TW202425825A - Aerosol generating device with heater control - Google Patents

Abstract

An aerosol generating device (1), comprising: a heater (12) configured to heat an aerosol forming substrate so that it can release an aerosol for inhalation; a timer (16) configured to measure a time elapsed from the start of a vaping session; and a processor (20) configured to calculate a temperature profile (105) that varies continuously as a function of time, using a temperature profile function, wherein the processor (20) is configured to send the calculated temperature profile (105) to the heater (12) in a control signal.

Description

Aerosol generating device with heater control

The present invention relates to an aerosol generating device, and more particularly to the control of a heater in the aerosol generating device.

The popularity and use of aerosol-generating devices and systems (also known as vaporizers) has grown rapidly over the past few years as an alternative to traditional tobacco products (such as cigarettes, cigars, cigarillos and roll-ups). Rather than burning the tobacco in traditional tobacco products, a variety of devices and systems can be used to heat or warm an aerosolizable substance, which may or may not contain nicotine or other active substances.

The type of aerosol generation system commonly used is the heated matrix aerosol generation type or the heat-not-burn type. This type of system generates an aerosol or vapor by heating a consumable product (i.e., a "heat-not-burn stick") containing an aerosol matrix (such as reconstituted tobacco) to a temperature typically in the range of 150°C to 350°C. The aerosol matrix is heated but not burned or ignited, releasing an aerosol containing the components desired by the user but not containing undesirable combustion byproducts. In addition, aerosols generated by heating tobacco or other aerosolizable materials generally do not contain burnt or bitter tastes that may be produced by combustion and are unpleasant to the user.

Typically, a heat-not-burn consumable product, such as a stick, is inserted into the cavity of the heat-not-burn device, with one end of the stick protruding from the device and forming an inhalation nozzle. The heat-not-burn device then provides heat to the stick to aerosolize the aerosolizable material contained in the aerosol matrix in the stick, and the resulting aerosol is provided to the user from the protruding end of the stick.

The amount of heat supplied to the rod by the heater can be varied using a control signal that varies the power supplied to the heater. Typically, the control signal used to control a heater in an aerosol generating device is defined by a set of discrete temperature values at a particular time, thereby defining a discrete temperature profile. For example, the discrete temperature profile may include a list having a series of discrete temperature values, each having a corresponding duration.

Using discrete temperature profiles can cause problems. First, sudden changes in the heater can cause thermal shock due to repeated switching on and off of power. Second, sudden changes in heater control can cause uneven heating of the aerosol-generating matrix by the heater. Third, discontinuities in the temperature profile can cause unexpected and undesirable control signals, which can result in heater damage, undesirable combustion byproducts, and danger to the user. Fourth, discrete temperature profiles are not easily customized and optimized for specific types of devices or consumable products.

Therefore, the object of the present invention is to solve the problems discussed above.

According to a first aspect of the present invention, an aerosol generating device is provided, comprising: a heater configured to heat an aerosol-forming matrix so that the heated aerosol-forming matrix can release an aerosol for inhalation; a timer configured to measure the time elapsed from the start of an inhalation process; and a processor configured to use a temperature distribution line function to calculate a temperature distribution line that continuously changes according to time, wherein the processor is configured to send the calculated temperature distribution line to the heater in the form of a control signal.

The calculated temperature profile can define a set point temperature for the heater, wherein the control signal sent to the heater is based on the set point temperature. For example, the control signal can be provided via a PID controller or a relay controller. Thus, the set point temperature profile varies continuously over time (before being converted into a control signal to be sent to the heater). Advantageously, the aerosol generating device can enable the heater to use a smooth heating profile that varies continuously over time based on a temperature profile function such as a Fourier series or a polynomial function. The ideal heating profile for the aerosol generating device can depend on the aerosol forming substrate and/or the heater used.

As used herein, the term "based on time" preferably means that the temperature profile function uses time as an input to provide the temperature profile, but it should be understood that the temperature profile function can use other inputs as well as time. Therefore, the temperature profile is preferably a function that depends on time. Preferably, the time that is the input to the temperature profile function is the time that has passed since the start of the inhalation process. As used herein, the term "continuously variable" or "continuously variable" preferably means that the temperature profile does not contain any discrete (or transient) changes or discontinuities. Preferably, the first-order derivative of the temperature profile does not contain any discontinuities and can itself be continuous or smoothly varying.

