Aerosol generator operable in aerosol release mode and pause mode

Abstract

The present invention relates to an aerosol generation device comprising an electric heating arrangement for heating an aerosol-forming substrate to generate an aerosol, the heating arrangement being configured to heat the aerosol-forming substrate at a first temperature level in an aerosol-emitting mode, and the heating arrangement being further configured to heat the aerosol-forming substrate at a second temperature level, below the first temperature level, in the pause mode in response to a pause signal.

Description

[Technical Field]

[0001] The present disclosure relates to an aerosol-generating device and an aerosol-generating system for heating an aerosol-forming substrate capable of forming an inhalable aerosol when heated. The present disclosure also relates to a method of operating such an aerosol-generating device. [Background technology]

[0002] Aerosol-generating devices for generating inhalable aerosols by electrically heating an aerosol-forming substrate capable of forming an inhalable aerosol when heated are generally known in the prior art. Such devices may comprise a cavity for removably receiving at least a portion of an aerosol-generating article, including the aerosol-forming substrate to be heated. The device further comprises an electrical heating arrangement for heating the substrate when the article is received in the cavity. For aerosol generation, the substrate must be heated to a sufficient operating temperature to allow volatile compounds to be released from the substrate. Once initiated, the user experience typically continues without interruption until the aerosol-forming substrate within the article is depleted. Nevertheless, there is a desire on the part of the user to be able to interrupt the user experience and resume it at a later stage using the same article, preferably until the substrate is completely depleted. However, once interrupted, the user experience can often be resumed only with degraded quality aerosol generated from an undepleted substrate. Summary of the Invention [Problem to be solved by the invention]

[0003] It would therefore be desirable to have an aerosol generating device and method of operating such a device that has the advantages of prior art solutions while mitigating their limitations. In particular, it would be desirable to have an aerosol generating device and method of operating such a device that allows a user to interrupt a user experience and resume the experience at a later stage with the aerosol still of acceptable quality. [Means for solving the problem]

[0004] According to the present invention, there is provided an aerosol generation device comprising an electric heating arrangement for heating an aerosol-forming substrate to generate an aerosol, the heating arrangement being configured to heat the aerosol-forming substrate at a first temperature level in an aerosol-emitting mode, the heating arrangement being further configured to heat the aerosol-forming substrate at a second temperature level below the first temperature level in the pause mode in response to a pause signal.

[0005] According to the present invention, it has been found that when the aerosol-forming substrate is kept in the pause mode of the heating arrangement at a temperature below the first temperature level used during normal use of the device (particularly during user experience), but still significantly above room temperature, the user experience may be interrupted and resumed at a later stage. That is, the second temperature level is preferably selected to avoid degradation of the undepleted substrate. In particular, the second temperature level is selected to be sufficiently low to minimize depletion of the substrate during the pause mode, and at the same time sufficiently high to avoid condensation of vapor within the device, which may affect the quality of the undepleted aerosol-forming substrate. In other words, during use of the device, particularly when user experience is taking place, the heating arrangement operates in the aerosol emission mode, while during pauses in use of the device, i.e., when user experience is not taking place, the heating arrangement operates in the pause mode. During both the aerosol emission mode and the pause mode of the heating arrangement, the heating arrangement is in operation, specifically in heating operation, but at different temperature levels, i.e., during the aerosol emission mode, at a first temperature level selected to be sufficiently high to generate aerosol, and during the pause mode, at a second temperature level below the first temperature level selected to be sufficiently low to avoid degradation while minimizing depletion of the substrate.

[0006] Depending on the type and composition of the specific aerosol-forming substrate used with the device, the first temperature level may be within the range of 325°C to 385°C, specifically 340°C to 370°C, and more specifically 350°C to 360°C. These temperatures are suitable operating temperatures sufficient to allow volatile compounds to be released from the aerosol-forming substrate. For example, the first temperature level for a liquid aerosol-forming substrate may be lower than the first temperature for a solid aerosol-forming substrate.

