Aerosol generating device, method and control circuit system thereof

Abstract

A method for controlling an aerosol-generating device is disclosed, the method comprising: receiving an indication to start an aerosol generation session via a user input element; receiving a temperature of a heater measured by a temperature sensor; retrieving a session counter value from a memory; controlling the heater to perform an aerosol generation session based on the heater temperature and the session counter value; and resetting the session counter value when the heater temperature falls below a first predetermined temperature. A control circuit system configured to perform the method is disclosed. An aerosol-generating device including the control circuit system is disclosed.

Description

Technical Field

[0001] The present disclosure relates to an aerosol-generating device in which an aerosol-generating substrate is heated to form an aerosol. The present disclosure is particularly applicable to portable aerosol-generating devices that can be self-contained and cryogenic. Such devices can heat tobacco or other suitable aerosol substrate materials by conduction, convection, and / or radiation, rather than by combustion, to generate an aerosol for inhalation. Background Art

[0002] Over the past few years, there has been a rapid increase in the popularity and use of reduced-risk or modified-risk devices (also known as vaporizers) to help habitual smokers who want to quit traditional tobacco products such as cigarettes, cigars, cigarillos, and cigarettes. Various devices and systems are available that heat or warm an aerosolizable substance, as opposed to burning tobacco in traditional tobacco products.

[0003] A commonly used device with reduced or modified risk is a heated substrate aerosol-generating device, or heat-not-burn device. This type of device generates an aerosol or vapor by heating an aerosol substrate, typically comprising moist tobacco leaves or other suitable aerosolizable material, to a temperature typically in the range of 150°C to 350°C. Heating, but not burning, or burning, the aerosol substrate releases an aerosol that includes the components sought by the user but without the toxic, carcinogenic byproducts of combustion and burning. Furthermore, the aerosol generated by heating tobacco or other aerosolizable material typically does not include the burnt or bitter taste that combustion and burning can produce, which may be unpleasant to the user. Thus, the substrate does not require sugars and other additives that are often added to such materials to make the smoke and / or vapor more palatable to the user.

[0004] Aerosol-generating devices are typically handheld. However, the operating temperatures of the aerosol generator are too high to allow direct contact with the user of the device. Therefore, it is desirable to provide a safe device that does not reach temperatures that would affect the comfort or safety of the user. Summary of the Invention

[0005] According to a first aspect, the present disclosure provides a method for controlling an aerosol generating device, the method comprising: receiving an indication to start an aerosol generating session via a user input element; receiving a temperature of a heater measured by a temperature sensor; retrieving a session counter value from a memory; controlling the heater to perform an aerosol generating session based on the temperature of the heater and the session counter value; and, when the temperature of the heater becomes lower than a first predetermined temperature, resetting the session counter value.

[0006] The session counter value is a counter indicating the number of aerosol generation sessions that have been performed while the device was kept in a relatively hot state (ie without the device reaching a thermal equilibrium state after a session).

[0007] Some heat will inevitably leak from the heater to the rest of the aerosol-generating device. By controlling the heater in dependence on the temperature of the heater and the session counter, the heat buildup in, and hence the temperature of, the rest of the aerosol-generating device can be estimated.

[0008] By setting a session limit, the temperature of the rest of the aerosol-generating device is also limited.The session limit may be set, for example, by experimentally determining how many consecutive sessions can be performed.

[0009] Optionally, the session counter value is incremented when the aerosol generation session begins.

[0010] Incrementing the session counter value at the start of an aerosol generation session improves device safety compared to counting completed aerosol generation sessions. For example, an aerosol generation session might not be completed if a user presses a button to turn off the device or removes a consumable from the device. However, this might occur after an aerosol generation session has delivered a significant amount of heat. By counting the session at the start, the session counter value is biased towards indicating that the temperature in the aerosol generating device is too high, further reducing the likelihood that the aerosol generating device will overheat for the user.

[0011] Resetting the session counter value based on the heater's temperature further increases safety because the rate at which the device cools down will depend on external factors such as ambient temperature, so directly verifying cooling is the most predictable way to ensure continued safety of the device.

[0012] Optionally, the method comprises resetting the session counter value when the temperature of the heater becomes lower than a second predetermined temperature higher than the first predetermined temperature and the session counter value is lower than a first predetermined session limit.

[0013] Providing a first absolute threshold and a second higher conditional temperature threshold to reset the session counter value may compromise safety and user convenience by enabling the user to perform more consecutive aerosol generation sessions if they have a cool down period between sessions.

[0014] Optionally, the aerosol generating session comprises a warm-up phase in which the temperature of the heater is raised to at least a third predetermined temperature, a keep-warm phase in which the temperature of the heater is maintained, and a cool-down phase in which the temperature of the heater is allowed to drop below the third predetermined temperature.

[0015] By maintaining the temperature of the heater during the phase of the aerosol generation session, aerosol can be generated effectively and efficiently.