The processor may be configured to modify one or more parameters of the temperature profile function based on user input. For example, the location and/or number of temperature rises and falls may be provided by user input. Advantageously, this enables the heater temperature to be precisely defined by the user.

The processor may be configured to verify that the user input satisfies one or more predetermined conditions. Advantageously, the one or more predetermined conditions may reduce the risk of damage to the aerosol generating device and/or may reduce the risk of danger to the user. For example, the one or more predetermined conditions may prevent the temperature profile from appearing: a defined temperature is above a maximum value, a temperature is maintained above a threshold for a duration exceeding a predetermined time, and/or changes faster than a maximum rate.

The aerosol generating device may further include a temperature sensor for measuring ambient temperature, wherein the processor is configured to modify one or more parameters of the temperature profile function based on the measured ambient temperature. Alternatively, the ambient temperature may be provided as a user input (e.g., from a separate device).

The processor may be configured to cause the temperature profile to drop during periods of time when the user is not taking a puff. Advantageously, during these periods of time, the power consumption of the device may be reduced, thereby improving battery performance. Additionally, vapor generation may be reduced, thereby minimizing vapor leakage and increasing the life of the aerosol generating substrate.

The aerosol generating device may further include a puff detector, wherein the processor is configured to cause the temperature profile to drop for a heat reduction time period after the puff detector detects a puff. The heat reduction time period may begin after a first time period from detection to the puff and end after a second time period from detection to the puff. In other words, the temperature profile drops after the first time period and returns to a normal temperature profile (i.e., with the temperature reduction removed) after the second time from detection to the puff. By dropping the temperature profile after the first time period (rather than immediately when the puff is detected), the initial puff is not affected by the dropping temperature profile. By restoring the temperature profile after the second time period, subsequent puffs are not affected by the decrease in temperature. The second time period may be less than the time a user typically takes between puffs. Since it is unlikely that a user takes two puffs in quick succession, the temperature profile only decreases during the time window (i.e., the heat reduction time period) when the user is unlikely to take a puff. Thus, after a puff is detected, the temperature profile may decrease and then increase. The decrease in temperature may result in a local minimum (or decrease) in the temperature profile.

The aerosol generating device may further include a position sensor, wherein the processor is configured to cause the temperature profile to drop for a heat reduction time period when the position sensor detects a predetermined position of the device and/or a change in the predetermined position of the device. The heat reduction time period may start after a first time period from the position detection and end after a second time period from the position detection. In other words, the temperature profile drops after the first time period and returns to a normal temperature profile (i.e., with the temperature reduction removed) after the second time from the position detection. For example, the temperature profile may drop in response to a user lowering the device and/or putting the device down (e.g., on a table). Since the user is less likely to puff in these positions, the temperature profile line can be allowed to drop without affecting the user experience. By allowing the temperature profile line to return to its normal value after a second time period from the change in orientation, the temperature profile line can drop and then grow again during the time period when the user is less likely to inhale; this can save power.

The heat reduction time period may be predetermined or may have a dynamically adjusted value. The heat reduction time period may be based on data collected by the processor about the user's use of the device. For example, where the temperature profile is caused to drop for a heat reduction time period after a puff is detected, the length of the heat reduction time period may be less than the shortest time a user typically takes between puffs. In a similar manner, where the temperature profile is caused to drop for a heat reduction time period after an orientation detection, the length of the heat reduction time period may be less than the shortest time a user typically takes from such an orientation detection to a subsequent puff. In this way, the device can optimize the battery usage of the device for each user, even though different users may puff at different frequencies or at different times after lowering or putting the device down. The heat reduction period can be updated based on other data collected by the processor during the user's continued use of the device, thereby taking into account changes in the habits of a particular user and/or changes in behavior during a puff. Accordingly, the device can provide dynamic adjustment to the length of the descending portion of the temperature profile.

The temperature profile function may be a Fourier series. Advantageously, the Fourier series utilizes trigonometric functions and mathematical operations that can be performed quickly by a processor. Furthermore, simply by changing the number of terms in the Fourier series, the Fourier series can approximate more complex functions with variable levels of accuracy, thereby allowing the aerosol generation device to adapt to the amount of processing power required by the processor.

The timer can be configured to measure the time elapsed from the start of the inhalation process until the maximum process duration. For example, the maximum process duration can be about 300 seconds, such as about 280 seconds. The maximum process duration can be determined by user input.