[0007] Generally, the second temperature level is selected to maintain the utility of the aerosol-emitting substrate for an extended period of time. The second temperature level may also depend on the type and composition of the aerosol-forming substrate used with the device. As a result, the second temperature level may be within the range of 175°C to 225°C, specifically 185°C to 215°C, and more specifically 195°C to 205°C. These temperatures are low enough to minimize substrate depletion during pause mode, yet high enough to avoid vapor condensation within the device.

[0008] To avoid condensation effects in the device, in particular to avoid condensation of substances within the aerosol-forming substrate, the second temperature level may be at least 150 degrees Celsius, in particular at least 175 degrees Celsius, preferably at least 185 degrees Celsius, more preferably at least 195 degrees Celsius.

[0009] Conversely, to minimize substrate depletion during the pause mode, the second temperature level may be at most 220° C., specifically at most 225° C., preferably at most 215° C., and more preferably at least 205° C. Specifically, the second temperature level may be selected to reduce aerosol formation by at least 50 percent.

[0010] Relatively, the second temperature level may be at least 50 degrees Celsius, particularly at least 75 degrees Celsius, more particularly at least 100 degrees Celsius lower than the first temperature level.

[0011] The above given temperature values ​​are preferably the average temperatures of the aerosol-forming substrate during operation of the device. In addition, as already mentioned, the temperature values ​​may depend, inter alia, on the type and composition of the aerosol-forming substrate used in the device.

[0012] As used herein, suspended mode refers to a first operational mode of the heating arrangement in which the heating arrangement is operated during a suspension of operation, i.e., suspension of use of the aerosol generating device, i.e., the user experience is suspended and aerosol generation does not occur or is at least reduced to a minimal level, i.e., in suspended mode, the aerosol generating device is in a suspended state of use.

[0013] Conversely, the aerosol delivery mode refers to a second operating mode of the heating arrangement, which is the normal heating operating mode of the heating arrangement for aerosol generation, in which the heating arrangement operates during use of the device by a user, i.e., when the user experience occurs, specifically when aerosol generation occurs. Generally, aerosol generation may occur continuously or on demand, specifically on a puff basis, i.e., in response to a user request when taking a puff.

[0014] The aerosol-generating device may include at least one sensor configured to output a sensor signal indicating whether the device is being operated by a user, whether it is in use by a user, or whether it is in a paused state, i.e., suspended from use. Advantageously, such a sensor may facilitate automatically detecting whether the operation of the heating arrangement can be switched to a paused mode because the device is not currently being used and is therefore in a paused state, i.e., suspended from use. Thus, aerosol generation may continue but be stopped in a timely manner to avoid undesired depletion of the aerosol-forming substrate. Similarly, such a sensor may facilitate automatically detecting whether the operation of the heating arrangement should be switched back to an aerosol-emitting mode, i.e., back to the normal heating operating mode for aerosol generation, when the user wishes to resume their user experience.

[0015] The at least one sensor may include one of a puff sensor for detecting a user's puff, a motion sensor for detecting movement of the device, and an orientation sensor for detecting the orientation of the device. The puff sensor advantageously allows for detecting normal operation of the device, specifically the start or resumption of a user experience. The motion sensor advantageously allows for monitoring the device for movement and may therefore, for example, allow for detecting that the user is handling the device. That is, if the motion sensor detects any movement of the aerosol generating device, this may indicate that the user is holding the device and therefore is likely currently having a user experience or is about to start or resume a user experience. For example, the motion sensor may detect movement of the aerosol generating device when the device is placed on a table and then picked up again. If no movement is detected, this typically means that the aerosol generating device is in an idle state. This may be the case when the aerosol generating device is placed in a power charging unit or is sitting idle on a table. As a result, the heating arrangement may be switched to a pause mode to avoid deterioration of the undepleted substrate.

[0016] As an example, the motion sensor may include at least one of an accelerometer for measuring device acceleration or a gyroscope for measuring angular orientation or angular velocity. That is, the motion sensor may be configured to detect at least one of the acceleration, angular orientation, and / or angular velocity of the aerosol generating device, particularly due to a user's handling of the device. Similarly, an orientation sensor may be used to detect the orientation of the device, which may result in an indication of a particular situation. For example, a horizontal orientation of the device (e.g., with respect to the length axis of the aerosol generating device) may indicate that the device is sitting idle on a table. Similarly, a vertical orientation of the device, or an orientation of the device between a vertical and horizontal orientation, may indicate that the device is in use during a user experience.

