The optional test switch 1958 is provided to allow the microprocessor 1929 to test the circuitry for faults. Specifically, it is possible for the master switch 1951 to fault into a permanently closed position, in which case, in the event one or more of the fuses 1734 melts and breaks the connection to ground, the master switch 1951 will not break the connection between the power supply 1921 and the heater electrodes 1564. However, by providing the test switch 1958, which can be opened and closed by the microprocessor 1929, the microprocessor 1929 can check that the master switch 1951 has not failed into a permanently closed state. In more detail, when the microprocessor 1929 opens the test switch 1958, this simulates a break in one of the fuses 1734, which should open the master switch 1951. The microprocessor 1929 can then monitor the temperature of one or more of the heater electrodes 1564 (using the op-amp 1997) in the manner discussed above. If the master switch 1951 is operating correctly, then the temperature of the or each monitored heater electrodes 1564 should drop (rapidly because the heater has a low thermal mass). If the temperature of any of the monitored heater electrodes 1564 remains above a threshold temperature after the test switch has been opened, then the microprocessor 1929 can assume the master switch 1951 has faulted in its closed state) and open all the switches 1995 to prevent further heating of the heater electrodes 1564.

As shown in Figure 19, the test switch 1958 and the switches 1995 are n-channel MOSFETs and the master switch 1951 is a p-channel MOSFET. The advantage of using n-channel switches is that they will go into an open state in the event of power being removed from the control circuit, which should remove all power to the heater electrodes 1564. Of course, other switches could be used. Feedback components

Figure 20 illustrates a particular embodiment of the hair styler 2001 , which is configured to provide feedback to a user. In particular, users will be unaccustomed to using a styler 2001 comprising multiple heating zones 467 or styling technology having such rapid heat-up and cooldown times. This can lead to user’s misusing the product, which may result in undesirable styling performance or longer styling times (possibly leading to damage to hair). It can therefore be advantageous to provide ‘feedback’ to a user regarding their use of the styler 2001 , in order to provide real-time updates on a status of the styler (e.g. temperatures) and potentially guide their use of the styler 2001 . This may be achieved by a combination of visual, audio and/or haptic feedback.

Visual feedback components typically include some form of user interface. In the particular embodiment illustrated in Figure 20, the user interface comprises an LED display 2010 provided on one of the arms 2004a, 2004b (this is illustrated on arm 2004b and on a surface external to the heater 2006b, for example opposite to the heater 2006b, so that it can be easily viewed by the user). Although the LED display 2010 may be monochromatic, it preferably comprises an array of RGB (red, green, blue) LEDs. The LEDs can be operated independently and in different configurations, and so can therefore provide displays of different patterns and - if RGB LEDs are used - different colours. This includes ‘animation’ displays, in which LEDs are illuminated in sequence over time.

Additionally, as also illustrated in Figures 20 and 21 , LED strips 2008, 2108 are provided adjacent each heater 2006, 2106. Again, while the LED strips 2008, 2108 may be monochromatic, preferably they comprise an array of RGB (red, green, blue) LEDs. The LED strips 2008, 2108 can be operated independently and in different configurations, and so can therefore provide displays of different colours and patterns, including animated displays. As can be seen from Figures 21 , 22 and 23, which show a plan view of the heater 2106a, 2206a, 2306a on an arm 2104a, 2204a, 2304a of the hair styler, the LED strips 2108, 2208, 2308 are divided into independently operable sections 2108a-1 to 2108a-20, 2208a-1 to 2208a-20 and 2308a-1 to 2308a-20. The sections 2108a-1 to 2108a-20, 2208a-1 to 2208a-20, and 2308a-1 to 2308a-20 correspond in location to the independently operable heating zones 21642, 22642, and 23642. For example, in Figure 21 , LED section 2108a-1 corresponds to and is physically aligned with heating zone 21642-1 , LED section 2108a-2 corresponds to and is physically aligned with heating zone 21642-2, and so on. Each LED section 2108a-1 to 2108a-20 is also provided adjacent its corresponding heating zone 21642-1 to 21642-20. As the LEDs within the LED strips 2008, 2108, 2208, 2308 can be illuminated independently, the sections 2108a-1 to 2108a-20, 2208a-1 to 2208a-20, and 2308a-1 to 2308a-20 can be illuminated independently in order to provide information relating to the operation of specific zones 21642, 22642, and 23642. In addition, the sections of the LED strips 2108a-1 to 2108a-20, 2208a-1 to 2208a-20, and 2308a-1 to 2308a-20 may relay information relating to general status update of the styler, unrelated to the heating zones, for example the progress of software updates.

Figure 21 illustrates a first implementation of the LED strips 2108a, divided into a first strip comprising sections 2108a-1 to 2108a-10, which runs along one side of the heater, and a second strip comprising sections 2108a-11 to 2108a-20, which runs along the other side of the heater. In particular, the LED strips 2108a run along the length of the elongate arm 2104a. In this example, the heater is comprised of twenty heating zones, 21642-1 to 21642-20 which are arranged in two rows of ten, such that the twenty sections of the LED strips 2108a-1 to 2108a-20 are located adjacent to their corresponding heating zone 21642-1 to 21642-20. Figure 22 shows a slightly altered implementation in which two further LED sections 2208a-21 and 2208a-22 are located at the distal end of the heater 2206a. These may, for example, correspond to their adjacent heating zones - for example, heating zone 22642-1 may be represented by both LED sections 2208a-1 and 2208a-21 and heating zone 22642-11 may be represented by LED sections 2208a- 11 and 2208a-22. Alternatively, the end sections 2208a-21 and 2208a-22 may be used to display information about the heater 2206a generally, the strips of heating zones 22642 and/or the styler 2001 generally. Figure 23 shows a yet further implementation in which the heater 2306a comprises only one row of heating zones 23642-1 to 23642-10 along the length of the heater 2306a (i.e. along the length of the elongate arm 2304a). In this instance, the LED strips 2308a again run along either side of the heater 2306a and the LED sections either side of each heating zone 23642-1 to 23642-10 will both represent that zone. As illustrated in Figure 23, this means that heating zone 23642-1 is represented by LED sections 2308a-1 and 2308a-11 , heating zone 23642-2 is represented by LED sections 2308a-2 and 2308a-12, and so on. Figure 23 also illustrates an implementation in which the heating zones 23642- 1 to 23642-10 are not all the same size and shape, in particular the width (in the length wise direction of the heater 2306a) of the heating zones 23642-1 to 23642-10 varies. The width of the LED sections 2308a-1 to 2308a-20 corresponds to the width of their respective heating zone 23642-1 to 23642-10 and so also varies. In alternative implementations (not illustrated), sections of the LED strips 2008 may represent more than one heating zone 21642, 22642, 23642. For example, sections of LED strips 2008 may represent two or more heating zones 21642, 22642, 23642 sequentially arranged along the length of the heater 2006a.

Figure 24 is a block diagram of the main components of this embodiment of the hair styling device 2001 (corresponding to that shown in Figure 2), illustrating that the LED strips 2008 and the LED display 2010 form part of the user interface 2411 which is coupled to the microprocessor 2429. The microprocessor 2429 is configured to implement one or more control methods that control the heating of the heaters 2006 in accordance with a desired operating temperature of the heaters 2006 and sensed temperatures of the heaters obtained from temperature measurement circuitry 2425. The microprocessor 2429 is further configured to implement one or more algorithms (stored in the memory 2430) for illuminating the LED strips 2008 and the LED display 2010 in dependence on desired operating temperatures of the heaters 2006 and/or sensed temperatures of the heaters 2006 obtained from the temperature measurement circuitry 2425. In particular, the desired operating temperatures and sensed temperatures of the heaters 2406 includes desired and sensed temperatures for each heating zone 21642, 22642, 23642 of each heater 2006, and the illumination of the LED strips 2008 and/or the LED display 2010 can also be controlled according to the sensed and/or desired temperature for the corresponding zone 21642, 22642, 23642.

Additionally, the microprocessor 2429 may be further configured to implement one or more algorithms (stored in the memory 2430) for illuminating the LED strips 2008 and the LED display 2010 in dependence on status updates sent via the communications circuitry 2427.

Particular processes and/or algorithms may be sent to the memory 2430 and microprocessor 2429 from an external source (such as an application on a mobile device) via the communications circuitry 2427. This may be in dependence on selections made via the user interface 2411.

In some preferable implementations, the hair styling device further comprises an optional Inertial Measurement Unit (IMU) 2412. The IMU 2412 typically comprises an accelerometer, a gyroscope, and in some instances also a magnetometer. This is configured to determine measurements indicative of movements (e.g. speed and orientation) of the styler 2001 , and so is configured to determine information relating to the manner in which the user is moving - and therefore using - the styler 2001. In some implementations, the styler 2001 may comprise an optional light sensor 2418, such as an ambient light sensor - the information from which may be used to control the brightness of the light strips 2008 (for example reducing their brightness as the ambient light intensity reduces).

Additionally, the hair styling device may optionally further comprise a haptics unit 2414 and a speaker 2416, both of which are coupled to the microprocessor 2429. The haptics unit 2414 typically comprises any kind of devices capable of exerting forces on a user to create tactile sensations, thereby providing haptic feedback. The speaker 2416 is typically configured to output audio sounds to a user, thereby providing audio feedback. The microprocessor 2429 is configured to implement processes (typically stored in the memory 2430) for outputting visual feedback (via the LED strips 2008 and/or the LED display 2010), haptic feedback (via the haptics unit 2414) and/or audio feedback (via the speaker 2416) in dependence on movement data from the IMU 2412 and/or temperature data from the temperature measurement circuitry 2425.

Exemplary feedback processes

The components described above can provide visual feedback to a user, providing intuitive and fast feedback. This can minimize the impact of user error by removing ambiguity of plate temperature and modifying user behaviour. This can be of particular benefit as the user will typically be unaccustomed to the capabilities of the kind of multi-zone very low thermal mass heaters 106, 206, 306, 406, 506, 806, 1306, 2006, 2106, 2206, 2306 described in this application. Particular examples of processes by which the styler 101 , 2001 might provide feedback will now be described in turn.

Heating up

As illustrated in Figures 25a and 25b, the LED strips 2008a, 2008b change colour as the heaters 2006a, 2006b heat up. This may, by way of example, comprise the LED strips 2008a, 2008b moving through different colours from blue to red to indicate the progression of the heating. In some implementations, this may pass from blue to green to yellow to orange to red as the temperature rises to indicate to the user how the heating is progressing. By way of example, Figure 25a illustrates the styler at a point in time during the heating process when the LED strips 2008a, 2008b display a first colour and Figure 25b illustrates a point when the heaters 2006a, 2006b have reached the desired temperature and the LED strips 2008a, 2008b display a second colour. When the heaters 2006a, 2006b reach the desired temperature the LED strips 2008a, 2008b typically flash (turning repeatedly on and off in quick succession). This can alert the user that the heaters 2006a, 2006b are at the desired temperature and so are ready to be used. The LED strips 2008a, 2008b can also indicate when the heaters 2006a, 2006b are cooling down, utilising the heat-up colour scheme in reverse. In some implementations this may be implemented with a low-frequency pulsing to highlight the styler 2001 is powered down.

In some implementations, regions of the LED strips 2008a, 2008b light up corresponding to particular heating zones 21642, 22642, 23642 on the heaters 2006a, 2006b, 2106a, 2106b, 2206a, 2206b, 2306a, 2306b. This can be useful to provide multizonal heater visualisation to the user, so that they can see the relative temperatures of the different heating zones 21642, 22642, 23642. Styling

When the user first loads hair onto the heaters 2006a, 2006b, it can be determined how much hair is loaded into the styler. These features can be determined at least from power measurements to the heaters 2006 and the drive circuitry 2423 in combination with or just based on temperature measurements from the temperature measurement circuitry 2425, which can indicate the thermal load of the hair applied to the heaters 2006. In particular, the thermal load on each of the heating zones 21642, 22642, 23642 can be determined individually and this thermal load indicates an amount of hair that has been loaded onto each heating zone 21642, 22642, 23642.

As shown in Figure 26, the load on each of the individual heating zones 21642 can be displayed via illumination of the corresponding sections of the LED strips 2108a. A lock of hair 2640 is positioned across the heater 2106a, falling across seven of the heating zones (21642-4, 21642-5, 21642-6, 21642-13, 21642-14, 21642-15, 21642-16). The seven LED sections (2108a-4, 2108a-5, 2108a-6, 2108a-13, 2108a-14, 2108a-15, 2108a-16) corresponding to the loaded seven heating zones (21642-4, 21642-5, 21642-6, 21642-13, 21642-14, 21642-15, 21642-16) are illuminated in a manner to indicate that they are loaded, in particular illuminated to a brightness and/or colour different to the rest of the LED strips 2108a. Additionally, as illustrated in the exemplary implementation of Figure 26, they may be illuminated at different brightness and/or colour to one another, dependent on the load (amount of hair) placed on each one. Based on this illumination, the user may be prompted to distribute the hair more evenly over the surface of the heater 2106a which can lead to better and more consistent styling results.

As a particular example, in addition to determining that hair has been placed on the heating zones, it can also be determined how wet the hair is, and what type of hair is loaded onto the plates. The optimum quantity of hair to be placed onto the heaters 2106 will be dependent on the hair type and how wet the hair is, and so the styler can provide feedback to a user how to improve their technique based on the determined optimum quantity (which can prevent overloading of the hair onto the styler 2001). In one example, if it is determined that too much hair is loaded, the LED strips 2108a, 2108b can indicate this by changing colour (perhaps yet further) or by changing animation (for example flashing).

In addition to the above, positive feedback can also be implemented to encourage users when they are styling by reinforcing beneficial habits. For example, if a user moves the styler 2001 over the hair at a correct speed, positive feedback can be output via any combination of the haptics unit 2414, speaker 2416, LED strips 2008a, 2008b and LED display 2010.

In some embodiments, the styler 2001 may be configured to output visual feedback, via the LED strips 2008a, 2008b and LED display 2010, relating to the speed and/or orientation of the styler as determined from the IMU 2412. In an example implementation, once the hair is loaded onto the styler 2001 , and the user begins to style the hair, the IMU 2412 determines the speed with which the user is moving the styler 2001 and the direction in which the user is rotating the styler 2001 . If the user moves the styler 2001 too fast over the hair, this can cause the hair to not be effectively styled; this may then cause the user to run the heaters 2006 over the same section of hair again, potentially causing damage to the hair. It is therefore typically preferable for a user to move the styler 2001 at the correct speed to style the hair effectively on the first pass. As such, if the user is moving too fast, the LED strips 2008a, 2008b and/or LED display 2010 may output an indication to slow down by changing illumination colour and/or animation to encourage the user to slow down and/or the haptics may vibrate the styler to encourage the user to slow down. The division of the LED strips 2008a, 2008b can in particular facilitate more complex animations, which can provide intuitive and adaptive feedback to the user.

The styler 2001 can further be configured to provide feedback on the user’s movements relative to a particular ‘styling protocol’ for a styling technique, where the styling protocol refers to the particular movements (including speed and rotation) and heating required to achieve a particular hair style. For example, there are different styling protocols for straightening hair, styling into curls and for styling into loose waves. The microprocessor 2429 can configure the feedback according to the particular styling protocol chosen by a user. In particular, the movements of the styler are compared to the optimum movements for a particular protocol and feedback output via the LED display 2010 and/or LED strips 2008a, 2008b to direct the user to make corrections to their technique. The feedback may comprise particular illumination animations and/or colours of the sections of the LED strips 2008a, 2008b to direct a user to, for example, change the orientation.

In some implementations, a styler 2001 is configured to provide feedback to a user regarding the timing of styling techniques. In other words, the styler 2001 may output feedback indicating to a user how long to keep a tress of hair on the heater or heaters 2006 in order to achieve effective styling. This can be particularly useful for styling techniques requiring holding a tress on the heater 2006 for a period of time, such as curling the hair. In such styling methods, if the hair is held on for too short a time interval, then styling can be ineffective as the hair does not reach the styling temperature. However, if the hair is held on for too long, then the hair can potentially become damaged - which often leaves users fearful of overheating their hair which causes them to hold their hair for too short a time interval on the heater. A styler, such as hair straighteners, curling wands, styling tongs, hot-rollers etc., can therefore be improved by providing feedback to the user indicating when the user should remove their hair, after an appropriate interval, in order to achieve effective styling.

