WO2025043699A1

WO2025043699A1 - Aerosol-generating device with sensor assembly

Info

Publication number: WO2025043699A1
Application number: PCT/CN2023/116459
Authority: WO
Inventors: Gianluca PAGANO
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2023-09-01
Filing date: 2023-09-01
Publication date: 2025-03-06
Anticipated expiration: 2026-03-01
Also published as: WO2025043699A8

Abstract

The present invention relates to an aerosol-generating device having a sensor assembly, the aerosol-generating device is particularly configured to receive an aerosol-generating article. The invention also relates to an aerosol-generating system including an aerosol-generating article and an aerosol-generating device having a sensor assembly. The aerosol-generating device includes a housing defining a device cavity that is configured to at least partially receive the aerosol-generating article and to operably locate the aerosol-generating article in a position for use within the aerosol-generating device. The aerosol-generating device also includes a time-of-flight sensor assembly. The time-of-flight sensor assembly is configured to measure at least one characteristic feature related to the aerosol-generating article within the device cavity.

Description

AEROSOL-GENERATING DEVICE WITH SENSOR ASSEMBLY

The present invention relates to an aerosol-generating device having a sensor assembly, the aerosol-generating device is particularly configured to receive an aerosol-generating article. The invention also relates to an aerosol-generating system including an aerosol-generating article and an aerosol-generating device having a sensor assembly.

Aerosol-generating articles in which an aerosol-forming substrate such as, but not limited to, a tobacco-or nicotine-containing substrate, is heated rather than combusted, are known in the art. Such articles are also known as heat-not-burn ( "HnB" ) products, or more generally as reduce risk products ( "RRP" ) . Typically in such heated smoking articles, an aerosol is generated by the transfer of heat from a heat source of an aerosol-generating device to a physically separate aerosol-forming substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol. As another variant, other aerosol-generating devices exist, where a nicotine-or other substance-containing liquid can vaporize, aerosolized, or otherwise atomized, for inhalation by a user, also known as e-vapor or e-cigarettes. Typically, for such products, the aerosol-generating article can include a cartridge, reservoir, or capsule holding the nicotine-containing liquid instead of a solid substrate, typically removably held by a holder having a battery or other electrical power supply, and a heater can be activated that is in contact with the liquid, for example but not limited to a wicking element and a heating wire in contact with the wicking element.

Other aerosol-generating devices are configured to form an aerosol for pharmaceutical or therapeutic purposes, for example to form an aerosol from a substrate having one or more active agent for pharmaceutical or medicinal applications, from botanicals, and flavoring, and a combination of the same.

A number of prior art documents disclose aerosol-generating devices for consuming aerosol from aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-forming material or liquid of a heated aerosol-generating article. Correct positioning of the aerosol-generating article within the aerosol-generating device is required in order to ensure a consistent aerosol for the user.

Certain known aerosol-generating systems require a user to manually activate the heating element after an aerosol-generating article is inserted into the aerosol-generating device. The heating element is energised once the user switches on the aerosol-generating device, requires a separate user action to initiate energising of the heating element before the user can obtain an aerosol.

Certain known aerosol-generating systems are switched on manually and continually energise the heating element, producing heat in the device cavity regardless of the presence of an aerosol-generating article.

It is an aim of certain examples of the present invention to solve, mitigate or obviate, at least partly, at least one of the problems and/or disadvantages associated with the prior art.

The invention is set out in the appended claims.

According to an aspect, there is provided an example an aerosol-generating device configured to receive an aerosol-generating article, the aerosol-generating device including a housing defining a device cavity that is configured to at least partially receive the aerosol-generating article and to operably locate the aerosol-generating article in a position for use within the aerosol-generating device, and a time-of-flight ( "TOF" ) sensor assembly, wherein the time-of-flight sensor assembly is configured to measure at least one characteristic feature related to the aerosol-generating article within the device cavity.

According to an aspect, there is provided an aerosol-generating system including an aerosol-generating device as described herein. The aerosol-generating system may also include an aerosol-generating article configured to be removably receivable within the device cavity of the aerosol-generating device.

Aspects of the present invention provide an aerosol-generating device in which the energy consumption of the aerosol-generating device is reduced. This arrangement ensures that the presence of the aerosol-generating article within the device cavity in order to energise the heating element.

Aspects of the present invention provide an advantage that the aerosol-generating device is activated automatically. That is the aerosol-generating device detects the insertion of the aerosol-generating article and the user is able to experience an aerosol without necessitating any input or activation by the user. The automatic activation is achieved using a reduced energy consumption. The automatic activation is achieved using a more precise timing of the activation.

Aspects of the present invention ensure that the aerosol-generating article is correctly positioned within the device cavity of the aerosol-generating device. In particular, aspects of the invention verify whether the aerosol-generating article is positioned in a position for use, for example to ascertain that the aerosol-generating article is at the correct position for proper heating, aerosol formation and correct resistance to draw. The heating element is energised once the aerosol-generating article is operably located in the position for use.

Aspects of the present invention enable the aerosol-generating device to be controlled to accommodate non-ideal positioning of the aerosol-generating article in the device cavity. The heating element is energised according to the detected position of the aerosol-generating article within the device cavity, thereby overcoming any misalignment or mispositioning.

The at least one characteristic feature may be one or more of:

a position of the aerosol-generating article within the device cavity;

a detection of a puff generated by aerosolization of an aerosol-forming material of the aerosol-generating article;

a surface characteristic of a surface portion of the aerosol-generating article;

a surface structure provided on the aerosol-generating article;

a presence detection of the aerosol-generating article within the device cavity;

or an identification tag or marker of the aerosol-generating article.

The time-of-flight sensor assembly may include an emitter configured to emit a signal, for example but not limited to a light signal or an acoustic signal, towards an aerosol-generating article received into the device cavity.

The emitter may include one or more of: a light emitting diode, a laser light source, or an acoustic signal generator.

The acoustic signal generator may generates an ultrasonic acoustic signal. The acoustic signal may be an ultrasonic acoustic signal. In this way, the component costs for time-of-flight sensor assembly may be reduced.

The emitter may be arranged to emit a signal, for example a light signal or an acoustic signal, at least in a direction parallel to a central longitudinal axis of the device cavity. That is, the signal, for example the light signal or the acoustic signal, is emitted to propagate along the central longitudinal axis of the device cavity. In this way, the time-of-flight sensor assembly may monitor either continuously, during a period of time, or at a time instance, the position of the aerosol-generating article as it is received within the device cavity.

The emitter may be arranged to emit a signal, for example a light signal or an acoustic signal, at least in a direction transverse to a central longitudinal axis of the device cavity. That is, the signal, for example the light signal or the acoustic signal, is emitted to propagate in a direction perpendicular to the central longitudinal axis. Typically, the signal, for example the light signal or the acoustic signal, is directed from a first portion of the peripheral wall of the device cavity towards an opposing portion of the peripheral wall.

In this way, the time-of-flight sensor assembly may be adapted to determine a first reference distance when the aerosol-generating article is distal from the position for use, and a second reference distance when the aerosol-generating article is in a position for use. The second reference distance will be significantly shorter than the first reference distance so that there is a clear demarcation between the first reference distance and the second reference distance. The controller will easily and clearly determine that the aerosol-generating article is in a position for use.

The emitter may emit a pulsed light signal or a pulsed acoustic signal.