The processor may be configured to receive user input from a separate device. Advantageously, the separate device may enable precise control of the heater temperature without requiring a complex user interface to be provided on the aerosol generating device. For example, a user may input instructions into a device such as a mobile phone, for example, via an application having a graphical user interface. The aerosol generating device may include a communication unit connected to the processor. The communication unit may receive user input from the separate device via Wi-Fi, Bluetooth, and/or any other suitable wireless communication protocol. Alternatively, the processor may be configured to receive user input from a user interface of the aerosol generating device.

According to another aspect of the present invention, there is provided a method for controlling a heater in an aerosol generating device, the method comprising the steps of: measuring the time elapsed from the start of a puffing process; and controlling the heater based on a calculated temperature profile that continuously changes with respect to time.

The present invention also describes an aerosol generating device, which includes: a heater configured to heat an aerosol-forming matrix so that the heated aerosol-forming matrix can release an aerosol for inhalation; a timer configured to measure the time elapsed from the start of the inhalation process; and a processor configured to use a temperature profile function to calculate a temperature profile that continuously changes with respect to time, wherein the processor is configured to send the calculated temperature profile to the heater in the form of a control signal. The preferred features of this aerosol generating device correspond to the features described above with respect to the first aspect.

Those skilled in the art will appreciate that any device or apparatus feature described herein may be provided as a method feature, and vice versa. It should be understood that specific combinations of various features described and defined in any aspect described herein may be independently implemented and/or provided and/or used. Furthermore, it should be understood that the present invention is described herein by way of example only, and that modifications of detail may be made within the scope of the present invention.

FIG. 1 depicts a schematic cross-section of an aerosol generating device 1 showing various internal components. It should be understood that the positions of the components in the device are schematic only and should not be considered as limiting the present invention. It should also be understood that multiple examples of components of the device 1 may be provided. In addition, the device 1 may include multiple additional components that are not relevant to understanding the present invention and therefore will not be depicted or described in detail herein.

As shown in Figure 1, the device 1 has a housing 10 with a cavity 11, which is configured to receive an aerosol-generating consumable product 5. The device 1 also includes a heater 12, which is configured to provide heat to the consumable product 5 when the aerosol-generating consumable product 5 is located in the cavity 11. The aerosol-generating consumable product 5 contains an aerosol-forming substrate (not shown) that generates an inhalable aerosol when heated.

As used herein, vapor is generally understood to refer to a substance that is in the gas phase at a temperature below its critical temperature, which means that the vapor can condense into a liquid by increasing its pressure without lowering the temperature, while an aerosol is a suspension of fine solid particles or droplets in the air or another gas. However, it should be noted that the terms "aerosol" and "vapor" may be used interchangeably in this specification, especially with respect to the form of the inhalable medium produced for inhalation by a user. Thus, the term "inhalation" or "inhalation process" may refer to any use of the aerosol generating device 1 that produces an aerosol and/or vapor that is provided to a user.

In this example, the aerosol generating device 1 is a heat-not-burn burner device 1, and the aerosol generating consumable product 5 is a heat-not-burn burner stick 5, but it should be understood that the present invention is applicable to any form of aerosol generating device 1 that uses a heater to generate an aerosol from an aerosol-forming substrate. For example, the aerosol generating device 1 can be a vaporizer that can provide heat to a fluid aerosol-forming substrate.

The device 1 also includes a power source (such as a battery 14) for supplying power to the heater 12 and other components of the device 1.

The device 1 also includes a timer 16. The timer 16 is configured to measure the time ( t ) elapsed from the start of the inhalation process. For example, the timer 16 may start counting when the user starts or starts the inhalation process (i.e., starting from t =0), and will continue to monitor the elapsed time until the process ends. The start of the inhalation process may be manually triggered by the user, such as manually triggered via a user interface or a button (not shown). The start of the inhalation process may also be detected by starting an inhalation measured by an air flow sensor. The end of the inhalation process may be when the user manually stops the inhalation process or stops inhalation. The end of the inhalation process may also occur when a predetermined maximum process duration is reached. The duration may be approximately 300 seconds, such as 280 seconds.