Figure 27 illustrates a first exemplary method of implementing such styling timing feedback. Loading of the hair on a heater 2006 can be detected by a sudden power demand by the heater 2006, as the loading of ‘cold’ (e.g. ambient temperature) hair on the heaters 2006 causes their temperature to drop.

With reference to Figures 12 and 19, and as described above, the temperature of each heating zone 467 is determined by closing the switch of the switch 1295, 1995 of the corresponding heater electrode 1264, 1564 and opening all other switches so that the selected heater electrode 1264, 1564 is provided in series with the resistor 12R, 19R. Since the heater electrodes 1264, 1564 are formed of a PTC or an NTC material whose resistance changes with the temperature of the heater electrode 1264, 1564, by measuring the voltage drop across the resistor 12R, 19R (using the operational amplifier 1297, 1997), the microprocessor 1229, 1929 can determine the resistance of the selected heater electrode 1264, 1564. In particular, as described above, the microprocessor 1229, 1929 uses voltage measured across the resistor 12R, 19R to work out the current flowing through the heater electrode 1264,1564 (by dividing the measured voltage across resistor 19R by the known resistance of resistor 19R). The microprocessor 1229, 1929 further receives a measurement of the voltage supplied to the heater electrodes 1264,1564 (typically, this value may be fixed at a supply voltage, but it may be directly sensed to determine if a battery power source depletes over time). The microprocessor 1929 can then determine the resistance of the heater electrode 1264,1564 by subtracting the voltage across resistor 19R from the sensed voltage applied to the heater electrode 1264,1564 and dividing that by the determined current. Using the determined resistance, the microprocessor 1229, 1929 can hence determine the temperature of the corresponding heating zone 467 through use of a look up table and/or formula relating resistance to temperature. In some implementations, additionally or alternatively, one or more separate hair temperature sensors are provided (for example, in each heating zone), which can determine the temperature of the styler. If the temperature of a heating zone 467 is lower than a setpoint target temperature, the microprocessor 1229, 1929 instructs the drive circuitry 2423 to increase the power to the heaters 2006 in order to maintain a styling temperature. In some implementations, the microprocessor 1229, 1929 may be configured to control the power in dependence on the determined resistance. When hair is loaded on to the heater 2006, the temperature will decrease and so the microprocessor will trigger an increase in power delivered to the heater. As such, the loading of the hair is characterised by a sudden increase in power delivered to the heater (i.e, the ‘power demand’ of the heater 2006). The very low thermal mass of the heaters 2006 facilitates a very quick response (i.e. real time response) to the loading of hair

The power delivered to heaters 2006 of a hair styler can be determined and tracked using the measurements of the voltage applied to each heater electrode, such as heater electrodes 1264 as illustrated in Figures 12 and heater electrodes 1564 as illustrated in Figure 19, in addition to the voltage across and the current through the resistor 12R, 19R (determined as described above). This method could of course be used for implementations comprising only one heater electrode or a plurality of heater electrodes. Additionally, this method can be used for implementations comprising only one heating zone or a plurality of heating zones. By tracking the power delivered to each heater electrode 1264, 1564 (and/or zone), the time at which hair is loaded on the heater can be determined due to the detection of a sudden increase in power demand of the heater 2006.

As illustrated in Figure 27, this detection event can be used to trigger a countdown over a specified styling interval. Such an interval is typically a known defined styling period (which may be based on empirical data), but in some cases may be defined based on detected styler values indicative of characteristics of the particular hair being styled and/or known characteristics of the hair. For example, the styler 2001 , 2701 may comprise components which can measure characteristics of the hair, such as an optical sensor, which can record images of the hair to determine, for example, hair type, hair thickness, moisture level etc. In some implementations, the styler 2001 , 2701 may be configured to determine characteristics of the hair, such as hair damage, from the thermal loading of the hair. Additionally or alternatively, the user may input information regarding their hair, either directly into the styler or via a software application in communication with the styler. This information can be used to define an appropriate styling period for the particular user’s hair.

Once the time interval has elapsed (i.e. the countdown has ended and a ‘release time’ has been reached), then the styler outputs feedback that the user should remove the hair. Such feedback may be communicated through visual, audio or haptic feedback, for example through illumination of LED displays, or by outputting sounds, etc., and any combination thereof. For example, Figure 27 illustrates a first styler, 2701 , which is a curling wand, comprising an LED strip 2708 that is illuminated a different colour when the countdown ends and a second styler 2001 , which is a hair straightener, comprising LED strips 2008a and 2008b (as previously described). For example, the LED strip 2708 or strips 2008a, 2008b may initially be illuminated a first colour (e.g. red) and change through other colours (e.g. orange) to a final colour (e.g. green) to indicate the countdown of the interval, and that the user can remove the hair once that countdown has elapsed. The LED strip 2708 may comprise independently illuminable regions and the strip 2708 or strips 2008a, 2008b may alternatively or additionally show the countdown and/or indicate the release time via animations such as increasing the size of an illuminated portion of the LED strip 2708 or strips 2008a, 2008b as the time progresses. Other exemplary implementations may include flashing a particular colour at the release time. In some implementations, an LED display 2010 may be illuminated and/or output instructions in addition or alternatively to illumination of the LED strips 2708, 2008a, 2008b. Haptic and/or audio feedback may alternatively or additionally be output, for example outputting a ‘beep’ at the release time. In some implementations the heaters 2006 remain at the styling temperature after the release time; however, in other implementations, after the release time, the drive circuitry 2423 may reduce the power to the heaters 2006 so that the temperature drops. This can further aid in avoiding overheating of the hair.

Figure 28 illustrates a second exemplary method of implementing styling timing feedback, which is based on the profile of power delivered to the heaters 2006. As discussed above, when hair is loaded on the heaters 2006, the thermal load increases and the temperature of the heaters drop. This is sensed by the microprocessor 1229, 1929, which triggers an increase in the power delivered to the heaters 2006 in order to maintain a styling temperature. The power delivered to each heater electrode 1264, 1564 can be calculated (and therefore tracked) using the values of current and/or current measured through the resistor 12R, 19R and the voltage measured across each heater electrode 1264, 1564, as also described above. As the hair heats up, the power demand changes according to a particular characteristic profile, as illustrated in Figure 28. In particular, there is an initial steep increase in power delivered to the heaters 2006 as more power is required to increase the temperature of an initially ‘cold’ tress of hair 2640. As the hair 2640 heats up, the power required decreases as the temperature difference between the heaters 2006 and the hair decreases. Once the hair 2640 is at the desired styling temperature, the power demand will plateau as an approximately consistent power is required to maintain the heaters 2006 and hair 2640 at the styling temperature. The plateau indicates that the hair is at styling temperature, so can be released; and, accordingly, feedback is output at this stage. In order to determine this release time, features of the power profile over time may be defined and detected; for example, the maximum point and the gradient (i.e. rate of change of power). The release point may typically be defined in relation to the profile characteristics. For example, the release point may be defined when the gradient of the power profile over time falls below a defined value, indicating the plateau (or at a predefined interval after determination of this gradient). Alternatively, determination of a maximum point may trigger a timer such that the release time occurs at a defined interval after the maximum point.

Again, Figure 28 illustrates a first styler 2701 , which is a curling wand, and a second styler, 2001 , which is a hair straightener. As described above, the release time may be indicated by visual (e.g. LED), audio, haptic etc. feedback. For example, this may be via the LED strips 2708, 2008a, 2008b, and/or the LED display 2010. In particular, visual displays may change corresponding to the progression of the power profile. For example, the LED strips 2708, 2008a, 2008b, and/or the LED display 2010 may change colour (e.g. red to orange to green), and/or may be animated (e.g. flashing at the release time and/or increasing the size of an illuminated portion). In some implementations, heating may be ceased or reduced at - or at an interval after - the release time.

Figure 29 illustrates a third exemplary method of implementing styling timing feedback, which comprises sensing the temperature of the hair. As described previously, the temperature of a heater electrode can be determined by calculating the resistance of that electrode and then determining the temperature using a formula and/or look-up table relating resistance to temperature. The resistance is determined and tracked (again, with reference Figures 12 and 19) using the voltage supplied to the heater electrodes 1264, 1564 and the current through the resistor 12R, 19R and the voltage measured across the resistor when the switch 1295, 1995 of the corresponding heater electrode 1264, 1564 is closed and all others are open. The microprocessor 1292, 1929 may determine the resistance of the heater electrode 1264, 1564 by subtracting the voltage across resistor 12R, 19R from the sensed voltage applied to the heater electrode 1264,1564 and dividing that by the determined current. In some implementations, additionally or alternatively, there may be provided one or more separate temperature sensors for measuring the temperature of the styler, for example measuring each heating zone 467.

As shown in Figure 29, the hair temperature will start off ‘cold’ (e.g. at ambient temperature) and then increase, initially at an increasing rate, and then asymptotically towards the styling temperature. Once the hair has reached the styling temperature, effective styling can be achieved, and so feedback can be output that the user can release the hair. This may be triggered by determining particular characteristics of the temperature profile over time, for example the release time may be defined at or after a predetermined interval from when a defined temperature is determined to be reached (this may be the styling temperature or a temperature within a margin of the styling temperature). Alternatively, the determined release time may be defined in reference to a gradient of the temperature profile over time (i.e. rate of change of temperature); for example, the release time may be defined as the time at which a predefined gradient is determined or at an interval after a predefined gradient is determined. Figure 29 also shows a first styler 2701 , which is a curling wand, and a second styler 2001 , which is a hair straightener. Again, the feedback may be by way of visual output (e.g. by LED strips 2708, 2008a, 2008b), audio output and/or haptic output. The feedback may change with progression of the heating profile over time - for example, as discussed in reference to the other methods, the colour of the LED output may change and/or be animated. The colour, illumination and/or animation of the LEDs may indicate the progression of the hair temperature, so that a user can track the heating. This may be indicated by zone, or a general value indicated which is illustrative of an average temperature across the loaded zones of the heater. In some implementations, heating may be ceased or reduced at - or at an interval after - the release time.

The three styling timing feedback methods described above may be used individually or in any combination. For example, the feedback and release times may be determined using a combination of the methods and may be based on a combination of tracking power and temperature. In some implementations, the feedback may additionally indicate those zones which are loaded with hair to be styled. The exemplary feedback scenarios described may be provided in any combination - for example, to provide feedback regarding the loading of the heating zones 21642, 22642, 23642 and the speed with which those heating zones 21642, 22642, 23642 are passed over the hair 2640 and/or the timing over which the heaters 2006 are applied to the hair 2640.

Training /teaching mode

The styler 2001 can further be operated in a ‘training mode’, in which the heaters 2006a, 2006b are not at the styling temperature but the user is guided how to move the styler 2001 in the correct motions to achieve their desired style, according to the relevant styling protocol. In this mode the user can effectively ‘practice’ the motions without heating the hair, thereby enabling the user to repeat the actions and to avoid accidentally causing damage to the hair (or burning themselves). In this training mode, the LED strips 2008a, 2008b are illuminated according to a colour scheme different to that used to indicate that the heaters 2006a, 2006b are heated. This can therefore communicate to a user that the heaters 2006a, 2006b are not at the styling temperature.

In some embodiments, the styler 2001 can be connected to an application (‘app’) via the communications circuitry 2427 (for example, via Bluetooth). The user can select a particular style via an app connected to the styler 2001 or via the LED display 2010 and then be taught via visual feedback how to achieve that style. For example, a user may select curling hair using a hair straightener, which requires rotating the styler 2001 at a correct angle and speed. The feedback provided via the illumination of different sections of the LED strips 2008a, 2008b can indicate to the user how to correct their speed and rotation angle.

Indicating firmware updates

In some implementations, the microprocessor 2429 instructs the LED strips 2008a, 2008b to indicate firmware updates. In this mode, the LED strips 2008a, 2008b are illuminated in the style of a loading bar, as is illustrated in Figures 30a and 30b. In Figure 30a, one LED strip 2008a is illuminated such that a portion corresponding to the download progress is illuminated in a solid colour, while the remainder of the LED strip 2008a is illuminated in a colour gradient. The other LED strip 2008b is illuminated in a solid colour (alternatively, it may be completely unilluminated). Figure 30b shows the styler 2001 once the firmware update has been completed, in which the first LED strip 2008a is now illuminated in a gradient. At this stage, the LED strip 2008a is also flashing (turning on and off in quick succession). In an alternative implementation as illustrated in Figures 31a and 31b, one LED strip 2008a is illuminated such that a portion corresponding to the download progress is illuminated in a solid colour, while the remainder of the LED strip 2008a is unilluminated (alternatively, it may be the other way around or the two sections may be illuminated in different colours). This manner of showing progress of the download is illustrated in Figure 31a. Then, when the download is complete, the whole of the LED strip 2008a is illuminated the same colour, typically flashing that colour - as is illustrated in Figure 31b. It is typically preferable that the colour scheme in which the LED strips 2008a, 2008b are illuminated to indicate the progress of a firmware update is not the same as a colour scheme used to portray that the plates are hot.

Low light mode

In some implementations, a computer vision algorithm (CVA) may be used to determine the movement and orientation of the styler in order to gather information regarding its use (such a use is detailed in the Applicant’s previous application WO2022/136866). If the conditions are too dark (i.e. there is a low light level) then computer vision techniques may not work effectively. In such an instance, the light sensor 2418 on the styler 2001 can detect that the light level is too low, and the microprocessor 2429 instructs that the LED strips 2008a, 2008b be illuminated in a unique pattern, which can allow the styler 2001 and its location to be identified more easily using the computer vision algorithm. In particular, the pattern is different on the two sides of the styler 2001 so that the computer vision algorithm can determine what side of the styler is being viewed and therefore the orientation of the device relative to the camera frame of reference. This is shown in the example illustrated in Figures 32a and 32b, which show the styler 2001 from the left and from the right, respectively. The sections of the LED strips 2008a, 2008b to the left are illuminated according to a first pattern while the sections of the LED strips 2008a, 2008b to the right are illuminated according to a second pattern different to the first.

Smart power usage

The styler 2001 can be configured to respond to user behaviour based on accelerometer readings of the IMU 2412. The styler 2001 can respond to that behaviour by adapting the settings of the styler 2001 . For example, if the styler is determined to be idle (i.e. not in the hand of a user) as it is detected not to have been moved for more than a specified period of time (for example 30 seconds), the styler 2001 is configured to enter a low power mode. This low power mode can be indicated via the LED strips 2008a, 2008b, which may change to a different colour scheme (for example, a more muted colour scheme) and/or be indicated on the LED display 2010.

User feedback algorithm

Figure 33 provides illustrates an exemplary process flow diagram of the algorithm for determining various states of the styler 2001 , so that corresponding feedback can then be output to a user. This algorithm is typically stored in the memory 2430 and implemented by the microprocessor 2429.

At 33100, the process starts - this may be initiated, for example, by a user turning on the styler 2001. This triggers at step 33102 the booting up of the components of the styler 2001 , for example the heaters 2006 via their drive circuitry 2423, along with other components such as the IMU 2414, the communications circuitry 2427, the temperature measurement circuitry and so on. At step 33104 the microprocessor 2429 determines if the styler 2001 is connected to an external application or ‘app’ (for example of a mobile device) via the communications circuitry 2427 (this connection may be made via Bluetooth, for example). If it is determined that there is a connection to an app, then the microprocessor 2429 will load the app features to the boot up procedure. This may comprise, for example, particular settings of the styler 2001 , which may be tailored for a particular styling technique or for the hair characteristics of the user.

Once the app features have been loaded in step 33106, the process moves to step 33108, in which the styler values are determined. Alternatively, if no app connection is determined, the process moves straight to step 33108. Reading the styler values in step 33108 comprises receiving data from the I MU 2414, which provides information regarding the movement and physical arrangement of the styler 2001. Receiving the styler values further comprises receiving data relating to the heaters 2006, which may be received from the temperature measurement circuitry 2425. Typically, this may also comprise information from the drive circuitry 2423 and heaters 2006 themselves, as the combination of the power data and the temperature data can be used to determine information relating to the thermal load on the heaters 2006 (from which can be derived information relating to hair condition and wetness). Relevant IMU data and heater data is collated at 33110.