The emitter may emit a light signal may have electromagnetic radiation within a range of from 100 nanometres to 3000 nanometres, for example including one more of infrared light, ultraviolet light, or visible light. The electromagnetic radiation may be in a range of 100 nanometres to 1400 nanometres, 300 nanometres to 700 nanometres, or 700 nanometres to 1000 nanometres.

The electromagnetic radiation may be in range including one more of infrared light, ultraviolet light, or visible light. The light signal may be a monochromatic or a polychromatic light signal.

The emitter may emit a light signal having a predetermined wavelength, or a predetermined range of wavelengths. The emitter may be a laser source, for example a vertical-cavity surface-emitting laser.

The emitter may emit a light signal having a predetermined waveform, for example a pulsed waveform. The waveform of a light signal from an emitter may be used as a time indicator.

The time-of-flight sensor assembly may be configured to measure a time interval between an emitted waveform and a reflected waveform. The time-of-flight sensor assembly may be configured to measure a phase change between an emitted waveform and a reflected waveforms.

The emitter may emit a light signal or other optical signal having a predetermined phase.

The controller may be configured to compare a first signal emitted by the emitter to a reflected signal received by the receiver so as to determine a change in the one or more of the predetermined wavelength, predetermined waveform, or predetermined phase of the signal.

The time-of-flight sensor assembly may include a receiver configured to receive at least one of a reflected acoustic signal or a reflected light signal.

The receiver may include one or more of: a photodiode, an avalanche photodiode (APD) , a single photon detection avalanche photodiode (SPAD) , or a microphone, or another device capable of receiving and detecting the radiation. The receiver may include an array or matrix including one or more of: a photodiode, an avalanche photodiode (APD) , a single photon detection avalanche photodiode (SPAD) , or a microphone.

The receiver may include a focussing element arranged to focus a signal, for example a reflected light signal, entering the receiver.

The focussing element may include one or more of: a pinhole aperture, a lens, or a mirror.

In these ways, the receiver is adapted to measure a characteristic feature of a two-dimensional region of a surface portion of the aerosol-generating article, or a three-dimensional surface structure provided on the aerosol-generating article. The two-dimensional region of the surface portion, or the three-dimensional region of the surface portion may be an identification tag or marker.

The controller may determine a unique identifier of a identification tag or marker using a pattern of reflected light signals reflected from the aerosol-generating article. In this way, the controller may modify or adapt the operation of the aerosol-generating device according to the nature of the aerosol-generating article. For example, the temperature, duration, heating profile, or a combination of these parameters of the heater may be adjusted according to the identification tag of the aerosol-generating article.

The time-of-flight sensor assembly may be selectively operable in either a time-of-flight signal measurement mode or an illumination mode.

The time-of-flight sensor assembly may be operable in a time-of-flight signal measurement mode to measure either: the position of the aerosol-generating article within the device cavity, or the presence detection of the aerosol-generating article within the device cavity.

The time-of-flight sensor assembly may be operable in an illumination mode to measure either: the surface characteristic of the surface portion of the aerosol-generating article, or the surface structure of the aerosol-generating article. The surface characteristic of the surface portion of the aerosol-generating article may be at least one of: a reflectance characteristic, an absorbance characteristic, a refractive characteristic, a diffuse reflection characteristic, or a scatter characteristic. In addition, in the illumination mode, if a matrix or array of receiver elements are used, it is possible to detect image information from the surface portion of the aerosol generating aerosol-generating article, for example to read and detect data from an identification tag or marker.

The illumination mode may be a secondary mode. That is, the time-of-flight sensor assembly may be operable, typically selectively operable, in both a time-of-flight signal measurement mode and an illumination mode.

In an illumination mode, the time-of-flight sensor assembly may be configured to detect a change of color or a change of grayscale of a front plug of the aerosol-generating article.

In these ways, an illumination mode may be used to detect whether the aerosol forming article has been used, is unused, or is partially used.

The time-of-flight sensor assembly may be configured to determine a statistical variation of a time-of-flight signal to measure the detection of a puff. The statistical variation may be determined using a time-of-flight diffraction or other statistical technique. In this way, the aerosol causes a diffusion or diffraction of the signal that leads to a scattering of the pulses or phases of the reflected signal, so that a puff can be detected. This can be done by TOF diffraction ( "TOFD" ) or other statistical analysis of the response signals, for example to detect a statistical spread of the response times that are indicative of aerosol diffusion and a puff taken.

The time-of-flight sensor assembly may include a light detection and ranging device.

The time-of-flight sensor assembly may be configured to measure a two-dimensional surface characteristic or a three-dimensional surface characteristic of one or more surface portions of the aerosol-generating article. The time-of-flight sensor assembly may include an emitter producing a light signal using a wide beam LED or a wide beam laser light.

The receiver may include an array of photodetectors, or may have a plurality of photodetectors. Each photodetector may be equipped with a pinhole lens. In case the photodetectors are arranged in an array, a common lens may be used for the array of photodetectors, for example a pinhole lens. In this way, the receiver could readily operate in more than one mode. The receiver may determine a position of the aerosol-generating article within the device cavity and also read an identification tag embossed onto an outer wall of the aerosol-generating article, or read information from a printed marker or image on the outer wall of the aerosol-generating article.

The time-of-flight sensor assembly may measure the position of the aerosol-generating article in the device cavity so as to verify that the aerosol-generating article is in the position for use.

The time-of-flight sensor assembly may periodically verify that the aerosol-generating article is located in a position for use. In this way, the time-of-flight sensor assembly may check during use whether the aerosol-generating article has been dislocated from the position for use, or removed from the device cavity of the aerosol-generating device.

The time-of-flight sensor assembly may include a temperature sensor, wherein the temperature sensor is configured to measure a temperature to determine an air temperature within the device cavity. In this way, the temperature sensor of the time-of-flight sensor assembly is used for compensating the temperature drift of the light speed, and may also be used to measure a value indicative of the air temperature within the device cavity.

The aerosol-generating device may include a controller.

The controller may configured to receive the air temperature from the temperature sensor and to use the air temperature to determine either a presence of a puff or an absence or a puff within the device cavity. Optionally, the controller may be adapted to process data to detect a puff by temperature, for example by using a power analysis.

The temperature sensor may be configured to determine a rate of change of air temperature within the device cavity.

The controller may be configured to receive the rate of change of air temperature from the temperature sensor to determine either a presence of a puff or an absence or a puff within the device cavity.

The controller may be configured to count the number of puffs. The controller may record the number of puffs. The controller may monitor the puffs until a predetermined number have been produced by the aerosol-generating article. The controller may be adapted to activate a suitable display means provided in the aerosol-generating system so as to display or otherwise visualise the amount of use to the user.

In these ways, the controller may indicate to the user the amount of use of an aerosol-generating article, or to indicate that the aerosol-generating article is approaching a maximum use.

The device cavity may be configured to receive an aerosol-generating article. The aerosol-generating article may have a variety of shapes, for example rod-shaped or stick-shaped articles, or the aerosol-generating article may have other shapes, for example rectangular cartridges, flat consumables and the like. The device cavity may have a central longitudinal axis such that, in the position for use, the aerosol-generating article is coaxial with the central longitudinal axis.

The device cavity may be substantially cylindrical. The device cavity may have a shape corresponding to, or complimentary to, a shape of an aerosol-generating article.

The housing may include a recessed chamber adjoining the device cavity. The time-of-flight sensor assembly may be arranged in the recessed chamber.

The housing may include a partition wall between the device cavity and the recessed chamber. The partition wall is formed of a material that is substantially transparent to a signal emitted by the emitter of a time-of-flight sensor assembly. For example, the partition wall may be formed of a material that is substantially transparent to a light signal emitted by the emitter.