[0016] Optionally, the method further comprises controlling the heater not to perform an aerosol generating session if the session counter value is not below a second predetermined session limit.

[0017] Disabling the aerosol generating session when the session limit is reached has the effect of reducing the risk of the aerosol generating device reaching excessively high temperatures.

[0018] Optionally, the method further comprises: if the temperature of the heater is greater than a fourth predetermined temperature when the indication to start the aerosol generation session is received, controlling the heater not to perform the aerosol generation session regardless of the session counter value.

[0019] By setting the heater temperature above which an aerosol generating session will not commence, a minimum level of cooling can be enforced between sessions, thereby increasing the number of closely consecutive sessions that can be performed while maintaining the safety and comfort of the user.

[0020] Optionally, if the temperature of the heater is below a fifth predetermined temperature when the indication to start an aerosol generation session is received, the session counter value is not incremented.

[0021] By setting the heater temperature below which sessions are considered discontinuous, the device is prevented from unnecessarily limiting aerosol generating sessions when the device is able to cool sufficiently between sessions.

[0022] Optionally, the method comprises, after receiving an indication to commence an aerosol generation session, controlling the heater not to perform an aerosol generation session, and controlling a user output element to indicate a status, wherein the indication was received but the aerosol generation session was not performed.

[0023] Providing a status indication when an aerosol generating session is inhibited allows the user to understand that the device is functioning properly and ensures that the above-mentioned safety features do not make the device more difficult to use.

[0024] Optionally, the method comprises, after receiving the indication to start the aerosol generation session, controlling the heater not to perform the aerosol generation session, and waiting until the temperature of the heater drops below a sixth predetermined temperature before performing the aerosol generation session.

[0025] By delaying the aerosol generating session until the heater temperature drops, safety and comfort are ensured, while also allowing aerosol generating sessions at a safer increased frequency.

[0026] Optionally, the heater comprises a heating element, and the temperature sensor is arranged to measure the temperature of the heating element.

[0027] Optionally, the heating element comprises a flexible sheet having a resistive track and a temperature sensor mounted thereon.

[0028] Optionally, the heater comprises a heating chamber for receiving the consumable and a heat insulator surrounding the heating chamber, and the temperature sensor is arranged between the heating chamber and the consumable.

[0029] Optionally, the heater comprises a can-shaped heating chamber having an open end for receiving the consumable product and comprising a heating element arranged to supply heat to the heating chamber through a side wall of the heating chamber.

[0030] According to a second aspect, the present disclosure provides control circuitry configured to perform the method as described above.

[0031] Optionally, when the control circuit system is used for an aerosol generating device, it further includes a second temperature sensor for measuring the temperature of the control circuit system, and the method further includes: if the temperature of the control circuit system is greater than a seventh predetermined temperature when an indication to start an aerosol generating session is received, then regardless of the session counter value, controlling the heater not to perform an aerosol generating session.

[0032] By specifically measuring the temperature of the control circuitry before performing an aerosol generation session, and setting a threshold above which the aerosol generation session will not be performed, safety may be improved by reducing the chance of the control circuitry leaving its normal operating temperature range.

[0033] According to a third aspect, the present disclosure provides an aerosol generating device comprising: a control circuit system as described above; a heater for heating an aerosol generating substrate of a consumable to generate an aerosol; a temperature sensor for measuring the temperature of the heater; a user input element for starting an aerosol generating session; and a memory for storing a session counter value. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic representation of an aerosol generating device;

[0035] Figure 2 is a schematic representation of a heater of an aerosol generating device;

[0036] Figure 3 is a flow chart schematically illustrating a method for controlling an aerosol generating device;

[0037] Figure 4is a graph schematically illustrating an aerosol generation session in an aerosol generating device, wherein the temperature of the heater is shown on the y-axis and time is shown on the x-axis;

[0038] Figure 5 is a flow chart schematically illustrating additional details of a method for controlling an aerosol-generating device;

[0039] Figure 6 is a flow chart schematically illustrating additional details of a method for controlling an aerosol-generating device;

[0040] Figure 7 is a graph schematically illustrating consecutive aerosol generation sessions in an aerosol generating device, wherein the temperature of the heater is shown on the y-axis and time is shown on the x-axis;

[0041] Figure 8 is a graph schematically illustrating consecutive aerosol generation sessions in an aerosol generating device, wherein the temperature of the heater is shown on the y-axis and time is shown on the x-axis;

[0042] Figure 9 is a flow chart schematically illustrating additional details of a method for controlling an aerosol-generating device. DETAILED DESCRIPTION

[0043] Figure 1 is a schematic illustration of an aerosol-generating device 1 comprising a heating chamber 11 , a heating element 12 , control circuitry 14 , a power supply 15 , a temperature sensor 13 , a user input element 16 , and a lid 17 .