At step 33112, the received data is used to determine whether the styler is idle. This can be determined from the IMU data indicating that the styler 2001 is not being moved by the user, but instead remains stationary. In some cases, the heater plate data can be used instead of or in combination with the IMU data, as the heater plate data will indicate there being no thermal load on the heaters 2006 when idle.

If it determined that the styler is idle 33132, the process enters the idle mode 33130. An idle mode timer keeps track of the length of time in which the styler 2001 remains in the idle mode - if it is determined to exceed a pre-set length of time, then the process moves to end at step 33120, switching the styler 2001 off. In the illustrated process flow of Figure 33, this time period is set as 10 minutes. This causes the styler 2001 to turn off automatically when left idle. This provides a safety back stop, for example, if a user forgets to turn off the styler 2001 . The processing also loops back to step 33108 to continue checking the styler values for any indication that the user is now using the device. If the styler values indicate at any point before the end of the pre-set time period that the styler 2001 is no longer idle, the process may move to step 33114 in which the idle mode timer is reset.

At step 33114, the microprocessor 2429 further instructs the drive circuitry 2423 to heat the heaters 2006 to the target temperature, Tt_arget. The microprocessor 2429 further implements instructions to illuminate the LED strips 2008 and/or the LED display 2010 to show the temperature of the heaters, T_piate- The IMU data is then used to determine whether the styler 2001 is closed, and if it is, the process moves to the styling mode 33140.

During styling mode 33140, the microprocessor 2429 continues to read the styler values by continuously cycling back through steps 33108, 33110, 33112, and 33114. This provides information on the heating and the movement of the styler 2001 . At step 33142, it is determined whether the user is moving the styler 2001 too fast. This can be determined from the IMU data alone, or the IMU data in combination with data relating to the thermal load on the heaters, which can indicate whether the hair is being heated sufficiently to cause styling on the first run. If the user is moving the styler 2001 too fast, this can mean that styling is not achieved effectively, which can then result in a sub-optimal end result. It can also lead to the user repeatedly using the styler 2001 on the same section of hair, which can cause unnecessary damage. As such, if it is determined in step 33142 that the user is moving too fast, then at step 33144, feedback is output to the user accordingly. Step 33144 typically further comprises adjusting (e.g. lowering) the heating of the heaters 2006 via the drive circuitry 2423. In some instances, positive feedback may be output to the user to indicate that the styling is being performed correctly (or that the styler is being used correctly).

Once the user has stopped styling the hair, they will typically initially still be holding the styler 2001 but it will no longer be closed. Once this occurs, the microprocessor will at step 33116 determine that the styler 2001 is not closed and accordingly proceed to step 33118 (instead of returning to steps 33108 and 33142). At step 33118, it is determined whether the off button has been pushed. If it has, the styler proceeds to step 33120 and the styler 2001 is turned off. If the off button has not been pushed, the process then returns to step 33108 and the styler values continue to be monitored to determine how the user is using the styler 2001.

Paired Sensing Hairbrush

Figure 34 illustrates an exemplary system in which one or more sensing brushes 3402 are in communication with one or more stylers 3401 . The brush(es) 3402 may be any type of hairbrush, for example a relatively flat paddle brush or cylindrical blow-drying brush. The styler(s) 3401 may be any type of styler, such as hair straightener, a curling iron, a hair dryer, a heated brush, etc. The communication of data between a brush (or brushes) 3402 and styler (or stylers) 3401 may be direct, for example via Bluetooth. Alternatively or additionally, the brush(es) 3402 and styler(s) 3401 may be in data communication via a cloud-based processing unit 3450 and/or a smart processing device 3460, such as a computer, mobile phone or tablet. For example, the smart processing device 3460 may run an ‘application’ which receives, and in some implementations records, information from the brush(es) 3402 and styler(s) 3401 regarding the user’s hair and styling.

Figure 35 shows a block diagram illustrating the main electronic components of a sensing brush 3402. In addition to the features normally found on a brush, such as a handle and bristles, the sensing brush 3402 comprises electronic components which enable an assessment of the state and/or condition of a user’s hair, user’s technique and/or the ambient conditions. The brush 3402 comprises a microprocessor 35202 and memory 35204 for processing data collected by sensing components mounted within and on the brush 3402, and communications circuitry 35240 for transmission of data to stylers 3401 and, in some cases, a cloud-based processing unit 3550 and/or smart processing device 3560. In some implementations, the communications circuitry 35240 is further configured to receive data and instructions from external devices such as stylers 3401 , a cloud-based processing unit 3550 and/or smart processing device 3560. Such data may comprise details of a user’s profile and such instructions may comprise instructions to collect specific data. The brush 3402 further comprises a power supply 35242 that, in this embodiment, derives power from a battery power source that is preferably rechargeable, e.g. from the mains or a DC supply via a charging lead. A mains power supply input may be provided to charge the battery via an AC to DC converter (not shown), which may be external or internal to the device 1. It can be advantageous that the brush 3402 be cordless, as this can improve the ease of use. However, alternatively, the power supply 35242 may derive power directly from an AC mains supply input. In some implementations, the sensing brush 3402 may be a heated brush which can be used itself as a styler for styling hair. In such a case, the brush 3402 would further comprise heater and associated drive circuitry, and typically temperature measurement circuitry (not illustrated in Figure 35).

The brush 3402 comprises sensing components, which can gather information relating to the user’s hair and/or behaviour, and, in some cases, information relating to the ambient conditions at the time of data capture. The brush 3402 acts as an auxiliary, peripheral device to the primary styling device (such as hair straightener, hair dryer, etc.) 3401 , which aids in styling the hair by determining and communicating auxiliary information relating to the hair being styled. In particular, some stylers 3401 , such as hair dryers, typically do not touch the hair itself. As such, there are some characteristics that such stylers 3401 cannot determine; for example, if the hair is wet or dry. Additionally, a sensing brush 3402 can comprise additional sensing components, which are typically not included on a styler 3401 as they would increase the bulk, complexity and/or cost of the styler 3401. As hairbrushes traditionally have no electronics, there is a lot of free space available for the inclusion of further components such as sensors.

As illustrated in Figure 35, the brush 3402 may optionally contain any of, and any combination of: an IR camera 35206 (for temperature modelling); a close range optical camera 35208; humidity sensor 35210; load cell 35212; LEDs 35214; proximity sensor 35216; magnetometer 35218; forcesensitive resistor 35220; accelerometer 35222; microphone 35224; gyroscope 35226; pressure sensor 35228; speaker 35230; haptic motors 35232; UV light 35234 (for sterilization); gas sensor 35236; and a clock 35238 (e.g. a CMOS clock). As discussed above, the brush 3402 may be integrated with a styling ‘application’ run on an external smart processing device 3460, such as a mobile phone, laptop computer or tablet. The brush 3402 may be in communication with such devices 3460 directly and/or via a cloud-based processing unit 3450 via the communications circuitry 35204 and a flash memory for storage and data transfer. Data may be stored, for example to a user profile, in the cloud-based processing unit 3450. A user may be able to install a software ‘application’ on a smart processing device 3460, through which they can then access such a profile. Information communicated from the brush 3402 may be saved to this profile, thereby gathering data relating to a user’s hair and/or styling technique both for the current styling session and over time. For example, the application may be configured to output ‘advice’ to a user during a styling session, based on information sensed and communicated by the brush 3402. The cloud-based processing unit 3450 may be configured to process the sensed and received data and/or the software of the application may be configured to instruct the processor of the smart processing device 3460 to process the received data in-situ (this can be useful if the device 3460 is in direct communication with the brush 3402 but the device 3460 and/or brush 3402 are not in connection with the cloud-based processing unit 3450, for example temporarily). An application may additionally or alternatively gather information about a user’s hair and/or styling technique to build a comprehensive ‘user profile’ over time.

By way of example, the close-range optical camera 35208 can capture images of the hair, from which hair type, density, moisture levels, scalp health, etc. can be determined. This determination may be performed by the microprocessor 35202 of the brush 3402, by the microprocessor 3529 of the styler 3401 , the cloud-based processing unit 3450, smart processing device 3460 or by any combination of these processors. The determined information can be used to adjust the performance settings of the styler 3401. For example, the setpoint temperature of the styler may be reduced if the hair is determined to be wet, thin or damaged. Furthermore, during styling, the brush 3402 is typically guiding the styler 3401 and therefore “sees” what the styler 3401 is about to encounter. Using the sensing brush 3402 for "future prediction", the styler 3401 can modify its settings, in some instances even during a ‘stroke’ of the styler 3401. For example, if the roots are dryer than the tips while straightening, the brush 3402 will determine (or “see”) this. Data communicated from the brush 3402 can be used to determine and communicate to the styler 3401 in real time that wet hair is approaching. The settings of the styler 3401 can accordingly be adjusted to anticipate wet hair, for example by lowering the target temperature to avoid damaging the wet hair. Another application of this moisture sensing would be to adjust settings of a hair dryer to blow less aggressively, which can help to prevent ‘fly aways’.

By way of a further example, the temperature of the hair may be determined using an IR camera 35206. In some implementations, a temperature profile of the hair could be determined by running the sensing brush 3402 through a tress of hair. This could be performed before and/or after styling, and could thus provide an indication of the response of the hair to heating. In particular, the response of hair along the length of a tress of hair may not be uniform; for example, the older ends of the hair may be more wet, or may simply be more damaged, which can increase the coefficient of heat transfer of the hair. If the brush 3402 is run through the hair after styling, it can sense the temperature profile along the hair, thereby providing information relating to how the regions of hair reacted to the application of heat. This in turn can provide information relating to the condition of the hair (e.g. moisture level, extent of damage). In some uses, the brush 3402 may be run through a tress of hair to establish an initial temperature profile, then the styler 3401 is used on that tress, and then the brush 3402 run through the same tress again to establish a temperature profile after styling. The initial temperature profile and the temperature profile after styling can be compared by the relevant one or more processors (as discussed above) to determine a more accurate profile of the heat response of the hair. (This may preferably further use information relating to the speed with which the styler 3401 was passed over the hair, which will be described in further detail below). The relevant one or more processors (as described above) may be configured to determine settings of the styler 3401 accordingly, and send instructions to the styler 3401 to adjust the settings. For example, the temperature of the heater may be varied as the styler passes along the length of the tress of hair. Additionally or alternatively, a message may be output to the user to adjust their technique in dependence on the analysis of the temperature profile of the hair tress. For example, a notification may be output via an application on a smart processing device 3460 and/or on the styler 3401 itself. Such a notification may instruct a user to move the styler more slowly, as the hair may not be reaching a sufficiently high temperature for styling to be effective.

The sensing brush 3402 can further record measurements which can be used to characterize styling technique. Such measurements can be received by the cloud-based processing unit 3550 and/or smart processing device 3560 to be processed - and/or be processed by the microprocessor 35202 of the brush 3402 itself - to determine adjusted settings of the styler 3401 and/or ‘instructions’ to a user regarding how to adjust their technique, the relevant one or more processors outputting associated instructions to the styler 3401 accordingly. For example, in some implementations, the sensor may comprise components for measuring the stroke speed, such as an odometer/speedometer, which can be used to detect the stroke speed directly (i.e. the speed at which the user is brushing - and, as the styler is typically moved along the tress in tandem with the brush, therefore also typically styling - the hair). This may be achieved by one or more of the microprocessors processing optical images captured by a close-range optical camera 35208, by an odometer comprising rotatable gear, or by any other type of speed meter. This data can be processed to provide - either alone or in combination with data from the styler 3401 itself and/or an application running on the smart processing device 3460 - an indication of a user’s styling technique. Furthermore, the stroke speed can affect a preferable setpoint temperature as it determines the time over which heat is applied to hair. If the speed is high, the target temperature used by the microprocessor of the styler 3401 may be increased; while if the speed is low, the target temperature used by the microprocessor may be decreased. The one or more relevant processor can also process the stroke speed and stroke length to determine the length of a user’s hair. As older hair at the end of a tress of hair is typically more damaged than new hair closer to the scalp, one or more relevant microprocessors (i.e. those within the cloud-based processing unit 3550, the smart processing device 3560 and/or the microprocessor 35202 of the brush 3402 itself) can then use this information to determine adjusted temperature settings of the styler 3401. For example, the microprocessor may reduce the temperature setpoint as the styler 3401 moves towards the ends of the tress. By way of a further example, the size of a tress may be determined using information from a load cell 35212, which measures the force applied to the brush 3402. Brushing a larger tress of hair will cause more force to be applied to the brush 3402, and thus by measuring the force and sending associated data to the one or more microprocessors, the microprocessor can determine (or at least estimate) the size and thickness of a tress. Similarly, a force-sensitive resistor 35220, typically formed of conductive polymers whose resistance changes due to changes in applied force, pressure or mechanical stress can be used (alternatively or additionally), to provide complementary measurements of the applied force. Again, one or more of the relevant processors can process this received information to determine the size and thickness of a tress of hair, and then the or a further one of the processors can then determine an adjusted temperature profile of the styler 3401 so as to accommodate the determined size of the tress. For example, the processor may set the heater of the styler 3401 to a higher temperature for a larger and/or thicker tress and set a lower temperature for a smaller tress. In some implementations, feedback may be output to a user via a user interface to adjust the size of the tress for improved styling, for example, to reduce the size of the tress for more effective styling. The feedback may be provided on the styler 3401 or via an application on an external smart processing device 3460. By way of a further example, the brush 3402 may comprise a humidity sensor 35210, which typically measures a change in capacitance, resistance and/or thermal conductivity between two electrodes (between which a hygroscopic material may be positioned) to determine the amount of water vapour in the air. One or more of the processors may use this information to adjust the temperature profile set by the processor of the styler 3401. For example, if the humidity is relatively high, then the one or more processors may set a lower setpoint temperature; and if the humidity is relatively low, then the one or more processors may set a higher setpoint temperature. ‘Remember my Settings’

As illustrated in Figure 36, a styler 3601 , such as a hair straightener, curling tong, hair dryer, heated brush etc., which may be the styler as described above, may typically be in communication with an external smart processing device 3660, such as a mobile telephone, tablet or computer, again which may be the smart processing device as described above. In particular, and in reference to Figure 2, the communications circuitry 27 of a styler is configured to communicate with external smart processing devices. This connection may via Bluetooth, Wi-Fi and/or 3GPP communication protocols, or by other such means. Figure 36 shows exemplary smart processing devices 3660 in communication with exemplary stylers 3601. By way of example, the smart processing devices 3660 may most frequently comprise a personal mobile telephone of a user, but may also comprise other personal computer devices such laptops, tablets and/or smart watches.

The user may typically have preferred ‘settings’ of a hair styler; for example, setpoint temperature of the heater(s), fan speed (for example, of a hair dryer), audio and/or haptic triggers, sound effects, illumination settings (e.g. LEDs), timer settings etc. These may typically be based on the user’s hair, such as length and condition, and on their styling preferences. For example, a user may choose a lower setpoint temperature for a hair dryer or straightener if their hair is damaged and they wish to minimize any further damage. Alternatively, they may choose a higher setpoint temperature if their preference is to dry or style their hair as quickly as possible. In some implementations, the user can input their desired settings into the smart processing device 3660. The input may be made via a dedicated software application, downloaded and run on the smart processing device 3660, for example as described above. In some implementations, the application software may be configured to output suggestions to the user regarding preferable settings based on information input by the user such as hair type and condition and style preferences. In some implementations, the smart processing device 3660 and/or the styler 3601 may be configured to further connect to a central server and/or database, for example a cloud-based processing unit as illustrated in Figure 34 and described above. Some settings may be communicated to and from and stored in such a central server and/or database.

It is normal for a user to change their smart processing device 3660 from time to time, for example, a user may change their mobile phone to a newer model; and it can be frustrating if they then need to save all of their preferred settings again. In order to avoid this, in some implementations, the styler 3601 is configured to ‘remember’ the settings of a user. In particular, the settings are saved to a memory of the styler 3601 and can be retrieved even if the user connects a new smart processing device 3660.

In further detail, the styler 3601 connects to a smart processing device 3660, as illustrated in Figure 36. The user inputs the styler settings into the smart processing device 3660, typically via interaction with a user interface of a dedicated software application. The smart processing device 3660 communicates with the processor of the styler 3601 to control the settings of the styler 3601 in dependence on the inputs of the user. These settings are saved to the memory of the styler 3660. As such, the user does not need to connect to their smart processing device 3660 again in order to activate the customised settings again.