[0017] The aerosol generating device can include a single sensor or multiple sensors, particularly multiple sensors of different types. Multiple sensors may be provided, for example, for redundancy reasons. The use of multiple sensors of different types may also facilitate detecting different conditions. In particular, the device may include at least one sensor configured to output a sensor signal indicating that the device is being operated by a user, i.e., in use by a user, and at least one other sensor configured to output a sensor signal indicating that the device is temporarily suspended.

[0018] In addition to or as an alternative to the at least one sensor, the aerosol generating device may comprise a user switch that allows a user of the device to initiate at least one of the device's operations, specifically to initiate the use of the device, specifically the user experience, i.e., to initiate aerosol generation, or to initiate a pause of operation, i.e., to (temporarily) stop aerosol generation. The user switch may be part of the device's user interface. Such a user interface may also be configured to indicate the actual operating mode of the aerosol generating device. To this end, the user interface may comprise a display or one or more light sources, such as, for example, one or more LEDs (light-emitting diodes).

[0019] The aerosol generating device may further include a controller configured to generate a pause signal in response to at least one of a sensor signal indicating a pause in operation, i.e., a pause in use, or a user-initiated pause in operation, i.e., a pause in use via a user switch. The pause signal may be received by the heating arrangement to initiate a pause mode. Specifically, the controller may be configured to generate the pause signal in response to a motion sensor detecting movement of the device that does not reach a predetermined movement threshold during a predetermined idle time, or in response to the motion sensor not detecting any movement during the predetermined idle time. The idle time may be within a range of 10 to 90 seconds, specifically 15 to 60 seconds, and preferably 15 to 40 seconds. The predetermined movement threshold may be defined by an acceleration value, an angle value, or an angular velocity value. The predetermined acceleration threshold is preferably within a range of 0.5 g to 1.5 g, specifically 0.7 g to 1.3 g, where g refers to the standard acceleration due to gravity as defined by the standard of 9.80665 m / s² (meters per second per second).

[0020] Additionally, the controller may be configured to generate an activity signal in response to a sensor signal indicating device operation and / or in response to a user initiating device operation via a user switch. Similarly, the activity signal may be received by the heating arrangement to initiate an aerosol emission mode. In particular, the controller may be configured to generate the activity signal in response to a motion sensor detecting device movement reaching or exceeding a predetermined movement threshold. Again, the predetermined movement threshold may be defined by an acceleration value, angle value, or angular velocity value. As defined above, the predetermined acceleration threshold may be in the range of 0.5 g to 1.5 g, specifically 0.7 g to 1.3 g, where g refers to the standard acceleration due to gravity as defined by the standard of 9.80665 m / s² [meters per second per second].

[0021] Generally, the controller may be configured to control the overall operation of the aerosol-generating device, and in particular, to control the heating process, preferably in a closed-loop configuration, and in particular to control the heating of the aerosol-forming substrate at each temperature level.

[0022] The controller may be or comprise a main control unit (MCU) of the aerosol generating device. The controller may comprise a microprocessor, such as a programmable microprocessor, a microcontroller, or an application specific integrated circuit chip (ASIC) or other electronic circuit capable of providing control. In particular, the heating arrangement may be, at least in part, part of the controller.

[0023] The heating arrangement may be configured to change from the pause mode to the aerosol-emitting mode after a predetermined maximum pause time has elapsed or in response to an activity signal. In particular, the heating arrangement may be configured to change from the pause mode to the aerosol-emitting mode after a predetermined maximum pause time has elapsed or in response to an activity signal, depending on which event occurs earlier. Advantageously, this prevents the aerosol-forming substrate from being held in the pause mode for an excessively long period of time, thereby impairing the user experience when subsequently resumed. The predetermined maximum pause time may be in the range of 1 minute to 15 minutes, specifically 2 minutes to 14 minutes, more specifically 3 minutes to 5 minutes, or 7 minutes to 12 minutes. These maximum pause times ensure that the aerosol-forming substrate is sufficiently protected from degradation.