The device 1 also includes a processor 20 for controlling the operation of the device 1. As will be described in more detail later, the processor 20 is used to control the temperature of the heater 12. More specifically, the processor 20 is configured to calculate a time-dependent temperature profile. Such a temperature profile may be referred to as a "set point temperature profile," which may represent a target or desired temperature profile of the heater 12 relative to time. The processor 20 may include a control unit that generates a control signal to be provided to the heater 12, wherein the control signal is based on the temperature profile. For example, the control unit may include a PID controller, a relay controller, or any other suitable type of controller. The control signal may change the power provided to the heater 12 by the power supply 14. Although the control unit is described herein as being part of the processor 20, it should be understood that a separate control unit may be provided anywhere in the device 1, and the processor 20 and the control unit may each perform processing and/or control operations.

One or more temperature sensors 31, 32 may be provided in the aerosol generating device 1 to provide data to the processor 20. For example, the first temperature sensor 31 may be configured to measure the temperature of the cavity and/or the heater 12. The first temperature sensor 31 (i.e., "heater temperature sensor 31") may directly measure the temperature of the cavity 11 and/or the heater 12, or the temperature may be calculated in another way (e.g., by monitoring the resistance of the heater 12). The first temperature sensor 31 may provide a feedback signal that the control unit uses to change the control signal to the heater 12. For example, the control unit may compare the measured temperature with a set point temperature profile and adjust the control signal based on the difference between them. The second temperature sensor 32 (i.e., "ambient temperature sensor 32") can be configured to measure the ambient temperature around the device 1, and the processor 20 can also use the ambient temperature in a manner that will be described in detail later. As described later with respect to Figures 4A and 4B, the device 1 may also include a puff detector (not shown) and/or an orientation sensor 22.

Temperature control in a typical aerosol generating device will now be described in conjunction with FIG. 2 . Typically, a typical set point temperature profile is discrete, where a set of discrete values is provided for temperature and time, such as in the form of an array. In the example shown in FIG. 2 , two example set point temperature profiles for use with a single heater are shown. The solid line indicates the set point temperature profile 101a in the first example, while the dashed line indicates the set point temperature profile 101b of the second example. As described above, the set point temperature profiles 101 may be provided to a control unit that generates a control signal. Since the set point temperature profile 101 in Fig. 2 is discrete, the profile 101 changes temporarily, resulting in the profile 101 being discontinuous at certain times (e.g., at 50 seconds, 100 seconds, and 150 seconds). Thus, the set point temperature profile 101 may not be clearly defined at the moment of change.

Data that may be used to represent the set point temperature profile 101 of Figure 2 is shown in Table 1. As shown in Table 1, a typical set point temperature profile 101 requires only a few parameters to control the temperature of the heater, thereby reducing the amount of storage space and the amount of processing power required. Example 1 Example 2 time temperature time temperature 0 230 0 230 15 270 50 100 100 170 150 280 180 230 210 230 280 230 280 230 [Table 1]

The use of conventional set point temperature profiles 101 (such as the set point temperature profiles in Examples 1 and 2) may cause a number of problems. First, they only define discrete temperatures that are maintained for a predetermined time; as a result, the profile is discontinuous, resulting in sudden changes in the temperature required by the heater. This may result in thermal shocks in the heater and/or components connected to the heater, which may shorten the service life of the aerosol generating device. Sudden changes may also result in uneven heating of the aerosol forming matrix in the device. In addition, sudden changes in the set point temperature profile 101 may be difficult to handle by the control unit; for example, in a PID controller, transient or sudden changes in the set point may produce overshoots in the control signal, which may damage the device or the aerosol forming matrix. In particular, this may result in spikes in the power provided by the battery 14, which may damage electrical components in the device. Furthermore, this may result in temperature peaks in the heater 12 which may be dangerous to the user, and/or may result in the generation of unwanted aerosol species by the aerosol-forming substrate. Adjusting or modifying the control unit to mitigate this problem may increase the computational burden required of the control unit. Furthermore, the discontinuous set point temperature profile 101 is inflexible and difficult to customize or optimize for a particular type of aerosol generating device or aerosol generating consumable product.

FIG3 depicts an exemplary set point temperature profile 105 according to the present invention. The set point temperature profile 105 shown in FIG3 can be calculated using the following equation or function: Wherein t is the time which has elapsed since the start of the inhalation process (measured, for example, by the timer 16), and the parameters a to m and T _o take the values shown in Table 2. Parameters value Parameters value a 25 i 1.12 b 80 j 4910 c 9.1 k 3.4 d 1 l 0.8 f 8.2 m 1.6 g 10 _To 200 h 0.7 [Table 2]

It should be understood that equation (1) (or may be referred to as function) and the corresponding parameters above are exemplary only, and other equations may be used within the scope of the present invention. More generally, the set point temperature profile 105 may be given by a function such as an equation of the following form: Where t is the time elapsed from the start of the smoking process, and where other parameters ( a , b , c , ...) can be functions of other parameters and/or functions of time. Alternatively, these parameters can be called coefficients.