[0044] In use, an aerosol-generating substrate is received in the heating chamber 11, and the heating element 12 supplies heat to the heating chamber 11 to heat the substrate and generate an aerosol. In addition, a temperature sensor 13 is arranged in or near the heating chamber 11. The heating chamber 11, the heating element 12, and the temperature sensor 13 may be collectively referred to as a heater.

[0045] The heating chamber 11 is a structure having an interior hollow and is suitable for receiving an aerosol-generating substrate. The heating chamber 11 can be formed, for example, from ceramic or metal. For example, the heating chamber 11 can be formed by bending or stamping a metal sheet. In one example, the heating chamber 11 can be a tubular structure comprising a sidewall extending between a first end and a second end. The first end is open or can be opened during use to allow the substrate to be added or removed. The second end can be open to provide an air inlet for air to flow through the consumable. Alternatively, the second end can be closed to reduce heat leakage.

[0046] The heater 12 can be any heater suitable for transferring heat into the heating chamber 11. For example, the heater 12 can be a planar heater attached to a flexible support and wrapped around the side walls of the heating chamber 11. Such a planar heater can be in the form of an electrically driven resistive track, and the support can be one or more plastic or polymer sheets, such as polyimide, a fluoropolymer such as PTFE, or polyetheretherketone (PEEK). Alternatively, other types of heaters can be used in which heat is provided by a chemical reaction such as the combustion of a fuel. Alternatively, the heating element 12 can be located inside the heating chamber 11 or on the surface of the heating chamber 11. The heating element 12 can also be formed integrally with the heating chamber 11.

[0047] The heating element 12 is typically surrounded by insulation so that heat is transferred more efficiently into the heating chamber 11 rather than to the rest of the device 1. However, generally at least some heat will be dissipated to the rest of the aerosol-generating device.

[0048] The heating element 12 and the temperature sensor 13 are operated by a control circuit system 14 that includes logic circuitry 141 (e.g., a general-purpose processor or an ASIC) and a memory 142 that stores at least a session counter value 143. The logic circuitry 141 may be configured to execute a series of instructions stored in the memory 142, for example using a general-purpose processor, and / or may be "hard-coded" with logic for controlling the heating element 12 based on the session counter value 143 and input from the temperature sensor 13.

[0049] Optionally, the control circuit system 14 may include a second temperature sensor 144 for measuring its own temperature.

[0050] Power source 15 may be an electrical power source such as a battery. The power source may be rechargeable, for example via an external power connector on an outer surface of device 1. Control circuitry 14 is configured to control the supply of power from power source 15 to heating element 12. Control circuitry 14 may also be configured to regulate the charging of power source 15.

[0051] Alternatively, the heating element 12 may be powered by a non-electrical power source, such as fuel combusted in the heating element 12. In such an embodiment, the control circuitry 14 may be configured to control the supply of fuel as a means of controlling the supply of power to the heating element 12.

[0052] The control circuit system 14 is further configured to receive input from a user input element 16. The user input element 16 may be any type of input element, such as a button, a slider, or a capacitive sensor, or a slider. The user input element 16 is operated by a user of the device 1 to indicate that an aerosol-generating substrate is ready in the heating chamber 11 and that the user wishes to begin an aerosol-generating session.

[0053] The user input element 16 may alternatively be integrated into the heater. More specifically, the user input element 16 may be a detection device for detecting the presence of an aerosol-generating substrate in the heating chamber 11, such as a light shutter for detecting a consumable product containing an aerosol-generating substrate. In this way, an aerosol-generating session may be automatically initiated upon provision of the aerosol-generating substrate.

[0054] The device 1 may also include additional user input elements for other purposes (such as configuring the strength of the aerosol produced), and may include input elements that are not directly operated by the user (such as a sensor for detecting the open / closed state of the lid 17).

[0055] The lid 17 is a preferred but optional feature. In this embodiment, the lid 17 is arranged to keep the heating chamber 11 closed and protected when not in use. The lid 17 can be, for example, a sliding lid constrained by a track to move between a closed position and an open position.

[0056] The components of the aerosol-generating device 1 are contained within a housing 10. The housing 10 may, for example, comprise a polymer such as polyetheretherketone (PEEK) or polyamide (PA), and / or comprise a metal frame such as aluminum. When an aerosol-generating session is performed, some heat leaks from the heater into the housing. The extent to which the housing 10 heats up during successive aerosol-generating sessions depends on the balance between the heat leaking from the heater and the heat dissipated from the exterior of the device 1.

[0057] Figure 2 is a schematic representation showing additional details of the heater in an embodiment of the aerosol-generating device 1 , and its use for heating a consumable 2 comprising an aerosol-generating substrate 21 .

[0058] More specifically, the consumable product 2 in this embodiment is a tubular structure comprising a section 21 along one end of its length, which contains the aerosol-generating substrate. Section 21 is inserted into the heating chamber 11 of the heater to generate the aerosol. Meanwhile, a mouthpiece end 22, which may include a filter, extends beyond the heating chamber 11 to provide a mouthpiece.