[0024] Similarly, the heating arrangement may be configured to stop (heating) operation, i.e., any operation in both the aerosol emission mode and the pause mode, A predetermined number of puffs; the passage of a predetermined operating time in the aerosol emission mode; and the passage of a predetermined operating time in the pause mode; and after at least one of a predetermined weighted cumulative operating time in the aerosol emission mode and a pause mode.

[0025] Using weighted cumulative operating times may advantageously take into account that the aerosol-forming substrate may still be slightly depleted during the pause mode, reducing the effective operating time in the aerosol-emitting mode. As an example, the time in the aerosol-emitting mode may be weighted by a factor of 1, while the time in the pause mode may be weighted by a factor of 1 / 6. As a result, to still achieve an acceptable amount of aerosol, if the effective operating time of a given aerosol-generating article is, for example, 6 minutes, the device may be operated for either 6 minutes in the aerosol-emitting mode or 0 minutes in the pause mode, or 5 minutes in the aerosol-emitting mode or 6 minutes in the pause mode, or 4 minutes in the aerosol-emitting mode or 12 minutes in the pause mode, etc. That is, the effective time pairs for overall operation in the aerosol-emitting mode and the pause mode may be 6 minutes and 0 minutes, or 5 minutes and 6 minutes, or 4 minutes and 12 minutes, etc.

[0026] The predetermined operating time in the aerosol emission mode may be in the range of 1 minute to 12 minutes, specifically 2 minutes to 10 minutes, more specifically 3 minutes to 8 minutes, for example 6 minutes.

[0027] Similarly, the predetermined operating time in the pause mode may be in the range of 1 to 15 minutes, specifically 2 to 14 minutes, more specifically 5 to 13 minutes, for example 12 minutes.

[0028] The predetermined weighted cumulative operating time in the aerosol emission mode and the pause mode may be in the range of 1 minute to 12 minutes, specifically 2 minutes to 10 minutes, more specifically 3 minutes to 8 minutes, for example 6 minutes. The coefficient for weighting the time in the aerosol emission mode is preferably equal to 1. The coefficient for weighting the time in the pause mode may be in the range of 1 / 10 to 1 / 2, specifically 1 / 8 to 1 / 2, or 1 / 4 to 1 / 2, for example 1 / 6.

[0029] Depending on the type, composition and volume of the aerosol-forming substrate used with the device, the predetermined number of puffs may be in the range of 5 to 400, particularly 5 to 250, more particularly 5 to 100, preferably 5 to 20, more preferably 5 to 15, for example 10 to 14.

[0030] The heating arrangement may be configured to change from heating at a first temperature level in the aerosol-emitting mode to heating at a second temperature level in the pause mode in response to the pause signal by stopping heating of the aerosol-forming substrate until the second temperature level is reached or by heating the aerosol-forming substrate at a reduced heating power or in a pulsed mode until the second temperature level is reached. Specifically, the heating arrangement may be configured to change from heating at a first temperature level to heating at a second temperature level via a cooling mode, in which the heating arrangement is configured to stop heating of the aerosol-forming substrate until the second temperature level is reached or to heat the aerosol-forming substrate at a reduced heating power or in a pulsed mode until the second temperature level is reached. The cooling mode may be part of the pause mode, specifically, the initial part of the pause mode. The cooling mode may also be a separate operating mode between the aerosol-emitting mode and the pause mode.

[0031] As used herein, the term "aerosol-forming substrate" refers to a substrate formed from or including an aerosol-forming material capable of releasing a volatile compound upon heating to generate an aerosol. The aerosol-forming substrate is intended to be heated, rather than combusted, to release the aerosol-forming volatile compound. The aerosol-forming substrate may be a solid aerosol-forming substrate, a liquid aerosol-forming substrate, a gel-like aerosol-forming substrate, or any combination thereof. The aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively, or additionally, the aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may further include an aerosol former. Examples of suitable aerosol formers are glycerin and propylene glycol. The aerosol-forming substrate may also include other additives and ingredients (such as nicotine or flavoring agents). The aerosol-forming substrate may also be a paste-like material, a sachet of porous material containing the aerosol-forming substrate, or, for example, loose tobacco mixed with a gelling or adhesive agent, which may include a common aerosol former such as glycerin, which is compressed or molded into a plug.