Figure 37 shows a logic flow which is followed by the processor of the styler 3601 when it connects with a smart processing device 3660. Initially, at step 3702, the styler 3601 determines an external smart processing device 3660 is nearby and in communication such that a connection can be made. For example, the styler 3601 may detect a Bluetooth signal of a nearby smart processing device 3660. At step 3704, it is determined whether the styler 3601 should connect with the detected nearby smart processing device 3660. For example, the styler 3601 may output this query to a user interface of the styler 3601 , and a user can input ‘yes’ or ‘no’ instructions to the styler 3601 , for example by pressing buttons or via a touchscreen user interface. In some implementations, a query may additionally or alternatively be output to the user interface of the smart processing device 3660 by the software running on it. If the user instructs the styler 3601 not to connect to the device 3660, then the styler progresses to clearing the current settings at 3710. In other words, any previous settings will not be used for the styling session; this means that the user can define their own settings. This can be beneficial when a different user is using the styler 3601 , for example the usual user may have lent the styler to a friend, who has a different hair type and so different preferred settings.

If the user inputs the instruction that the styler 3601 should connect to the smart processing device 3660, then the processor progresses to step 3706, in which it determines whether the smart processing device 3660 is known to the styler 3601. In particular, the smart processing device 3660 is considered ‘known’ to the styler 3601 if it has previously been connected to the styler 3601. This is determined by reviewing the data stored in the memory of the styler 3601 , as when a smart processing device 3660 connects to the styler 3601 , the processor of the styler 3601 saves data relating to that device to the memory of the styler (such as the phone number, phone ID number or MAC address of the smart processing device 3660). Therefore, by reviewing this stored data and comparing it to the currently connected smart processing device 3660, the processor of the styler 3601 can determine if the device is ‘known’. Figure 38 illustrates an exemplary data structure stored in the memory of the styler 3601. In particular, the details of the particular device, such as a phone ID number of a mobile phone, are converted to a compressed format 3804, which is then encrypted for storage 3806. (A phone ID number is a unique number used by wireless carriers to identify a mobile phone; this is typically a 10-digit number, but a simplified number is shown in Figure 38.) This data compression, encryption and storage may typically further include data relating to the user, such as their login (e.g. an email address) and details of the user’s preferred settings (e.g. temperature, sounds, LEDs and haptics), as indicated in the table 3802. This data format is memory efficient, so that the settings of multiple users can be stored on each styler 3601 . For example, if the styler 3601 has available memory capacity of 5 M B, then the data for up to 10 users can be stored in the memory.

If the styler 3601 determines that the smart processing device 3660 is known, then the styler 3601 and the device 3660 connect automatically. The logic flow then progresses to step 3708, in which the processor applies the associated saved settings. See, for example, table 3802 of Figure 38, which saves the hair type, temperature, sounds, LEDs and haptics settings for each user associated with their phone ID number. For example, with particular reference to Figure 38, if the processor of the styler 3601 recognises the phone number ID T, then it recognises that the associated user ‘g@ghd.com’ is using the styler 3601 . The data stored to this profile is that this user has hair type 2b and their preferred settings are for the temperature setpoint to be at 195°C, the sounds to be set at ‘12’, the RGB levels of the LEDs to be set at ‘123,234,098’, and the haptics to be off. As such, when the processor of the styler 3601 recognises a smart processing device 3660 has the phone number ID T, the styler 3601 automatically connects to the device 3660 and the styler 3601 applies these associated settings.

If, in the alternative, the processor of the styler 3601 does not recognize the smart processing device 3660 (for example, the ID number of the device 3660 is not one stored in the memory of the styler 3601), then it proceeds to step 3712, in which a prompt is output to the user requesting whether the user wishes to log in to the new, unknown device 3660 using an account currently stored in the memory of the styler 3601. This prompt may typically be output via a user interface on the styler 3601 , but in some implementations the prompt may additionally or alternatively be output on the smart processing device 3660. Upon successful login, the processor of the styler 3601 progresses to step 3708, and applies the settings associated with the user. The processor of the styler 3601 further communicates those associated settings to the new smart processing device 3660. For example, with particular reference to Figure 38, the ‘phone ID’ is not recognized by the styler 3601 , but then the user logs in with ‘c@ghd.com’. This user login is associated with the data that the user has type 1a hair, and has a preferred settings comprising a temperature setpoint of 187°C, default sound settings, ‘234,234,234’ RGB settings of the LEDs, and the haptics on. The styler 3601 applies these settings, and sends these settings data to the new smart processing device 3660. This means that if, for example, user ‘c@ghd.com’ has bought a new mobile telephone, they do not need to enter all their preferred settings again, as the styler 3601 stored them and can then send them to the new phone.

If, however, it is a new, unknown user who logs in (i.e. a user whose details are not stored the data storage, as illustrated in Figure 38), then the processor of the styler 3601 progresses to step 3710, in which the current settings are cleared. This means that the new user can adjust the settings to their own preference. Furthermore, upon a new user logging in, an option of a ‘factory reset’ is also output in step 3714 (typically via the user interface of the styler 3601 and/or via the smart processing device 3660 itself). A full factory reset clears all the history of previous users (rather than simply clearing the current settings). In other words, the factory reset clears the data saved in the memory of the styler 3601 comprising user logins and preferred settings (e.g. the data illustrated in Figure 38).

From time to time, a user will also acquire a new styling device 3601. The settings of the styler 3601 can typically be chosen and communicated to the styler 3601 from the smart processing device 3660. The smart processing device 3660 typically also stores data relating to the user, including their hair type and preferred settings. This may be saved locally on the device, in the data associated with the software application. In some implementations, the smart processing device 3660 is further connectable to a central database, in which user profiles and associated settings are stored. In some preferable implementations, if a new styling device 3601 is connected to a smart processing device 3660 running the dedicated software application, then the smart processing device 3660 can communicate the settings associated with that user to the new styler 3601 , so that they can also be saved to the storage of the styler 3601. In particular, the application on the smart processing device 3660 may output a prompt to the user to apply the stored settings to the styler 3601 . The user can then choose whether to apply these settings to the newly connected styling device 3601 .

Furthermore, the user may use more than one styling device, which they connect to their smart processing device 3601 . For example, a user may have a hair straightener, a hair dryer and a curling tong. The smart processing device 3660 may typically be configured to store data gathered when using all of these devices. Such data is stored to the user’s profile (which may, for example, also be stored to a central database). The smart processing device 3660 can communicate to each of the stylers the user data collected and stored during use of any of the other stylers. This can be particularly beneficial if changes to the user’ hair are detected during styling. By way of example, a styler may be used after a haircut and the styling technique indicates a shorter hair length as the stroke length is shorter. This information is saved to the user profile in the styler being used and communicated to the smart processing device 3660, where it is also stored. In turn, the smart processing device 3660 can communicate this updated data associated with the user profile to the other stylers in which the user data is stored.

Subscription Settings

Figure 39 shows an exemplary system comprising a styler 3901 , which may be the styler as described above, in communication with a smart processing device 3960, again which may be the smart processing device as described above. Typically such a connection is made via Bluetooth, but the connection may be via Wi-Fi and/or 3GPP communication protocols or other similar communication systems, protocols and means. The styler 3901 may, by way of example, be a hair straightener, a hair dryer, a curling iron or curling tong, a heated brush etc., for example any styler as described above. The smart processing device 3960 may, by way of example, be a mobile phone, a tablet, a laptop etc. As previously described above, the smart processing device 3960 typically runs a software application. The software application outputs a user interface, with which a user can interact to control the styler 3901 , for example by adjusting settings (e.g. temperature setpoint, fan speed, light settings, haptic settings etc.). The instructions input by the user are communicated to the styler 3901 , for example via the Bluetooth connection, to control the styler 3901. The smart processing device 3960 is further in communication with a service which stores a database 3950, for example located in a remote data server. The database may be located in the cloud-based processing unit as described above, or linked and connected to the cloud-based processing unit as described above. Typically, the smart processing device 3960 is in communication with the database 3950 via a WiFi connection, but may also be in communication via 3GPP communication protocols or other similar communication systems, protocols and means. In some implementations, the styler 3901 may optionally be directly in communication with the database 3950 (for example in the manner illustrated in Figure 34 and described above).

In some implementations, the smart processing device 3960 is configured to connect to the database 3950 on a regular basis. In particular, the smart processing device 3960 is configured to receive information relating to the styler 3901 through the communication and control of the styler 3901. For example, the smart processing device will keep track of the version of software and/or firmware currently installed on the styler 3901 . The smart processing device 3960 is then further configured to communicate this information with the database 3950, which stores information relating to the latest versions of the software and/or firmware. By comparing, a check can be performed whether the software and/or firmware of the styler 3901 is up to date. This can improve safety by ensuring that the most up-to-date software and/or firmware is being used. In some implementations, the smart processing device 3960 is further configured to send reports to the database 3950 regarding the functioning of the styler 3960. In this way, the performance of the styler 3960 can be monitored. For example, the device 3960 may automatically send an error report if the styler 3960 errors. The system administrator can then respond appropriately, for example by sending a replacement styler to the user.

Furthermore, database 3950 typically comprises data relating to any subscriptions the user may have. For example, the user may pay for the styler 3901 on a subscription basis such as paying for the styler (and typically any technical support) in monthly or weekly installments. Different types of subscription may be available. By way of example, an individual user may have a different type of subscription to a salon, as the salon typically has many stylists using multiple stylers so pays for all these, while a private individual user will typically pay for just one styler of a given type. The database 3950 comprises data relating to whether the user is up to date on their obligations to a subscription. For example, the database 3950 may comprise information on all the payments made by the user to date. In some embodiments, the styler 3901 itself comprises a clock which continues time keeping even when the styler 3901 is powered down; for example, this may be implemented by a clock (e.g. CMOS clock). This can also be used to keep track of when regular user obligations are due, for example user payments. The smart processing device 3960 is configured to receive data from the database 3950, and then output appropriate corresponding instructions and actions in dependence on this data. Such instructions and actions may comprise: ‘locking out’ the styler 3901 (i.e. instructing the styler not to function, for example not to heat up); outputting a message to the user indicating the problem (e.g. that the user has not fulfilled their obligations, for example as payment is overdue), typically by outputting a message on the smart processing device 3960; and/or outputting an error message on the styler 3901 itself (for example, a verbal error message may be output on a user interface, LED lights may flash red, haptics may be output and/or audio error messages may be output etc.). In some implementations, messages may be output to the user (for example via the smart processing device 3960 and/or directly via the styler 3901) reminding them of upcoming actions and obligations. By way of example, such a message may read: "New software for your styler will be released in one day, be sure to update it then!".

Different rules and levels of leniency may be applied depending on the type of service and the type of subscription. For example, in some implementations a grace period may be implemented before actions, such as ‘locking out’ the styler, are implemented. Different logic flows are illustrated in Figures 40 to 42 and will be described below.

Figure 40 shows a flow diagram which a system follows every time it is powered on in the case that the styler 3901 must connect to the database every time it is switched on. Such a protocol is typically implemented for a subscription by a private individual user, for example when the user has a weekly payment plan. The instructions for following this flow are typically saved and stored in both the memory of the styler 3901 itself and in the memory of the smart processing device 3960 (as part of the dedicated software application). The flow starts 4002 when the user powers the styler 3901 on at step 4004. The processor of the styler 3901 attempts to connect with the smart processing device 3960, via their respective communications circuitry, and determines at step 4006 if the connection is successful. If the connection between the styler 3901 and the smart processing device 3960 is successful, at step 4010 the smart processing device 3960 then attempts to connect to the database 3950. A defined number of attempts, x, will be made by the smart processing device 3960 to connect to the database 3950. The defined number of attempts may simply be 1 , but more typically will be a number greater than 1 , for example, between 2 and 10, to provide further chances to connect. For example, a user may need to ensure that their smart processing device has a stable WiFi connection, and then make further attempts at connection. If the smart processing device 3960 successfully connects to the database 3950 within x number of attempts, then the flow moves to step 4018, in which data is retrieved from the database regarding whether the user has fulfilled their obligations. Such obligations may be payment on a scheduled basis, in which case the data will relate to whether the user is up to date on payments. The obligations may comprise other actions required by the user; for example (but not limited to) updating software and/or firmware in a timely manner. If it is determined at step 4018 that the obligations have been fulfilled, and such information is retrieved by the smart processing device 3960, then the smart processing device 3960 sends instructions to the processor of the styler 3901 to operate as normal (step 4020).

On the other hand, if the data stored in the database 3950 and received by the smart processing device 3960 indicates that the user’s obligations are not fulfilled, then the system progresses to step 4014, in which it is determined who is at fault. In particular, it is determined whether the user/consumer is at fault themselves or whether it is the fault of the system or system administrator (e.g. the company which supplied the styler 3901 and/or the entity operating the database); for example, there may be an error receiving payment or an error distributing software or firmware updates. By way of another example, the database itself may not be up to date. Alternatively, the smart processing device 3960 may not be able to determine the cause of the fault. If it is determined that the user/consumer is at fault, the system progresses to step 4016 in which a ‘Time Out’ error is output and the smart processing device 3960 instructs the styler 3901 not to operate. In particular, the smart processing device 3960 instructs the styler 3901 not to heat up and so the user cannot style their hair. In some implementations, these instructions may be determined and output by the processor of the styler 3901 itself. The styler 3901 and/or the smart processing device 3960 will typically output an error message indicating the problem. However, if it is determined that the system and/or system administrator is at fault or the cause of the fault cannot be determined, then the smart processing device 3960 instructs the styler 3901 to operate as normal at step 4020. Again, in some implementations, these instructions may be determined and output by the processor of the styler 3901 itself.

Similarly, if no successful connection is made between the smart processing device 3960 and the database 3950 at step 4012 even after ‘x’ number of attempts, then the smart processing device 3960 determines at step 4014 who is at fault. In particular, it determines whether it is a fault of the consumer, for example they have not properly established an external connection means for the smart processing device 3960 (e.g. a WiFi connection); or whether it is the fault of the system, database and/or system administrator. By way of example, the database itself may have connection issues. Alternatively, the smart processing device 3960 may be unable to locate the fault which is preventing it from connecting to the database 3950. If is determined that the user/consumer is at fault for preventing the successful connection, then the smart processing device 3960 instructs the styler 3901 not to operate, and sends instructions to output a ‘Time Out’ throw error, at step 4016. In some implementations, these instructions may be determined and output by the processor of the styler 3901 itself. The styler 3901 will therefore not heat up and the user will not be able to use it to style hair. Alternatively, if the cause of the fault cannot be determined or is determined to be the database, system or system administrator, then the smart processing device 3960 instructs the styler 3901 to operate as normal in step 4010. Again, in some implementations, these instructions may be determined and output by the processor of the styler 3901 itself. This is to prevent the user being prevented from using the styler because of an issue which is not their fault.

In some instances, there may be no successful connection of the styler 3901 and the smart processing device 3960 in step 4006. If this occurs, then at step 4008 the styler determines whether a defined number of minutes, y, have yet passed. This number y can be determined for each system, but may typically be between 1 and 5 minutes. If the defined number of minutes, y, has not yet passed, then the styler 3901 returns to step 4006 and attempts to make the connection again. This process repeats until a connection is formed at step 4006 or until it is determined at step 4008 that the defined number, y, of minutes have passed. In the former case, the system progresses to step 4010, in which the smart processing device 3960 attempts to connect to the database 3950 (as described above). In the latter case, once y number of minutes have elapsed without a connection being formed between the styler 3901 and the smart processing device 3960, then the styler 3901 is configured to move to the ‘Time Out’ Throw Error 4016. The styler 3901 is configured not to operate as normal; in particular, the styler is configured not to heat up the styling element(s) so that the user cannot style their hair.