The partition wall may be formed of a plastic material. The plastic material may be a polycarbonate (PC) material or any other suitable high performance plastic material having suitable optic and temperature characteristics, for example a Polyetherimide (PEI) material, a Polyetheretherketone (PEEK) material, a Polyimide (PI) material, or a Fluoropolymer material, such as PTFE, FEP, or PFA.

The partition wall may be formed of a non-crystalline solid material such as a glass material, for example a glass material having optical qualities and temperature-resistance to temperatures present in the device cavity. The partition wall may be formed of a transparent glass ceramic material.

In these ways, the time-of-flight sensor assembly may be isolated from the device cavity. That is the time-of-flight sensor assembly is fluidly separated from the device cavity.

The recessed chamber may be provided in a base of the device cavity. In this way, the light signal or the acoustic signal may be directed along the central longitudinal axis of the device cavity. In this way, the time-of-flight sensor assembly may continuously monitor the position of the aerosol-generating article as it is received within the device cavity.

The recessed chamber may be provided in a peripheral wall of the device cavity. In this way, the emitter may be particularly arranged to emit a light signal or an acoustic signal at least in a direction transverse to a central longitudinal axis of the device cavity.

The aerosol-generating article may includes one or more of: an aerosol-forming material, a surface portion, a surface structure, or an identification tag. In this way, the aerosol-generating article may be particularly configured to be mutually compatible with aspects of the aerosol-generating device.

The aerosol-generating article may include a substrate configured to modify the characteristic feature of the aerosol-generating article in response to heat applied to the aerosol-generating article by the aerosol-generating device. The substrate may be a thermal print material or a thermochromic paper. The heat may be provided when a heater of the aerosol-generating device is energised by a controller.

In these ways, the substrate provides a visual indicator of the degree of use of the aerosol-generating article. The visual indicator may be readily determined using one or more of the time-of-flight sensor assemblies described herein.

The aerosol-generating article may include an identification tag having one or more of: an embossed region or a debossed region. The identification tag may be easily read using one or more of the time-of-flight sensor assemblies described herein. In this way, an aerosol-generating device may selectively modify or adapt its operation according to the nature of the aerosol-generating article. For example, the temperature or the duration of the heater may be adjusted according to the identification tag of the aerosol-generating article.

As used herein, “to measure” refers to the use of the time-of-flight sensor assembly to evaluate, to read, or otherwise to determine at least one characteristic feature of an aerosol-generating article. Correspondingly, a “measurement” refers to a determinable amount, identifier, location, position or other physical measure of a characteristic feature.

As used herein, “signal” refers to a first signal emitted into the device cavity by the emitter. The first signal may be a light signal or an acoustic signal provided by the emitter.

As used herein, “reflected signal” refers to a second signal reflected to the receiver within the device cavity. The reflected signal is a reflection of the first signal to the receiver. The reflected signal is a reflection of the first signal to the receiver from the aerosol-generating article. The reflected signal is typically a reflection of the first signal from a surface portion or surface structure provided on the aerosol-generating article. The reflected signal may be a reflection or a scattering of the first signal by an aerosol dispersed within the device cavity.

As used herein, a “light signal” refers to a signal generated by a light source providing electromagnetic radiation either at a predetermined wavelength, or at wavelengths within a predetermined range.

As used herein, an “acoustic signal” refers to a signal generated by an acoustic signal generator providing acoustic energy either at a predetermined frequency, or at frequencies within a predetermined range.

As used herein, in a “direct time-of-flight mode” , the controller determines a time interval between a first signal emitted by the emitter, and a second signal received by the receiver, where the second signal is a reflection of the first signal from the aerosol-generating article within the device cavity. The first signal of a direct time-of-flight mode may be a light signal or an acoustic signal.

As used herein, in an “indirect time-of-flight mode” , the controller determines a phase change between a first signal emitted by the emitter, and a second signal received by the receiver, where the second signal is a reflection of the first signal from the aerosol-generating article within the device cavity. The first signal of an indirect time-of-flight mode may be a light signal or an acoustic signal.

As used herein, “position” or “first position” refers to a location relative to a reference point within the device cavity, or a to an orientation relative a reference point or axis, for example relative to the central longitudinal axis.

As used herein, “surface portion” refers to a predetermined target surface provided on an aerosol-generating article. Thus an aerosol-generating device is adapted to receive an aerosol-generating article so that a surface portion will be located in a predetermined three-dimensional position within the device cavity in a position for use. The aerosol-generating system is thereby configured to ensure the surface portions of successive aerosol-generating articles are repeatedly provided in the same position for use within the device cavity. In this way, a predetermined surface portion of the aerosol-generating articles is intentionally used as a target surface so that the time-of-flight sensor assembly reliably measures a common characteristic feature of successive aerosol-generating articles during use.

As used herein, “illumination” refers to the illumination, irradiation or propagation of signal by the time of flight sensor assembly towards an aerosol-generating article within, or partially within, the device cavity. Illumination may include using an emitter to provide a light signal or an acoustic signal.

As used herein, an “identification tag” refers to a suitable physical identifier provided on an aerosol-generating article to provide a unique pattern or other unique identification means associated with the aerosol-generating article. The identification tag may be read by the controller using information determined from the reflected signal received by the receiver. The identification tag may include one or more of: a bar-code, a QR code, encrypted code, an image or pattern, a tracking marker, or an optical marker; a region of markings imparting varying reflection characteristics to a reflected signal; an embossed region, for example including embossed dots and/or embossed dashes; or a debossed region, for example including debossed dots and/or debossed dashes.

As used herein, a “puff” refers to an event in which the user applies suction to the mouth end of an aerosol-generating article, or the mouth end of an aerosol-generating device, to draw air through the aerosol-generating article and the aerosol-generating device. The air is drawn into an upstream end of the aerosol-generating article and may entrain aerosols that may have accumulated within the device cavity prior to the application of suction by the user.

The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

Example Ex1: 1. An aerosol-generating device configured to receive an aerosol-generating article, the aerosol-generating device comprising:

a housing defining a device cavity that is configured to at least partially receive the aerosol-generating article and to operably locate the aerosol-generating article in a position for use within the aerosol-generating device; and

a time-of-flight sensor assembly;

wherein the time-of-flight sensor assembly is configured to measure at least one characteristic feature related to the aerosol-generating article within the device cavity.

Example Ex2. The aerosol-generating device according to claim 1, wherein the at least one characteristic feature is one or more of:

a position of the aerosol-generating article within the device cavity;

a surface structure provided on the aerosol-generating article;

a presence detection of the aerosol-generating article within the device cavity; or

an identification tag of the aerosol-generating article.

Example Ex3. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly comprises an emitter configured to emit a light signal or an acoustic signal towards an aerosol-generating article received into the device cavity.

Example Ex4. The aerosol-generating device according to Ex3, wherein the emitter comprises one or more of: a light emitting diode, a laser light source, or an acoustic signal generator.

Example Ex5. The aerosol-generating device according to Ex4, wherein the acoustic signal generator generates an ultrasonic acoustic signal.

Example Ex6. The aerosol-generating device according to Ex3, wherein the emitter is arranged to emit a light signal or an acoustic signal at least in a direction parallel to a central longitudinal axis of the device cavity.

Example Ex7. The aerosol-generating device according to Ex3, wherein the emitter is arranged to emit a light signal or an acoustic signal at least in a direction transverse to a central longitudinal axis of the device cavity.

