Profile Selection for Aerosol Generating Device

Abstract

An aerosol generating device for generating an aerosol from an aerosol generating article comprising an aerosol forming substrate. The aerosol generating device is configured to generate an aerosol during a usage session including the start and the end of the usage session. The aerosol generating device comprises a heater assembly for heating the aerosol forming substrate. The aerosol generating device further comprises a power source configured to supply power to the heater assembly. The aerosol generating device further comprises a control circuit comprising a memory in which a plurality of predetermined heating profiles are stored. At least one of the plurality of predetermined heating profiles has a first duration, and at least one of the predetermined heating profiles has a second duration different from the first duration. The control circuit is configured to detect a trigger condition and select, based on the detected trigger condition, a predetermined heating profile for use during the usage session. The selected predetermined heating profile has either the first duration or the second duration. The trigger condition depends on at least one of a user interaction with the aerosol generating device or a characteristic of the aerosol generating article used with the device.

Description

Technical Field

[0001] The present disclosure relates to an aerosol generating device, an aerosol generating system including the aerosol generating device, and a method for controlling power supplied to a heater assembly of the aerosol generating system.

Background Art

[0002] Aerosol generating systems configured to generate an aerosol from an aerosol-forming substrate, such as a tobacco-containing substrate, are known in the art. Many known aerosol generating systems generate an aerosol by applying heat to the substrate by a heater assembly. In an electrically-operated aerosol generating system, when power is supplied from a power source to the heater assembly, heat is applied to the substrate. The generated aerosol can then be inhaled by a user of the system as part of a user's smoking. A usage session of an aerosol generating system typically includes a plurality of user smokes.

[0003] Many aerosol generating systems include a controller configured to control the supply of power to the heater assembly according to a predetermined heating profile. The predetermined heating profile is typically optimized so that a consistent aerosol is generated throughout the usage session, assuming that it follows a particular smoking behavior during that usage session. User smoking behavior may be characterized, for example, by the frequency of smoking throughout the usage session or the interval between subsequent smokes throughout the usage session.

[0004] If the user does not follow the particular smoking behavior for which the predetermined heating profile is optimized, the aerosol generated throughout the usage session may lack consistency. For example, the amount of aerosol or the chemical composition of the aerosol may vary significantly from one user smoke to the next.

[0005] In one particular embodiment, a first subset of users of the aerosol generation system prefer a first smoking behavior that includes a smoking interval of about 20 seconds, and a second subset of users of the aerosol generation system have been found to prefer a second smoking behavior that includes a longer smoking interval of about 40 seconds. If a given heating profile implemented by the aerosol generation system is optimized for the first smoking behavior, but the second smoking behavior is followed during the use session, the aerosol generated throughout the use session may lack consistency.

[0006] The longer smoking intervals of the second subset of users are smoking behaviors similar to those typical of users of conventional cretic paper cigarettes.

[0007] It would be desirable to provide an aerosol generation system that provides consistent aerosol generation for different smoking behaviors followed during a use session. It would be desirable to provide an aerosol generation system that can be optimized for users who were previously smokers of either or both conventional cretic and non-cretic paper cigarettes. SUMMARY OF THE INVENTION

[0008] In a first aspect, an aerosol generation device is provided. The aerosol generation device may be for generating an aerosol from an aerosol-generating article. The aerosol-generating article may include an aerosol-forming substrate. The aerosol generation device may be configured to generate an aerosol during a use session. The use session may include a use session start. The use session start may include a use session end.

[0009] The aerosol generation device may comprise a heater assembly for heating the aerosol-forming substrate.

[0010] The aerosol generation device may comprise a power source. The power source may be configured to supply power to the heater assembly.

[0011] The aerosol generating device may comprise a control circuit. The control circuit may comprise a memory. A plurality of predetermined heating profiles may be stored in the memory. At least one of the plurality of predetermined heating profiles may have a first duration. At least one of the plurality of predetermined heating profiles may have a second duration different from the first duration.

[0012] The control circuit may be configured to detect a trigger condition. The control circuit may be configured to select a predetermined heating profile for use during a usage session. The selection may be based on the detected trigger condition.

[0013] The selected predetermined heating profile may have either the first duration or the second duration. The trigger condition may depend on at least one of a user interaction with the aerosol generating device or a characteristic of the aerosol generating article used with the device.

[0014] A predetermined heating profile having the first duration may be optimized for a first smoking behavior. A predetermined heating profile having the second duration may be optimized for a second smoking behavior different from the first smoking behavior. A control circuit configured to select a predetermined heating profile for use during a usage session may advantageously mean that an appropriate predetermined heating profile can be selected by the control circuit for a particular usage scenario followed by a particular smoking behavior. In this way, a consistent aerosol may be generated during usage sessions with different smoking behaviors. Advantageously, the user may be able to follow one of various smoking behaviors during a usage session using the same aerosol generating device and the same aerosol forming substrate.

[0015] The trigger condition depending on the user interaction with the aerosol generating device may mean that the trigger condition depends on the user smoking behavior (smoking the device is a user interaction). In such cases, the control circuit may be configured to determine the user smoking behavior. The control circuit may then be configured to use the determined user smoking behavior to select a predetermined heating profile having a first or second duration.

[0016] When the trigger condition depends on the user smoking behavior, the control circuit may advantageously select a predetermined heating profile having a first or second duration automatically.

[0017] Alternatively, or in addition, the trigger condition depending on the user interaction with the aerosol generating device may mean that the trigger condition depends on the output, state, or user operation of one or more user interface elements of the aerosol generating device. The one or more user interface elements may comprise, for example, buttons or switches. The control circuit may be configured to use the state of the one or more user interfaces to select a predetermined heating profile having a first or second duration.

[0018] Alternatively, or in addition, the trigger condition may depend on the characteristics of the aerosol generating article used with the device. The control circuit may be configured to detect the characteristics of the aerosol generating article used with the device. The control circuit may be configured to use the detected characteristics to select a predetermined heating profile having a first or second duration. The characteristics configured to be detected by the control circuit preferably relate to the characteristics of an identifier of the aerosol generating article, such as a barcode or a tagant.

[0019] When the trigger condition depends on one or more user interface elements or the characteristics of the aerosol-generating article used with the device, the selection of a predetermined heating profile having a first or second duration can advantageously enable the user to determine which heating profile is preferred based on their typical smoking behavior. In particular, the user may use one or more user interface elements to select the duration of a predetermined heating profile, or may select an aerosol-generating article having specific characteristics, preferably a specific identifier.

[0020] In all of the above examples, it is advantageous to make the selection of the duration of the predetermined heating profile based on the trigger condition, as this may enable the user to follow one of various user smoking behaviors during a usage session using the same aerosol-generating device and the same aerosol-forming substrate.

[0021] As used herein, "user smoking behavior" can refer to any characteristic of the user's smoking that can vary between different usage patterns. For example, user smoking behavior can be defined by at least one of smoking frequency, smoking interval, smoking intensity, smoking length, number of times smoked, amount of aerosol generated per puff, or amount of aerosol generated. One or more of these characteristics may differ between a "first" user smoking behavior and a "second" user smoking behavior. Preferably, user smoking behavior can refer to smoking frequency or smoking interval.

[0022] The control circuit may be configured to control the supply of power to the heater assembly according to a selected predetermined heating profile having a first or second duration.

[0023] Both the first duration and the second duration may be at least 1 minute, preferably at least 2 minutes, preferably at least 3 minutes. In this way, the predetermined heating profiles of the first and second durations continue between multiple user smokes during a usage session.

[0024] The first duration may be longer than the second duration.

[0025] The first user smoking behavior may include a longer smoking interval and a lower smoking frequency than the second user smoking behavior. Regardless of whether the user follows the first user smoking behavior or the second user smoking behavior, the user has typically been found to perform a similar number of smoking sessions during a usage session. Therefore, the total length of the usage session may be longer when the user follows the first user smoking behavior than when the user follows the second user smoking behavior. A predetermined heating profile having a first (longer) duration may advantageously be selected when the first user smoking behavior should be followed, and a predetermined heating profile having a second (shorter) duration may advantageously be selected when the second user smoking behavior should be followed.

[0026] The first duration may be at least 30% longer than the second duration, preferably at least 40% longer, preferably at least 50% longer, preferably at least 75% longer.

[0027] The first duration may be longer than 5 minutes, preferably longer than 6 minutes, preferably longer than 8 minutes.

[0028] The first duration may be 18 minutes or less, preferably 15 minutes or less, preferably 12 minutes or less.

[0029] The second duration may be 8 minutes or less, preferably 6 minutes or less, preferably 4 minutes or less.

[0030] The duration of the usage session may depend on the duration of a selected predetermined heating profile. As described above, users have typically been found to perform a similar number of smoking events regardless of other characteristics of their smoking behavior, such as the smoking interval and frequency. Thus, for example, a user following a first user smoking behavior with a longer interval or lower smoking frequency may perform the desired number of smoking events over a longer period of time than a user following a second user smoking behavior. As such, the length of the usage session may vary according to the determined user smoking behavior, and it may be advantageous for the duration of the selected predetermined heating profile to correspond to the varying time in which the user performs the desired number of smoking events.

[0031] When the selected predetermined heating profile has a first duration, the maximum duration of the usage session may be at least 5 minutes, preferably at least 6 minutes, preferably at least 8 minutes, preferably at least 10 minutes, preferably at least 12 minutes.

[0032] When the selected predetermined heating profile has a second duration, the maximum duration of the usage session may be 10 minutes or less, preferably 8 minutes or less, preferably 7 minutes or less, preferably 6 minutes or less.

[0033] The plurality of predetermined heating profiles may include a first predetermined heating profile having a first duration and a second predetermined heating profile having a second duration.

[0034] The plurality of predetermined heating profiles may comprise a first subset of the predetermined heating profiles, each profile of the first subset having a first duration. The plurality of predetermined heating profiles may comprise a second subset of the predetermined heating profiles, each profile of the second subset having a second duration.

[0035] Each predetermined heating profile may include one or more target temperatures. When the control circuit is configured to supply power to the heater assembly according to a specific predetermined heating profile, the control circuit may be configured to heat the heater assembly while referring to one or more target temperatures. The one or more target temperatures may advantageously be selected to ensure that a consistent amount of aerosol is generated throughout at least a second period of the use session. For example, the initial target temperature of a predetermined heating profile may be high to ensure that the aerosol-forming substrate reaches its operating temperature. The subsequent target temperature of the predetermined heating profile may be lower than the initial target temperature to avoid overheating of the aerosol-forming substrate.

[0036] Preferably, the first predetermined heating profile may be configured such that the average of the target temperatures throughout the duration of the first predetermined heating profile is lower than the average of the target temperatures throughout the duration of the second predetermined heating profile.

[0037] The use session preferably includes a plurality of puffs. The use session more preferably does not include more than four user puffs, even more preferably does not include more than five user puffs, even more preferably does not include more than six user puffs, even more preferably does not include more than seven user puffs, even more preferably does not include more than eight user puffs, even more preferably does not include more than nine user puffs, even more preferably does not include more than ten user puffs, even more preferably does not include more than eleven user puffs, and even more preferably does not include more than twelve user puffs.