[0059] In this example, the heating chamber 11 is a tubular structure that includes ribs 111 along the sidewalls for maintaining space between the consumable 2 and the sidewalls, and includes platforms 112 for maintaining space between the consumable 2 and the end walls of the heating chamber 11. In use, the user inhales an aerosol from the consumable 2 via the mouthpiece 22. Air flows into the heating chamber 11, between the consumable 2 and the sidewalls of the chamber 11, at arrow F1, into the consumable 2 at arrow F2, and out at arrow F3.

[0060] This is only one example configuration of the heating chamber 11 and aerosol-generating substrate 21. In other alternative examples, air may be caused to flow through the loose aerosol-generating substrate in the heating chamber 11. The mouthpiece may form part of the aerosol-generating device 1 rather than part of the consumable 2. The heating chamber 11 may include an air inlet that is separate from the air outlet.

[0061] The specific configuration of the heater and aerosol-generating substrate is not limited herein. Rather, the present invention relates to measures to improve the safety of the device 1 using a specific method of controlling the heater.

[0062] Aerosol generation is typically performed in sessions. In the case of consumables 2, a "session" may be the period of time during which the consumable is fully used. Alternatively, a "session" may be the period of time during which a predetermined amount (exact or approximate) of aerosol is generated by the aerosol generating device 1.

[0063] Figure 3 is a graph schematically illustrating an example aerosol generation session in an aerosol generating device, with the temperature of the heater shown on the y-axis and time shown on the x-axis.

[0064] In this example, the aerosol generation session includes a warm-up phase t1, during which the temperature of the heater is raised to at least an aerosol generation temperature T3. The length of the warm-up phase t1 may be predetermined. In another example, the warm-up phase t1 may continue until feedback from the temperature sensor 13 indicates that the aerosol generation temperature T3 has been reached. The aerosol generation temperature T3 is selected based on the type of aerosol generating substrate and is the temperature at which an aerosol is generated by heating the aerosol generating substrate. Figure 3 As shown, the temperature of the heater is raised to a certain extent above the aerosol generation temperature T3, and the aerosol generation temperature is the lower limit of aerosol generation. In an example where the aerosol generating substrate includes tobacco and an aerosol former such as glycerol, 170°C has been found to be suitable as the value of T3, and aerosol generation is improved by continuing to heat the aerosol generating substrate to 230°C.

[0065] Then, a hold-warm phase t2 occurs, in which the temperature of the heater is maintained. Although the temperature is shown as flat, it may vary around the desired temperature. For example, pulse width modulation (PWM) control of the heater may be used to maintain the temperature. During this period, an aerosol may be drawn from the aerosol-generating substrate one or more times. In an example where the aerosol-generating substrate includes tobacco and an aerosol-forming agent, it has been found that 4 minutes and 10 seconds is a suitable example length for t2.

[0066] Finally, a cool-down phase t3 occurs, during which the heater temperature is allowed to drop below the aerosol generation temperature T3. Generally, the heater is not powered during the cool-down phase, although controlling the cool-down rate may be beneficial, for example, to clean the heating chamber after use. The duration of the cool-down phase t3 is generally not limited, and in some cases, the cool-down phase may be interrupted by the start of the next aerosol generation session. However, in some embodiments, a minimum duration t3 may be set, such as 20 seconds.

[0067] Figure 3 Also shown is a 'cool' temperature T1 at which the aerosol-generating device 1 is considered sufficiently cool that there is no need to track cumulative heating of the device over multiple sessions, as will be explained further below. In a particular example, 65°C has been found to be a suitable temperature T1.

[0068] Figure 4 is a flow chart schematically illustrating a method for controlling an aerosol generating device.

[0069] In step S410 , the control circuitry 14 receives an indication via the user input element 16 to commence an aerosol generation session.

[0070] At step S420, the control circuit system 14 receives the temperature of the heater measured by the temperature sensor. This measurement can be indirect. For example, if the temperature sensor 13 is a thermistor, the control circuit system 14 uses an electrical connection across the temperature sensor 13 to measure the resistance and then uses a known relationship between resistance and temperature (e.g., a lookup table or a continuous function) to identify the temperature.

[0071] In step S430, the control circuit system 14 retrieves the session counter value 143 from the memory 142. The session counter value is a counter indicating the number of aerosol generation sessions that have been performed while the device remains in a relatively hot state (i.e., without the device reaching a thermal equilibrium state after a session). In different embodiments, the relatively hot state may be defined differently. For example, a "relatively hot state" may be any temperature above the cooling temperature T1. In addition, the meaning of a "relatively hot state" may depend on the session counter value, as further described below. The session counter value 143 is stored to persist between aerosol generation sessions. When the control circuit system 14 is first enabled, the session counter value 143 may be initialized with a default value of, e.g., zero. As further described below, the session counter value may increase in response to an aerosol generation session and may be reset to its default value under certain conditions.