[0032] The heated aerosol-forming substrate may specifically be part of an aerosol-generating article that is engaged with or received within an aerosol-generating device to heat the aerosol-forming substrate contained therein. As used herein, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate capable of emitting a volatile compound capable of forming an aerosol. The aerosol-generating article is preferably a heated aerosol-generating article, i.e., an aerosol-generating article comprising at least one aerosol-forming substrate intended to be heated, rather than combusted, to emit a volatile compound capable of forming an aerosol. The aerosol-generating article may also be a consumable product, particularly one that is discarded after a single use. For example, the article may be a cartridge containing a liquid or gel-like aerosol-forming substrate to be heated. As another example, the article may be a rod-shaped article, specifically a tobacco article, resembling a conventional cigarette, comprising a solid tobacco-containing aerosol-forming substrate.

[0033] The aerosol-generating device may comprise a cavity for removably receiving at least a portion of an aerosol-forming substrate to be heated, specifically a cavity for removably receiving at least a portion of an aerosol-generating article including the aerosol-forming substrate to be heated. The cavity may comprise an insertion opening through which the aerosol-forming substrate or aerosol-generating article may be inserted into the cavity. As used herein, the direction in which the aerosol-forming substrate or aerosol-generating article is inserted is denoted as the insertion direction. The insertion direction preferably corresponds to the extension of the length axis, specifically the central axis, of the cavity.

[0034] After insertion into the cavity, at least a portion of the aerosol-forming substrate or aerosol-generating article may still extend outward through the insertion opening. Preferably, the outwardly extending portion of the aerosol-generating article is provided for interaction with a user, specifically for placement into the user's mouth. Thus, during use of the device, the insertion opening may be proximate to the mouth. Consequently, as used herein, sections that are proximate to the insertion opening or proximate to the user's mouth when the device is in use are denoted with the prefix "proximal," respectively. Sections that are disposed further away are denoted with the prefix "distal."

[0035] The cavity may have any suitable cross-section as viewed in a plane perpendicular to the longitudinal axis of the cavity or perpendicular to the direction of insertion of the article. Specifically, the cross-section of the cavity may correspond to the shape of the aerosol-generating article to be received therein. Preferably, the cavity has a substantially circular cross-section. Alternatively, the cavity may have a substantially elliptical cross-section, a substantially oval cross-section, a substantially square cross-section, a substantially rectangular cross-section, a substantially triangular cross-section, or a substantially polygonal cross-section.

[0036] The electric heating arrangement may be an induction heating arrangement for inductively heating the aerosol-forming substrate. The induction heating arrangement may include an induction source including an induction coil for generating a varying magnetic field, specifically an alternating magnetic field. The varying magnetic field is preferably generated at the aerosol-forming substrate, specifically within the cavity, during use of the apparatus. The varying magnetic field may be a high-frequency varying magnetic field. The varying magnetic field may be in the range of 500 kHz (kilohertz) to 30 MHz (megahertz), specifically 5 MHz to 15 MHz, and preferably 5 MHz to 10 MHz. The varying magnetic field is used to inductively heat the susceptor due to at least one of eddy currents or hysteresis losses, depending on the electrical and magnetic properties of the susceptor material. During use, the susceptor is in thermal contact or thermal proximity with the aerosol-forming substrate to be heated when the aerosol-forming substrate or an aerosol-generating article including the substrate is received by the apparatus, specifically within the cavity of the apparatus. In general, the susceptor may either be part of the aerosol-generating device or part of the aerosol-generating article that includes the heated aerosol-forming substrate.

[0037] The at least one induction coil may be a helical coil or a flat, planar coil, specifically a pancake coil or a curved, planar coil. The at least one induction coil may be held within one of the main bodies or housings of the aerosol generating device. The induction coil may be disposed so as to surround at least a portion of a cavity of the device or at least a portion of the inner surface of such a cavity, respectively. For example, the induction coil may be a helical coil disposed within a sidewall of the cavity.