[0038] The end of the use session may correspond to the end of the selected predetermined heating profile.

[0039] The aerosol generating device may comprise a detection assembly. The detection assembly may be configured to detect at least one of user interaction with the aerosol generating device or the characteristics of the aerosol generating article used with the device.

[0040] When the detection assembly is configured to detect the characteristics of the aerosol generating article used with the device, the detected characteristics may preferably not be the characteristics of the aerosol-forming substrate comprised in the aerosol generating article. Instead, the detected characteristics may be another feature of the aerosol generating article. In particular, the aerosol generating article may comprise an identifier such as a barcode or a tagant. The detector may be configured to detect the identifier. The control circuit may be configured to distinguish between different identifiers. The trigger condition may be related to the detected identifier. The control circuit may be configured to select a predetermined heating profile having a first duration or a second duration during a usage session based on the detected identifier.

[0041] The aerosol generating device may comprise a device housing defining a cavity for receiving the aerosol generating article. The cavity may be configured to receive at least a portion of the aerosol generating article comprising the aerosol-forming substrate. The detection assembly may be configured to detect the characteristics of the aerosol generating article received within the cavity, preferably the identifier of the aerosol generating article.

[0042] The detector assembly may be configured to distinguish between a first identifier and a second identifier different from the first identifier. The aerosol generating article used with the device may comprise the first or the second identifier.

[0043] The control circuit may be configured to select a predetermined heating profile having either a first duration or a second duration depending on whether the first or second identifier is detected. The control circuit may be configured to select a predetermined heating profile having a first duration when the first identifier is detected. The control circuit may be configured to select a predetermined heating profile having a second duration when the second identifier is detected.

[0044] In this way, the user of the aerosol generating device can advantageously choose to use the device with an aerosol generating article that includes characteristics related to the user's preferred smoking behavior during the usage session. For example, if the user desires to follow a first user smoking behavior, the user may select an aerosol generating article that includes a first characteristic, in particular a first identifier, for use with the device. If the user desires to follow a second user smoking behavior that is different from the first user smoking behavior, the user may select an aerosol generating article that includes a second characteristic different from the first characteristic or identifier, in particular a second identifier, for use with the device.

[0045] The aerosol generating article that includes the first identifier may include an aerosol forming substrate of substantially the same type as the article that includes the second identifier. For example, the chemical composition of the aerosol forming substrate may be substantially the same for aerosol generation with the aerosol generating article that includes the first identifier and for the aerosol generating article that includes the second identifier. Therefore, the control circuit configured to select a predetermined heating profile of either the first or second duration may do so in consideration of the user's preferred smoking behavior rather than considering differences in the type of aerosol forming substrate used with the device.

[0046] As used herein, an aerosol forming substrate being "substantially the same" means that the aerosol forming substrate of a first aerosol generating article that includes a first identifier has the same characteristics as the aerosol forming substrate of a second aerosol generating article that includes a second identifier, other than differences arising from manufacturing tolerances.

[0047] As used herein with respect to the present invention, the term "tagant" refers to a chemical or physical marker added to a component, the presence of which may be detected by a suitable detector and which enables the component to be identified. Physical tagants can take many different forms, but are typically very small in size, present at low levels and easy to detect. A tagant may include a uniquely coded material.

[0048] The tagant may be any tagant. For example, the tagant may include a photoluminescent material having a luminescence half-life of 50 microseconds to 1000 microseconds after photoexcitation of the photoluminescent material.

[0049] The tagant may be provided on any component on a downstream section of the aerosol-generating article. For example, the tagant may be provided on one or more of an adhesive, wrapper, tipping paper, filter plug, susceptor, mouthpiece filter, air tube, or, if present, a flavorant. The tagant may be provided on two or more components. This can advantageously make the detection of the tagant by the detector a more reliable detection.

[0050] The control circuit may be configured to determine a user smoking behavior during a first period of a usage session.

[0051] The control circuit may be configured to select a predetermined heating profile having either a first duration or a second duration in response to the determined user smoking behavior.

[0052] The control circuit may be configured to control the supply of power to the heater assembly according to a predetermined heating profile selected during a second period of the usage session.

[0053] It is advantageous that the control circuit is configured to select one of a plurality of predetermined heating profiles using the determined user smoking behavior during a first period, meaning that a predetermined heating profile optimized for the smoking behavior determined during the first period can be selected and applied during a second period. In this way, a consistent aerosol may be generated throughout the second period of the usage session for different smoking behaviors.

[0054] It has been found that users of an aerosol generation system tend to maintain a consistent smoking behavior throughout a usage session, and thus it may be assumed that the determined smoking behavior during the first period will be maintained throughout the second period of the usage session.

[0055] The first period of the usage session may include one or more user smokes. Preferably, the first period of the usage session includes a plurality of user smokes.

[0056] The control circuit may be configured to determine user smoking behavior based on one or more user smokes during the first period of the usage session. Preferably, the control circuit is configured to evaluate the user smoking behavior determined over a plurality of user smokes during the first period.

[0057] The control circuit may be configured to determine an average smoking behavior for a plurality of user smokes during the first period. While user smoking behavior may vary from smoke to smoke, it has been found that smoking behavior may be substantially consistent throughout the usage session for a plurality of smokes. Thus, the average of the smoking behavior may typically be substantially uniform throughout the usage session, and for this reason user smoking behavior may be effectively characterized based on the average smoking behavior during the first period. The average smoking behavior may reduce the influence of differences in smoking behavior from smoke to smoke.

[0058] The first period of the usage session may include one or more user smokings. It is preferable that the first period of the usage session includes multiple user smokings.

[0059] The control circuit may be configured to determine user smoking behavior based on one or more user smokings during the first period of the usage session. Preferably, the control circuit is configured to evaluate the user smoking behavior determined over multiple user smokings during the first period.

[0060] The control circuit may be configured to determine an average smoking behavior for multiple user smokings during the first period. While the user smoking behavior may vary from smoking to smoking, it has been found that the smoking behavior may be substantially consistent throughout the usage session for multiple smokings. Thus, the average of the smoking behavior may typically be substantially uniform throughout the usage session, and for this reason, the user smoking behavior may be effectively characterized based on the average smoking behavior during the first period. The average smoking behavior may reduce the influence of differences in smoking behavior from smoking to smoking.

[0061] The user smoking behavior determined during the first period may relate to at least one of smoking frequency, smoking interval, smoking intensity, smoking duration, number of times smoked, amount of aerosol generated per smoking, or amount of aerosol generated during the first period.

[0062] Preferably, the user smoking behavior determined during the first period is at least one of average smoking frequency, average smoking interval, average smoking intensity, average smoking duration, or average amount of aerosol generated per smoking.

[0063] The first period may include the start of the first period and the end of the first period. The end of the first period may be at least 20 seconds after the start of the first period, preferably, the end of the first period may be at least 30 seconds after the start of the first period, preferably, the end of the first period may be at least 40 seconds after the start of the first period, preferably, the end of the first period may be at least 50 seconds after the start of the first period, preferably, the end of the first period may be at least 75 seconds after the start of the first period, preferably, the end of the first period may be at least 90 seconds after the start of the first period. The start of the first period may be 150 seconds or less, preferably 140 seconds or less, preferably 130 seconds or less, preferably 120 seconds or less, preferably 110 seconds or less from the start of the first period.

[0064] As described above, the first period may include one or more smoking events, preferably a plurality of smoking events. Therefore, the duration between the start of the first period and the end of the first period may be long enough to include one or more smoking events, preferably long enough to include a plurality of smoking events. Of course, the number of smoking events within a given time may depend on the smoking behavior followed by the user of the device. In any case, at least 20 seconds between the start of the first period and the end of the first period may be longer than the time sufficient to include a single smoking event. The longer the first period, the higher the likelihood that more smoking events are contained within the first period. Therefore, the longer values disclosed above for the time between the end of the first period and the start of the first period may be preferred when the determined user smoking behavior is based on a plurality of user smoking events, and particularly when the determined user smoking behavior is an average user smoking behavior.

[0065] The end of the first period may be after a predetermined time from the start of the first period. The predetermined time may be at least 20 seconds, preferably at least 30 seconds, preferably at least 40 seconds, preferably at least 50 seconds, preferably at least 75 seconds, preferably at least 90 seconds. The predetermined time may be 150 seconds or less, preferably 140 seconds or less, preferably 130 seconds or less, preferably 120 seconds or less, preferably 110 seconds or less.

[0066] The control circuit may be configured to monitor the number of smoking occurrences during a first period. The control circuit may be configured such that the end of the first period is when the control circuit detects that a predetermined number of smoking occurrences have occurred within the first period. The number of times a predetermined user smokes during the first period may be at least 2 smoking occurrences, preferably at least 3 smoking occurrences. The advantage of the end of the first period depending on when a predetermined number of smoking occurrences are taken is that the first period may be dynamic. If the user follows a smoking behavior with a low interval between smoking, it means that the first period may be short, and a predetermined heating profile for the second period may advantageously be selected and may follow more quickly within the usage session. However, if the user follows a slow smoking behavior with a longer interval between smoking, the dynamic first period may advantageously extend to be long enough to achieve a reliable measurement of the user's smoking behavior.

[0067] It is preferable that the start of the first period corresponds to the start of the usage session. In other words, the first period of the usage session is the initial period of the usage session.

[0068] The second period of the usage session may include multiple user smokings. The second period of the usage session may preferably include more than three, preferably more than five, preferably more than seven, preferably more than eight, preferably more than nine user smokings. The controller is preferably configured to control the supply of power to the heater assembly during each of the smokings in the second period according to a selected predetermined heating profile.

[0069] The second period may include a second period start and a second period end.

[0070] The start of the second period may correspond to the end of the first period. In other words, the second period may follow immediately after the first period, whereby the first period and the second period are sequential to each other.

[0071] The end of the second period may correspond to the end of the usage session. In such cases, the control circuit may be configured to control the supply of power to the heater assembly according to a predetermined heating profile selected using the determined user smoking behavior of the first period until the end of the usage session.

[0072] The length of the usage session may depend on the length of the selected predetermined heating profile. The end of the usage session may correspond to the end of the selected predetermined heating profile.

[0073] Users have typically been found to perform a similar number of smoking events regardless of other characteristics of their smoking behavior, such as smoking intervals and frequencies. Thus, for example, a user following a first user smoking behavior with longer intervals or lower smoking frequencies may perform the desired number of smoking events over a longer period of time than a user following a second user smoking behavior. Thus, it may be advantageous to vary the length of the usage session according to the determined user smoking behavior and the selected predetermined heating profile to accommodate the varying times in which a user performs the desired number of smoking events.

[0074] The control circuit may be configured to detect user smoking based on the signal received from the detector. The control circuit may be configured to determine the user smoking behavior based on the signal received from the detector. For example, the control circuit may be configured to detect the smoking frequency or the smoking interval for the first period by measuring the time between subsequent detected user smokes. As another example, the control circuit may be configured to detect the length of the detected user smoke or the intensity of the detected user smoke. If the user smoking behavior is average user smoking behavior, the control circuit may be configured to detect a plurality of user smokes and determine the average user smoking behavior for the plurality of detected user smokes.