Figure 41 shows a slightly modified flow for a system in which a styler 3901 only needs to connect to the database 3950 once a month. The instructions for following this flow are typically saved and stored on both the styler 3901 and the smart processing device 3960. Typically, during this monthly connection, an update will be sent from the database 3950, via the smart processing device 3960, and to the styler 3901. This can ensure that the styler 3901 has the latest software and/or firmware updates installed, and so can help to ensure that it is operating as efficiently and safely as possible. Such a protocol may also be more appropriate, for example, for a salon which has a multi-product subscription service. In such a case, it would typically be impractical to require the salon to connect their styling devices to the database 3950 every use. Instead, during a monthly connection to the database 3950, data confirming that the salon is up to date on its obligations (e.g. payments) can be sent to stylers 3901 and/or smart processing devices 3960, which then implement instructions to operate the stylers 3901 as normal for the next 28 days (i.e. until the next update). It may also be implemented for individual users, for example paying on a monthly basis or where the obligations simply comprise updating software and/or firmware; as it may be more convenient not to be required to connect to the database every session. In particular, as shown in Figure 41 , the flow starts 4102 when the styler 3901 is powered on, this step further comprising checking the clock at step 4104 (for example, a CMOS clock). The clock keeps track of time even when the styler 3901 is powered off. It can therefore be used to determine the time elapsed since the last update. In step 4106, the processor of the styler 3901 determines whether the last update was performed in the last four weeks (28 days). If the answer is yes, then the styler 3901 progresses straight to operating as normal at step 4122. As such, the styler 3901 does not need to connect to the smart processing device 3960 or the database 3950 every time it is powered on. The instructions to implement this step (at least) are therefore stored in the memory of the styler 3901 itself.

However, if at step 4106, the styler 3901 determines that there has been no update in the last 4 weeks, it progresses to step 4108, in which is attempts to connect to the smart processing device 3960. From this point, the flow is the same as that illustrated in Figure 40 and described above. Namely, if the styler 3901 connects to the smart processing device at step 4108, the smart device 3960 connects to the database 3950 (within x number of attempts) at steps 4112 and 4114, and then the data from the database indicates that the consumer’s obligations have been fulfilled at step 4120, then the styler 3901 is instructed to operate as normal at step 4122. However, if no successful connection can be made to the database 3950 at step 4144 or if at step 4120, data from the database 3950 indicates that the obligations have not been fulfilled, and it is determined in step 4116 that the user/consumer is at fault; then the styler progresses to stage 4188 in which it times out (i.e. it does not heat up as normal and so cannot be used to style hair). In either case, if instead it is determined in step 4116 that the database, system or system administrator (e.g. the company running the database and/or supplying the styler 3901) is at fault, or it cannot be determined who it at fault; then the styler is configured to progress to step 4122 and operate as normal. Similarly, if, after determining at step 4106 that there has been no update in the last 4 weeks, the styler 3901 is unable to connect to the smart processing device 3960 at step 4108, then the styler determines whether a predetermined number, y, of minutes has elapsed since powering on and/or since the first connection attempt. If the time elapsed is less than y minutes, a further attempt to connect to the smart processing device 3960 is attempted. This cycle continues until either a successful connection is made or until y minutes have elapsed. If no connection has been made after y minutes, then the styler 3901 progresses to stage 4118, in which a ‘Time Out’ message is output and the styler does not operate (e.g. the styling component does not heat up).

Of course, different time intervals may be established in which the styler 3901 should connect to the database and the regular update be performed. For example, this may be more every one week or every two weeks. Alternatively, in some implementations it may be determined that once every three months is more appropriate; for example, if a payment plan requires payment installments every three months or if the obligations relate only to updates and these are released every few months on average.

In some implementations, different levels of leniency and different levels of ‘lockout’ of the styler 3901 may be applied in the ‘Time Out’ stage 4016, 4118. By way of example, if the data retrieved from the database 3950 indicates that the user has not fulfilled their obligations, further logic steps may be implemented to ascertain how long the unpaid status has been active or how long a software and/or firmware update is overdue. By way of example, the styler 3901 may be instructed to operate normally for a week but with limited customization features after the initial determination of an unpaid status or that updates are overdue. If the payments are made and/or updates installed, as appropriate, then the styler 3901 returns to normal operation. If, however, the required obligations are not fulfilled during that week, then the styler moves to a total ‘lockout’ status.

The connectivity of the styler 3901 to the database 3950 can similarly facilitate the transmission of information from the styler 3901 to the database 3950, and thereby to a system administrator, such as a technical support team and/or supplier of the styler 3901. Figure 42 illustrates a logic flow of the system in the case an error is detected within the styler 3901 . The flow starts 4202, and at step 4204 the styler 3901 is powered on and connected to the smart processing device 3960, which is in turn connected to the database 3950. Further at step 4204, the styler 3901 errors. The flow progresses to step 4206 where it is determined whether this is a new error, or a previously logged error. This can typically be achieved by comparing the details of this error to those already logged. If it is determined to be a new error, then the system progresses to step 4212, which comprises sending an automatic error report to a central system, for example the database 3950. This also comprises sending an email (either automatically or manually) to the consumer detailing actions the system and/or system administrators are taking and outlining any actions the consumer may need to take. This may typically be after an internal process at the central system to determine the best course of action. By way of example, this may comprise replacing the styler 3901 , rebooting it or repairing it. This functionality can allow the system and/or system administrator to monitor any faults and replace any faulty stylers without the user being required to file a report. This can provide more efficient and safer operation of the styler 3901.

Multi-user Architecture

As described above, a styler may have multiple users. For example, Figure 38 illustrates an exemplary protocol by which preferred settings data may be stored on a styler associated with particular different users. Each of these users (and their associated smart processing devices) are ‘known’ to the styler as they have all connected to the styler previously and so their data is stored in the memory of that styler. By way of example, in a private household setting, a family may share one or more hair stylers. By way of a further example, stylists at a hair salon may share multiple stylers. Similarly, as described above, each user may use several different hair stylers; for example, one user may use a hair straightener, a hair dryer and a curling tong. The smart processing device of each user is beneficially connectable to each of these stylers. As further described above, stylers and smart processing devices may typically be configured to connect automatically (for example, when within range of one another) if they are ‘known’ to one another (i.e. if relevant identification data is stored in the memory of the respective styler and/or smart processing device).

Figure 43 illustrates an exemplary arrangement in which a styler 4301 is connectable to four different smart processing devices: a first smart processing device 4362 associated with ‘User T, a second smart processing device 4364 associated with ‘User 2’, a third smart processing device 4366 associated with ‘User 3’, and a fourth smart processing device 4368 associated with ‘User 4’. The styler 4301 may be a styler as described above, and the smart processing devices 4362, 4364, 4366, 4368 may be a smart processing device as described above. Each of the smart processing devices 4362, 4364, 4366, 4368 are individually connectable to the styler 4301. Typically, communications circuitry within the styler 4301 communicates with communications circuitry within the smart processing devices 4362, 4364, 4366, 4368 via Bluetooth; however, in some implementations the communication may be via Wi-Fi and/or 3GPP communication protocols or other similar communication systems, protocols and means. The styler 4301 may, by way of example, be a hair straightener, a hair dryer, a curling iron or curling tong, a heated brush etc., for example any styler as described above. The smart processing devices 4362, 4364, 4366, 4368, by way of example, may be mobile phones, tablets, laptops etc. and any combination of such devices. As previously described above, the smart processing devices 4362, 4364, 4366, 4368 typically run a software application. The software application outputs a display to a user interface 4370, 4372, 4374, 4376, with which a user can interact to control the styler 4301 , for example by adjusting settings (e.g. temperature setpoint, fan speed, light settings, haptic settings etc.). The instructions input by the user are communicated to the styler 4301 , for example via the Bluetooth connection, to control the styler 4301.

Typically, when the styler 4301 is powered on and/or when it is ‘plugged in’ by connection to a power source (but not necessarily powered on), it will be connectable by the smart processing devices 4362, 4364, 4366, 4368. For example, when the styler is powered on and/or connected to a power source, Bluetooth is also powered on and any of the smart processing devices 4362, 4364, 4366, 4368 within a range can connect to it. Multiple smart processes devices 4362, 4364, 4366, 4368 can simultaneously connect to the styler 4301 via the connection, but only one user has control to adjust the settings. In the example illustrated in Figure 43, User 1 can adjust the settings of the styler 4301 by inputting settings via a user interface of the application running on the smart processing device 4362. The styler 4301 communicates with the second, third and fourth smart processing devices 4364, 4366, 4368, associated with User 2, User 3 and User 4 respectively, that they are not able to adjust the settings of the styler 4301 . In effect Users 2, 3 and 4 are ‘locked out’ from adjusting the settings of the styler 4301. Accordingly, each styler 4301 communicates to each of the smart processing devices 4362, 4364, 4366, 4368, to which it is connected, information relating to: styler identification data; styler power status (e.g. when it is turned on); and the control status (i.e. whether it is currently under the control of another smart processing device or whether it is available for control). The smart processing devices 4362, 4364, 4366, 4368 receive this information, and can be configured to output such information via the user interface of the devices 4362, 4364, 4366, 4368.

Figure 44 illustrates an exemplary user interface 4370 output by the application running on the first smart processing device 4362, associated with User 1 . In particular, the display output to the user interface 4362 comprises sections 4410, 4420, 4430, 4440, 4450, each of which relates to a different styler in communication with the smart processing device 4362. Section 4410 as illustrated relates to the styler 4301 of Figure 43, and in the illustrated exemplary embodiment includes an image representation 4412 of the styler 4301. Furthermore, the section 4410 may, by way of example, display the date code 4418 of the styler 4301 (the date on which the styler 4301 was manufactured) as a further identifier to indicate which styler 4301 is being referenced. Other identifiers such as the product name, colour, model etc. may be used. The section 4410 of the user interface 4370 further displays a styler status indicator 4416 for the styler 4301 . By way of example, section 4410 of Figure 44 indicates that the styler 4301 is powered on by the styler status indicator 4416 showing a ‘power’ symbol in a circle. Of course, alternative indicators may be used. Typically, a styler status indicator 4416 may be illuminated green if the styler is powered on (indicated in Figure 44 without a pattern) and red if the styler is turned off (indicated in Figure 44 by a spotted pattern), but of course different colour and/or pattern schemes may be used.

As the first smart processing device 4362 is controlling the settings of this styler 4301 , a status message 4414 within the section 4410 reads “You are using this styler”. This confirms to the user that they are in control of the settings of this styler 4301.

In some implementations, a user interface button ‘Forget this device’ may be present in each section 4410, 4420, 4430, 4440, 4450. A user can actuate such a button if it no longer wishes the smart processing device 4362 to display the details of the styler 4301. In some implementations, this will actuate deletion of the data relating to the styler 4301 in the memory of the smart processing device so that automatic connection does not take place in future. This may be beneficial if a user no longer uses a particular styler, for example as they have replaced it with an upgraded model.

Section 4420 of the user interface 4370 indicates the status of a further styler to which the smart processing device 4362 is connected. Again, the section 4420 identifies the styler by outputting a representative image 4422 and an identifier 4428 (in this example, a date code). This styler also communicates information regarding its status to the first smart processing device 4362. In particular, this styler is turned on but is currently being controlled by the second smart processing device 4364, associated with User 2. The styler status indicator 4426 indicates that the styler is powered on as it is a clear circle (in practice, by way of example, this may be illuminated green). However, the styler status indicator 4426 further shows a lock symbol, which indicates that the smart processing device 4362 is ‘locked out’ of this styler (it cannot control the settings). The status message 4424 reads “User 2: is using this styler”. Thereby, the user interface indicates that, the smart processing device 4362 cannot control the settings of the styler as another smart processing device 3464 is controlling the settings of that styler. This is further indicated by the hatching of the section 4420 (in practice the section may be ‘greyed out’).

Section 4430 of the user interface 4370 indicates the status of a further styler to which the smart processing device 4362 is connected. Again, the section 4430 identifies the styler by outputting a representative image 4432 and an identifier 4438 (in this example, a date code). This styler is powered on but not currently controlled by any smart processing device, and transmits this status information to the first smart processing device 4362 while they are connected. This styler is therefore available for control by the first smart processing device 4362. In the exemplary display output to the user interface 4370, this the styler status indicator 4436 indicates that the styler is powered on and available as it is a clear circle (e.g. it may be illuminated green) in which is displayed a power symbol. Additionally, the section 4430 is not hatched or ‘greyed out’. Furthermore, the status message 4434 reads “No one is using this styler” and outputs to the user an additional ‘USE’ button. A user can actuate this button to commence taking over control of the settings of the styler.

Section 4440 of the user interface 4370 indicates the status of a further styler to which the smart processing device 4362 is connected. This styler is not powered on but is also not currently being controlled by any of the smart processing devices 4362, 4364, 4366, 4368. It is connected to the first smart processing device 4362, for example as Bluetooth is switched on; this may, for example, be because the styler is connected to a power source. It transmits this information relating to its status to the first smart processing device 4362. Again, the section 4440 identifies the styler by outputting a representative image 4442 and an identifier 4448 (in this example, a date code). In the illustrated exemplary display output to the interface 4370, the styler status indicator 4446 indicates that the styler is powered off (in practice, the indicator may be illuminated red). No other smart processing device is in control of the settings of this styler, as indicated by the section 4440 not being displayed as hatched or ‘greyed out’, and as indicated by the status message 4434 reading “No one is using this styler”. The styler is therefore available for the smart processing device 4362 to control, and the section 4440 of the user interface outputs a USE’ button, which can be actuated by a user to commence taking over control of the settings of the styler. In this way, the user of the smart processing device 4362 can therefore also power on the styler via the user interface 4370.

Finally, section 4450 of the user interface 4370 indicates the status of a further styler to which the smart processing device 4362 is connected. Again, the section 4450 identifies the styler by outputting a representative image 4452 and an identifier 4458 (in this example, a date code). This styler is powered off but is still under the control of the third smart processing device 4366, associated with User 3. This may be because User 3 has not yet relinquished control of the styler; for example, User 3 may have paused their styling session temporarily and styler 3 has powered off during this pause. As the styler is in communication with the first smart processing device 4362, it communicates this information to it. The exemplary display output to the user interface 4370 shows that styler status indicator 4456 indicates that the styler is powered off (in practice, the indicator may be illuminated red), and the status message 4454 reads “User 3: is using this styler”. As the styler is not available the section 4450 is displayed as hatched or ‘greyed out’. In this case, therefore, User 3 is still assigned control over the styler, even though it is currently powered off. No other smart processing device can then take over control. Such functionality can be of particular advantage in controlling who can power and use stylers. For example, this can facilitate parents preventing a child from being able to turn on and control a styler.

As described above, each user may use several different stylers. Accordingly, multiple stylers can be connected to the same smart processing device at the same time. Figure 45 illustrates an exemplary embodiment in which the first smart processing device 4362, associated with User 1 , is in communication with a first styler 4301 , which is a hair straightener; a second styler 4501 , which is a hair curling tong; and a third styler 4502, which is a hair dryer. Of course, other types of stylers may also be used. Figure 46 illustrates an exemplary display output to the user interface 4370 of the smart processing device 4362 in this case. A first section 4610, second section 4620 and third section 4630 display information relating to the first styler 4301 , second styler 4501 and third styler 4502 respectively. Each of these sections 4610, 4620, 4630 identifies the relevant styler 4301 , 4501 , 4502 by means of a representative image 4611 , 4621 , 4631 and an identifier 4618, 4628, 4638 (in this example, a date code).

In the illustrated example of Figure 46, the first styler 4301 is powered off and is not currently in communication with the first smart processing device 4362 as the first smart processing device 4362 is not within a suitable range of the styler 4301 to connect. As such, in the exemplary display output to the user interface 4370, section 4610, which configured to display information relating to the first styler 4301 , is completely hatched (or ‘greyed-out’), indicating that the first styler 4301 is unavailable. The status message 4612 reads “Not connected” and the auxiliary status message 4614 reads “Out of Range”. This indicates that the first styler 4301 is unavailable for control by the first processing device 4362 because the first processing device 4362 is not within the communication range of the styler 4301. In such a case, a time stamp 4617 is output indicating the last time that the styler 4301 was in communication (i.e. connected to) the smart processing device 4362. The smart processing device 4362 is typically configured to determine this with reference to its own clock (for example, a CMOS clock), and store this in association with data relating to the styler 4301.