[0038] The induction source may comprise an alternating current (AC) generator. The AC generator may be powered by a power supply of the aerosol generating device. The AC generator is operably coupled to at least one induction coil. Specifically, the at least one induction coil may be an integral part of the AC generator. The AC generator is configured to generate a high-frequency oscillating current that passes through the at least one induction coil to generate an alternating magnetic field. The AC current may be supplied to the at least one induction coil continuously after activation of the system, or may be supplied intermittently (e.g., after each puff).

[0039] The inductive source preferably includes a DC / AC converter connected to a DC power source including an LC network, the LC network including a series connection of a capacitor and an inductor. Additionally, the inductive source may include a matching network for impedance matching. Specifically, the inductive source may include a power amplifier, such as a class C power amplifier, a class D power amplifier, or a class E power amplifier.

[0040] In the case of an inductively heated aerosol generator, the aerosol generator may further comprise a flux concentrator disposed around at least a portion of the induction coil and configured to distort the alternating magnetic field of the at least one induction source towards the cavity. Thus, when an article is received within the cavity, the alternating magnetic field, if present, is distorted towards the inductively heatable liquid conduit. Preferably, the flux concentrator comprises a flux concentrator foil, in particular a multi-layer flux concentrator foil.

[0041] It is also possible that the electrical heating arrangement may be a resistive heating arrangement for resistively heating the aerosol-forming substrate. In this configuration, the heating element may comprise a resistive heating element. The resistive heating element may be, for example, a resistive heating wire, or a resistive heating coil, or a resistive heating track (particularly a resistive heating track provided with a heating blade), a resistive heating grid, or a resistive heating mesh. During use of the device, the resistive heating element is in thermal contact with or in thermal proximity to the aerosol-forming substrate to be heated.

[0042] The heating arrangement may be configured to modify at least one of the first temperature level or the second temperature level based on environmental data. The environmental data may comprise, for example, humidity in the environment of the device or temperature in the environment of the device. Humidity can affect condensation effects within the device, particularly in the immediate vicinity of the aerosol-forming substrate, during use of the device. Similarly, temperature in the environment of the device can affect aerosol formation and release.

[0043] To record such environmental data, the aerosol generating device may further comprise at least one environmental data sensor, in particular a humidity sensor for measuring humidity in the device's environment or a temperature sensor for measuring temperature in the device's environment.

[0044] The aerosol generating device may include a power source, specifically a DC power source configured to provide a DC supply voltage and a DC supply current to the induction source. The power source is preferably a battery, such as a lithium iron phosphate battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging, i.e., the power source may be rechargeable. The power source may have a capacity that allows for storage of energy sufficient for one or more user experiences. For example, the power source may have a capacity sufficient to allow continuous generation of aerosol for approximately six minutes, or a multiple of six minutes. In another embodiment, the power source may have a capacity sufficient to allow for a predetermined number of puffs, or for discontinuous activation of the induction source.

[0045] The aerosol generating device may comprise a main body, which preferably includes at least one of a heating arrangement, a controller, a power source, and, if present, at least a portion of the cavity. In addition to the main body, the aerosol generating device may further comprise a mouthpiece, particularly if the aerosol-generating article used with the device does not comprise a mouthpiece. The mouthpiece may be attached to the main body of the device. As used herein, the term "mouthpiece" refers to a portion of the article through which the aerosol exits the device. The mouthpiece may be configured to close the receiving cavity when the mouthpiece is attached to the main body. If the device does not comprise a mouthpiece, the aerosol-generating article used with the aerosol generating device may comprise a mouthpiece, such as a filter plug.

[0046] The aerosol generating device may comprise at least one air outlet, for example an air outlet in the mouthpiece (if present).

[0047] The aerosol-generating device preferably comprises an air path extending from at least one air inlet, through the cavity, and optionally further to an air outlet in the mouthpiece (if present). The aerosol-generating device preferably comprises at least one air inlet in fluid communication with the cavity. As a result, the aerosol-generating system may comprise an air path extending from the at least one air inlet into the cavity, and optionally further through an aerosol-forming substrate and mouthpiece within the article and into the user's mouth.