[0075] The aerosol generating device may include an air flow channel. The air flow channel may extend from an air inlet that is at least partially defined by the housing of the aerosol generating device. The air flow channel may extend to an air outlet that is at least partially defined by the aerosol generating device housing. The parameter indicating user smoking, which is configured to be detected by the detector, may be a parameter of the air within the air flow channel.

[0076] The parameter that may be configured to be detected by the detector may be at least one of flow rate, pressure, temperature, or aerosol amount.

[0077] The heater assembly may include a heating element. The heating element may be a resistive heating element. The heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped ceramics and undoped ceramics.

[0078] The aerosol generating device may include a power source configured to supply an electric current to the resistive heating element.

[0079] The heating element may include a substrate layer of a flexible material. The substrate layer may include a thermally stable polymer, preferably polyimide.

[0080] The heating element may be disposed on the substrate layer. The heating element may be a resistive heating element. The heating element may include a wired connection configured to connect to a controller of the aerosol generating device. The heating element may include a heating track disposed on the substrate layer. The heating track may include a thermally conductive material, preferably a metal such as stainless steel. The heating track may be electrically connected to the wired connection.

[0081] The heating element may take other forms. For example, it may be one or more metal grids, a flexible printed circuit board, a molded circuit part (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique such as plasma deposition on a substrate of an appropriate shape.

[0082] In another embodiment, the heater assembly may include one or more inductor coils, and the heating element may include one or more susceptor elements.

[0083] One or more susceptor elements may be configured to be heatable by an alternating magnetic field generated by one or more inductor coils. In use, the power supplied to the inductor coil (e.g., by the aforementioned power supply of the device) results in the inductor coil inducing eddy currents within the susceptor element. These eddy currents then result in the susceptor element generating heat. The power is supplied to the inductor coil as an alternating magnetic field. The alternating current may have any suitable frequency. The alternating current may preferably be a high-frequency alternating current. The alternating current may have a frequency of 100 kilohertz (kHz) to 30 megahertz (MHz). When the aerosol-forming substrate is received within the chamber, the heat generated by the susceptor element may heat the aerosol-forming substrate to a temperature sufficient to produce an aerosol from the substrate. The susceptor element is formed of a material having the ability to absorb electromagnetic energy and convert it into heat. As an example, the susceptor element may be formed of a ferromagnetic material such as steel, but is not limited thereto.

[0084] The detector may include a sensor. The sensor may include a pressure sensor, a flow sensor, a temperature sensor, or an aerosol amount sensor.

[0085] When the heater assembly includes a heating element, the heating element may form a detector. In such cases, the control circuit may be configured to detect user smoking based on changes in the temperature of the heating element during a usage session. For example, the control circuit may be configured to detect user smoking based on a decrease in the temperature of the heating element. The control circuit may be configured to detect the length or intensity of user smoking based on at least one of the length or magnitude of the decrease in the temperature of the heating element.

[0086] The control circuit may be configured to monitor the electrical resistance of the heating element. The electrical resistance of the heating element may preferably be temperature-dependent. Therefore, the control circuit may be configured to determine changes in the temperature of the heating element based on changes in the electrical resistance of the heating element. In particular, the control circuit may be configured to detect user smoking based on a decrease in the resistance of the heating element. The control circuit may be configured to detect the length or intensity of user smoking based on at least one of the length or magnitude of the decrease in the resistance of the heating element.

[0087] The control circuit may be configured to select a predetermined heating profile having a first or second duration based on a comparison of the detected user smoking behavior with a predetermined threshold value. The predetermined threshold value may be stored in the memory of the control circuit.

[0088] In one embodiment, the detected user smoking behavior may be the smoking interval during a first period, and preferably the average smoking interval for the first period. The control circuit may be configured to select a predetermined profile having a first duration if the smoking interval is greater than a predetermined threshold value for the smoking interval. The control circuit may be configured to select a predetermined profile having a second duration if the smoking interval is less than or equal to a predetermined threshold value for the smoking interval.

[0089] In another embodiment, the detected user smoking behavior may be the smoking frequency during the first period, preferably the average smoking frequency for the first period. The control circuit may be configured to select a predetermined profile having a first duration if the smoking frequency is below a predetermined threshold for the smoking frequency. The control circuit may be configured to select a predetermined profile having a second duration if the smoking frequency is greater than a predetermined threshold for the smoking interval.

[0090] The control circuit may be configured to select a first predetermined heating profile if a first user smoking behavior is detected. The control circuit may be configured to select a second predetermined heating profile if a second user smoking behavior is detected. The first user smoking behavior may be different from the second user smoking behavior.

[0091] The control circuit may be configured to select a first predetermined profile or a second predetermined profile based on a comparison of the detected user smoking behavior with a predetermined threshold. The predetermined threshold may be stored in the memory of the control circuit. Advantageously, the control circuit may use the predetermined threshold to distinguish between a first user smoking behavior and a second user smoking behavior.

[0092] The first user smoking behavior may include an interval between smoking that is greater than 20 seconds, preferably greater than 22 seconds, preferably greater than 24 seconds, preferably greater than 26 seconds, preferably greater than 28 seconds, preferably greater than 30 seconds, preferably greater than 32 seconds, preferably greater than 34 seconds.

[0093] Preferably, the interval may be an average interval. The average interval may be the time between pairs of successive smokings within the first period divided by the number of pairs of smokings.

[0094] The second user smoking behavior may include an interval between smoking sessions that is less than 34 seconds, preferably less than 32 seconds, preferably less than 30 seconds, preferably less than 28 seconds, preferably less than 26 seconds, preferably less than 24 seconds, preferably less than 22 seconds, preferably less than 20 seconds.

[0095] The predetermined threshold value for the user smoking behavior stored in the memory may be a threshold value for the smoking interval or the average smoking interval. The predetermined threshold value may be a value between 20 seconds and 34 seconds, preferably between 22 seconds and 32 seconds, preferably between 24 seconds and 30 seconds.

[0096] The plurality of predetermined heating profiles may include a third predetermined heating profile that is different from the first predetermined heating profile and the second predetermined heating profile. The control circuit may be configured to control the supply of power to the heater assembly during the first period according to the third predetermined heating profile.

[0097] If the first period includes a first period start and a first period end, and the first period end is a predetermined time after the first period start, the third predetermined heating profile may have the same duration as the predetermined time.

[0098] The third predetermined heating profile may include a third profile start. The third profile start may correspond to the first period start. In other words, the control circuit may be configured to control the supply of power to the heater assembly throughout the first period according to the third predetermined heating profile.

[0099] The third predetermined heating profile may be shorter than the first predetermined heating profile and the second predetermined heating profile.

[0100] The third predetermined heating profile may include a target temperature that is higher than the target temperature of the first predetermined heating profile or the second predetermined heating profile. Preferably, the third predetermined heating profile may include a target temperature that is higher than the target temperature of either the first predetermined heating profile or the second predetermined heating profile. This can be particularly advantageous when the control circuit is configured to control the heater assembly to rapidly increase the temperature to the vaporization temperature during the first period of the use session.

[0101] Regardless of the smoking behavior, controlling the supply of power to the heater assembly during the first period according to the third predetermined heating profile may be advantageous for the control circuit. This may be particularly preferred when it is desired to rapidly reach the vaporization temperature during the first period of the use session, when this is required by the heater assembly.

[0102] At least one of the plurality of predetermined heating profiles may comprise a first portion that is substantially identical to a first portion of another of the plurality of predetermined heating profiles. Each of the plurality of predetermined heating profiles may comprise a first portion that is substantially identical to a first portion of another of the plurality of predetermined heating profiles. The first portion may be an initial portion of each respective predetermined heating profile.

[0103] In certain embodiments, at least a first portion of the first predetermined heating profile may be substantially identical to a first portion of the second predetermined heating profile. The first portion of the first predetermined heating profile may correspond to the first portion of the second predetermined heating profile. Preferably, the first portion of each of the first predetermined heating profile and the second predetermined heating profile may be an initial portion of each respective heating profile.

[0104] The control circuit may be configured to control the supply of power to the heater assembly during a first period according to a first portion of one of a plurality of predetermined heating profiles. This may be an alternative to controlling the supply of power to the heater assembly according to a third predetermined heating profile dedicated to the first period, as described above.

[0105] Each first portion of a predetermined heating profile may comprise a target temperature configured such that the heater assembly rapidly raises its temperature to the vaporization temperature during a first period of a usage session. This may be advantageous for the heater assembly thus controlled during the first period, regardless of the smoking behavior or the predetermined heating profile selected.

[0106] One or more of the plurality of predetermined heating profiles may comprise a second portion. The second portion or each second portion may be subsequent to the first portion of the respective predetermined heating profile. The second portion of the first predetermined heating profile and the second predetermined heating profile, or the second portion of each of the first predetermined heating profile and the second predetermined heating profile, may start immediately after the end of the first portion of the respective predetermined heating profile.

[0107] The control circuit may be configured to control the supply of power to the heater assembly during a second period according to a second portion of the selected predetermined heating profile. The control circuit may be configured to include selecting, during the second period, the supply of power to the heater assembly such that the selection of controlling the supply of power to the heater assembly is to supply power according to a second portion of one of the predetermined heating profiles.

[0108] The aerosol generating device may comprise one or more user interface elements. A detection assembly, which may be configured to detect user interaction with the aerosol generating device, may comprise one or more user interface elements. In this embodiment, it is preferable that the user interaction may include at least one user operation of one or more of the user interface elements.

[0109] One or more user interface elements may be configured such that at least a first state and a second state may be selectable by a user of the device using one or more of the user interface elements. The control circuit may be configured to select a predetermined heating profile having either a first duration or a second duration depending on whether the first state or the second state of the user interface is selected.

[0110] The first state may correspond to a predetermined heating profile having a first duration. The second state may correspond to a predetermined heating profile having a second duration. The control circuit may be configured to select a predetermined heating profile having a first duration when the first state is selected by the user interface element. The control circuit may be configured to select a predetermined heating profile having a second duration when the selected state is selected by the user interface element.

[0111] One or more user interface elements may comprise one or more buttons or switches.

[0112] The aerosol generating device may be configured to generate an aerosol from an aerosol-forming substrate provided within the aerosol generating article.

[0113] As used herein, the term "aerosol-forming substrate" relates to a substrate having the ability to release volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. Advantageously, the aerosol-forming substrate may be part of an aerosol-generating article or a smoking article.

[0114] The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both a solid component and a liquid component. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds released from the substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise an aerosol former that facilitates the formation of a high-density and stable aerosol. Examples of suitable aerosol formers are glycerin and propylene glycol.