In contrast to the example shown in FIG. 2 , the set point temperature profile 105 is continuous. As used herein, the term “continuous” preferably refers to a line that is smooth and does not include any transient changes or discontinuities. The first-order derivative of the temperature profile may also not include any discontinuities and may itself be continuous or smoothly varying. For each time value, the set point temperature may be uniquely defined and may be calculated for any moment in the inhalation process by using a function. More specifically, the set point temperature profile function may be used to calculate the set point temperature at any moment in the inhalation process without the need to approximate or interpolate using other time or temperature values. In this way, the set point temperature profile 105 may be considered to have arbitrarily high resolution. This is achieved even though the temperature profile function itself can be defined using only a few parameters.

In this way, the device 1 can provide a precise set point temperature profile 105 defined by only a few parameters. Advantageously, the set point temperature profile 105 does not define any discontinuous or sudden temperature jumps; instead, the set point temperature profile 105 can be gradually warmed. This reduces the risk of thermal shock, damage due to thermal cycling stresses and/or uneven heating of the aerosol forming matrix. Furthermore, the continuous set point temperature profile 105 is easier to handle by the control unit, thereby reducing the risk of overshoots that could damage the heater or other electronics in the device.

Furthermore, having a continuous profile can allow the set point temperature profile 105 to be more customizable for certain types of devices 1 or sticks 5. For example, it may be beneficial to vary the temperature of the heater 12 throughout a puff to facilitate a more continuous delivery of aerosol to the user; more specifically, a gradual increase in heater temperature can provide a constant delivery of aerosol even when the aerosol-forming substrate is depleted.

The set point temperature profile 105 may include trigonometric functions, including sums, products, and/or moduli of such trigonometric functions in any suitable combination. In this manner, the set point temperature profile 105 may be calculated using only simple arithmetic functions and well-defined functions, thereby allowing calculations to be performed in only a few milliseconds on current microcontrollers without significant lag. It should be understood that the number of parameters required to define the continuous set point temperature profile 105 may be much less than the number of parameters required in an array containing discrete values of temperature and time. Therefore, the continuous set point temperature profile 105 may be more data efficient and less computationally intensive than existing control methods.

In one embodiment, the set point temperature profile 105 may be defined using a Fourier series, where the period of the Fourier series is given by the maximum process duration (e.g., 280 seconds). When the process ends, the heater 12 may be switched off and the timer 16 may be reset to t = 0. Advantageously, the Fourier series uses only well-defined trigonometric functions and simple mathematical operations that can be quickly performed by the processor 20. Furthermore, the Fourier series may be used to approximate any suitable optimal function of the heater temperature, with the accuracy of the approximation being easily modified by changing the number of terms in the Fourier series. A large number of terms may increase the complexity of the set point temperature profile 105. Thus, the set point temperature profile 105 may be adapted to best utilize the processing power available in the device 1.

Optionally, the set point temperature profile 105 may also have a continuous first order derivative. In this configuration, the set point temperature profile 105 may be referred to as a set point temperature curve. Advantageously, having a continuous first order derivative may avoid any discontinuities when using certain types of control units (such as a PID controller) to control the heater 12, thereby further reducing the risk of temperature spikes or other undesirable behavior. In some embodiments, even the second order derivative may be continuous.

Any parameter in the set point temperature profile 105 can be a user-controlled and/or environmentally controlled variable. Specifically, the processor 20 can be configured to modify one or more of the parameters of the set point temperature profile 105 based on user input. For example, the location and/or number of temperature increases and decreases can be provided with high accuracy by user input. Alternatively or additionally, the user can specify a maximum process duration, such as the user wants to smoke for 1 minute instead of 4 minutes; in the example of equation (1) above, this can be achieved by changing the parameter d . It should be understood that the user can adjust any other parameter that defines the set point temperature profile 105.