[0072] In step S440, the control circuit system 14 controls the heater to perform an aerosol generation session based on the temperature of the heater and the session counter value obtained in steps S420 and S430. More specifically, the control circuit system 14 determines whether to perform an aerosol generation session based on the user request in step S410, and if an aerosol generation session is to be performed, controls the heating element 12 during the aerosol generation session. For example, the aerosol generation session may be as described above with reference to Figure 3 The session in question.

[0073] Figure 5 is a flow chart schematically illustrating additional details of a particular method for controlling an aerosol-generating device.

[0074] exist Figure 5 In the embodiment, step S440 is specified in more detail as steps S510 to S540.

[0075] In steps S510 and S520, the control circuit system 14 compares the session counter value 143 retrieved in step S430 with the maximum continuous session limit S max Compare and decide that the session counter value 143 is lower than the session limit S max In an embodiment, it has been found that S max Suitably 3 (three), although this depends on the particular configuration of the device 1, and in particular on how much heat leaks from the heater to the rest of the device during an aerosol generation session.

[0076] At step S530, the control circuitry 14 increments the session counter value 143. Typically, this means increasing the value by one, although any counting unit may be used. In a preferred embodiment, a minimum starting temperature T2 is defined for counting sessions, at which a session is not considered continuous and is not counted. In a specific example, the minimum starting temperature T2 may preferably be a temperature in the range of 100°C to 120°C, and most preferably 100°C.

[0077] At step S540, the control circuitry 14 controls the heater to perform an aerosol generating session based on the temperature of the heater. This may be as follows: Figure 3 The aerosol generating session.

[0078] exist Figure 5 In the example of FIG, the session counter value 143 is incremented at step S530 and then the aerosol generation session is performed at step S540. However, the session counter value 143 may be incremented at other times to record the aerosol generation session. For example, referring to FIG. Figure 3 For example sessions of , the session counter value 143 may instead be incremented after the warm-up phase t1 , or after the keep-warm phase t2 , or after a predetermined time has elapsed from the start of the aerosol generation session.

[0079] On the other hand, if the session counter value 143 is not lower than the session limit S in step S520, max , the control circuit system 14 controls the heater to not perform an aerosol generating session (ie, the control circuit system 14 does not enable the heater).

[0080] Optionally, when the control circuitry 14 decides not to perform an aerosol generation session, the apparatus 1 indicates a status in which the user input is acknowledged in step S410, but the aerosol generation session is not performed. By way of example, this status indication may take the form of a static light indicator, a flashing light indicator, an animated combination of several light indicators, a vibration output, or an audible output.

[0081] Alternatively, when the control circuitry 14 decides not to perform an aerosol generation session, the control circuitry 14 may wait for suitable conditions for performing an aerosol generation session after a delay. For example, instead of proceeding from step S520 to Figure 5 At the end of the method, the control circuit system 14 may alternatively wait until the temperature of the heater drops below the sustained temperature threshold before performing the aerosol generation session. The sustained temperature threshold is preferably equal to Figure 3The "cooling" temperature T1 described in

[15] is set to the "cooling" temperature T1 described above, although the sustained temperature threshold can be configured separately. This alternative has the advantage that the device 1 can automatically perform an aerosol generation session as soon as it is ready, but has the disadvantage that the user may not anticipate this. Preferably, if the device 1 is to provide a delayed aerosol generation session, this is indicated as part of the status indication described above.

[0082] Figure 6 is a flow chart schematically illustrating additional details of a method for controlling an aerosol-generating device.

[0083] Specifically, Figure 6 The control flow for resetting the session counter value 143 is shown.

[0084] In step S610 , the control circuit system 14 receives the temperature of the heater measured by the temperature sensor.

[0085] At step S620, the control circuitry 14 determines whether the received temperature indicates that the temperature of the heater has become below the absolute reset temperature and, if so, jumps to step S670 where the session counter value 143 is reset to its initial value, typically zero.

[0086] In an example, the absolute reset temperature may be the previously described "cooling" temperature T1, 65°C. For example, the control circuitry 14 may store a previous temperature measurement in the memory 142, and if the previous temperature measurement is above the absolute reset temperature T1 and the temperature received in step S610 is below the absolute reset temperature T1, then the temperature has become (transitioned to) below the absolute reset temperature. By detecting temperature transitions, rather than single temperature measurements, resets do not occur repeatedly when the device 1 is not being heated. Alternatively, when the session counter value 143 is at its initial value, Figure 6 The step of tc may be disabled, in which case the single temperature measurement received in step S610 may be used.

[0087] If the heater temperature has not become lower than the absolute reset temperature, the process proceeds to step S630. In step S630, the control circuit system 14 determines whether the received temperature indicates that the heater temperature has become lower than the early reset temperature T2. If not, the process ends.