[0115] The aerosol-forming substrate may comprise an aggregated and crimped sheet of homogenized tobacco material. As used herein, the term "crimped sheet" means a sheet having a plurality of substantially parallel ridges or undulations. Alternatively or additionally, the aerosol-forming substrate may comprise strands, shreds of homogenized tobacco material. Preferably, the aerosol-forming substrate may comprise cut homogenized tobacco containing glycerin. Glycerin may be applied to the cut homogenized tobacco. Preferably, glycerin may be sprayed onto the homogenized tobacco.

[0116] The aerosol-generating system may comprise a cartridge containing the aerosol-forming substrate. The cartridge may be receivable within a chamber of the aerosol-generating device. The aerosol-forming substrate may be solid or liquid, or may comprise both a solid component and a liquid component. Preferably, the aerosol-forming substrate is liquid.

[0117] The aerosol-forming substrate may comprise a plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds released from the aerosol-forming substrate upon heating. Preferably, the aerosol-forming substrate may alternatively comprise a non-tobacco-containing material.

[0118] The aerosol-generating article may comprise a wrapper surrounding the aerosol-forming substrate. The aerosol-forming substrate may be a solid aerosol-forming substrate.

[0119] The aerosol-generating device may comprise a defining device housing. The device housing may define a cavity. The cavity may be for receiving the aerosol-forming substrate.

[0120] The control circuit may be configured such that the selection of a predetermined heating profile is further based on the detected type of the aerosol-forming substrate used with the aerosol-generating device. This is preferably in addition to the selection based on the trigger condition.

[0121] When the control circuit is configured such that the selection of a predetermined heating profile is further based on the detected type of the aerosol-forming substrate, the plurality of predetermined heating profiles may include a first subset including a heating profile having a first duration and a second subset including a heating profile having a second duration. The control circuit may be configured to select the first subset or the second subset based on the trigger condition. The control circuit may be configured to select one of the heating profiles from the first or second subset respectively based on the determined type of the aerosol-forming substrate.

[0122] The aerosol generating device may comprise a substrate detector configured to detect the type of aerosol forming substrate used with the device. The substrate detector may be configured to detect the properties of the aerosol forming substrate used with the device, or the properties of the aerosol generating article comprising the aerosol forming substrate. The properties may be physical or chemical properties of the aerosol forming substrate. The substrate detector may comprise an emitter of electromagnetic radiation and a receiver of electromagnetic radiation, and the properties may be spectroscopic properties associated with the aerosol forming substrate or the aerosol generating article. The properties may be associated with a tagant or other indicia incorporated into the aerosol forming substrate or the aerosol generating article.

[0123] The control circuit may be configured to determine the type of aerosol forming substrate to be used with the device based on the signal received from the substrate detector. The control circuit may be configured to determine the type of aerosol forming substrate to be used with the device during or prior to a use session. If the control circuit is configured to determine the type of aerosol forming substrate used with the device during a use session, it may be configured to determine during a first period.

[0124] In a second aspect, an aerosol generating system is provided. The aerosol generating system may comprise an aerosol generating device. The aerosol generating device may be the aerosol generating device described in the first aspect.

[0125] The aerosol generating system may further comprise one or more aerosol generating articles. Each of the one or more aerosol generating articles, or the one or more aerosol generating articles, may comprise a rod of aerosol forming substrate.

[0126] As described with respect to the first aspect, the control circuit of the aerosol generating device may advantageously select a predetermined heating profile having a first or second duration based on a trigger condition. In one embodiment, the control circuit may make this selection regardless of the type of aerosol-forming substrate used with the device. In another embodiment, the control circuit may be configured to use the detected type of aerosol-forming substrate in addition to the determined smoking behavior to select a particular predetermined heating profile from a subset of predetermined heating profiles having a first or second duration.

[0127] The aerosol generating system may comprise a plurality of aerosol generating articles. At least two of the aerosol generating articles may comprise a rod of a first type of aerosol-forming substrate.

[0128] The first aerosol generating article of the plurality of aerosol generating articles may comprise a first identifier. The second aerosol generating article of the plurality of aerosol generating articles may comprise a second identifier different from the first identifier. The first and second aerosol generating articles may comprise a rod of a first type of aerosol-forming substrate.

[0129] Preferably, except for the first and second identifiers, the first and second aerosol generating articles may have substantially the same structure as each other.

[0130] The first and second identifiers may each comprise a taggant, barcode or other printed mark. Preferably, the first identifier comprises a first taggant and the second identifier may comprise a second taggant.

[0131] Providing a taggant on the aerosol generating article may enable the aerosol generating article to be detected and identified by an aerosol generating device comprising a suitable detector. For example, the taggant may comprise a photoluminescent material having a photoluminescence decay half-life of from 50 microseconds to 1000 microseconds after photoexcitation of the photoluminescent material.

[0132] As used herein with reference to the present invention, the term "luminescence half-life" refers to the time it takes for the intensity of the radiated luminescence by the photoluminescent material to decay by half after the photoluminescent material has been irradiated by a radiation source and after the radiation source has been removed or switched off.

[0133] An aerosol generating article may include an aerosol forming substrate, a downstream section provided downstream of the aerosol forming substrate, and a tagant provided on the downstream section, wherein an upstream end of the tagant is at least 0.5 millimeters from a downstream end of the aerosol generating substrate.

[0134] Providing the tagant at a position 0.5 millimeters downstream of the aerosol generating substrate provides several advantages. First, this provides allows the detector to be located away from and downstream of a portion of the cavity that is heated by one or more electric heater elements. During repeated use, the portion of the cavity that is heated may result in the accumulation of heating by-products and slurries, which may condense on the inner walls of the cavity. Positioning the tagant at least 0.5 millimeters away from the aerosol generating substrate may also allow the detector to be located at least 0.5 millimeters away from the portion of the cavity that is most susceptible to the effects of the accumulation of heating by-products and slurries. This may advantageously improve the reliability of the detector.

[0135] Second, this provision prevents the tagant itself from being directly heated during use because the tagant is located downstream of the location of the aerosol-generating article that needs to be heated. Some tagants are expected to degrade or be damaged when heated. Therefore, positioning the tagant downstream of the aerosol-generating substrate can advantageously improve the reliability of tagant detection because it can prevent the tagant from being damaged. Additionally, this provision may prevent the tagant from contacting the heating by-products and slurries that are most likely to be located in the cavity portion that is heated during use. Therefore, this can further improve the reliability of tagant detection by preventing contamination of the tagant.

[0136] Third, this provision enables the tagant to be located very close to the opening of the cavity when the aerosol-generating article is fully inserted into the cavity. This may enable the detector to be located near the opening of the cavity. This may also enable the detector to be easily cleaned using appropriate tools if heating by-products and slurries deposit on the detector. This can advantageously improve the reliability of the detector.

[0137] The upstream end of the tagant may be at least 0.5 millimeters from the downstream end of the aerosol-generating substrate. For example, the upstream end of the tagant may be at least 1 millimeter, at least 1.5 millimeters, or at least 2 millimeters from the downstream end of the aerosol-generating substrate.

[0138] The tagant may be provided on any component on the downstream section. For example, the tagant may be provided on one or more of an adhesive, a wrapper, tipping paper, a filter plug, a susceptor, a mouthpiece filter, a space tube, or, if present, a flavorant. The tagant may be provided on two or more components. This can advantageously make the detection of the tagant by the detector more reliable.

[0139] The downstream section may comprise a wrapper. The wrapper may surround one or more components of the downstream section. The wrapper may couple the downstream section to the aerosol-generating substrate. The downstream section may comprise two or more wrappers. For example, the downstream section may comprise tipping paper or a bonding wrapper. Where the downstream section comprises two or more wrappers and the wrappers overlap, the tagant may be provided on the outermost wrapper. The outermost wrapper may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in particular embodiments of the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap.

[0140] The tagant may be provided on the inner surface of the wrapper. Advantageously, this may further protect the tagant from damage or contamination. Advantageously, this may improve the reliability of the tagant.

[0141] The tagant may be provided on the inner surface of the outermost wrapper.

[0142] The tagant may be provided on the outer surface of the wrapper. The tagant may be provided on both the inner and outer surfaces of the wrapper.

[0143] The tagant may be printed on the inner surface of the wrapper. The tagant may be sprayed or applied on the inner surface of the wrapper.

[0144] The length of the rod of the aerosol-forming substrate may be at least 30 percent of the length of the aerosol-generating article. The rod of the aerosol-forming substrate may have a tobacco content of from 30 weight percent to 90 weight percent on a dry weight basis.

[0145] The aerosol-generating article may comprise a hollow tubular element at the downstream end of the rod of the aerosol-forming substrate. The aerosol-generating article may comprise a mouthpiece element at the downstream end of the hollow tubular element.

[0146] In some aerosol-generating articles, it may be desirable to include components other than tobacco and aerosol-forming substances within the rod of the aerosol-forming substrate. For example, it may be desirable to include one or more flavorants within the rod of the aerosol-forming substrate.

[0147] The term "flavorant" refers to a sensory-stimulating compound, composition, or material that modifies, or is intended to modify, the taste or aroma characteristics of one or more components of the aerosol-forming substrate during consumption or inhalation thereof. A flavorant may, for example, modify the taste or aroma characteristics of nicotine during consumption or inhalation thereof, and / or may be intended to do so. For the purposes of the present disclosure, nicotine is not considered a "flavorant" or a flavor.

[0148] The rod of the aerosol-forming substrate may contain one of a greater number of flavorants. The rod of the aerosol-forming substrate may contain a plurality of flavorants.

[0149] The rod of the aerosol-forming substrate may have a flavorant content of at least 0.1 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 1 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 3 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 5 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 8 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 10 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 13 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 15 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of at least 18 weight percent on a dry weight basis.

[0150] The rod of the aerosol-forming substrate may have a flavorant content of 25 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 20 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 18 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 15 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 13 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 10 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 8 weight percent or less on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of 5 weight percent or less on a dry weight basis.

[0151] The rod of the aerosol-forming substrate may have a flavorant content of from 0.1 to 25 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of from 0.1 to 20 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of from 5 to 20 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of from 10 to 20 weight percent on a dry weight basis. The rod of the aerosol-forming substrate may have a flavorant content of from 15 to 20 weight percent on a dry weight basis.

[0152] One or more flavorants may be one or more of clove, ginger, mint, rosemary, star anise, and tea. A plurality of flavorants may be a combination of two or more of clove, ginger, mint, rosemary, star anise, and tea.

[0153] In one embodiment, the rod of the aerosol-forming substrate may also include clove.

[0154] The rod of the aerosol-forming substrate may contain at least 30 milligrams of flavorant. The rod of the aerosol-forming substrate may contain at least 35 milligrams of flavorant. The rod of the aerosol-forming substrate may contain at least 40 milligrams of flavorant. The rod of the aerosol-forming substrate may contain at least 45 milligrams of flavorant. The rod of the aerosol-forming substrate may contain at least 50 milligrams of flavorant.

[0155] The hollow tubular element may have a length of at least 15 millimeters. The hollow tubular element may have a length of at least 17 millimeters. The hollow tubular element may have a length of at least 19 millimeters.

[0156] The hollow tubular element may have a length of 30 millimeters or less. The hollow tubular element may have a length of 25 millimeters or less. The hollow tubular element may have a length of 23 millimeters or less.