Example Ex8. The aerosol-generating device according to Ex3, wherein the emitter emits a pulsed light signal or a pulsed acoustic signal.

Example Ex9. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly comprises a receiver configured to receive at least one of a reflected acoustic signal or a reflected light signal.

Example Ex10. The aerosol-generating device according to Ex9, wherein the receiver comprises one or more of: a photodiode, an avalanche photodiode, a single photon detection avalanche photodiode, or a microphone.

Example Ex11. The aerosol-generating device according to Ex9, wherein the receiver includes a focussing element arranged to focus light entering the receiver.

Example Ex12. The aerosol-generating device according to Ex11, wherein the focussing element comprises one or more of: a pinhole aperture, a lens, or a mirror.

Example Ex13. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly is selectively operable in either a time-of-flight signal measurement mode or an illumination mode.

Example Ex14. The aerosol-generating device according to Ex2, wherein the time-of-flight sensor assembly is operable in a time-of-flight signal measurement mode to measure either: the position of the aerosol-generating article within the device cavity, or the presence detection of the aerosol-generating article within the device cavity.

Example Ex15. The aerosol-generating device according to Ex2, wherein the time-of-flight sensor assembly is operable in an illumination mode to measure either: the surface characteristic of the surface portion of the aerosol-generating article, or the surface structure of the aerosol-generating article. Preferably, the aerosol-generating device according to Ex2 is operable in an illumination mode as well as a time-of-flight signal measurement mode.

Example Ex16. The aerosol-generating device according to Ex15 wherein, in the illumination mode, the time-of-flight sensor assembly is configured to detect a change of color or a change of grayscale of a front plug of the aerosol-generating article.

Example Ex17. The aerosol-generating device according to Ex2, wherein the surface characteristic of the surface portion of the aerosol-generating article is at least one of: a reflectance characteristic, an absorbance characteristic, a refractive characteristic, a diffuse reflection characteristic, or a scatter characteristic.

Example Ex18. The aerosol-generating device according to Ex2, wherein the time-of-flight sensor assembly is configured to determine a statistical variation of a time-of-flight signal to measure the detection of a puff, or a time-of-flight statistical spread by scattering.

Example Ex19. The aerosol-generating device according to Ex18, wherein the statistical variation is determined using a time-of-flight diffraction, or by using time-of-flight statistical spread by scattering.

Example Ex20. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly includes a light detection and ranging device.

Example Ex21. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly is configured to measure a two-dimensional surface characteristic or a three-dimensional surface characteristic of one or more surface portions of the aerosol-generating article.

Example Ex22. The aerosol-generating device according to Ex2, wherein the time-of-flight sensor assembly measures the position of the aerosol-generating article in the device cavity so as to verify that the aerosol-generating article is in the position for use.

Example Ex23. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly comprises a temperature sensor, wherein the temperature sensor is configured to measure a temperature to determine an air temperature within the device cavity.

Example Ex24. The aerosol-generating device according to Ex23, further comprising a controller, wherein the controller is configured to receive the air temperature from the temperature sensor and to use the air temperature to determine either a presence of a puff or an absence or a puff within the device cavity.

Example Ex25. The aerosol-generating device according to Ex23, wherein the temperature sensor is configured to determine a rate of change of air temperature within the device cavity.

Example Ex26. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly is configured to measure a time interval between an emitted waveform and a reflected waveform.

Example Ex27. The aerosol-generating device according to Ex1, wherein the time-of-flight sensor assembly is configured to measure a phase change between an emitted waveform and a reflected waveforms.

Example Ex28. The aerosol-generating device according to Ex23, further comprising a controller, wherein the controller is configured to receive the rate of change of air temperature from the temperature sensor to determine either a presence of a puff or an absence or a puff within the device cavity.

Example Ex29. The aerosol-generating device according to Ex24 or Ex28, wherein the controller is configured to count the number of puffs.

Example Ex30. The aerosol-generating device according to Ex1, wherein the device cavity is configured to receive a rod-shaped aerosol-generating article, and the device cavity has a central longitudinal axis such that, in the position for use, the aerosol-generating article is coaxial with the central longitudinal axis.

Example Ex31. The aerosol-generating device according to Ex30, wherein the device cavity is substantially cylindrical.

Example Ex32. The aerosol-generating device according to Ex1, wherein the housing comprises a recessed chamber adjoining the device cavity, and wherein the time-of-flight sensor assembly is arranged in the recessed chamber.

Example Ex33. The aerosol-generating device according to Ex32, wherein the housing further comprises a partition wall between the device cavity and the recessed chamber, and wherein the partition wall is formed of a material that is substantially transparent to a signal emitted by the time-of-flight sensor assembly.

Example Ex34. The aerosol-generating device according to Ex32, wherein the recessed chamber is provided in a base of the device cavity.

Example Ex35. The aerosol-generating device according to Ex32, wherein the recessed chamber is provided in a peripheral wall of the device cavity.

Example Ex36. An aerosol-generating system comprising an aerosol-generating device according to any one of Ex1 to Ex35, and an aerosol-generating article configured to be receivable within the device cavity of the aerosol-generating device.

Example Ex37. The aerosol-generating system according to Ex36, wherein the aerosol-generating article comprises one or more of: an aerosol-forming material, a surface portion, a surface structure, or an identification tag.

Example Ex38. The aerosol-generating system according to Ex37, wherein the aerosol-generating article comprises a substrate configured to modify the characteristic feature of the aerosol-generating article in response to heat applied to the aerosol-generating article by the aerosol-generating device.

Example Ex39. The aerosol-generating system according to Ex38, wherein the substrate is a thermal print material or a thermochromic paper.

Example Ex40. The aerosol-generating system according to Ex37, wherein the aerosol-generating article comprises an identification tag having one or more of: an embossed region or a debossed region.

Examples will now be described with reference to the figures in which:

FIG. 1 shows a schematic cross-sectional view of a comparative aerosol-generating device and a comparative aerosol-generating system;

FIG. 2A shows a schematic cross-sectional view of an example aerosol-generating system;

FIG. 2B a close up view of a portion of the example of FIG. 2A;

FIG. 3A shows a schematic cross-sectional view of another example aerosol-generating system;

FIG. 3B a close up view of a portion of the example of FIG. 3A; and

FIG. 4 shows the example of FIG. 2A and FIG. 2B during use.

Certain terminology is used in the following description for convenience only and is not limiting. The word ‘outer’ refer to directions toward and away from, respectively, a designated centreline or a geometric centre of an element being described (e.g. central axis) , the particular meaning being readily apparent from the context of the description.

Further, as used herein, the term ‘mounted’ is intended to include direct connections between two members without any other members interposed therebetween, as well as, indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.

Further, unless otherwise specified, the use of ordinal adjectives, such as, ‘first’ , and ‘second’ , etc. merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner.

Referring to FIG. 1, there is shown an exemplary, non-limiting aerosol-generating system 100 including a comparative aerosol-generating device 110 and an aerosol-generating article 120. The aerosol-generating device 110 includes a housing 104, extending between a mouth end 102 and a distal end. The housing 104 includes a peripheral wall 106. The peripheral wall 106 defines a device cavity for receiving an aerosol-generating article 120.

The device cavity defined by the peripheral wall 106 is configured to receive the aerosol-generating article 120 in a position for use, for example by cooperating locating means provided in the cavity and on the aerosol-generating article 120.