[0088] The early reset temperature is a temperature that, although higher than the absolute reset temperature, indicates that significant cooling has occurred since the last aerosol generation session. The early reset temperature is preferably equal to the above Figure 5 More specifically, in the aforementioned specific example embodiment, a temperature in the range of 100° C. to 120° C., most preferably 100° C., was found to be a suitable example value for the early reset temperature.

[0089] Otherwise, the flow proceeds to step S640 .In step S640 , similar to step S430 , the session counter value 143 is retrieved from the memory 142 .

[0090] In steps S650 and S660, the session counter value 143 is compared with the early reset session limit. The early reset session limit may be equal to Figure 5 The maximum continuous session limit S in step S510 max Thus, if the session counter value 143 is below the early reset session limit, this indicates that the device 1 has not yet reached the maximum safe temperature due to heat leakage from the heater under continued use. In a specific example, the early reset session limit may be 3 (three) sessions.

[0091] If the session counter value 143 is below the early reset session limit, the session counter value 143 is reset at step S670. Otherwise, Figure 6 The process ends.

[0092] The control circuit system 14 can be connected to Figure 4 or Figure 5 Methods executed in parallel Figure 6 For example, Figure 6 The process may be triggered by an interrupt input of the logic circuit 141 connected to the hardwired temperature comparison unit.

[0093] Alternatively, Figure 4 or Figure 5 Steps and Figure 6 The steps may be performed alternately in a continuous control loop which controls responding to a user indication to start an aerosol generation session and controls resetting of a session counter value.

[0094] In some embodiments, the early reset temperature and its associated logic at steps S630 to S660 may be omitted, in which case the process ends after a negative outcome at step S620.

[0095] Furthermore, in some embodiments, the process of resetting the session counter value 143 may be omitted entirely, for example, the user may be required to turn off the device to reset the session counter value 143. This may be achieved by storing the session counter value 143 in volatile memory.

[0096] Figure 7 is a graph schematically illustrating consecutive aerosol generation sessions in an aerosol generating device, wherein the temperature of the heater is shown on the y-axis and time is shown on the x-axis.

[0097] Figure 7Four aerosol generation sessions from S1 to S4 are shown.

[0098] At the start of session S1, the session counter value 143 is at its initial value (zero). The device 1 is started below the above-mentioned minimum starting temperature T2, so for session S1, the session counter value 143 is not incremented in step S530. Figure 5 In step S540, Figure 3 Stages t1, t2, and t3.

[0099] However, before the device 1 can cool completely at stage t3 of session S1, the control circuit system 14 receives a further instruction to start an aerosol generation session (step S410) and starts session S2. This time, the temperature of the heater at the start of the session is greater than the minimum start temperature T2, and the session counter value 143 is incremented (from zero to one) at step S530. Then, at step S540, the execution Figure 3 stages t1, t2 and t3.

[0100] This time, at stage t3 of session S2, the temperature of the heater becomes lower than Figure 6 The control circuitry 14 evaluates the condition of step S660, determines that the session counter value 143 (one) is below the early reset session limit (three), and resets the session counter value in step S670.

[0101] The user then gives further instructions (step S410) to perform further sessions S3 and S4, such as Figure 7 However, because the session counter value 143 has been reset and session S3 was started below the minimum start temperature T2, the session counter value records a value of only one at the end of step S4. Thus, it can be seen how the control flow can extend the number of consecutive sessions allowed if the user allows the device to partially cool.

[0102] Figure 8 is a flow chart schematically illustrating additional details of a method for controlling an aerosol-generating device.

[0103] Figure 8 The method is largely similar to Figure 5 , but additional conditions for the aerosol generation session are introduced in step S810.

[0104] That is, a maximum starting temperature T4 is defined.If the temperature received at step S420 is not lower than the maximum starting temperature, the user input at step S410 is discarded and the aerosol generating session is not performed.

[0105] Alternatively, similar to the alternative embodiment of step S520 described above, when the control circuit system 14 decides not to perform an aerosol generation session, the control circuit system 14 may wait for suitable conditions for performing an aerosol generation session after a delay. For example, instead of proceeding from step S810 to Figure 5 The method ends, the control circuit system 14 may alternatively wait until the temperature of the heater drops below the sustained temperature threshold and then perform the aerosol generation session. In the case of step S810, the sustained temperature threshold may be equal to Figure 3 The aerosol generation temperature T3 is described above, although the sustained temperature threshold can be configured separately. This alternative has the advantage that the device 1 can automatically perform an aerosol generation session as soon as it is ready, but has the disadvantage that the user may not anticipate this. Preferably, if the device 1 is to provide a delayed aerosol generation session, this is indicated as part of the status indication, as described above.