In the illustrated example of Figure 46, the second styler 4501 is powered off but is in communication with the first smart processing device 4362. Additionally, it is not being controlled by any other smart processing device and so is available for control. The second styler 4501 communicates this status information to the first smart processing device 4362. Section 4620, configured to display information relating to the second styler 4501 , indicates via the status indicator 4626 that the second styler 4501 is powered off, but that it is available for control by the smart processing device 4362. In particular, the status message 4624 reads “Connect to device” and an interface button is output which a user can actuate to request to connect to the second styler 2. Additionally, an information icon 4622 is output to the second section 4620 of the interface 4370; a user can select this icon to retrieve further information relating to the styler 4501 , such as warranty period, how to clean, and other FAQs. Such information may be stored in the memory of the smart processing device 3262 itself. By way of example, the information may have been retrieved in from the styler 4501 and/or from a reference database to which the smart processing device 4362 can also connect (for example, a database and/or cloud-based processing unit as preciously described). In some implementations, this information may be retrieved directly from the styler 4622 in each session; this can be useful if the information includes further data relating to a current status of the styler (for example, current temperature; the presence of any attachments; remaining battery level for a battery-operated styler, etc.).

The third styler 4502 is powered on and is currently being controlled by the first smart processing device 4362, and it communicates this information to the first smart processing device 4362. Accordingly, in the exemplary display output to the user interface 4370, section 4630, configured to display information relating to the third styler 4502, indicates via the status indicator 4636 that the second styler 4501 is powered on. Furthermore, the status message 4634 indicates that the smart processing device 4362 is connected to and in control of the third styler 4502, reading “You are using this hairdryer”. Additionally, the smart processing device 4362 receives from the third styler 4502 data relating to any attachments being attached to the third styler 4502. The styler 4502 may be able to detect that an attachment is connected onto the styler 4502 for example via activation of one or more switches during physical interconnection of the attachment to the styler 4502 and/or via communication by the attachment in proximity to the styler 4502. By way of example, the attachment may comprise a radiofrequency identification (RFID) chip which can be read by a corresponding detector located on the styler 4502. Upon receiving from the communications circuitry of the styler 4502 information that an attachment is connected to the styler, the smart processing device 4362 can be configured to output this information to relevant section 4630 of the user interface. In particular, in the example as illustrated in Figure 46, a visual representation of a diffuser attachment 4633 is displayed and the status message 4634 further reads “diffuser head”.

Figure 47 shows an example system architecture for multiple smart processing devices 4362, 4364, 4366, 4368 in relation to a styler 4301 . The styler 4301 is powered on and can communicate with smart processing devices located within a range 4701. The first smart processing device 4362 and the second smart processing device 4364 are both located within the range 4701 , while the third smart processing device 4366 and the fourth smart processing device 4368 are not. Additionally, the first smart processing device 4362, the second smart processing device 4364, and the third smart processing device 4366 are connected to a network 4702, while the fourth smart processing device 4376 is not connected to the network 4702.

The user interfaces 4370, 4372, 4374, 4376 of each smart processing device 4362, 4364, 4366, 4368 each outputs a section 4710, 4720, 4730, 4740 in respect of the styler 4301 , as described above. These identify the styler 4301 by a representation image 4712, 4722, 4732, 4742 and an identifier 4718, 4728, 4738, 4748 (in the illustrated example, a date code), as also described above.

The first smart processing device 4362 is within the range 4701 of the styler 4301 and in control of the styler 4301. Therefore, the user interface 4370 outputs to the relevant section 4710 a status indicator 4716 indicating that the styler is powered on and a status message 4714 of “You are using this styler”. The styler 4301 communicates the information that it is currently being controlled by the first smart processing device 4362 to any further smart processing devices with which it is connected.

The second smart processing device 4364 is within the range 4701 of the styler 4301 and so in communication with the styler 4301 . The styler 4301 outputs to the second smart processing device 4364 its status, in particular that it is powered on and that the first smart processing device 4362 is currently in control of the styler 4301. Therefore, the option of control is not available to the second smart processing device 4364. As such, the relevant section 4720 of the user interface 4372 outputs a status indicator 4726 indicating that the styler 4301 is powered on, but that the second smart processing device 4364 is ‘locked out’ from control. The status message 4724 further indicates that User 1 , who is associated with the first smart processing device 4362, is using the styler.

The third smart processing device 4366 is outside the range 4701 of the styler 4301 , and so it cannot communicate with the styler 4301 directly. The auxiliary status message 4735 outputs this information to the user in the relevant section 4730 of the user interface 4374; in the example illustrated, the auxiliary status message 4735 reads “Out of range”. However, the third smart processing device 4366 is connected to the network 4702, to which the first smart processing device 4362 and the second smart processing device 4364 are also connected. The first smart processing device 4362 and/or the second smart processing device 4364 can communicate with the third smart processing device 4366 over the network 4702. In particular, information relating to the status of the styler 4301 can be communicated to the third smart processing device 4366 even though it is out of the range 4701 of the styler 4301. This status comprises the information that the styler 4301 is currently powered on and being controlled by the first smart processing device 4362. Accordingly, the relevant section 4730 of the user interface 4374 outputs a status indicator 4736 indicating that the styler 4301 is on but unavailable to the third processing device 4366 and the status message 4734 indicates that User 1 , the user associated with the first smart processing device 4362, is using the styler. Such functionality can facilitate a user having oversight of one or more stylers even if they are not within the range of the styler. This can be a beneficial safety measure. For example, a parent can have oversight of household stylers and whether children are using them. In some implementations, one or more accounts may have overriding administrative authority, even remotely, through which a user can remotely power off stylers, grant permission for use and ‘lock out’ stylers to prevent use.

By contrast, the fourth smart processing device 4368 is outside the range 4701 of the styler 4301 and is not connected to the network 4702. It therefore does not receive any current status information from either the styler 4301 or the other smart processing devices 4362, 4364, 4366. Consequently, the fourth smart processing device 4368 does not output any current status information relating to the styler 4301 . The status message 4744 simply reads “Not connected” and the auxiliary status message 4745 reads “Out of Range”, as the device 4368 has not received any information regarding the first smart processing device 4362 being connected to and controlling the styler 4747. The fourth smart processing device 4368 retrieves from its own memory the time of the last connection 4747 to the styler 4301 , and outputs this information to the relevant section 4740 of the user interface 4376.

As described above, in some implementations, the architecture of a multi-user system comprises one or more users having administrator status. Such an administrator has overriding access, meaning they can input instructions to the styler to be locked off or remotely turned off, and they can grant permission for other users, etc. This can be implemented remotely by the administrator connecting to the relevant network. By way of example, an administrator may be a parent, and thus by utilising the network as discussed above, child protections can be accessed remotely. As described in relation to Figure 38, a user ID is associated with a particular one or more smart processing devices and the relevant data stored in associated with one another. However, a user can also identify themselves on an unknown device by inputting their user login. Figure 48 illustrates an exemplary implementation of a user assigned administrator status. The user ‘P’ (for example, a parent), associated with an administrator smart processing device 4846, has administrator status. The user ‘C’ (for example, a child) is associated with a standard smart processing device 4860, and does not have administrator status. The standard smart processing device 4860 is in connection with the styler 4301 while the administrator smart processing device 4864 is not in communication with the styler 4301. However, the administrator smart processing device 4864 and the standard smart processing device 4860 are connected to one another via a network 4802. As illustrated, when the standard smart processing device 4860 connects to the styler 4301 , the protocol states that it is unable to control the styler 4301 until permission has been granted by the administrator smart processing device 4864. As such, the standard smart processing device 4860 outputs to the relevant section 4810 of the user interface 4862 a status indicator 4816 indicating that the styler 4301 is powered on but that control access is locked. Additionally, there is output to the user an option to request to use 4814 the styler 4301. Upon actuation of this request the standard smart processing device 4860 communicates it to the administrator smart processing device 4864, which outputs a notification 4834 and the request 4835 to the relevant section 4830 of the user interface 4866 of the administrator smart processing device 4864. The user P can agree to grant permission and input this into the user interface. While the user C waits for the administrator to grant permission, the status message output to the relevant section 4810 of the user interface 4862 changes to indicate that it is awaiting a response from P, the administrator. If user P actuates an input indicating permission into the interface 4866 of the administrator smart processing device 4864, then the administrator smart processing device 4864 communicates this to the standard smart processing device 4860 over the network 4802. The standard smart processing device 4860 is then able to control the settings of the styler 4301 .

In some implementations, the administrator smart processing device 4864 can control powering the styler 4301 on and off remotely over the network 4802 (for example, even if it is not within the range of the styler 4301). This can facilitate an administrator checking that all devices are powered off, and if not, then instructing them to be powered off remotely. In a similar manner, the administrator smart processing device 4864 can remove permissions for another smart processing device to control a styler as well as grant permissions; again, these can be communicated remotely via the network 4802. In some implementations, the controller and/or microprocessor of the styler 4301 is configured to implement instructions received from a smart processing device only in combination with an authorization from the administrator smart processing device 4864.

In order to remove or alter the current administrator (or ‘parent’), for example, if the styler 4301 moves to a new user, digital verification methods can be adopted. For example, such a change can be effected by connection to a database, as described previously, from which data can be retrieved indicating if a new administrator has acquired the styler (and, for example, fulfilled all relevant obligations). The styler can then be ‘released’.

Modifications and alternatives

Detailed embodiments and some possible alternatives have been described above. As those skilled in the art will appreciate, a number of modifications and further alternatives can be made to the above embodiments whilst still benefiting from the inventions embodied therein. It will therefore be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the scope of the claims appended hereto.

Any invention which has been described above by way of implementation in a hair styling device for straightening hair (‘hair straighteners’) which employ flat hair styling heaters 106, 2006 could alternatively be implemented in any form of hair styling device, such as (but not limited to) crimpers, curlers or heated brushes. The heaters 106, 206, 306, 406, 506, 806, 1306, 2006, 2106, 2206, 2306 may define a heating surface that is flat, curved, ridged or in the shape of a barrel. The hair styling device may have two arms like the device illustrated in Figure 1 or it may be a single armed device. Further, two-armed devices such as stylers may comprise one fixed and one moveable arm rather than two moveable arms. The heaters described above may also be used in hair dryers or in combination devices that use conductive heating and air to dry and style the user’s hair (such as those described in the applicant’s earlier PCT application WO 2021/019239). In embodiments where air is used, the heaters 6 may be perforated so that air passes through the heater and is warmed by the heater as the air passes through.

In the above embodiments, Metal Oxide Semiconductor Field Effect Transistor (MOSFET) switches were used to control powering and sensing of the heater electrodes. As those skilled in the art will appreciate, other switches could be used instead. For example, Field Effect Transistors (FETs) could be used, such as Gallium Nitride FETs or bipolar junction transistors (BJTs).

In the above embodiments, a DC power source was used to provide electrical power for heating the heater electrodes 64. This DC power source will typically be one or more batteries, although DC supplies that derive their power from a mains power AC signal may be used. Thicker or more dielectric layers are typically used between the heater electrodes 64 and the hair contacting surface of the hair styler when AC power is used to heat the heaters.

In the above-described examples the hair styling device 101 , 2001 , 2701 may comprise a single heater 106, 2006, or may alternatively comprise two or more heaters 10, 2006.

It should be understood that different combinations of feedback components may be provided and that different specific feedback protocols may be implemented. For example, different illumination colour schemes may be implemented. Additionally, the illuminated strips may have a different configuration for different drying and/or styling appliances, typically according to the particular configuration of the heaters and heating zones. Furthermore, further methods of implementing feedback may be implemented in any combination, in particular a combination of visual, haptic and/or audio feedback.

In the above description, communication is described as between particular entities. However, implementations are possible in which direct communication between entities is alternatively possible. For example, a styler may interact directly with a cloud-based processing unit and/or database. As a further example, multiple styling products belonging to a particular user may be in direct communication with each other, for example there may be interaction between a styler, a hairdryer and a curler, for example to share user information such as hair type, hair health, styling preferences, etc.

Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “containing”, means “including but not limited to”, and is not intended to (and does not) exclude other components, integers or steps.

The expressions “to dry hair”, “drying hair” or “decrease a moisture level of hair” and the like, as used in the present disclosure, can refer both to the removal of “unbound” water that exists on the outside of hair when wet, or the removal of “bound” water, which exists inside individual hairs, and which can be interacted with when heat styling hair. The “bound” water need not necessarily be removed when drying hair, although removal of some bound water may occur during a drying or styling process.

Various other modifications will be apparent to those skilled in the art and will not be described in further detail here. Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the scope of the claims appended hereto.

Clauses

Paired Sensing Hairbrush

Hair drying and/or styling appliances can only provide a limited amount of information regarding user behaviour, properties of the hair, ambient conditions etc. Including too many further components on such appliances can make them heavy, bulky, expensive and difficult to engineer. The following numbered clauses 1-36 aim to a way to at least alleviate the above problem.

1. A hairbrush, comprising: a processor; at least one sensing component; and communications circuitry; wherein the at least one sensing component is configured to collect data relating to hair, motion and/or ambient conditions; and wherein the processor is configured to receive the data, and to communicate said data to external devices via the communications circuitry.

2. The hairbrush of clause 1 , wherein the processor is further configured to process the data to determine hair characteristics and/or styling technique.

3. The hairbrush of clause 1 or 2, wherein the processor is further configured to communicate hair characteristics and/or styling technique via the communications circuitry.

4. The hairbrush of any of clauses 1 to 3, wherein the processor is further configured to communicate styler settings to a styler, preferably in dependence on the hair characteristics and/or styling technique.

5. The hairbrush of clause 4, wherein the styler settings comprise one or more of: setpoint temperature; and air speed settings.

6. The hairbrush of any of clauses 2 to 5, wherein the hair characteristics comprise one or more of: hair moisture level; hair damage; hair type; hair length; and hair temperature.

7. The hairbrush of any of clauses 2 to 6, wherein the styling technique comprises one or more of: stroke speed; stroke length; and tress size.

8. The hairbrush of any of clauses 1 to 7, wherein the at least one sensing component comprises one or more of: IR camera; optical camera; humidity sensor; load cell; LEDs; proximity sensor; magnetometer; force-sensitive resistor; accelerometer; odometer; speedometer; microphone; gyroscope; pressure sensor; speaker; haptic motors; UV light; and gas sensor. 9. The hairbrush of any of clauses 1 to 8, further comprising a clock.

10. The hairbrush of any of clauses 1 to 9, wherein the processor is configured to communicate the measurements in real time.

11. The hairbrush of any of clauses 1 to 10, wherein the processor is configured to determine hair moisture, preferably wherein the at least one sensing component comprises an optical camera.

12. The hairbrush of any of clauses 1 to 11 , wherein the processor is configured to determine stroke speed, preferably wherein the at least one sensing component comprises an odometer and/or speedometer.

13. The hairbrush of any of clauses 1 to 12, wherein the processor is configured to communicate the measurements to at least one of: an external styler; a smart processing device; and a cloud-based processing unit.

14. A hair drying and/or styling system, comprising: a hairbrush, comprising: a processor; at least one sensing component; and communications circuitry; and a hair drying and/or styling apparatus, comprising: a heater for providing heat for drying and/or styling hair; a further processor; and further communications circuitry; wherein the hairbrush and the apparatus are external to one another and in communication via their respective communications circuitry; and wherein the hairbrush is configured to collect data relating to hair, motion and/or ambient conditions using the at least one sensing component; and the processor is configured to receive the measurements, and to communicate them to the appliance via the communications circuitry.

15. The system of clause 14, wherein the processor and/or the further processor is configured to process the data to determine hair characteristics and/or styling technique.

16. The system of clause 15, wherein the processor is further configured to communicate hair characteristics and/or styling technique via the communications circuitry. 17. The system of any of clauses 14 to 16, wherein the processor and/or further processor is further configured to determine settings of the apparatus in dependence on the determined hair characteristics and/or styling technique.

18. The system of clause 17, wherein the settings of the apparatus comprise one or more of: setpoint temperature; and air speed settings.

19. The system of any of clauses 15 to 18, wherein the hair characteristics comprise one or more of: hair moisture level; hair damage; hair type; hair length; and hair temperature.

20. The system of any of clauses 15 to 19, wherein the styling technique comprises one or more of: stroke speed; rotation; stroke length; and tress size.

21. The system of any of clauses 14 to 20, wherein the at least one sensing component comprises one or more of: IR camera; optical camera; humidity sensor; load cell; LEDs; proximity sensor; magnetometer; force-sensitive resistor; accelerometer; odometer; speedometer; microphone; gyroscope; pressure sensor; speaker; haptic motors; UV light; and gas sensor.