The device cavity is further defined by a closed, distal end and an open, mouth end 102. The mouth end 102 of the device cavity is located at the mouth end of the aerosol-generating device 110. The aerosol-generating article 120 is configured to be received through the mouth end 102 of the device cavity and is configured to abut the closed end of the device cavity in the position for use.

In the example, an air-flow path 126 is defined around the aerosol-generating article 120 and between the peripheral wall 106 of the aerosol-generating device housing 104. This enables air to flow through an upstream side of the rod 112, for example the rod end surface, and further downstream through the rest of the aerosol-generating article 120 upon suction being created by user at the mouth end 102 of the aerosol-generating article 120.

The aerosol-generating device 110 further includes a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided to control such supply of power to the heater. The heater is configured to heat the aerosol-generating article 120 during use, when the aerosol-generating article 120 is received within the aerosol-generating device 110. Many different heaters and combinations thereof can be used, and the herein described invention is not limited to any specific type of heater.

In this non-limiting and exemplary example, the aerosol-generating article 120 includes a filter having a circular surface forming an upstream end of the rod 112, a hollow support segment 114, a hollow tubular segment 116 and a mouthpiece segment 118. These four elements are arranged in an end-to-end, longitudinal alignment and are circumscribed by a wrapper 122 to form the aerosol-generating article 120. The aerosol-generating article 120 shown in FIG. 1 is particularly suitable for use with an electrically operated aerosol-generating device 110 including a heater for heating the rod 112.

In the variant shown, the rod 112 is cylindrical in shape and has a substantially circular cross-section. The rod 112 can include a gathered sheet of homogenised tobacco material, or other material for aerosolization, including but not limited to aerosol former, botanicals, pharmaceutical agents, flavoring agents, or a combination thereof.

The aerosol-generating article 120 may include a ventilation zone 124. The ventilation zone 124 may be provided at least about 5 millimetres from an upstream end of the mouthpiece segment 118. The ventilation zone 124 may be at least about 12 millimetres from the downstream end of the aerosol-generating article 120. The ventilation zone 124 may be at least about 21 millimetres from a downstream end of the rod 112. The ventilation zone 124 may include a series or line of perforations extending through the wrapper 122.

As shown in FIG. 1, the ventilation zone 124 of the aerosol-generating article 120 is exposed during use of the aerosol-generating system 100.

In alternative aerosol-generating systems, the aerosol-generating article may include a fluid reservoir, capsule or cartridge suitable for use with an electrically operated aerosol-generating device. The fluid contained in the fluid reservoir forms an aerosol when heated. The aerosol-generating system may include a heater for heating the fluid of the fluid reservoir to form an aerosol. The heater may be mounted within the aerosol-generating article of the aerosol-generating system. The aerosol-forming article may include a wicking element to controllably release fluid from the fluid reservoir to the heater.

Referring now FIG. 2A and FIG. 2B, there is shown an example aerosol-generating system. The example includes an aerosol-generating device 210 configured to receive an aerosol-generating article 220. The aerosol-generating device 210 includes a housing 204 defining a device cavity 205 that is configured to at least partially receive the aerosol-generating article 220 and to operably locate the aerosol-generating article 220 in a position for use within the aerosol-generating device 210.

The aerosol-generating device 210 also includes a time-of-flight sensor assembly 250. The time-of-flight sensor assembly 250 is configured to measure at least one characteristic feature related to the aerosol-generating article 220 that is located at least partially within the device cavity 205. In the example shown, the time-of-flight sensor assembly 250 is configured to measure a position of the aerosol-generating article 220 within the device cavity 205 as is explained in more detail below.

In the exemplary and non-limiting example shown, the device cavity 205 is substantially cylindrical. The device cavity 205 defines a central longitudinal axis 224 extending from a closed end to a mouth end of the device cavity 205. The aerosol-generating article 220 is received into the device cavity 205 from the mouth end.

The housing 204 may include a recessed chamber 228 adjoining the device cavity 205. The recessed chamber 228 is provided in a base 226 of the housing 204. The recessed chamber 228 can be located at the closed end of the device cavity 205, for example having a transparent protection wall or separator at the closed end of the device cavity 205. In this way, the time-of-flight sensor assembly is positioned to measure a characteristic feature of the aerosol-generating article located on a surface portion or surface structure at an upstream end, or front surface of a front plug (for example the front plug 112 as shown in FIG. 1) of the aerosol-generating article 220.

It is possible that the recessed chamber 228 and the time-of-flight sensor assembly 250 is arranged at the base of the recessed chamber 228, or further recessed into recessed chamber 228, so that the emission and reception surface of emitter 230 and receiver 232 are further located inside recessed chamber 228. The distance of the emitter 230 and the receiver 232 from the surface portion 222 or surface structure of the upstream end of aerosol-generating article 220, or another surface portion or structure of the aerosol-generating article 220 is lengthened. In this way, it is possible to increase a distance d between emitter 230 and receiver 232 and the upstream end of aerosol-generating article 220, or another surface portion or structure of the aerosol-forming article 220. For example, it may be possible to increase the distance to more than 3 mm, preferably more than 5 mm, even more preferably more than 8 mm.

The time-of-flight sensor assembly 250 may be arranged in the recessed chamber 228. In this way, an emitter 230, receiver 232, controller 234 and temperature sensor 236 of the time-of-flight sensor assembly 250 are mounted within the recessed chamber 228. The time-of-flight sensor assembly 250 is mounted within the aerosol-generating device 210 without limiting or impeding the volume of the device cavity 205. The emitter 230, receiver 232 and temperature sensor 236 are operably connected to the controller 234 in the recessed chamber 228. In the example, the time-of-flight sensor assembly 250 is provided on a silicon chip or multi-chip module ( "MCM" ) including each of the emitter 230, receiver 232, controller 234 and temperature sensor 236.

The time-of-flight sensor assembly 250 includes a temperature sensor 236 to measure an air temperature of the medium through which the signal propagates. In this way, the time-of-flight sensor assembly 250 is used for compensating the temperature drift of the signal emitted by the emitted. The temperature sensor 236 therefore can be configured to also provide for an air temperature that is indicative of the temperature inside the device cavity 205. The air temperature provided by the temperature sensor 236 may also be used for a secondary purpose, for example to enable detection of a puff within the device cavity, as is also described here.

The temperature sensor 236 is mounted within the recessed chamber 228, or in close proximity thereto, to operably determine the air temperature within the device cavity 205. Preferably, the temperature sensor 236 is part of, or integrated with, the time-of-flight sensor assembly 250.

The emitter 230 is mounted within the recessed chamber 228 to be operable within the device cavity 205. In the example, the emitter 230 generates an electromagnetic radiation to provide a light signal 238. The emitter 230 includes a light emitting diode to generate the light signal 238.

The emitter 230 is mounted to emit the light signal 238 into the device cavity 205 in a direction generally oriented along the central longitudinal axis 224 of the device cavity 205. In this way, the emitter 230 is mounted to emit a first signal towards the aerosol-generating article 220 as it is inserted and received into the device cavity 205. In the example, the emitter 230 is configured to emit a narrow beam source into the device cavity 205 so that the light signal 238 is directed towards a specific surface portion 222 of the aerosol-generating article 220 as the aerosol-generating article 220 is received into the device cavity 205.

The receiver 232 is mounted within the recessed chamber 228 to operably receive a second signal from the device cavity 205. The receiver includes a photodiode configured to measure the reflected light signal 240 during use.

The second signal is a reflected light signal 240, that is a reflection of the first signal from the aerosol-generating article 220. The receiver 232 is mounted in a position to receive a reflected signal from the aerosol-generating article 220 as it is received into the device cavity 205.