The processor 20 may be configured to verify whether the user input satisfies one or more predetermined conditions. If the user input satisfies the one or more predetermined conditions, the processor 20 may update the set point temperature profile 105 based on the user input. However, if the user input does not satisfy the one or more predetermined conditions, the set point temperature profile 105 is not updated and an error indication may be provided to the user. The one or more predetermined conditions may prevent the temperature profile 105 from occurring if: the temperature reached is above a maximum value, the temperature is maintained above a threshold for a duration exceeding a predetermined time, and/or changes faster than a maximum rate. In this way, one or more predetermined conditions can reduce the risk of overheating of the heater, thereby reducing the risk of damage to the aerosol generating device 1 and/or reducing the risk of danger to the user. One or more predetermined conditions can be hard-coded limits to limit the modification of the temperature profile 105 to dangerous configurations.

The user input may be provided to the processor 20 via a user interface (not shown) of the device 1. Alternatively or additionally, the processor 20 may be configured to receive the user input from a separate device. The separate device may be a mobile phone that may run an application that may have a graphical user interface. Using the graphical user interface, a user may create their own inhalation profile or modify an existing profile and then send them to the device 1. The separate device may communicate with the processor 20 via the communication unit 18 in the aerosol generating device 1. The communication unit 18 may receive the user input from the separate device via Wi-Fi, Bluetooth and/or any other suitable wireless communication protocol.

The processor 20 can be configured to modify one or more parameters of the temperature distribution line function based on the ambient temperature around the device 1. More specifically, the measurements made by the second temperature sensor 32 can be used to modify one or more parameters of the temperature distribution line function. For example, the ambient temperature can provide a temperature offset to the temperature distribution line function. In equation (1), the parameter T _o can define the temperature offset based on the ambient temperature. Optionally, in addition to the data from the second temperature sensor 32, the user can also provide user input to change the temperature offset.

Advantageously, by taking the ambient temperature into account, external conditions can be compensated. For example, in a cold environment (such as when outdoors in the winter), the set point temperature profile line 105 can be raised to provide more optimal heating of the aerosol generating substrate. Subsequently, if the user moves indoors (such as into an office), the set point temperature profile line 105 can be lowered again.

4A and 4B depict additional exemplary set point temperature profiles 110a, 110b according to the present invention. Set point temperature profile 110a corresponds closely to the set point temperature profile shown in FIG. 3 and may be referred to as a "normal" profile. Set point temperature profile 110b includes at least one temperature reduction portion 111 and may therefore be referred to as a "falling temperature" profile. Although only a single temperature reduction portion 111 is shown in FIG. 4B , it should be understood that more than one temperature reduction portion 111 may be present.

The set point temperature profiles 110a, 110b shown in FIGS. 4A and 4B may be calculated using the following equation or function: Wherein t is the time which has elapsed since the start of the inhalation process (e.g. measured by the timer 16), and the parameters a to w take the values shown in Table 3. Parameters value Parameters value a 25 l 0.8 b 80 m 1.6 c 9.2 n 2.92 d 1.06 o 2.1 f 8.2 p 0 or 1 g 10 q 20,000 h 0.7 u 1.7 i 0.85 v 3.38 j 4910 w 0.32 k 3.4 _To 200 [table 3]

Parameter p acts as a Boolean function. When it is 0, the distribution line is normal (as shown in FIG. 4A ), and when it is 1, the decreasing temperature distribution line is effective (as shown in FIG. 4B ). Alternatively, parameter p can be a continuous parameter that can be changed to any value between 0 and 1. Processor 20 can change the value of parameter p to switch between the normal distribution line 110 a and the decreasing temperature distribution line 110 b.

The processor 20 may be configured to cause the temperature profile to drop during periods when the user is not taking a puff. In other words, the processor 20 may adjust one or more parameters of the temperature profile function so that the temperature drop portion 111 occurs when the user is not taking a puff. In this way, the puff is not affected by the temperature drop portion 111 and the user experience is not affected. Advantageously, by causing the temperature profile to drop, the power consumption of the device 1 is reduced, thereby improving the performance of the battery 12. In addition, vapor generation may be reduced, thereby minimizing vapor leakage and increasing the life of the aerosol generating substrate.

For example, the aerosol generating device 1 may include a puff detector (not shown), and the processor 20 may be configured to cause the temperature profile to drop for a heat reduction time period after the puff detector detects a puff. After the puff is detected, the heat reduction time period may begin after a first time period from detection to the puff, and end after a second time period from detection to the puff. In other words, the temperature profile drops after the first time period, and returns to a normal temperature profile (i.e., with the temperature drop removed) after the second time period from detection to the puff.