[0157] The hollow tubular element may have a length of from 15 millimeters to 30 millimeters. The hollow tubular element may have a length of from 17 millimeters to 25 millimeters. The hollow tubular element may have a length of from 19 millimeters to 23 millimeters. In one embodiment, the length of the hollow tubular element is 12 millimeters.

[0158] In a third aspect, a method is provided for controlling the power supplied to the heater assembly of an aerosol-generating device to generate an aerosol from an aerosol-generating article comprising an aerosol-forming substrate during a use session. The use session may include a use session start and the use session may comprise a use session end.

[0159] The method may include detecting a trigger condition. The trigger condition may depend on at least one of a user interaction with the aerosol-generating device or a characteristic of the aerosol-generating article used with the device.

[0160] The method may include selecting one of a plurality of predetermined heating profiles for use during a usage session. The selection may be based on detected trigger conditions.

[0161] At least one of the plurality of predetermined heating profiles may have a first duration. At least one of the plurality of predetermined heating profiles may have a second duration. The second duration may be different from the first duration. The selected predetermined heating profile may have either the first duration or the second duration.

[0162] The method may include controlling the supply of power to the heater assembly in accordance with the selected predetermined heating profile having either the first duration or the second duration.

[0163] The method may include detecting at least one of user interaction with the aerosol generating device or characteristics of the aerosol generating article used with the device.

[0164] The aerosol generating device may comprise a device housing defining a cavity for receiving the aerosol generating article. The cavity may be configured to receive at least a portion of the aerosol generating article comprising the aerosol forming substrate. The method may include detecting characteristics of the aerosol generating article received within the cavity, preferably an identifier of the aerosol generating article.

[0165] The method may include selecting a predetermined heating profile having either the first duration or the second duration depending on whether the first or second identifier has been detected. The method may include selecting a predetermined heating profile having the first duration when the first identifier is detected. The method may include selecting a predetermined heating profile having the second duration when the second identifier is detected.

[0166] The method may include determining the user's smoking behavior during a first period of a usage session.

[0167] The method may include selecting a predetermined heating profile having either a first duration or a second duration according to the determined user smoking behavior.

[0168] The method may include controlling the supply of power to the heater assembly during a second period of the usage session according to the selected predetermined heating profile.

[0169] The method may include determining the user's smoking behavior based on one or more user smokes during the first period of the usage session. The method may include determining the user's smoking behavior over a plurality of user smokes during the first period.

[0170] The method may include determining the average smoking behavior for a plurality of user smokes during the first period.

[0171] The method may monitor the number of smokes that occurred during the first period. The end of the first period may be when the control circuit detects that a predetermined number of smokes have occurred within the first period.

[0172] The method may include detecting the user's smoking behavior based on a signal received from a detector of the aerosol generating device.

[0173] Features described with respect to one aspect may be applied to other aspects of the present disclosure. Specifically, advantageous features or optional features described with respect to a first aspect of the present disclosure may be applied to a second disclosure and a third disclosure, and vice versa.

Example

[0174] The present invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more of the features of these examples may be combined with any one or more of the features of another example, embodiment, or aspect described herein.

[0175] Example 1. An aerosol generating device for generating an aerosol from an aerosol generating article comprising an aerosol forming substrate, the aerosol generating device being configured to generate an aerosol during a use session including the start and end of the use session, the aerosol generating device a heater assembly for heating the aerosol forming substrate, and a power source configured to supply power to the heater assembly, and a control circuit comprising a memory in which a plurality of predetermined heating profiles are stored, at least one of the plurality of predetermined heating profiles having a first duration and at least one of the predetermined heating profiles having a second duration different from the first duration, the control circuit, and the control circuit is configured to detect a trigger condition and select a predetermined heating profile for use during the use session based on the detected trigger condition, the selected predetermined heating profile having either the first duration or the second duration, and the trigger condition depending on at least one of a user interaction with the aerosol generating device or a characteristic of the aerosol generating article used with the device, the aerosol generating device. Example 2. The aerosol generating device according to Example 1, wherein the control circuit is configured to control the supply of power to the heater assembly according to a selected predetermined heating profile having either the first duration or the second duration. Example 3. The aerosol generating device according to Example 1 or 2, wherein both the first duration and the second duration are longer than 1 minute, preferably longer than 2 minutes. Example 4. The aerosol generating device according to any one of Examples 1 to 3, wherein the first duration is longer than the second duration. Example 5. The aerosol generating device according to any one of Examples 1 to 4, wherein the first duration is at least 30% longer than the second duration, preferably at least 40% longer, preferably at least 50% longer, preferably at least 75% longer. Example 6. The aerosol generating device according to any one of Examples 1 to 5, wherein the first duration is 18 minutes or less, preferably 15 minutes or less, preferably 12 minutes or less. Example 7. The aerosol generating device according to any one of Examples 1 to 6, wherein the first duration is longer than 5 minutes, preferably longer than 6 minutes, preferably longer than 8 minutes. Example 8. The aerosol generating device according to any one of Examples 1 to 7, wherein the second duration is 8 minutes or less, preferably 6 minutes or less, preferably 4 minutes or less. Example 9. The aerosol generating device according to any one of Examples 1 to 8, wherein the second duration is longer than 1 minute, preferably longer than 2 minutes. Example 10. The aerosol generating device according to any one of Examples 1 to 9, wherein the duration of the usage session depends on the duration of a selected predetermined heating profile. Example 11. The aerosol generating device according to any one of Examples 1 to 10, wherein when the selected predetermined heating profile has the first duration, the maximum duration of the usage session is at least 5 minutes, preferably at least 6 minutes, preferably at least 8 minutes, preferably at least 10 minutes, preferably at least 12 minutes. Example 12. The aerosol generating device according to any one of Examples 1 to 11, wherein when the selected predetermined heating profile has the second duration, the maximum duration of the usage session is 10 minutes or less, preferably 8 minutes or less, preferably 7 minutes or less, preferably 6 minutes or less. Example 13. The aerosol generation system according to any one of Examples 1 to 12, wherein the plurality of predetermined heating profiles includes a first predetermined heating profile having a first duration and a second predetermined heating profile having a second duration. Example 14. The aerosol generating device according to any one of Examples 1 to 13, wherein the usage session includes a plurality of smoking events. Example 15. The aerosol generating device according to Example 14, wherein the usage session includes at least 6 smoking events, preferably at least 8 smoking events, preferably at least 10 smoking events, preferably at least 12 smoking events. Example 16. The aerosol generating device according to any one of Examples 1 to 15, wherein the end of the usage session corresponds to the end of a selected predetermined heating profile. Example 17. The aerosol generating device according to any one of Examples 1 to 16, further comprising a detection assembly configured to detect at least one of user interaction with the aerosol generating device or characteristics of the aerosol generating article used with the device. Example 18. The aerosol generating device according to Example 17, wherein the aerosol generating device comprises a device housing defining a cavity for receiving an aerosol forming substrate. Example 19. The aerosol generating device according to Example 18, wherein the detection assembly is configured to detect characteristics of the aerosol generating article received within the cavity. Example 20. The aerosol generating device according to Example 19, wherein the detection assembly is configured to detect an identifier of the aerosol generating article received within the cavity. Example 21. The aerosol generating device according to Example 20, wherein the detector assembly is configured to distinguish between a first identifier and a second identifier different from the first identifier. Example 22. The aerosol generating device according to embodiment 21, wherein the control circuit is configured to select a predetermined heating profile having either a first duration or a second duration according to which of the first identifier or the second identifier is detected. Embodiment 23. The aerosol generating device according to embodiment 21 or 22, wherein the control circuit is configured to select a predetermined heating profile having a first duration when the first identifier is detected. Embodiment 24. The aerosol generating device according to any one of embodiments 21 to 23, wherein the control circuit is configured to select a predetermined heating profile having a second duration when the second identifier is detected. Embodiment 25. The aerosol generating device according to any one of embodiments 1 to 24, wherein the control circuit is configured to determine user smoking behavior during a first period of a usage session. Embodiment 26. The aerosol generating device according to embodiment 25, wherein the control circuit is configured to select a predetermined heating profile having either a first duration or a second duration depending on the determined user smoking behavior. Embodiment 27. The aerosol generating device according to embodiment 26, wherein the control circuit is configured to control the supply of power to the heater assembly according to a predetermined heating profile selected during a second period of a usage session. Embodiment 28. The aerosol generating device according to embodiment 26 or 27, wherein the first period of the usage session includes one or more user smokes. Embodiment 29. The aerosol generating device according to embodiment 28, wherein the first period of the usage session includes a plurality of user smokes. Embodiment 30. The aerosol generating device according to any one of embodiments 26 to 29, wherein the control circuit is configured to determine user smoking behavior based on one or more user smokes during a first period of a usage session. Embodiment 31. The aerosol generating device according to embodiment 30, wherein the control circuit is configured to evaluate user smoking behavior determined over a plurality of user smokes during a first period. Embodiment 32. The aerosol generating device according to embodiment 31, wherein the control circuit is configured to determine an average smoking behavior over a plurality of user smokes during a first period. Embodiment 33. The aerosol generating device according to any one of embodiments 26 to 32, wherein the first period includes a first period start and a first period end. Embodiment 34. The aerosol generating device according to embodiment 33, wherein the end of the first period is at least 20 seconds after the start of the first period, preferably at least 30 seconds after the start of the first period, preferably at least 40 seconds after the start of the first period, preferably at least 50 seconds after the start of the first period, preferably at least 75 seconds after the start of the first period, preferably at least 90 seconds after the start of the first period. Embodiment 35. The aerosol generating device according to embodiment 33 or 34, wherein the start of the first period is 150 seconds or less, preferably 140 seconds or less, preferably 130 seconds or less, preferably 120 seconds or less, preferably 110 seconds or less from the start of the first period. Embodiment 36. The aerosol generating device according to any one of embodiments 33 to 35, wherein the end of the first period is after a predetermined time from the start of the first period. Embodiment 37. The aerosol generating device according to embodiment 36, wherein the predetermined time is at least 20 seconds, preferably at least 30 seconds, preferably at least 40 seconds, preferably at least 50 seconds, preferably at least 75 seconds, preferably at least 90 seconds. Embodiment 38. The aerosol generating device according to embodiment 36 or 37, wherein the predetermined time is 150 seconds or less, preferably 140 seconds or less, preferably 130 seconds or less, preferably 120 seconds or less, preferably 110 seconds or less. Embodiment 39. The aerosol generating device according to any one of Examples 26 to 38, wherein the control circuit is configured to monitor the number of smoking occurrences during the first period. Example 40. The aerosol generating device according to Example 39, wherein the control circuit is configured such that the end of the first period is when the control circuit detects that a predetermined number of smoking occurrences have occurred during the first period. Example 41. The aerosol generating device according to Example 40, wherein the predetermined number of user smoking occurrences during the first period may be at least 2 smoking occurrences, preferably at least 3 smoking occurrences. Example 42. The aerosol generating device according to any one of Examples 33 to 41, wherein the start of the first period corresponds to the start of the usage session. Example 43. The aerosol generating device according to Example 42, wherein the first period of the usage session is the initial period of the usage session. Example 44. The aerosol generating device according to any one of Examples 25 to 43, further comprising a detection assembly configured to detect user interaction with the aerosol generating device, wherein the user interaction includes user smoking. Example 45. The aerosol generating device according to Example 44, wherein the control circuit is configured to determine user smoking behavior during the first period of the usage session based on a signal received from the detection assembly. Example 46. The aerosol generating device according to Example 44 or 45, wherein the detection assembly is configured to detect a parameter representing user smoking. Example 47. The aerosol generating device according to Example 46, wherein the control circuit is configured to detect user smoking based on a change in the detected parameter. Example 48. The aerosol generating device according to any one of Examples 24 to 30, wherein the detection assembly comprises a pressure sensor, a flow sensor, a temperature sensor, or a sensor for the amount of aerosol. Example 49. The aerosol generating device according to any one of Examples 1 to 48, further comprising one or more user interface elements. Example 50. The aerosol generating device according to Example 49, further comprising a detection assembly configured to detect user interaction with the aerosol generating device, the detection assembly comprising a user interface element. Example 51. The aerosol generating device according to Example 50, wherein the user interaction includes at least one user operation of one or more of the user interface elements. Example 52. The aerosol generating device according to Example 50 or 51, wherein the one or more user interface elements are configured such that a first state and a second state can be selected by a user of the device using the one or more user interface elements. Example 53. The aerosol generating device according to Example 52, wherein the control circuit is configured to select a predetermined heating profile having either a first duration or a second duration depending on whether the first state or the second state of the user interface is selected. Example 54. The aerosol generating device according to Example 52 or 53, wherein the first state corresponds to a predetermined heating profile having a first duration, and the second state corresponds to a predetermined heating profile having a second duration. Example 55. The aerosol generating device according to any one of Examples 52 to 53, wherein the control circuit is configured to select a predetermined heating profile having a first duration when the first state is selected by the user interface element. Example 56. The aerosol generating device according to any one of Examples 52 to 55, wherein the control circuit is configured to select a predetermined heating profile having a second duration when the selected state is selected by the user interface element. Example 57. An aerosol generator configured to generate an aerosol from an aerosol-forming substrate provided within an aerosol-generating article, the aerosol generator according to any one of Examples 1 to 56. Example 58. An aerosol generator according to any one of Examples 1 to 57, wherein the aerosol-generating article comprises a wrapper surrounding the aerosol-forming substrate. Example 59. An aerosol generator according to any one of Examples 1 to 58, wherein the aerosol-forming substrate is a solid aerosol-forming substrate. Example 60. An aerosol generator according to any one of Examples 1 to 59, comprising a device housing defining a cavity for receiving the aerosol-forming substrate. Example 61. An aerosol-generating system comprising an aerosol generator according to any one of Examples 1 to 60 and one or more aerosol-generating articles comprising a rod of an aerosol-forming substrate. Example 62. The aerosol-generating system according to Example 61, comprising a plurality of aerosol-generating articles comprising a first type of rod of an aerosol-forming substrate. Example 63. The aerosol-generating system according to Example 61 or 62, wherein a first aerosol-generating article of the plurality of aerosol-generating articles comprises a first identifier and a second aerosol-generating article of the plurality of aerosol-generating articles comprises a second identifier different from the first identifier. Example 64. The aerosol-generating system according to Example 63, wherein, apart from the first and second identifiers, the first and second aerosol-generating articles comprise substantially the same structure as each other. Example 65. The aerosol-generating system according to Example 63 or 64, wherein the first and second identifiers each comprise a tagant. Example 66. An aerosol generation system according to any one of Examples 63 to 65, wherein the rod of the aerosol-forming substrate contains one or more flavoring agents. Example 67. An aerosol generation system according to Example 66, wherein the rod of the aerosol-forming substrate contains a plurality of flavoring agents. Example 68. An aerosol generation system according to Example 67 or 68, wherein the one or more flavoring agents are one or more of clove, ginger, mint, rosemary, star anise, and tea. Example 69. An aerosol generation system according to Example 68, wherein the rod of the aerosol-forming substrate contains clove. Example 70. A method of controlling the power supplied to a heater assembly of an aerosol generating device to generate an aerosol from an aerosol generating article comprising an aerosol-forming substrate during a usage session including a usage session start and a usage session end, the method comprising: detecting a trigger condition that depends on at least one of user interaction with the aerosol generating device or a characteristic of the aerosol generating article used with the device; selecting, based on the detected trigger condition, one of a plurality of predetermined heating profiles for use during the usage session, wherein at least one of the plurality of predetermined heating profiles has a first duration and at least one of the predetermined heating profiles has a second duration different from the first duration; The method, wherein the selected predetermined heating profile has either the first duration or the second duration.