The housing 204 further includes a partition wall 262 between the device cavity 205 and the recessed chamber 228. The partition wall 262 is formed of a material that is transparent to the light signal 238 emitted by the emitter 230. In the example, the partition wall 262 is formed of a transparent plastic material. The plastic material may be a polycarbonate (PC) material or any other suitable high performance plastic material having suitable optic and temperature characteristics, for example a Polyetherimide (PEI) material, a Polyetheretherketone (PEEK) material, a Polyimide (PI) material, or a Fluoropolymer material such as PTFE, FEP, or PFA.

Optionally, the partition wall may be formed of a non-crystalline solid material such as a glass material, for example a glass material having optical qualities and temperature-resistance to temperatures present in the device cavity. Optionally, the partition wall may be formed of a transparent glass ceramic material.

In a non-limiting example, the aerosol-generating article 220 is rod-shaped such that, in the position for use, the aerosol-generating article 220 is coaxial with a central longitudinal axis 224. The aerosol-generating article 220 includes a cylindrical outer wall as well as a disc-shaped front plug at the upstream end to enclose the aerosol-forming materials. The surface portion 222 is provided on the front plug of the aerosol-generating article.

The aerosol-generating device 210 further includes a heater (not shown) and a power source (not shown) for supplying power to the heater. The heater is configured to heat the aerosol-generating article 120 during use, when the aerosol-generating article 120 is received in a position for use within the aerosol-generating device 110. The controller 234 is configured to control such supply of power to the heater so as to selectively energise the heater, according to the position of the aerosol-generating article 220 within the device cavity 205. Different technologies for the heater can be used, or a combination of different types of heater technologies.

In use, the aerosol-generating device 210 of the aerosol-generating system 200 is used to measure the position of the aerosol-generating article 220 within the device cavity 205, for example to determine a position of the aerosol-generating article 220 relative to the device cavity 205. In particular, the time-of-flight sensor assembly 250 is used to verify whether the aerosol-generating article 220 is positioned in a position for use, for example to ascertain that the aerosol-generating article 220 is at the correct position for proper heating, aerosol formation and correct resistance to draw ( "RTD" ) . The controller 234 of the aerosol-generating device 210 is thus configured to selectively energise the heater only when the aerosol-generating article 220 is located in the position for use. The controller 234 of the aerosol-generating device 210 is thus configured to selectively deactivate the heater when the aerosol- generating article 220 is not in the position for use, for example when the aerosol-generating article 220 is misaligned, or removed during use.

Thus, to use the aerosol-generating device 210, an aerosol-generating article 220 is inserted into the mouth end of the device cavity 205 and moved in a direction along the central longitudinal axis 224 towards the closed end of the device cavity 205.

As will be appreciated, the time-of-flight sensor assembly 250 may be configured to emit alternative a signal of an alternative nature to a light signal, for example an acoustic signal. In this way, the receiver 232 may be suitably configured to operably receive a second signal, that is a reflected signal, depending on the nature of the emitted signal. For example, if the time-of-flight sensor assembly 250 generates an acoustic signal then the receiver may be a microphone configured to measure a reflected acoustic signal from the aerosol-generating article received into the device cavity.

The time-of-flight sensor assembly 250 is set to be operable in a direct time-of-flight signal measurement mode. The emitter 230 generates a pulsed light signal 238 and emits the light signal 238 into the device cavity 205 from the closed end of the device cavity 205 towards the mouth end. A first time is recorded at the controller 234 as each pulse of the pulsed light signal 238 is emitted by the emitter 230.

The light signal 238 reaches the aerosol-generating article 220, specifically the surface portion 222 of aerosol-generating article 220, and is reflected back towards the closed end of the device cavity 205. The receiver 232 receives the reflected light signal 240 from the surface portion 222 of the aerosol-generating article 220. A second time is recorded at the controller 234 as each reflected light signal pulse is received by the receiver 232.

While performing TOF measurements, the controller 234 can use air or environmental temperature data that is provided by the temperature sensor 236 to determine an instantaneous or present propagation rate or speed for the light or acoustic signal 238 and the reflected light or acoustic signal 240. Or, the controller 234 can use the temperature of the time-of-flight sensor assembly 250, for example a microchip temperature sensor, to perform temperature-based calibrations. For example, the controller 234 can continuously or intermittently calibrate the measurements taking into account the measured temperature. In this respect, the propagation rate of the light or acoustic signal 238 and the reflected light or acoustic signal 240 can vary as a function of temperature of the medium or space where these signals 238, 240 travel. A typical propagation rate of the light or acoustic signal 238 and the reflected light or acoustic signal 240 for a given air or environmental temperature in the device cavity 205 can known by the controller 234 and stored as a reference value. The controller 234 can thereby ensure accurate measurement by the time-of-flight sensor assembly 250 to compensate for a temperature drift or environmental temperature of the signal during use.

The controller 234 calculates a time interval between the first time and the second time. The controller 234 uses the time interval and the instantaneous propagation rate to determine the distance between surface portion 222 and the emitter 230. The controller 234 thereby accurately determines the position of the aerosol-generating article 220 within the device cavity 205. The controller 234 accurately determines the axial position of the aerosol-generating article 220 along the central longitudinal axis 224 and, hence, the distance of the surface portion 222 from the closed end of the device cavity 205.

By providing a stream of pulsed light signals 238, the time-of-flight sensor assembly 250 enables the controller 234 to continuously monitor the axial position of the aerosol-generating article 220 within the device cavity 205. Once the aerosol-generating article 220 is located in an axial position corresponding to a position for use, the controller 234 energises the heater of the device cavity 205.

The controller 234 of the aerosol-generating device 210 may also be configured to determine either a presence of a puff within the device cavity 205. The determination of a presence of a puff may be, for example, simultaneous with the position or presence measurements, or by alternating measurements.

When a user applies suction to the mouth end of the aerosol-generating article 220 the residual air within the device cavity 205, which has been heated by the heater, is drawn into the aerosol-generating article 220 and replaced by air at an ambient temperature that is drawn into the device cavity 205. The air temperature within the device cavity 205 thus falls and a corresponding change in air temperature is detected by the controller 234 by monitoring the air temperature data provide to it by the temperature sensor 236. Preferably, the controller 234 may count the number of puffs generated from an aerosol-generating article 220.

The aerosol-generating system 200 described with reference to FIG. 2A and FIG. 2B may be adapted or modified to include other features of the time-of-flight sensor assembly as described herein.

The aerosol-generating device 210 may be used in an illumination mode, in which the time-of-flight sensor assembly 250 is configured to detect a change of color or a change of grayscale of a front plug of the aerosol-generating article.

In an example, the aerosol-generating device may include a time-of-flight sensor assembly configured to measure a surface characteristic of a surface portion of the aerosol-generating article. For example, the time-of-flight sensor assembly may measure a change in a reflectance characteristic, an absorbance characteristic, a reflective characteristic, a diffuse reflect characteristic, or a scatter characteristic.

The aerosol-generating article may include a substrate configured to modify the characteristic feature, such as a reflectance characteristic, an absorbance characteristic, or a scatter characteristic, of the aerosol-generating article in response to heat applied to the aerosol-generating article by the aerosol-generating device. In an example, the substrate may be a thermal print material or a thermochromic paper.

In an example, the substrate may be an upstream filter of the aerosol-generating article whereby the time-of-flight sensor assembly may be used to monitor a colour change of the substrate over a period of use.