22. The system of any of clauses 14 to 21 , wherein the hairbrush and/or the hair drying and/or styling apparatus further comprises a clock.

23. The system of any of clauses 14 to 22, wherein the hairbrush is configured to communicate the measurements in real time, and the processor and/or the further processor is configured to determine settings of the appliance in real time.

24. The system of any of clauses 14 to 23, wherein the processor is configured to determine hair moisture, preferably wherein the at least one sensing component comprises an optical camera.

25. The system of any of clauses 14 to 24, wherein the processor is configured to determine stroke speed, preferably wherein the at least one sensing component comprises an odometer and/or speedometer.

26. The system of any of clauses 14 to 25, wherein the hairbrush and/or the hair drying and/or styling apparatus are configured to be in further communication with: a smart processing device; and/or a cloud-based processing unit, preferably to send information to an application running on the smart processing device and/or application data saved in a cloud-based processing unit.

27. The system of any of clauses 14 to 26, wherein the hairbrush is the hairbrush of any of clauses 1 to 13.

28. A method of controlling a hair drying and/or styling apparatus, comprising: receiving data from an external hairbrush; processing the data to determine hair characteristics and/or styling technique; and defining settings of the hair drying and/or styling apparatus in dependence on the hair characteristics and/or styling technique.

29. The method of clause 28, wherein the hair characteristics comprise one or more of: hair moisture level; hair damage; hair type; hair length; and hair temperature.

30. The method of clause 28 or 29, wherein the styling technique comprises one or more of: stroke speed; rotation; stroke length; and tress size.

31. The method of any of clauses 28 to 30, wherein the settings of the apparatus comprise one or more of: setpoint temperature; and air speed settings.

32. The method of any of clauses 28 to 31 , wherein the defining is performed in real time.

33. The method of any of clauses 28 to 32, wherein the receiving comprises receiving data from one or more of: IR camera; optical camera; humidity sensor; load cell; LEDs; proximity sensor; magnetometer; force-sensitive resistor; accelerometer; odometer; speedometer; microphone; gyroscope; pressure sensor; speaker; haptic motors; UV light; and gas sensor.

34. The method of any of clauses 28 to 33, wherein the processing comprises determining a hair moisture level, preferably wherein the receiving comprises receiving data from an optical camera and the processing comprises processing the data from the optical camera.

35. The method of any of clauses 28 to 34, wherein the processing comprises determining stroke speed, wherein the receiving comprises receiving data from an odometer and/or speed sensor and the processing comprises processing the data from the odometer and/or speedometer.

36. A computer program product comprising computer implementable instructions for causing a programmable device to carry out the method of any of clauses 28 to 35.

‘Remember my Settings’

The enhanced capabilities of the disclosed stylers means that there is much scope for a user to adjust styler settings to their own preferences. However, it can be inconvenient for a user to need to readjust the styler to their own preferences each use. In many implementations, the styler connects with an application run on a smart processing device (for example, a user’s mobile phone). Via the application and smart processing device, a user can adjust the settings, and the application and smart processing device may typically store their preferences. However, these preferences can typically be lost if a user changes their device (for example, by upgrading to a new mobile phone).

The following numbered clauses 37-73 aim to address or at least partially ameliorate one or more of the above problems.

37. A hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, a controller; and a memory; wherein the controller is configured to control settings of the appliance and wherein the memory is configured to store the settings as settings data in association with user data.

38. The appliance of clause 37, wherein the memory is configured to store multiple (different) sets of settings data each associated with respective user data.

39. The appliance of clause 37 or 38, wherein the controller is configured to retrieve the settings data in dependence on an input of the associated user data, and preferably to implement the settings of the settings data in dependence on an input of the associated user data.

40. The appliance of any of clauses 37 to 39, further comprising communications circuitry configured to communicate with, and preferably to receive instructions from, an external smart processing device; preferably wherein the controller is configured to control settings of the appliance in dependence on instructions received from the external smart processing device.

41. The appliance of any of clauses 37 to 40, wherein the memory is further configured to store the settings data and user data associated with an identifier of a smart processing device.

42. The appliance of clause 41 , wherein the controller is configured to establish a connection with a smart processing device automatically when the identifier of that smart processing device is stored in the memory.

43. The appliance of clause 41 or 42, wherein the controller is configured to retrieve settings data associated with an identifier of a smart processing device upon connection to the same smart processing device.

44. The appliance of any of clauses 41 to 43, wherein the controller is configured to implement the settings of the settings data stored in association with the identifier of a smart processing device upon connection to the smart processing device. 45. The appliance of any of clauses 41 to 44, wherein the controller is configured to output a prompt for input of user data, preferably a user login, upon detection of a smart processing device having an identifier not stored in the memory.

46. The appliance of any of clauses 41 to 45, wherein the controller is configured to communicate to a smart processing device settings data in dependence on input of the associated user data, in the event that the smart processing device has an identifier different to the identifier associated with the user data stored in the memory.

47. The appliance of any of clauses 37 to 46, wherein the controller is configured to reset any current settings of the appliance in dependence on input of user data not stored in the memory.

48. The appliance of any of clauses 37 to 47, wherein the controller is configured to output an option of a full reset in dependence on input of user data not stored in the memory, wherein the full reset comprises deleting all data stored in the memory.

49. The appliance of any of clauses 37 to 48, wherein the settings data and user data (and preferably the identifier) are saved to the memory in a compressed format.

50. The appliance of any of clauses 37 to 49, wherein the settings data and user data (and preferably the identifier) are saved to the memory in an encrypted format.

51. The appliance of any of clauses 37 to 50, further comprising: a speaker; a light display (preferably and LED display); a haptics unit; and/or an IMU.

52. The appliance of any of clauses 37 to 51 , wherein the settings data comprises: temperature settings; sound settings; light settings (e.g. LED colour and/or brightness); and/or haptic settings.

53. The appliance of any of clauses 37 to 52, wherein the user data comprises: user login; and/or user hair type.

54. A system comprising: a hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, a processor; a memory; and communications circuitry; and a smart processing device external to the appliance, comprising: a further processor; a user interface; and further communications circuitry; wherein the communications circuitry and further communications circuitry are configured to communicate to effect connection of the appliance and the smart processing device; wherein the processor and/or the further processor are configured to control settings of the appliance; and wherein the memory is configured to store settings data in association with user data.

55. The system of clause 54, wherein the appliance is the appliance of any of clauses 37 to 53.

56. The system of clause 54 or 55, wherein the smart processing device is further configured to store settings data in association with user data.

57. The system of any of clauses 54 to 56, wherein the smart processing device is configured to communicate the settings data to a further appliance upon connection.

58. A method of operating a hair drying and/or styling appliance comprising a heater, comprising: adjusting settings of the appliance in dependence on user input; and storing to a memory within the appliance the settings of the appliance as settings data in association with user data.

59. The method of clause 58, further comprising: retrieving the settings data in dependence on an input of the associated user data.

60. The method of clause 58 or 59, wherein the storing further comprises storing an identifier of an external smart processing device in association with the settings data and user data, and preferably implementing the settings of the settings data in dependence on an input of the associated user data.

61. The method of clause 60, further comprising: automatically connecting the appliance to a smart processing device having an identifier stored in the memory within the appliance.

62. The method of clause 60 or 61 , further comprising: retrieving settings data associated with an identifier of a smart processing device upon connection to the same smart processing device.

63. The method of any of clauses 60 to 62, further comprising: implementing the settings of the settings data associated with the identifier of a smart processing device upon connection to the smart processing device.

64. The method of any of clauses 60 to 63, further comprising: outputting a prompt for input of user data, preferably a user login, upon detecting a smart processing device having an identifier not stored in the memory. 65. The method of any of clauses 60 to 64, further comprising: communicating to a smart processing device the settings data in dependence on input of the associated user data, in the event that the smart processing device has an identifier different to the identifier associated with the user data stored in the memory.

66. The method of any of clauses 58 to 65 further comprising: resetting any current settings of the appliance in dependence on input of user data not stored in the memory.

67. The method of any of clauses 58 to 66 further comprising: outputting an option of a full reset in dependence on input of user data not stored in the memory, wherein the full reset comprises deleting all data stored in the memory within the appliance.

68. The method of any of clauses 58 to 67 further comprising: storing the settings data in association with the user data to a further memory, preferably wherein the further memory is within the smart processing device or on a server.

69. The method of any of clauses 58 to 68, wherein the storing to a memory comprises storing the settings data and user data (and preferably the identifier) in a compressed format.

70. The method of any of clauses 58 to 69, wherein the storing to a memory comprises storing the settings data and user data (and preferably the identifier) in an encrypted format.

71. The method of any of clauses 58 to 70, wherein the settings data comprises: temperature settings; sound settings; light settings (e.g. LED colour and/or brightness); and/or haptic settings.

72. The method of any of clauses 58 to 71 , wherein the user data comprises: user login; and/or user hair type.

73. A computer program product comprising computer implementable instructions for causing a programmable device to carry out the method of any of clauses 58 to 72.

Subscription Settings

As firmware becomes an evolving and updating feature, regular updates to ensure user safety can be very important. Additionally, subscription-based services may enhance user interaction with a hair drying and/or styling appliance. Furthermore, it can be beneficial, for safety reasons and for consumer experience, for an error in an appliance to be reported as quickly as possible. The numbered clauses 74-106 aim to provide improved apparatus, system and methods facilitate devices and systems remaining up-to-date.

74. A hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry for connecting to an external database; wherein the controller is configured to prevent user actuation of heating of the heater in dependence on data received from the database.

75. The apparatus of clause 74, wherein the data comprises data received from a database indicating whether a user has fulfilled obligations.

76. The apparatus of clause 74 or 75, wherein the communication means is configured to connect to the database via an external smart processing device in communication with the database.

77. The apparatus of clause 76, wherein the smart processing device is configured to receive data from the database indicating whether a user has fulfilled obligations and in dependence on said data to communicate instructions to the controller to prevent user actuation of heating of the heater.

78. The apparatus of clause 75 or 77, wherein the obligations comprise maintenance actions, preferably comprising payments, subscription payments, and/or installing software and/or firmware updates.

79. The apparatus of any of clauses 74 to 78, wherein the apparatus is configured to connect to the database (directly or indirectly) each time the apparatus is powered on.

80. The apparatus of any of clauses 74 to 78, wherein the apparatus is configured to connect to the database (directly or indirectly) regularly at a defined interval, preferably wherein the interval is one week, two weeks or four weeks.

81. The apparatus of any of clauses 74 to 80, wherein the apparatus further comprises a clock.

82. The apparatus of any of clauses 74 to 81 , wherein the communications circuitry is configured to attempt connection to the database in dependence on determining that a period of time greater than the defined interval has elapsed since the apparatus last connected to the database, preferably wherein the determining the period of time is based on data from the clock.

83. The apparatus of any of clauses 74 to 82, wherein the controller is further configured to prevent user activation of heating of the heater in dependence on successful connection to the database.

84. The apparatus of any of clauses 74 to 83, wherein the apparatus is further configured to output a notification in the event that the controller prevents user actuation of heating of the heater. 85. The apparatus of any of clauses 74 to 84, wherein the controller is configured not to prevent user actuation of heating of the heater in the event that it is determined that it is not the fault of the user that the apparatus is not connected to the database or that the obligations are not fulfilled.

86. A system comprising: a hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry; and a smart processing device external to the apparatus, comprising: a processor; and further communications circuitry; and a database comprising data; wherein the communications circuitry is configured to communicate with the further communications circuitry such that the apparatus and the smart processing device are connectable; and the further communications circuitry is further configured to communicate with the database to retrieve the data; and wherein the controller is configured to prevent user actuation of heating of the heater in dependence on the data received from the database.

87. The system of clause 86, wherein the apparatus is the apparatus of any of clauses 73 to 84.

88. The system of clause 86 or 87, wherein the data comprises data received from a database indicating whether a user has fulfilled obligations.

89. The system of clause 88, wherein the obligations comprise maintenance actions, preferably comprising at least one of: payments, subscription payments, and/or installing software and/or firmware updates.

90. The system of any of clauses 86 to 89, wherein the communications circuitry is configured to attempt connection to the smart processing device and/or database in dependence on determining that a period of time greater than the defined interval has elapsed since the apparatus last connected to the database, preferably wherein the determining the period of time is based on data from the clock.

91. The system of any of clauses 86 to 90, wherein the controller is configured to prevent user activation of heating of the heater in the event that the apparatus is not connected to the smart processing device or in the event that the smart processing device is not connected to the database. 92. The system of any of clauses 86 to 91 , wherein the apparatus and/or the smart processing device is further configured to output a message in the event that the controller prevents user actuation of heating of the heater.

93. The system of any of clauses 86 to 92, wherein the controller is configured not to prevent user actuation of heating of the heater in the event that it is determined that it is not the fault of the user that the apparatus does not connect to the smart processing device and/or database or that the obligations are not fulfilled.

94. A method of controlling a hair drying and/or styling apparatus, comprising: attempting connection of the apparatus to a database comprising data; and preventing user actuation of heating of the heater in dependence on: unsuccessful connection to the database or in dependence on data received from the database.

95. The method of clause 94, wherein the data comprises data received from a database indicating whether a user has fulfilled obligations, and the method further comprising determining, from the data, whether a user has fulfilled their obligations.

96. The method of clause 95, wherein the obligations comprise maintenance actions, preferably comprising at least one of: payments, subscription payments, and/or installing software and/or firmware updates.

97. The method of any of clauses 94 to 96, wherein the connection of the apparatus to the database is via an external smart processing device in communication with the database.

98. The method of any of clauses 94 to 97, wherein the attempting connection is performed each time the apparatus is powered on.

99. The method of any of clauses 94 to 97, wherein the attempting connection is performed in dependence on determining that a period of time greater than a defined interval has elapsed since the apparatus last connected to the database, preferably wherein the determining the period of time is based on data from a clock forming part of the apparatus.

100. The method of any of clauses 94 to 99, wherein the attempting connection is performed for a defined number of attempts and/or over a defined time interval, preferably wherein unsuccessful connection to the database is confirmed if connection is unsuccessful during defined number of attempts and/or over the defined time interval.

101 . The method of any of clauses 94 to 100, further comprising: outputting a notification in the event of preventing user actuation of heating of the heater. 102. The method of any of clauses 94 to 101 , further comprising: determining who is at fault for the unsuccessful connection to the database.

103. The method of any of clauses 95 to 102, further comprising: determining who is at fault for any unfulfilled obligations.

104. The method of clause 102 or 103, further comprising: in the event that it is determined that a user is not at fault, allowing user actuation of heating of the heater.

105. A method of controlling a hair drying and/or styling apparatus, comprising: connecting the apparatus to a central database or server; automatically sending an error report from the apparatus to the central database or server in the event of an error.

106. A computer program product comprising computer implementable instructions for causing a programmable device to carry out the method of any of clauses 94 to 105.

Multi-user Architecture

In many instances, a particular user will use multiple drying and/or styling appliances; and furthermore, in some instances, a particular hair drying and/or styling appliance will be used by multiple users. The numbered clauses 107-137 aim to provide improved apparatus, system and methods to facilitate improved architectures for multi-user and multi-styler systems.

107. A hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry for communicating with smart processing devices; wherein the controller is configured to implement control instructions received from smart processing devices via the communications circuitry; and wherein the controller is configured to implement control instructions of one smart processing device at any one time.

108. The apparatus of clause 107, wherein the communications circuitry is configured for communicating with multiple smart processing devices simultaneously.

109. The apparatus of clause 107 or 108, wherein the controller is further configured to output to smart processing devices styler status, wherein the styler status comprises an indication whether a smart processing device is currently controlling the hair drying and/or styling apparatus, and preferably wherein the styler status comprises identification of a smart processing device currently controlling the hair drying and/or styling apparatus.

110. The apparatus of clause 109, wherein the styler status further comprises the hair drying and/or styling apparatus being locked from control by any further smart processing device in dependence on a smart processing device currently controlling the hair drying and/or styling apparatus.

111. The apparatus of clause 109 or 110, wherein the styler status further comprises power status of the hair drying and/or styling apparatus.

112. The apparatus of any of clauses 107 to 111 , wherein the hair drying and/or styling apparatus is configured to detect connection to an attachment, and wherein the styler status comprises data relating to connection of an attachment.