Brief Description of the Drawings

[0176] Here, the examples will be further described with reference to the drawings.

[0177]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0178] Figure 1 is a schematic cross-sectional view of a first aerosol generating device 100. The aerosol generating device 100 includes a cavity 10 defined by a device housing 11. The cavity 10 is tubular and has a base 12 at its upstream end. The cavity 10 is configured to receive an aerosol generating article 200.

[0179] The aerosol generating article 200 is received within the cavity 10. The aerosol generating article 200 is shown separately from the aerosol generating device 100 in FIG. 2. FIG. 2 is also a schematic cross-sectional view of the aerosol generating article 200.

[0180] The aerosol generating article 200 includes a rod 212 of an aerosol forming substrate and a downstream section 214 at a location downstream of the rod 212 of the aerosol forming substrate. The downstream section 214 includes a hollow tubular element 220 and a mouthpiece element 204.

[0181] The aerosol generating article 200 includes an upstream wrapper 244 surrounding the aerosol forming substrate 212 and the hollow tubular element 220.

[0182] The aerosol generating article 200 also includes a tipping wrapper 252 surrounding the hollow tubular element 220 and the mouthpiece element 204. The tipping wrapper 252 is on top of a portion of the upstream wrapper 244 that is on top of the hollow tubular element 220. In this way, the tipping wrapper 252 effectively couples the mouthpiece element 204 to the remaining components of the aerosol generating article 200. In this embodiment, the width of the tipping wrapper 252 is about 26 millimeters.

[0183] The aerosol generating article 200 has an overall length of about 45 millimeters and an outer diameter of about 7.2 mm.

[0184] The rod 212 of the aerosol-forming substrate contains shredded tobacco material. In this example, the rod 212 of the aerosol-forming substrate also contains cloves. The rod 212 of the aerosol-forming substrate contains 150 milligrams of shredded tobacco material containing 13% to 16% by weight of glycerin. The density of the aerosol-forming substrate is about 300 mg per cubic centimeter. The RTD of the rod 212 of the aerosol-forming substrate is about 6 to 8 mmH2O. The rod 212 of the aerosol-forming substrate also contains 52 milligrams of cloves. The rod 212 of the aerosol-forming substrate is individually wrapped by a plug wrap (not shown).

[0185] The hollow tubular element 220 is located immediately downstream of the rod 212 of the aerosol-forming substrate. The hollow tubular element 220 is in axial alignment with the rod 212 of the aerosol-forming substrate. The upstream end of the hollow tubular element 220 abuts against the downstream end of the rod 212 of the aerosol-forming substrate.

[0186] The hollow tubular element 220 defines a hollow section of the aerosol-generating article 10. The hollow tubular element does not substantially contribute to the overall RTD of the aerosol-generating article. More specifically, the RTD of the hollow tubular element 220 is about 0 mmH2O.

[0187] The hollow tubular element 220 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular element 220 defines an internal cavity 222 that extends all the way from the upstream end of the hollow tubular element 20 to the downstream end of the hollow tubular element 220. The internal cavity 222 is substantially empty, and thus allows for a substantially unobstructed airflow along the internal cavity 22. The hollow tubular element 220 does not substantially contribute to the overall RTD of the aerosol-generating article 200.

[0188] In this example, the hollow tubular element 220 has a length of about 21 millimeters, an outer diameter of about 7.2 millimeters, and an inner diameter of about 6.7 millimeters. Therefore, the thickness of the peripheral wall of the hollow tubular element 20 is about 0.25 millimeters.

[0189] The aerosol generating article 200 comprises a ventilation zone 230 provided at a location along a hollow tubular element 20.

[0190] The ventilation zone 230 may also comprise a circumferential row of perforations provided on an upstream wrapper 244. The perforations of the upstream wrapper 244 overlap the perforations provided on a hollow tubular element 220. As a result, the upstream wrapper 244 is above the perforations of the ventilation zone 230 provided on the hollow tubular element 220.

[0191] The mouthpiece element 204 extends from the downstream end of the hollow tubular element 220 to the downstream or mouth side end of the aerosol generating article 200. The mouthpiece element 204 has a length of about 7 mm. The outer diameter of the mouthpiece element 204 is about 7.2 mm. The mouthpiece element 204 comprises a low density cellulose acetate filter segment. The RTD of the mouthpiece element 204 is about 8 millimeters H2O. The mouthpiece element 204 may be individually wrapped by a plug wrap (not shown).

[0192] As shown in FIG. 1, the aerosol generating device 100 together with the aerosol generating article 200 may be referred to as an aerosol generating system.

[0193] The aerosol generating device 100 of the aerosol generating system comprises a heater assembly including a heating element 110. The heating element 110 surrounds a cavity 10 along a portion of the cavity in which the aerosol forming substrate of the aerosol generating article 200 is received. In an alternative embodiment, the heating element 110 forms a portion of a housing 11 that defines a part of the cavity for receiving the aerosol forming substrate. The heating element 110 is a resistive heating element.

[0194] The airflow channel 120 extends from the air inlet 122 of the aerosol generating device 100. Upstream of the cavity, the airflow channel 120 is mainly defined by the airflow channel wall 124. Downstream of the airflow channel wall 124, the airflow channel 120 passes through an air outlet defined within the base 12 of the cavity. The airflow channel 120 then extends through the cavity 10. When the aerosol generating article 200 is received within the cavity 10, the airflow channel 120 passes through the aerosol generating article 200 and extends through the mouthpiece 204.

[0195] The aerosol generating device 100 further comprises a power source 130 in the form of a rechargeable battery for supplying power to a heating element 110 that can be controlled by a control circuit 132. The power source is connected to the control circuit 132 and the heating element 110 via electrical wires and connectors not shown in the figure. The aerosol generating device may comprise further elements not shown in the figure, such as a button for activating the aerosol generating device.

[0196] A usage session of the aerosol generating device 100 is started, for example, after the user of the aerosol generating device switches the device on using a button or switch on the aerosol generating device. The usage session includes a usage session start corresponding to the point at which the aerosol generating device 100 is started and a usage session end corresponding to the point at which the aerosol generating device 100 is switched off.

[0197] The start of the aerosol generating device 100 at the start of the usage session causes the control circuit 132 to supply power from the power source 130 to the heating element 110, whereby an electric current passes through the heating element 110 causing heating of the heating element 110. Heat is transferred to the aerosol forming substrate, whereby the volatile compound is vaporized from the aerosol forming substrate.