More specifically, as shown in FIG4B , a puff may be detected at time t _0. The temperature reduction portion 111 may begin to decrease the temperature profile at time t ₁ , and may increase the temperature profile at time t ₂ to return it to its normal level. It should be understood that the specific values and positions shown in FIG4B are merely exemplary and are not necessarily drawn to scale.

The first time period is given by Δt ₁ = t ₁ − t _0. The first time period may have a predetermined value so that the temperature reduction portion 111 does not affect the initial puff occurring at time t _0. The value of the first time period may be personalized and adjusted according to the user. For example, the first time period may be about 2 seconds.

The second time period is given by Δt ₂ = t ₂ - t _0. The second time period may have a predetermined value so that the temperature reduction portion 111 does not affect the user's subsequent puffs. Preferably, the duration of the second time period is selected based on the minimum time period between successive puffs. The value of the second time period may be personalized and adjusted according to the user. In this way, the user is less likely to take subsequent puffs during the descending temperature profile, so that the user experience is not affected.

Thus, the temperature profile 110b decreases only during the heat reduction time period given by Δt _r = t ₂ - t _1. The time periods Δt ₁ , Δt ₂ , Δt _r may be selected by varying one or more parameters of the temperature profile function 110b. For example, in equation (3), the timing of the temperature reduction portion 111 depends on the parameter w , and the length of the temperature reduction portion 111 depends on the parameter q . Additional temperature reduction portions 111 may be provided for each puff taken by the user.

The puff detector may be provided by a temperature sensor which may be attached to a wall of the chamber 11, such as the inner or outer bottom surface. The temperature sensor 31 may be used for this purpose, or a separate temperature sensor may be used. The temperature sensor detects the rapid drop in temperature caused by the user puffing. Alternatively or additionally, a pressure sensor may detect the reduction in pressure caused by the user puffing or a reduction in pressure within the chamber 11. Other puff detectors may be used, such as a flow sensor.

The heat reduction time period can be predetermined or can have a dynamically changing value. The heat reduction time period can be based on data collected by the processor 20 about the user's use of the device 1. In other words, the heat reduction time period can be personalized. More specifically, the length of the heat reduction time period can be less than the minimum time that the user usually takes between puffs. This minimum time can be determined by the device for each user, because different users may puff at different frequencies from each other. In this way, the device 1 can optimize battery use and reduce unwanted vapor leakage in a way customized for each user. The heat reduction time period can be updated based on other data collected by the processor 20 during the user's continued use of the device 1, thereby taking into account changes in the habits of a particular user. Furthermore, if the processor 20 determines that the user puffs at a different frequency at the start of a process than at the end, the heat reduction period can be adjusted accordingly, thereby maximizing the efficiency of the device 1 without compromising the user experience. Accordingly, the device 1 can provide dynamic adjustment of the length of the descending portion of the temperature profile.

Alternatively or additionally, the temperature reduction portion 111 may be configured to occur in response to the device 1 being in a predetermined position and/or in response to a change in a predetermined position. In order to detect such position information, the device 1 may include an orientation sensor 22 that is capable of detecting the position (i.e., orientation) of the device 1 and/or a change in the position (i.e., movement) of the device 1. For example, the orientation sensor 22 may include a gyroscope and/or an accelerometer. For example, the temperature reduction portion 111 may be configured to occur when the user lowers the device 1 or puts the device 1 down (e.g., on a table). Since the user is less likely to inhale when the device 1 is lowered or moved to a particular position, the power supplied to the heater 12 may be reduced without affecting the user experience. More specifically, after the position detection at time _t0 , the temperature reducing portion 111 may start to reduce the temperature distribution line at time _t1 , and may increase the temperature distribution line at time _t2 in a manner similar to the above description to return it to its normal level. Accordingly, the processor 20 is configured to reduce the temperature distribution line within the heat reduction time period ( _Δr = _t2 - _t1 ) when the position sensor 22 detects the predetermined position of the device 1 and/or the predetermined position change of the device 1.