113. The apparatus of any of clauses 107 to 112, wherein the controller is further configured to output to smart processing devices styler identification data.

114. A system comprising: a hair drying and/or styling apparatus comprising: a heater for providing heat for drying and/or styling hair; a controller; and communications circuitry; and multiple smart processing devices external to the apparatus, each comprising: a processor; and further communications circuitry; wherein the communications circuitry and further communications circuitry are configured such that the processor of the smart processing devices can output control instructions to the controller; and wherein the controller is configured to implement control instructions received from one smart processing device at any time.

115. The system of clause 114, wherein the controller is further configured to output to smart processing devices styler status, wherein the styler status comprises an indication whether a smart processing device is currently controlling the hair drying and/or styling apparatus, and preferably wherein the styler status comprises identification of a smart processing device currently controlling the hair drying and/or styling apparatus.

116. The system of clause 115, wherein the styler status further comprises the styler being locked from control by any further smart processing device in dependence on a smart processing device currently controlling the styler. 117. The system of any of clauses 114 to 116, wherein the hair drying and/or styling apparatus is the hair drying and/or styling apparatus of any of clauses 107 to 113.

118. The system of any of clauses 114 to 117, wherein the multiple smart processing devices further each comprise a user interface, wherein the processor of each smart processing device is configured to output to the user interface information relating to the hair drying and/or styling apparatus, preferably wherein the information comprises the styler status.

119. The system of any of clauses 114 to 118, wherein, in the event that a smart processing device is not connected to the hair drying and/or styling apparatus, the processor of that smart processing device is further configured to output an unconnected status to the user interface.

120. The system of any of clauses 114 to 119, wherein the multiple smart processing devices are configured to be connectable to multiple hair drying and/or styling apparatuses at the same time.

121. The system of any of clauses 114 to 120, wherein the multiple smart processing devices are configured to be in communication with one another via a network.

122. The system of any of clauses 114 to 121 , wherein the multiple smart processing devices comprise an administrator smart processing device, wherein the administrator smart processing device is configured to output instructions granting permissions to further smart processing devices, preferably wherein the permissions comprise permissions to power on and off the hair drying and/or styling apparatus, and/or to send control instructions to the hair drying and/or styling apparatus.

123. The system of clause 122, wherein the administrator smart processing device is configured to output instructions granting permissions to further smart processing devices via the network.

124. A method of operating a hair drying and/or styling apparatus comprising a heater, comprising: connecting simultaneously to multiple external smart processing devices; receiving from one of the smart processing devices control instructions for the hair drying and/or styling apparatus; and implementing control instructions received from one smart processing device at any one time.

125. The method of clause 124, further comprising outputting to the smart processing devices styler status, wherein the styler status comprises an indication whether a smart processing device is currently controlling the hair drying and/or styling apparatus, and preferably wherein the styler status comprises identification of a smart processing device currently controlling the hair drying and/or styling apparatus. 126. The method of clause 125, wherein the styler status further comprises the hair drying and/or styling apparatus being locked from control by any further smart processing device in dependence on a smart processing device currently controlling the hair drying and/or styling apparatus.

127. The method of clause 125 or 126, wherein the styler status further comprises power status of the hair drying and/or styling apparatus.

128. The method of any of clauses 124 to 127, further comprising automatically connecting to external smart processing devices in dependence on identification data for a smart processing device being stored within a memory of the hair drying and/or styling apparatus.

129. The method of any of clauses 125 to 128, further comprising detecting the connection of an attachment to the hair drying and/or styling apparatus, and wherein the styler status further comprises information relating to the attachment.

130. The method of any of clauses 125 to 129, further comprising outputting information to user interfaces of the smart processing devices in dependence on the styler status.

131 . The method of any of clauses 124 to 130, further comprising outputting to the smart processing devices styler identification data.

132. The method of any of clauses 124 to 131 , further comprising connecting the multiple smart processing devices to one another via a network.

133. The method of any of clauses 124 to 132, further comprising authorizing permissions for a smart processing device in dependence on authorization of an administrator smart processing device, preferably wherein the administrator smart processing device is in communication with the smart processing device via the network.

134. The method of clause 133, wherein the permissions comprise permissions to power on and off the hair drying and/or styling apparatus, and/or to send control instructions to the hair drying and/or styling apparatus.

135. The method of any of clauses 124 to 134, further comprising implementing control instructions received from a smart processing device in dependence on authorization of an administrator smart processing device, preferably wherein the administrator smart processing device is in communication with the smart processing device via the network.

136. The method of any of clauses 124 to 134, wherein the hair drying and/or styling apparatus is the hair drying and/or styling apparatus of any of clauses 107 to 113. 137. A computer program product comprising computer implementable instructions for causing a programmable device to carry out the method of any of clauses 124 to 136.

Claims

1. A hair drying and/or styling apparatus comprising: an elongate hair treatment portion comprising: a heater having a hair contacting surface for heating hair that comes into contact with the hair contacting surface, wherein the heater comprises a plurality of independently operable heating zones arranged sequentially along the length of the elongate hair treatment portion; and an illumination display comprising a plurality of independently operable illumination portions arranged sequentially along the length of the elongate hair treatment portion at a side of the heater so that each illumination portion is positionally aligned with at least one heating zone; and a controller for controlling the operation of the heater and the illumination display; wherein the controller is configured to receive styler values and to control illumination of the independently operable illumination portions in dependence on the styler values.

2. The apparatus of claim 1 , wherein individual portions of the illumination display are configured to portray information relating to at least one corresponding heating zone.

3. The apparatus of claim 2, wherein the controller is configured to determine thermal load of the heating zones in dependence on the styler values and the individual portions of the illumination display are configured to portray information relating to the thermal load of the at least one corresponding heating zone, preferably wherein thermal load comprises thermal load of hair applied to the heating zone.

4. The apparatus of claim 2 or 3, wherein the controller is configured to determine temperature of the heating zones and/or temperature of hair loaded in the heating zones in dependence on the styler values and the individual portions of the illumination display are configured to portray information relating to the temperature of the at least one corresponding heating zone and/or relating to the temperature of hair loaded in the at least one corresponding heating zone.

5. The apparatus of any preceding claim, wherein each heating zone has an extent along the length of the hair treatment portion, wherein each illumination portion is positionally aligned with a respective heating zone and has an extent along the length of the hair treatment portion that is equal to or less than the extent of the corresponding heating zone.

6. The apparatus of any preceding claim, wherein the portions of the display are located adjacent to heating zones and configured to display information relating to those same heating zones.

7. The apparatus of any preceding claim, wherein the styler values relate to progression of a styler process, preferably wherein the styler process comprises: heating up; cooling down; styling; loading firmware; or loading firmware updates.

8. The apparatus of any preceding claim, wherein the control of illumination of the independently operable illumination portions comprises control of colour and/or pattern and/or animation of the illumination.

9. The apparatus of any preceding claim, further comprising a light sensor, wherein the controller is configured to control illumination of the illumination display in dependence on detection of a light level below a threshold value.

10. The apparatus of any preceding claim, wherein the illumination display comprises a plurality of LEDs, preferably a plurality of LEDs of different colours.

11. The apparatus of any preceding claim, wherein the appliance further comprises a control display, preferably wherein the control display is configured to allow a user to control settings of the styler.

12. The apparatus of any preceding claim, further comprising an inertial measurement unit (IMU), wherein the controller is further configured to receive styler values from the IMU and to control illumination of the independently operable illumination portions in dependence on the orientation and/or speed of the styler.

13. The apparatus of claim 12, wherein the controller is configured to determine from the styler values from the IMU that the styler is idle and to control the illumination the independently operable illumination portions to portray that the styler is idle, preferably wherein the illumination comprises an alternative colour scheme.

14. The apparatus of any preceding claim, wherein the apparatus is configured to operate in a styling mode and a training mode, wherein the heater is set to a higher temperature in the styling mode than in the training mode, and wherein illumination of the independently operable illumination portions is controlled according to different colour schemes in the styling mode and the training mode.

15. The apparatus of any preceding claim, further comprising a haptics unit for outputting haptic feedback and/or a speaker for outputting audio feedback.

16. The apparatus of any preceding claim, wherein the heater has a heat up rate greater than 30 °C per second.

17. The apparatus of any preceding claim, further comprising a handle portion to facilitate holding of the appliance.

18. The apparatus of any preceding claim, wherein the heating zones are arranged immediately adjacent each other along the length of the hair treatment portion.

19. The apparatus of any preceding claim, wherein the illumination portions are arranged immediately adjacent each other along the length of the hair treatment portion.

20. The apparatus of any preceding claim, wherein the heater is a multilayer heater comprising a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating, wherein the multilayer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a conductive material that generates heat when a current is passed through the one or more heater electrodes; and at least one upper dielectric layer over the heater electrode layer to electrically isolate the heater electrode layer; wherein the multilayer heater has a thickness, as measured across all of the plurality of layers of the multilayer heater, which is between 30pm and 2mm.

21. The apparatus of any preceding claim, wherein the controller is configured to control illumination of the independently operable illumination portions in dependence on determining a styling release time in dependence on the styler values.

22. The apparatus of claim 21 , wherein the controller is configured to determine thermal load of the heating zones in dependence on the styler values, and to determine a styling release time in dependence on the timing of the thermal load.

23. A hair drying and/or styling apparatus comprising: a multilayer heater having a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating; a controller; and at least one feedback component comprising at least one of: an illumination display; a haptics unit; and a speaker; wherein the controller is configured to detect a thermal loading time of hair on the hair contacting surface of the heater based on styler values and to determine a styling release time relative to the thermal loading time, and wherein the controller is further configured to instruct the at least one feedback component to output feedback in dependence on the styling release time, preferably comprising outputting feedback at the styling release time.

24. The apparatus of claim 22 or 23, wherein the controller is configured to determine the styling release time at a predefined interval after detection of a thermal load.

25. The apparatus of any of claims 22 to 24, wherein the controller is configured to determine thermal load over time based on values of power to the heater and to determine the styling release time in dependence on the power and/or rate of change of the power.

26. The apparatus of claim 25, wherein the controller is configured to determine the styling release time in dependence on determining a rate of change of power below a threshold value.

27. The apparatus of any of claims 22 to 26, wherein the controller is configured to determine hair temperature over time based on values of power to the heater, and to determine the styling release time in dependence on determined hair temperature and/or rate of change of hair temperature.

28. A hair drying and/or styling apparatus, comprising: a heater for providing heat for drying and/or styling hair; a temperature sensor and/or a power sensor; and a controller; wherein the controller is configured to receive signals from the temperature sensor and/or the power sensor to determine when hair is loaded onto heater, and wherein the controller is further configured to determine when hair should be released from the heater and to cause feedback to be provided to a user.

29. The apparatus of claim 28, wherein the controller is configured to determine when hair should be released from the heater using a timer that is started in response to when the controller determines hair is loaded on the heater.

30. The apparatus of claim 28 or 29, wherein the controller is configured to determine when hair should be released from the heater by tracking the power delivered to the heater and determining when the power delivered to the heater meets a predetermined condition.

31. The apparatus of any of claims 28 to 30, wherein the controller is configured to determine by tracking the temperature of the hair and/or the heater and determining when the temperature meets a predetermined condition.

32. The apparatus of any of claims 28 to 31 , wherein the controller is configured to determine power and/or temperature using received styler values, the styler values comprising voltage and/or current values.

33. A method of operating a hair drying and/or styling appliance comprising an elongate hair treatment portion comprising: a heater comprising a plurality of independently operable heating zones and an illumination display located adjacent the heater; and comprising a plurality of independently operable illumination portions arranged sequentially along the length of the elongate hair treatment portion at a side of the heater so that each illumination portion is positionally aligned with at least one heating zone; wherein the method comprises: receiving styler values; processing the styler values to determine at least one styler and/or styling status; and controlling illumination of the independently operable illumination portions to portray information relating to the styler status.

34. The method of claim 33, wherein the at least one styler status comprises a series of statuses of the independently operable heating zones and the controlling the illumination comprises controlling illumination of individual portions of the illuminated display to portray information relating to the status of at least one corresponding heating zone.

35. The method of claim 34, wherein the series of statuses comprises thermal loads of the heating zones and controlling the illumination comprises controlling illumination of individual portions of the illuminated display to portray information relating to the thermal load of at least one corresponding heating zone, preferably wherein thermal load comprises thermal load of hair applied to the heating zone.

36. The method of claim 34 or 35, wherein the series of statuses comprises temperatures of the heating zones and/or temperatures of hair loaded on the heating zones and controlling the illumination comprises controlling illumination of individual portions of the illuminated display to portray information relating to the temperature of at least one corresponding heating zone and/or the temperature of hair loaded on the at least one corresponding heating zone.

37. The method of any of claims 33 to 36, wherein the status comprises progress of a styler process, preferably wherein the styler process comprises: heating up; cooling down; styling; loading firmware; or loading firmware updates.

38. The method of any of claims 33 to 37, wherein the controlling of the illumination is performed according to a different colour scheme in dependence on a mode of the styler, preferably wherein the mode may comprise at least one of: styling mode, training mode, low light mode and idle mode.

39. The method of any of claims 33 to 38, wherein the status comprises status of the hair, and preferably comprises temperature of the hair.

40. The method of any of claims 33 to 39, wherein the status comprises a styling release time and/or a countdown to a styling release time.

41. The method of claim 40, wherein the processing comprises determining the styling release time in dependence on values of power to the heater and/or rate of change of power to the heater.

42. The method of claim 40 or 41 , wherein the processing comprises determining a thermal loading time of the heater in dependence on values of power to the heater and/or rate of change of power to the heater, and determining the styling release time at a predefined interval after the thermal loading time.

43. The method of any of claims 40 to 42, wherein the determining the styling release time comprises determining a rate of change of power below a threshold value.

44. The method of any of claims 40 to 43, wherein the determining the styling release time comprises determining hair temperature, preferably by determining resistance of the heater, and determining the styling release time in dependence on determined hair temperature and/or rate of change of hair temperature.

45. A method of operating a hair drying and/or styling appliance comprising a heater, the method comprising: receiving styler values; determining a thermal loading time in dependence on the styler values; and determining a styling release time relative to the thermal loading time.

46. The method of claim 45, wherein the determining a styling release time comprises defining a styling release time at a predefined interval after the thermal loading time.

47. The method of claim 45 or 46, wherein the styler values comprise values of power to the heater and/or temperature of the heater and/or hair.

48. The method of claim 47, wherein the determining thermal loading time and/or determining a styling release time is in dependence on rate of change of power to the heater.

49. The method of claim 48, wherein determining a styling release time comprises determining a rate of change of power below a threshold value.

50. The method of any of claims 47 to 49, wherein determining a styling release time comprises determining hair temperature, preferably in dependence on heater resistance, and defining the styling release time is dependence on hair temperature and/or rate of change of temperature.

51. The method of any of claims 33 to 50, wherein the hair drying and/or styling appliance is the hair drying and/or styling appliance of any of claims 1 to 32.

52. A hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, wherein the heater comprises independently operable heating zones; a processor; and an illumination display located adjacent to at least one side of the heater and comprising independently operable illumination portions; wherein the processor is configured to receive styler values and control illumination of the independently operable illumination portions in dependence on the styler values.

53. A hair drying and/or styling appliance comprising: a heater for providing heat for drying and/or styling hair, wherein the heater comprises a plurality of independently controllable heating zones arranged along a length of the appliance; a processor; and an illumination strip located adjacent to at least one side of the heater and comprising a plurality of independently controllable illumination portions corresponding to the plurality of heating zones; wherein the processor is configured to control illumination of the independently controllable illumination portions and to control heating of the independently controllable heating zones.

54. The hair drying and/or styling appliance of claim 52 or 53, wherein each independently controllable illumination portion is positioned adjacent a corresponding one or more of the independently controllable heating zones.

55. The hair drying and/or styling appliance of claims 52 to 54, wherein each independently controllable illumination portion is aligned with a corresponding one or more of the independently controllable heating zones.

56. The hair drying and/or styling appliance of any of claims 52 to 55, wherein the processor is configured, in a first mode, to control the plurality of independently controllable illumination portions in dependence upon a temperature or a loading of the corresponding independently controllable heating zones.

57. A computer program product comprising computer implementable instructions for causing a programmable device to carry out the method of any of claims 33 to 51.