[0198] During use, the user inhales multiple times through the mouthpiece 204 of the received aerosol-generating article 200. During each user inhalation, inhalation through the mouthpiece 204 of the received aerosol-generating article 200 results in air being drawn towards the user's mouth through the airflow channel 120. During inhalation, air is drawn from outside the aerosol-generating device, through the air inlet 122 defined within the base 12 of the cavity 10, and into the cavity, and through the air inlet and into the airflow channel 120. Since the aerosol-generating article 200 is received within the cavity 10, the air drawn into the cavity 10 will enter the aerosol-generating article 200 at its distal end 216. Therefore, the air passes through the aerosol-forming substrate 212. By doing so, the volatile compounds generated by heating the substrate 212 become entrained in the air. As the air continues to travel towards the mouth-side end of the aerosol-generating article 200, the volatile compounds are cooled to form an aerosol, which is then inhaled by the user of the device.

[0199] As described in more detail below, the control circuit 132 is configured to control the supply of power to the heater assembly according to one or more of a predetermined heating profile throughout the use session. The control circuit 132 comprises a memory in which a plurality of different predetermined heating profiles are stored. The predetermined heating profile is an effective instruction for the control circuit to control the supply of power to the heater assembly, whereby the heating element is heated while referring to a plurality of target temperatures. Each predetermined heating profile includes information regarding the value of the target temperature, the order of the target temperatures, and the length of time the control circuit is configured to supply power to the heater assembly with respect to each individual target temperature. Each predetermined heating profile is configured to ensure consistent aerosol generation throughout the use session, assuming a particular user smoking behavior.

[0200] The first predetermined heating profile and the second predetermined heating profile are stored in the memory of the control circuit 132, and the control circuit 132 is configured to select one of the first and second predetermined heating profiles based on a trigger condition.

[0201] In a first embodiment, the trigger condition depends on the user's smoking behavior. In particular, the user's smoking behavior during an initial portion of a usage session is determined, and the determined user smoking behavior is used to select the first or second predetermined heating profile. This is described in more detail with respect to FIGS. 3-6.

[0202] FIG. 3 is a graph 300 representing a first predetermined heating profile and a second predetermined heating profile stored in the memory of the control circuit 132. Graph 300 is a schematic diagram and is not drawn to scale.

[0203] Graph 300 includes time on the x-axis 302 and temperature on the y-axis 304, and shows a complete usage session where the usage session start is at t = 0 seconds. The usage session is divided into a first period 306 and second periods 308a, 308b. As will be described similarly, the second period 308a is associated with the first predetermined heating profile and the second period 308b is associated with the second predetermined heating profile.

[0204] The first period includes a first period start at t = 0 seconds and further includes a first period end corresponding to the second period start, whereby the first period and the second period are sequential.

[0205] The first predetermined heating profile is represented by 310 on graph 300, and the second predetermined heating profile is represented by 312. Each of the first predetermined heating profile and the second predetermined heating profile includes four target temperatures. The target temperatures change in a stepwise manner as the usage session progresses. The first predetermined heating profile 310 has a longer overall duration than the second predetermined heating profile 312.

[0206] Throughout the entirety of the first period 306, the initial target temperatures for each of the first predetermined heating profile and the second predetermined heating profile are the same, whereby the initial portion of the first predetermined heating profile is identical to the initial portion of the second predetermined heating profile.

[0207] The initial target temperatures for each of the first predetermined heating profile and the second predetermined heating profile are higher than the subsequent target temperatures of the predetermined heating profile. In this way, when either the first predetermined heating profile or the second predetermined heating profile is selected, power is supplied to the heater assembly to rapidly increase the temperature of the heating element at the start of the usage session.

[0208] After the first period 306, the first predetermined heating profile 310 is different from the second predetermined heating profile 312. Specifically, each of the second through fourth target temperatures of the first heating profile 310 is lower than each of the respective second through fourth target temperatures of the second heating profile 312. Moreover, the first predetermined heating profile 310 includes heating the heating element to each of the second through fourth target temperatures for a longer period than each of the second through fourth target temperatures of the second heating profile 312.

[0209] The first predetermined heating profile 310 is suitable for different user smoking behaviors as compared to the second predetermined heating profile 312. Specifically, the first predetermined heating profile 310 that is longer and at a lower temperature is suitable for user smoking behaviors having an average smoking interval longer and an average smoking frequency lower than that of a second user smoking behavior.

[0210] The second period includes the end of the second period corresponding to the end of the usage session. Since the first predetermined heating profile is longer than the second predetermined heating profile, the second period varies depending on which predetermined heating profile is selected. Specifically, the second period 308a on the graph 300 corresponds to the second period when the first predetermined heating profile is selected, and the second period 308b corresponds to the second period when the second predetermined heating profile is selected.

[0211] FIG. 4 is a flowchart of a method for controlling the power supplied to the heater assembly of the aerosol generating device 100 during a usage session. FIG. 5 is a graph 500 of the temperature of the heater element 110 during a usage session in which the user follows a first user smoking behavior and the method of FIG. 4 is applied. The graph 500 is a schematic view and is not drawn to scale.

[0212] Similar to the graph 300, the graph 500 includes time on the x-axis 502 and temperature on the y-axis 504, and shows a complete usage session with the start of the usage session at t = 0 seconds. The usage session is again divided into a first period 306 and a second period 308a.

[0213] Step 402 of the method for controlling the power supplied to the heater assembly of the aerosol generator 100 during a usage session includes supplying power to the heater assembly during a first period 306 in accordance with an initial portion of a first predetermined heating profile. As described with respect to FIG. 3, the target temperature during the first period 306 is high, so that the temperature of the heating element 100 rapidly rises to the operating temperature at the start of the first period 306, whereby aerosol is generated for the user to inhale during user smoking.

[0214] The initial portions of the first predetermined heating profile and the second predetermined heating profile are the same. Thus, in an alternative example, step 302 of the method includes controlling the power supplied to the heater assembly during the first period 306 in accordance with an initial portion of the second predetermined heating profile. Graph 500 will initially appear the same during the first period 306, whether following the first predetermined heating profile or the second predetermined heating profile.

[0215] Step 404 of the method includes determining a user smoking behavior during a first period 306 of a usage session. Specifically, the user smoking behavior is the average interval between smoking puffs during the first period.

[0216] The average interval between smoking puffs is determined by detecting individual user smoking during the first period by detecting a temporary drop in the temperature of the heating element 110. The drop in the temperature of the heating element 110 is caused by the air drawn through the aerosol generator 100 during user smoking, which has a cooling effect on the heating element 110 during use. Thus, smoking is indicated by valley 510 in FIG. 5. Valley 510 can be used to identify individual smoking puffs.

[0217] The subsequent individual smoking intervals can be determined when individual smoking is identified by measuring the time between the starts of subsequent individual smokings. The first period is long enough to result in three or more smokings, so some smoking intervals for subsequent smokings can be calculated throughout the first period. Then, the average of those smoking intervals can be calculated. The average interval between subsequent smokings during the first period 306 is 36 seconds.

[0218] In this embodiment, the control circuit 132 is configured to perform steps 402 and 404 of method 400. The aerosol generating device 100 includes a temperature sensor (not shown) configured to measure the temperature of the heating element 110. The control circuit 132 is configured to receive a signal from the temperature sensor and detect user smoking based on a change (specifically, a decrease) in the temperature of the heating element 1110. The control circuit is then configured to calculate an average smoking interval based on the determined intervals between subsequent smokings.

[0219] In an alternative example, the heating element 110 includes a material having a temperature-dependent electrical resistance. For example, the heating element 110 is preferably made of a material in which the resistance increases when the temperature resistance increases and the relationship between the resistance and the temperature is substantially linear at least within the operating temperature range of the heating element 110. In this embodiment, the control circuit 132 is configured to monitor the electrical resistance of the heating element 110. Then, the electrical resistance can be used to estimate or calculate the temperature of the heating element 110. Specifically, the control circuit is configured to detect user smoking based on a decrease in the resistance of the heating element 110 that represents a decrease in the temperature of the heating element 110.

[0220] Step 406 of the method includes using the determined user smoking behavior for a first period to select one of a plurality of predetermined heating profiles stored in the memory of the control circuit 132 for a second period. Specifically, step 406 of the method includes comparing the average smoking interval determined for the first period 306 determined in step 404 of the method with a predetermined threshold. If the determined average smoking interval is greater than the predetermined threshold, the first predetermined heating profile is selected. If the determined average smoking interval is less than or equal to the predetermined threshold, the second predetermined heating profile is selected.

[0221] In this embodiment, the predetermined threshold is 25 seconds. The determined average smoking interval for the first period 306 is 36 seconds (i.e., greater than the predetermined threshold). Therefore, the first predetermined heating profile is selected in step 406 of the method.

[0222] Step 408 of the method includes controlling the supply of power to the heating assembly until the end of the second period according to the selected predetermined heating profile. Therefore, as the first predetermined heating profile is selected in step 406 of the example of FIG. 5, the method includes continuing to control the supply of power to the heating assembly according to the first predetermined heating profile during the second period.

[0223] Graph 500 of FIG. 5 shows the result of the method of FIG. 4 when the user follows the first user smoking behavior. FIG. 6 shows, instead, a graph 600 of the temperature of the heater element 110 during a use session in which the user follows the second user smoking behavior and the method of FIG. 4 is applied. Graph 600 is a schematic view and is not drawn to scale.

[0224] In this case, steps 402 and 404 of method 400 are the same as those described above. However, the smoking interval in FIG. 6 is shorter than the smoking interval in FIG. 5. Thus, the average smoking interval determined in step 404 of the method is shorter than the first user's smoking behavior when the user follows the second user's smoking behavior. The average smoking interval for the second user's smoking behavior in FIG. 6 during the first period is 20 seconds.

[0225] Since 20 seconds is less than a predetermined threshold, in step 406 of the method, a second predetermined heating profile is selected. Step 408 of the method includes controlling the supply of power to the heating assembly during a second period according to the second predetermined heating profile. Specifically, step 408 of the method includes controlling the supply of power to the heating assembly following an initial portion according to a portion of the second predetermined heating profile. This corresponds to the portion of the second predetermined heating profile in the second period 308b of FIG. 3.

[0226] Since the second predetermined heating profile is shorter than the first predetermined heating profile, the usage session in FIG. 6 is shorter than the usage session in FIG. 5. Similarly, the second period 308b in FIG. 6 is shorter than the second period 308a in FIG. 5.

[0227] In the above-described embodiment, step 402 of the method includes supplying power to the heater assembly during the first period 306 according to an initial portion of the first (or second) predetermined heating profile. In an alternative, the first predetermined heating profile, the second predetermined heating profile, and the third predetermined heating profile are each stored in the memory of the control circuit 132.

[0228] The third predetermined heating profile has a duration corresponding to the duration of the first period 306 and is identical to the initial portions of the first and second predetermined heating profiles described with respect to FIG. 3.