[0106] In addition to or as an alternative to the maximum start temperature T4 of the heater, the maximum start temperature of the control circuit system 14 can be compared to the temperature measurement received from the temperature sensor 144, and if the control circuit system 14 exceeds its maximum start temperature, the aerosol generation session is not performed. This has the advantage of preventing the control circuit system 14 from continuing to heat itself up, at the risk of overheating and becoming unreliable or unpredictable. In a specific example, the maximum start temperature of the control circuit system 14 is preferably 65°C.

[0107] Figure 9 is a graph schematically illustrating consecutive aerosol generation sessions in an aerosol generating device, wherein the temperature of the heater is shown on the y-axis and time is shown on the x-axis.

[0108] Figure 9 Can be used to understand Figure 8 The above-mentioned maximum starting temperature T4.

[0109] More specifically, after each session S1 and S2, regardless of the session counter value, the next session cannot start until the temperature of the heater has dropped below the maximum start temperature T4. For ease of explanation, the maximum start temperature T4 is shown as being higher than the aerosol generation temperature T3. However, the maximum start temperature T4 is preferably equal to the aerosol generation temperature T3.

[0110] In the above embodiment, an aerosol-generating device 1 is provided having a control circuit system 14 configured to execute the method for safely operating a heater. The control circuit system 14 may also be provided as a standalone component that is used with the aerosol-generating device 1 but is separate from the rest of the aerosol-generating device. Furthermore, the aerosol-generating device 1 may be similar to the above-described devices, but may be externally controlled according to the above-described method without including the control circuit system 14 as a component of the device.

[0111] The heating element 12 can be any device for outputting sufficient thermal energy to form an aerosol from the aerosol matrix. The transfer of thermal energy from the heating element 12 to the aerosol matrix can be conductive, convective, radiative, or any combination thereof. As non-limiting examples, conductive heaters can directly contact and press against the aerosol matrix, or these heaters can contact a separate component, such as a heating chamber, which itself causes heating of the aerosol matrix by conduction, convection, and / or radiation.

[0112] The heating element can be electrically driven, driven by combustion, or driven in any other suitable manner. The electrically driven heating element can include a resistive tracking element (optionally including an insulating package), an induction heating system (e.g., including an electromagnet and a high-frequency oscillator), etc. The heating element 12 can be arranged around the outside of the aerosol matrix, can partially or completely penetrate the aerosol matrix, or any combination thereof. For example, in addition to the heater of the above embodiment, the aerosol generating device can have a blade-type heater extending into the aerosol matrix in the heating chamber 11.

[0113] The term "temperature sensor" is used to describe an element that is capable of determining the absolute or relative temperature of a portion of the aerosol-generating device 1 . This may include thermocouples, thermopiles, thermistors, and the like. The temperature sensor 13 may be provided as part of another component, or it may be a separate component. In some examples, more than one temperature sensor may be provided, for example to monitor the heating of different portions of the aerosol-generating device 1 in order to determine a thermal profile. Furthermore, in some examples, a temperature sensor may be combined with another feature. For example, the thermistor property of a resistive heating element may be used to measure temperature.

[0114] Aerosol generation matrix comprises tobacco, for example, in a dried or cured form, and in some cases has the additional component for seasoning or producing smoother or other more pleasant experience.In some examples, matrix such as tobacco can be processed with vaporizer.Vaporizer can improve the generation of steam from matrix.For example, vaporizer can comprise polyols such as glycerol or ethylene glycol such as propylene glycol.In some cases, matrix may not contain tobacco or even contain nicotine, but may contain natural or artificially extracted ingredients, for seasoning, volatilization, improvement of smoothness and / or providing other pleasant effects.Matrix can be set to the material of solid or paste type in shredded, pill-shaped, powdered, granular, strip or sheet form, optionally its combination form.Additionally, aerosol matrix can comprise liquid or gel.

[0115] The aerosol-generating device 1 may, in some embodiments, be referred to as a "heated tobacco device," a "heat-not-burn tobacco device," a "device for vaporizing tobacco products," or the like, and this is to be interpreted as being suitable for devices that achieve these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol substrate.

[0116] The aerosol generating device 1 can be arranged to receive an aerosol matrix in a pre-packaged matrix carrier. The matrix carrier can be substantially similar to a cigarette, having a tubular area with an aerosol matrix arranged in an appropriate manner. In some designs, a filter, a vapor collection area, a cooling area and other structures can also be included. An outer layer of paper or other flexible planar materials such as foil can also be provided, for example, to hold the aerosol matrix in an appropriate position to further resemble a cigarette, etc. The matrix carrier can be assembled in the heating chamber 11, or can be longer than the heating chamber 11, so that when the aerosol generating device 1 is provided with the matrix carrier, the lid 17 remains open. In such an embodiment, an aerosol can be provided directly from the matrix carrier, which serves as the mouthpiece of the aerosol generating device.