In a manner similar to the above description, the heat reduction time period can be predetermined or can have a dynamically changing value. The heat reduction time period can be based on data collected by the processor 20 about the user's use of the device 1. In other words, the heat reduction time period can be personalized. More specifically, the length of the heat reduction time period can be less than the minimum time period that a user usually detects from this orientation to a subsequent puff. This minimum time can be determined by the device for each user, because different users can perform subsequent puffs faster after changing the orientation of the device 1 or putting the device 1 down. In this way, the device 1 can optimize battery use and reduce unwanted vapor leakage in a manner customized for each user. The heat reduction time period can be updated based on other data collected by the processor 20 during the user's continued use of the device 1, thereby taking into account changes in the habits of a particular user. Accordingly, the device 1 can provide dynamic adjustment of the length of the descending portion of the temperature distribution line.

The amount of temperature reduction can be varied by modifying parameters n , o and/or v . A greater reduction can further reduce power consumption and vapor leakage, but can increase the time it takes for the temperature to return to its normal level before a subsequent puff.

Although the above is directed to exemplary embodiments of the present invention, it should be understood that the present invention is described herein by way of example only and that modifications of detail may be made within the scope of the present invention. In addition, those skilled in the art will understand that the present invention may not be limited to the embodiments disclosed herein, or to any details shown in the accompanying drawings that are not described in detail herein or defined in the scope of the application.

In addition, other and further embodiments of the present invention will be apparent to those skilled in the art from consideration of the specification and may be designed without departing from the basic scope of the present invention as determined by the appended claims.

1: Aerosol generating device 10: Housing 101, 101a, 101b, 105, 110a, 110b: Set point temperature distribution line 111: Temperature reduction portion 11: Cavity 12: Heater 14: Battery 16: Timer 20: Processor 22: Position sensor 31: First temperature sensor 32: Second temperature sensor 5: Aerosol generating consumables

One or more embodiments will now be described by way of example only with reference to the accompanying drawings, in which: [FIG. 1] shows a schematic cross-section of an embodiment of an aerosol generating device; [FIG. 2] shows a set point temperature profile that may be used for a typical aerosol generating device; [FIG. 3] shows an embodiment of a set point temperature profile that is continuous; and [FIG. 4A] shows an embodiment of a set point temperature profile that is continuous, and FIG. 4B shows the set point temperature profile of FIG. 4A including a temperature reduction portion.

105: Set point temperature distribution line

Claims (13)

An aerosol generating device comprises: a heater configured to heat an aerosol-forming matrix so that the heated aerosol-forming matrix can release an aerosol for inhalation; a timer configured to measure the time elapsed from the start of the inhalation process; and a processor configured to calculate a temperature distribution line that continuously changes according to time using a temperature distribution line function, wherein the processor is configured to send the calculated temperature distribution line to the heater in the form of a control signal. An aerosol generating device as described in claim 1, wherein the processor is configured to modify one or more parameters of the temperature distribution line function based on user input. An aerosol generating device as described in claim 2, wherein the processor is configured to verify whether the user input satisfies one or more predetermined conditions. An aerosol generating device as described in any preceding claim, further comprising a temperature sensor for measuring ambient temperature, wherein the processor is configured to modify one or more parameters of the temperature distribution line function based on the measured ambient temperature. An aerosol generating device as claimed in any preceding claim, wherein the processor is configured to cause the temperature profile to decrease during a period of time when the user is not taking a puff. The aerosol generating device as described in claim 5 further includes a puff detector, wherein the processor is configured to cause the temperature distribution line to drop for a heat reduction period after the puff detector detects the puff. The aerosol generating device as described in claim 5 or 6 further includes a position sensor, wherein the processor is configured to cause the temperature distribution line to drop for a continuous heat reduction period when the position sensor detects a predetermined position of the device and/or a change in the predetermined position of the device. An aerosol generating device as described in claim 6 or 7, wherein the heat reduction time period is determined based on data collected by the processor regarding the user's use of the device. An aerosol generating device as claimed in any of the preceding claims, wherein the temperature profile function is a Fourier series. An aerosol generating device as claimed in any of the preceding claims, wherein the timer is configured to measure the time elapsed from the start of the puffing process until the maximum process duration. An aerosol generating device as described in any of the preceding claims, wherein the first-order time derivative of the temperature profile is continuous with respect to time. An aerosol generating device as described in claim 2, wherein the processor is configured to receive the user input from a separate device. A method for controlling a heater in an aerosol generating device, the method comprising the steps of: measuring the time elapsed from the start of a puffing process; and controlling the heater based on a calculated temperature distribution line that changes continuously over time.