The controller may be adapted to record the surface characteristic as the aerosol-generating article is used in the aerosol-generating device. Thus, the controller may monitor a surface characteristic until a predetermined change in the surface characteristic is determined, such as to indicate the duration of use of an aerosol-generating article, or that the aerosol-generating article is approaching a maximum use duration. The controller may be adapted to activate a suitable display means provided in the aerosol-generating system so as to display the duration to the user.

The aerosol-generating device may be configured to detect a puff in an alternative manner to the air temperature described above. For example, the aerosol-generating device may be configured to detect a puff by taking advantage of the scattering, diffusion, or diffraction of the time-of-flight signal response, caused by the aerosol particles in the airflow path that are more prominent after or during the taking of the puff. While most aerosol particles will exit by the downstream or mouthpiece end, there is always a scattering effect caused by some aerosol particles in the upstream airflow path as the air can pass close to or by the aerosol-forming aerosol-generating article 220, where some particles will egress from the article 220. For example, a time-of-flight diffraction ( "TOFD" , also time-of-flight scattering) measurement principle can be used as described with reference to FIG. 4. In this way, the aerosol causes a diffusion, diffraction, or scattering that leads to a dispersion or scattering of the reflected signal, typically the reflected signal pulses or phases, so that a puff can be detected. This can be done by TOF diffraction ( "TOFD" ) or other statistical analysis of the response signals, e.g, to detect a statistical spread of the response times that are indicative of aerosol diffusion and puff taken.

Another way to detect the puff can be based by the change of air temperature caused by the fresh incoming air, which can be sensed by the time-of-flight assembly as the change in temperature will cause a different time-of-flight response, for example a change in the propagation speed of the signal.

The aerosol-generating device may be configured so that the time-of-flight sensor assembly is selectively operable in either a time-of-flight signal measurement mode or an illumination mode. The time-of-flight sensor assembly may be initially used in a time-of-flight mode, for example to measure a position of an aerosol-generating article as it is received into the device cavity of the aerosol-generating device. Once the aerosol-generating article is in a position for use, then the time-of-flight sensor assembly may be used subsequently in an illumination mode, for example to measure a surface characteristic of the surface portion.

Referring now to FIG. 3A and FIG. 3B, there is shown another aerosol-generating system 300 including an aerosol-generating device and a time-of-flight sensor assembly 350. Where the features are the same as the example of FIG. 2A and FIG. 2B, the reference numbers are also kept the same, but with a “3” as the initial digit.

The aerosol-generating device 310 is substantially similar to the aerosol-generating device 210 of FIG. 2A and FIG. 2B other than the recessed chamber 328 is provided in a peripheral wall of the device cavity 305. The aerosol-generating device 310 includes a housing 304 defining a device cavity 305 that is configured to at least partially receive the aerosol-generating article 320 and to operably locate the aerosol-generating article 320 in a position for use within the aerosol-generating device 310.

The aerosol-generating device 310 also includes a time-of-flight sensor assembly 350. The time-of-flight sensor assembly 350 is configured to measure at least one characteristic feature related to the aerosol-generating article 320 within the device cavity 305. In the example shown, the time-of-flight sensor assembly 350 is configured to measure, specifically to read identification information or other information, for example an identification tag from the aerosol-generating article 320, as is explained in more detail below.

In the variant shown, the device cavity 305 is substantially cylindrical. The device cavity 305 has a central longitudinal axis 324 extending from a closed end to a mouth end of the device cavity 305. The aerosol-generating article 320 is received into the device cavity 305 via the mouth end.

The housing 304 includes a recessed chamber 328 adjoining the device cavity 305. The recessed chamber 328 is provided in a peripheral wall of the device cavity 305. The recessed chamber 328 can be located towards the closed end of the device cavity 305. In this way, the time-of-flight sensor assembly 350 is positioned to measure a characteristic feature of the aerosol-generating article 320. The characteristic feature is located on a surface portion 322 or surface structure on a cylindrical outer wall towards an upstream end, or front plug, of the aerosol-generating article 320.

The housing 304 further includes a partition wall 352 between the device cavity 305 and the recessed chamber 328. The partition wall 352 is formed of a material that is transparent to the light signal 338 emitted by the emitter 330.. In case a light signal is used for the time-of-flight measurement, the partition wall 352 should be transparent to the light wavelength of the used light signal. In case an acoustic signal is used, for example ultrasound, then partition wall 352 should be transparent to the wave spectrum covered by the ultrasound or other acoustic signal. In the example, the partition wall 352 can be formed of an optically transparent plastic material or a quartz glass material. The plastic material may be a polycarbonate (PC) material or any other suitable plastic material as indicated herein. The partition wall 352 may also be made of a ceramic material as indicated herein. If an ultrasonic signal is used, the partition wall 352 may be made of a temperature resistant plastic or ceramic material.

The time-of-flight sensor assembly 350 is arranged in substantially the same manner as the time-of-flight sensor assembly 250 of FIG. 2A and FIG. 2B, other than the recessed chamber 328 adjoins the peripheral wall of the device cavity 305. In this way, the emitter 330 is mounted to emit a first signal in a direction transverse to the central longitudinal axis 324 of the device cavity 305. The first signal is a light signal 338 provided by a light emitting diode. The emitter 330 is configured to emit a wide beam source into the device cavity 305 so that the light signal 338 is directed towards the surface portion 322 of the aerosol-generating article 320 as the aerosol-generating article 320 is received into the device cavity 305. The wide beam source enables the light signal 338 to be directed towards a two-dimensional or a three-dimensional surface portion of an aerosol-generating article.

The receiver 332 includes a focussing element arranged to focus light entering the receiver. The focussing element includes a lens 342.

The receiver 332 includes an array of photodiodes, particularly a two-dimensional array of photodiodes, or other photosensitive technology, for example a linear or surface image sensor. In certain examples, depending on the nature of the signal and characteristic feature of the aerosol-generating article that is measured, the receiver 332 may include an avalanche photodiode (APD) , a single photon detection avalanche photodiode (SPAD) , a microphone, or another device capable of receiving and detecting the radiation. The receiver may include an array or matrix including one or more of: a photodiode, an avalanche photodiode (APD) , a single photon detection avalanche photodiode (SPAD) , or a microphone.

The aerosol-generating article 320 includes an identification tag or marker having a series of projections 344a to 344d. The projections together form an embossed region on the aerosol-generating article 320. The projections include unique spacings and/or patterns which, together, provide a unique identifier for the aerosol-generating article 320 on a two-dimensional surface portion 322 provided on the outer wall of the aerosol-generating article 320.

In use, the time-of-flight sensor assembly 350 is set to be operable in an illumination mode. The light signal 338 illuminates the proj ections 344a to 344d, providing a series of reflected light signals 340 reflected back to the receiver 332. The reflected light signals 340 are received by the receiver and analysed by the controller 334 to detect the characteristic features of the identification tag. The controller 334 determines the unique identifier of the identification tag using the pattern of the reflected light signals 340. In this way, the controller 334 may modify or adapt the operation of the aerosol-generating device 310 according to the nature of the aerosol-generating article 320. For example, the temperature or the duration of the heater may be adjusted according to the identification tag of the aerosol-generating article.

The aerosol-generating system 300 described with reference to FIG. 3A and FIG. 3B may be adapted or modified to include other features of the time-of-flight sensor assembly as described herein.