[0117] As used herein, the term "fluid" should be understood to broadly refer to non-solid materials capable of flowing, including but not limited to liquids, pastes, gels, powders, and the like. "Fluidized material" should accordingly be interpreted as a material that is inherently fluid, or a material that has been modified to behave as a fluid. Fluidization may include, but is not limited to, powderization, dissolution in a solvent, gelation, thickening, and dilution.

[0118] As used herein, the term "volatile" refers to a substance that can readily change from a solid or liquid state to a gaseous state. As a non-limiting example, a volatile substance may be a substance that has a boiling or sublimation temperature close to room temperature at ambient pressure. Thus, "volatilize" or "volatilise" should be interpreted as meaning to volatilize (a material) and / or to cause it to evaporate or disperse in a vapor.

[0119] As used herein, the term "vapour" or "vapor" means: (i) the form to which a liquid naturally transforms when subjected to sufficient heat; or (ii) liquid / moisture particles suspended in the atmosphere and visible as clouds of steam / fume; or (iii) a fluid that fills space like a gas but liquefies under pressure alone below its critical temperature.

[0120] Consistent with this definition, the terms "vaporize" or "vaporize" refer to: (i) to change or cause to change into a vapor; and (ii) the condition where a particle changes physical state (ie, from a liquid or solid to a gas).

[0121] As used herein, the term "atomize" shall mean: (i) reducing (a substance, especially a liquid) into very small particles or droplets; and (ii) maintaining the particles in the same physical state (liquid or solid) as before atomization.

[0122] As used herein, the term "aerosol" shall refer to a system of particles dispersed in air or a gas (such as mist, dust cloud or smoke). Therefore, the term "aerosolize" or "aerosolize" refers to making and / or dispersing into an aerosol. It should be noted that the meaning of aerosol / aerosolization is consistent with each of volatilization, atomization and vaporization defined above. For the avoidance of doubt, aerosol is used to consistently describe a mist or droplet comprising atomized, volatilized or vaporized particles. Aerosol also includes a mist or droplet comprising any combination of atomized, volatilized or vaporized particles.

Claims

1. A method for controlling an aerosol-generating device, the method comprising: receiving, via a user input element, an indication to begin an aerosol generating session; receiving a temperature of the heater measured by a temperature sensor; Retrieve the session counter value from storage; controlling the heater to perform an aerosol generating session based on the temperature of the heater and the session counter value; and When the temperature of the heater becomes lower than a first predetermined temperature, the session counter value is reset.

2. The method according to claim 1, wherein The session counter value is incremented when the aerosol generation session begins. 3 . The method of claim 1 , further comprising resetting the session counter value when the temperature of the heater becomes lower than a second predetermined temperature higher than the first predetermined temperature and the session counter value is lower than a first predetermined session limit.

4. The method according to any one of claims 1 to 3, wherein The aerosol generation session includes: a heating phase in which the temperature of the heater is increased to at least a third predetermined temperature; a keep-warm phase in which the temperature of the heater is maintained; and A temperature drop phase in which the temperature of the heater is allowed to drop below the third predetermined temperature.

5. The method according to any one of claims 1 to 3, further comprising: If the session counter value is not below a second predetermined session limit, the heater is controlled not to perform an aerosol generating session.

6. The method according to any one of claims 1 to 3, further comprising: If the temperature of the heater is greater than a fourth predetermined temperature when the indication to start an aerosol generation session is received, the heater is controlled not to perform an aerosol generation session regardless of the session counter value.

7. The method according to any one of claims 1 to 3, wherein If the temperature of the heater is below the fifth predetermined temperature when the indication to start an aerosol generation session is received, the session counter value is not incremented.

8. The method according to any one of claims 1 to 3, wherein The method includes: After receiving an indication to commence an aerosol generating session, controlling the heater to not perform an aerosol generating session, and The user output element is controlled to indicate a status, wherein the indication is received but the aerosol generating session is not being performed.

9. The method according to any one of claims 1 to 3, wherein The method includes: After receiving an indication to commence an aerosol generating session, controlling the heater to not perform an aerosol generating session, and Waiting until the temperature of the heater drops below a sixth predetermined temperature and then performing an aerosol generating session.

10. Control circuitry configured to perform a method according to any preceding claim.

11. The control circuit system according to claim 10, wherein the control circuit system is used for an aerosol generating device, further comprising a second temperature sensor for measuring the temperature of the control circuit system, wherein: The method further comprises: If the temperature of the control circuitry is greater than a seventh predetermined temperature when the indication to commence an aerosol generation session is received, the heater is controlled not to perform an aerosol generation session regardless of the session counter value.

12. An aerosol generating device comprising: The control circuit system according to claim 10 or claim 11, The heater is used to heat the aerosol generating substrate of the consumable product to generate aerosol, The temperature sensor is used to measure the temperature of the heater. the user input element for starting an aerosol generating session, and The memory is used to store the session counter value.

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