[0229] The first predetermined heating profile and the second predetermined heating profile of this embodiment do not include an initial portion and correspond to the portions of the first predetermined heating profile and the second predetermined heating profile described with respect to FIG. 3 for each of the second periods 308a, 308b.

[0230] In this alternative, step 402 of the method includes supplying to the heater assembly during the first period 306 according to a third predetermined heating profile, step 406 includes selecting one of the first and second predetermined heating profiles for the second period using the user smoking behavior determined for the first period, and step 408 includes controlling the supply of power to the heating assembly according to the selected predetermined heating profile until the end of the second period.

[0231] In the above-described embodiment, the first period has a constant duration of 100 seconds. Of course, other durations can be used for the first period, but it is advantageous for the first period to span several smoking sessions.

[0232] In some alternatives, the first period is not constant. Instead, the end of the first period is when the control circuit detects that a predetermined number of smoking events have occurred since the start of the first period. Specifically, the predetermined number of smoking events is three smoking events. The method of controlling the power supplied to the heater assembly of the aerosol generator 100 during a use session in this embodiment is basically the same as that described with respect to FIG. 4. The only difference is that the first period has a dynamic length rather than a fixed length.

[0233] In the second embodiment, the trigger condition depends on the output, state, or user operation of one or more user interface elements of the aerosol generator. In particular, the user interface element is a rocker switch. This embodiment is described in connection with FIGS. 7 and 8.

[0234] FIG. 7 is a schematic cross-sectional view of a second aerosol generating device 700 comprising an aerosol generating article 702 received within a cavity. The first aerosol generating device 700 and the aerosol generating article 702 are very similar to the aerosol generating device 100 and the aerosol generating article 200 shown in FIG. 1, and like features are labeled accordingly. Compared to the first aerosol generating device 100, the second aerosol generating device 700 comprises a switch 704 which is a rocker switch having a first position and a second position. FIG. 7 shows the switch 704 in the first position.

[0235] FIG. 8 is a flow diagram of a method of controlling the power supplied to the heater assembly of the aerosol generating device 700 during a use session.

[0236] Step 802 of the method includes detecting the state of the switch 702. In this example, the state of the switch 702 is a trigger condition.

[0237] Step 804 of the method includes using the detected state of the switch 702 to select one of a plurality of predetermined heating profiles for use during the use session. If the switch is in the first position shown in FIG. 7, step 804 of the method includes selecting a first predetermined heating profile as shown in FIG. 3. If the switch is in the second position, step 804 of the method includes selecting a second predetermined heating profile as shown in FIG. 3. Thus, if a second state is detected, the use session will be shorter than if a first state is detected.

[0238] Step 806 of the method includes controlling the supply of power to the heater assembly according to the selected predetermined heating profile.

[0239] In a third embodiment, the trigger condition depends on the characteristics of the aerosol generating article used with the device. In particular, the trigger condition depends on the detection of a taggant incorporated into the aerosol generating article. This is described in connection with FIGS. 9, 10 and 11.

[0240] FIG. 9 is a schematic cross-sectional view of an aerosol generating article 900. The aerosol generating article 900 is very similar to the aerosol generator 200 shown in FIG. 2, and similar features are labeled accordingly. The difference between the aerosol generating articles 200 and 900 is that the aerosol generating article 900 additionally includes a first tagant 902.

[0241] The first tagant 902 is provided as a continuous band surrounding the downstream section of the aerosol generating article 10. The first tagant 902 is printed on the inner surface of the tipping wrapper 252. The upstream end of the first tagant 902 is located 2 millimeters downstream of the downstream end of the aerosol generating substrate 212. The first tagant 902 has a length of 6.5 millimeters. The upstream end of the first tagant 902 is aligned with the upstream end of the tipping wrapper 252. The downstream end of the first tagant 902 is 3.5 millimeters upstream from the ventilation zone 30. Thus, the entire length of the first tagant 902 overlaps the hollow tubular element 220. The first tagant 902 is provided at a concentration of approximately 200 milligrams per square meter. In this example, the first tagant 902 includes a first photoluminescent material.

[0242] FIG. 10 is a schematic cross-sectional view of a third aerosol generating device 1000 for use with the aerosol generating article 900. The aerosol generating device 1000 is similar to the first aerosol generating device 100 shown in FIG. 1, and similar features are numbered accordingly. Compared to the first aerosol generating device 100, the third aerosol generating device 1000 includes a tagant detector 1002. When the aerosol generating article 1000 is fully inserted into the device cavity 10, the tagant 902 of the aerosol generating article 1000 is aligned with the tagant detector 1002 of the aerosol generating device 1000. The tagant detector 1002 is configured to detect the first tagant 902.

[0243] An aerosol generation system (not shown) includes an aerosol generator 1000 and a plurality of aerosol generation articles 900. A first aerosol generation article 900 of the plurality of aerosol generation articles includes a first tagant 902, as shown in FIG. 9. A second aerosol generation article of the plurality of aerosol generation articles is identical to the first aerosol generation article 900 shown in FIG. 9 but includes a second tagant different from the first tagant 902.

[0244] The tagant detector 1002 can distinguish between the first tagant and the second tagant.

[0245] FIG. 11 is a flowchart of a method for controlling the power supplied to the heater assembly of the aerosol generator 1100 during a use session.

[0246] Step 1102 of the method includes the user inserting an aerosol generation article 900 containing either the first tagant or the second tagant into the cavity of the aerosol generator 900.

[0247] Step 1104 of the method includes using the tagant detector 1002 to confirm the identity of the tagant of the aerosol generation article 900 received in the cavity. In this example, the determined identity of the tagant of the aerosol generation article 900 is the trigger condition.

[0248] Step 1106 of the method includes using the determined identity of the tagant of the inserted aerosol generation article 900 to select one of a plurality of predetermined heating profiles for use during the use session. If the first tagant is identified in step 1104, the first predetermined heating profile is selected. If the second tagant is identified in step 1104, the second predetermined heating profile is selected.

[0249] Step 1108 of the method includes controlling the supply of power to the heater assembly according to the selected predetermined heating profile.

[0250] As a result of the above method, it becomes possible to select a heating profile using a specific aerosol-generating article inserted into the cartridge of the aerosol-generating device. The user of the aerosol-generating device can select the aerosol-generating article according to their preferred smoking behavior. Since the aerosol-generating articles are identical, the selection may not depend on the type of aerosol-forming substrate contained in the aerosol-generating article, since the aerosol-forming substrates in each of the articles may be identical.

[0251] In the above example, two different taggants are used as a way to distinguish aerosol-generating articles. However, in other examples, the taggant may be detectable and replaced with other identifiers suitable for distinguishing two or more aerosol-generating articles. For example, a barcode may be printed on the outer surface of the aerosol-generating article.

[0252] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, etc. are to be understood as being modified in all instances by the term "about". Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A ± 10%. In this context, the number A may be considered to include numerical values within the general standard error of the measured value of the property being modified by the number A. The number A may deviate by the percentages recited above in some cases where used in the appended claims, provided that the amount by which A deviates does not substantially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, which may or may not be specifically recited herein.

Claims

1. An aerosol generator for generating an aerosol from an aerosol generating article comprising an aerosol-forming substrate, wherein the aerosol generator is configured to generate the aerosol during a usage session, including the start and end of the usage session, and the aerosol generator is configured to generate the aerosol during the usage session, A heater assembly for heating the aerosol-forming substrate, A power supply configured to supply power to the aforementioned heater assembly, A control circuit comprising a memory for storing a plurality of predetermined heating profiles, wherein at least one of the plurality of predetermined heating profiles has a first duration, and at least one of the predetermined heating profiles has a second duration different from the first duration, The control circuit is configured to detect a trigger condition and, based on the detected trigger condition, select a predetermined heating profile for use during the usage session, wherein the selected predetermined heating profile has either the first duration or the second duration, and the trigger condition depends on at least one of the following: user interaction with the aerosol generator or the characteristics of the aerosol generating article used with the device. The termination of the aforementioned usage session corresponds to the termination of the selected predetermined heating profile. An aerosol generator in which the length of the usage session depends on the length of the selected predetermined heating profile.

2. The aerosol generating apparatus according to claim 1, wherein the first duration is at least 30% longer than the second duration.

3. The aerosol generating apparatus according to any one of claims 1 to 2, wherein the first duration is longer than 5 minutes, preferably longer than 8 minutes.

4. The aerosol generator according to claim 1, further comprising a detection assembly configured to detect at least one of the following: user interaction with the aerosol generator, or the characteristics of an aerosol generating article used with the device.

5. The aerosol generating apparatus according to claim 4, wherein the detection assembly is configured to detect an identifier of the aerosol generating article received in the cavity, and is suitable for distinguishing a first identifier from a second identifier different from the first identifier.

6. The aerosol generator according to claim 5, wherein the control circuit is configured to select a predetermined heating profile having either the first duration or the second duration, depending on whether the first identifier or the second identifier is detected.

7. The aerosol generator according to claim 1, wherein the control circuit is configured to determine user smoke inhalation behavior during a first period of the usage session, select a predetermined heating profile having either a first duration or a second duration according to the determined user smoke inhalation behavior, and control the supply of power to the heater assembly according to the selected predetermined heating profile during a second period of the usage session.

8. The aerosol generating apparatus according to claim 1, further comprising one or more user interface elements.

9. The aerosol generator according to claim 8, wherein one or more user interface elements are configured such that a first state or a second state can be selected by a user of the device using the one or more user interface elements.

10. The aerosol generator according to claim 9, wherein the control circuit is configured to select a predetermined heating profile having either the first duration or the second duration, depending on whether the first state or the second state of the user interface is selected.

11. The aerosol generating device according to claim 1, wherein the aerosol generating device is configured to generate an aerosol from an aerosol-forming substrate provided within the aerosol generating article, and the aerosol generating article comprises a wrapper surrounding the aerosol-forming substrate.

12. An aerosol generating system comprising the aerosol generating device described in claim 1, and one or more aerosol generating articles having a rod of an aerosol forming substrate.

13. The aerosol generating system according to claim 12, wherein the first aerosol generating article of the plurality of aerosol generating articles includes a first identifier, and the second aerosol generating article of the plurality of aerosol generating articles includes a second identifier different from the first identifier.

14. The aerosol generating system according to claim 13, wherein the first and second aerosol generating articles have substantially the same structure as each other, except for the first and second identifiers.

15. A method for controlling the power supplied to a heater assembly of an aerosol generator to generate an aerosol from an aerosol generating article containing an aerosol forming substrate during a usage session, including the start and end of the usage session, wherein the method is The detection of trigger conditions that depend on at least one of the following: user interaction with the aerosol generator, or the characteristics of the aerosol generating article used with the device; Based on the detected trigger conditions, the selection of one of a plurality of predetermined heating profiles for use during the usage session, wherein at least one of the plurality of predetermined heating profiles has a first duration and at least one of the predetermined heating profiles has a second duration different from the first duration, The selected predetermined heating profile has either the first duration or the second duration. The termination of the aforementioned usage session corresponds to the termination of the selected predetermined heating profile. A method wherein the length of the usage session depends on the length of the selected predetermined heating profile.

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