Typically, the illumination mode is a secondary mode of operation of the time-of-flight sensor assembly 350. Thus, the aerosol-generating device 310 is configured so that the time-of- flight sensor assembly is also operable in time-of-flight signal measurement mode, in which the time-of-flight sensor assembly is configured to measure a presence detection of the aerosol-generating article 320 within the device cavity 305. In particular, the aerosol-generating device 310 may be configured to verify that the aerosol-generating article 320 is located in a position for use.

In one example time-of-flight signal measurement mode, the aerosol-generating device is adapted to emit a pulsed light signal such as described for the example of FIG. 2A and FIG. 2B.The pulsed light signal may be a narrow beam source, focused to be directed across the device cavity 305 in a direction substantially perpendicular to the central longitudinal axis 324. In this way, the emitter 330 time-of-flight sensor assembly 350 may be configured to be a narrow beam source as well as a wide beam source, depending on the mode of operation.

As an aerosol-generating article 320 is initially received into the device cavity 305, the light signal is reflected from the far surface of the peripheral wall of the device cavity 305. The controller 334 thus measures a first reference distance. When the aerosol-generating article is received sufficiently into the device cavity 305 to be at a position for use, the light signal is reflected from the outer wall of the aerosol-generating article 320. The controller 334 thus measures a second reference distance that is significantly shorter than the first reference distance. The controller 334 determines that the aerosol-generating article 320 is in a position for use when the first reference distance changes to a second reference distance.

Referring now to FIG. 4 there is shown the aerosol-generating system 200 of FIG. 2A and FIG. 2B, in which the time-of-flight sensor assembly 250 is operably used in a further time-of-flight signal measurement mode. The time-of-flight signal measurement mode is particularly used provide an alternative way of measuring a puff when the aerosol-generating article 220 is in the position for use.

In use, the emitter 230 continues to emit a light signal 238 as the heater of the aerosol-generating device is energised by the controller 234. The receiver 232 continues to receive a reflected light signal 240, reflected from the surface portion 222 of the aerosol-generating article 220. After the heater is initially energised, aerosol 260 begins to accumulate in the device cavity 205 due to the heating of the aerosol-forming material of the aerosol-generating article 220. Thus, increasing proportions of the light signal 238 and the reflected light signal 240 are scattered by the aerosol 260. The reflected light signal 240 received by the receiver 232 decreases in intensity as the aerosol-generating article 220 is heated in the aerosol-generating device 210 by the heater.

The controller 234 is configured to monitor the intensity of the reflected light signal 240 during use. As the reflected light signal 240 decreases in intensity, or is at a reduced intensity to an initial intensity, then the controller 234 determines there is an absence of a puff.

When a user applies suction to the mouth end of the aerosol-generating article 220 the residual air within the device cavity 205, including the aerosol 260 accumulated in the device cavity 205, is drawn into the aerosol-generating article 220 and replaced by air without aerosol 260 that is drawn into the device cavity 205. The intensity of the reflected light signal 240 within the device cavity 205 increases significantly and a change is detected by the controller 234. The controller determines a puff has occurred.

Additionally, or in the alternative, the time-of-flight sensor assembly 250 may be configured to determine a statistical variation of a time-of-flight signal to measure the detection of a puff. For example, the statistical variation may be determined using a statistical spread of a response, that is of a second signal, caused by light scattering or by the use of a time-of-flight diffraction measurement principles. In this way, as aerosol 260 accumulates in the device cavity 205 between each puff, then the statistical variation in reflected light signals 240 is changed by the scattering caused by the aerosol. The statistical variation may then be determined by the controller.

The controller may be configured to record details of the statistical variation, or to count the number of puffs generated from an aerosol-generating article 220. Thus, the controller may monitor the puffs, using either an air temperature method or a TOFD method, until a predetermined number have occurred. In this way, the controller may indicate the amount of use of an aerosol-generating article, or may indicate that the aerosol-generating article is approaching a maximum use. The controller may be adapted to activate a suitable display means provided in the aerosol-generating system so as to display the amount of use to the user.

It will be appreciated by persons skilled in the art that the time-of-flight sensor assemblies described with reference to the examples in the figures may be adapted to provide alternative types of signal to light signal, for example an acoustic signal to measure the characteristic feature of the aerosol-generating article.

It will be appreciated that the above detailed examples have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims. Various modifications to the detailed examples described above are possible.

Claims

An aerosol-generating device configured to receive an aerosol-generating article, the aerosol-generating device comprising:

a housing defining a device cavity that is configured to at least partially receive the aerosol-generating article and to operably locate the aerosol-generating article in a position for use within the aerosol-generating device; and

a time-of-flight sensor assembly;

wherein the time-of-flight sensor assembly is configured to measure at least one characteristic feature related to the aerosol-generating article within the device cavity.
The aerosol-generating device according to claim 1, wherein the at least one characteristic feature is one or more of:

a position of the aerosol-generating article within the device cavity;

a detection of a puff generated by aerosolization of an aerosol-forming material of the aerosol-generating article;

a surface characteristic of a surface portion of the aerosol-generating article;

a surface structure provided on the aerosol-generating article;

a presence detection of the aerosol-generating article within the device cavity; or

an identification tag of the aerosol-generating article.
The aerosol-generating device according to claim 1, wherein the time-of-flight sensor assembly comprises an emitter configured to emit a light signal or an acoustic signal towards an aerosol-generating article received into the device cavity.
The aerosol-generating device according to claim 1, wherein the time-of-flight sensor assembly comprises a receiver configured to receive at least one of a reflected acoustic signal or a reflected light signal.
The aerosol-generating device according to claim 2, wherein the time-of-flight sensor assembly is operable in a time-of-flight signal measurement mode to measure either: the position of the aerosol-generating article within the device cavity, or the presence detection of the aerosol-generating article within the device cavity.
The aerosol-generating device according to claim 2, wherein the time-of-flight sensor assembly is operable in an illumination mode to measure either: the surface characteristic of the surface portion of the aerosol-generating article, or the surface structure of the aerosol-generating article.
The aerosol-generating device according to claim 2, wherein the surface characteristic of the surface portion of the aerosol-generating article is at least one of: a reflectance characteristic, an absorbance characteristic, a refractive characteristic, or a diffuse reflection characteristic, or a scatter characteristic.
The aerosol-generating device according to claim 2, wherein the time-of-flight sensor assembly is configured to determine a statistical variation of a time-of-flight signal to measure the detection of a puff.
The aerosol-generating device according to claim 1, wherein the time-of-flight sensor assembly is configured to measure a two-dimensional surface characteristic or a three-dimensional surface characteristic of one or more surface portions of the aerosol-generating article.
The aerosol-generating device according to claim 1, wherein the time-of-flight sensor assembly comprises a temperature sensor, wherein the temperature sensor is configured to measure a temperature to determine an air temperature within the device cavity.
The aerosol-generating device according to claim 10, further comprising a controller, wherein the controller is configured to receive the air temperature from the temperature sensor and to use the air temperature to determine either a presence of a puff or an absence or a puff within the device cavity.
The aerosol-generating device according to claim 1, wherein the housing comprises a recessed chamber adjoining the device cavity.
The aerosol-generating device according to claim 1, wherein the time-of-flight sensor assembly is configured to measure a time interval between an emitted waveform and a reflected waveform.
The aerosol-generating device according to claim 1, wherein the time-of-flight sensor assembly is configured to measure a phase change between an emitted waveform and a reflected waveforms.
The aerosol-generating device according to claim 1, wherein the device cavity is configured to receive a rod-shaped aerosol-generating article, and the device cavity has a central longitudinal axis such that, in the position for use, the aerosol-generating article is coaxial with the central longitudinal axis.