[0048] The aerosol generating device is preferably a smoke extractor for generating an aerosol that can be directly inhaled by a user through the user's mouth, particularly a handheld aerosol generating device.

[0049] According to the present invention there is also provided an aerosol generation system comprising an aerosol generating device according to the present invention and as described herein and an aerosol-generating article for use with the device, the article comprising an aerosol-forming substrate heated by the device.

[0050] As used herein, the term "aerosol-generating system" refers to a combination of an aerosol-generating article, as further described herein, and an aerosol-generating device according to the present invention and as described herein. In the system, the article and device may cooperate to generate an inhalable aerosol. As already described further above, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate that, when heated, releases a volatile compound capable of forming an aerosol. The aerosol-generating article is preferably a heated aerosol-generating article, i.e., an aerosol-generating article comprising at least one aerosol-forming substrate intended to be heated, rather than combusted, to release a volatile compound capable of forming an aerosol. The aerosol-generating article may also be a consumable product, particularly one that is discarded after a single use. For example, the article may be a cartridge containing a liquid aerosol-forming substrate that is heated. As another example, the article may be a rod-shaped article resembling a conventional cigarette, particularly a tobacco product.

[0051] As already further described above, the second temperature level is preferably selected to maintain the usefulness of the aerosol-emitting substrate for an extended period of time, more particularly by reducing aerosol formation by at least 50 percent and / or by avoiding condensation of materials in the aerosol-forming substrate.

[0052] If the aerosol-generating device includes an induction heating arrangement, the aerosol-generating system may include at least one susceptor for inductively heating the aerosol-forming substrate. The susceptor may be an integral part of the aerosol-generating article. Consequently, the aerosol-generating article may include at least one susceptor positioned in thermal proximity or thermal contact with the aerosol-forming substrate, such that the susceptor can be inductively heated by the induction heating arrangement during use when the article is received in the cavity of the device. Alternatively, the susceptor may be part of the aerosol-generating device. Similarly, in this configuration, the susceptor is disposed within the device so as to be in thermal proximity or thermal contact with the aerosol-forming substrate when the article is received in the cavity of the device.

[0053] The article may comprise one or more of the following elements: a first support element, a base element, a second support element, a cooling element, and a filter element. Preferably, the aerosol-generating article comprises at least a first support element, a second support element, and a base element located between the first and second support elements.

[0054] The substrate element preferably comprises at least one aerosol-forming substrate which is heated. If the aerosol-generating system is based on induction heating, the substrate element may further comprise a susceptor in thermal contact with or in thermal proximity to the aerosol-forming substrate.

[0055] As used herein, the term "susceptor" refers to an element comprising a material capable of being inductively heated in an alternating electromagnetic field, which may be the result of at least one of hysteresis losses or eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0056] At least one of the first support element and the second support element may comprise a central air passageway. Preferably, at least one of the first support element and the second support element may comprise a hollow cellulose acetate tube. Alternatively, the first support element may be used to cover and protect the distal forward end of the base element.

[0057] The aerosol cooling element is an element having a large surface area and low draw resistance (e.g., 15 mmWG to 20 mmWG). In use, the aerosol formed by the volatile compounds released from the base element is drawn through the aerosol cooling element before being conveyed to the proximal end of the aerosol-generating article.

[0058] The filter element preferably functions as a mouthpiece or as part of a mouthpiece together with the aerosol cooling element. As used herein, the term "mouthpiece" refers to the portion of the article through which the aerosol exits the aerosol-generating article.

[0059] All of the aforementioned elements may be sequentially disposed along the longitudinal axis of the article in the order described above, with the first support element preferably disposed at the distal end of the article and the filter element preferably disposed at the proximal end of the article. Each of the aforementioned elements may be substantially cylindrical. Specifically, all elements may have the same outer cross-sectional shape. Additionally, the elements may be surrounded by an outer wrapper to hold the elements together and maintain the desired cross-sectional shape of the rod-shaped article. The wrapper is preferably made of paper.

[0060] Further features and advantages of the aerosol generating system according to the present invention are described with respect to the aerosol generating device and apply equally.

[0061] According to the present invention there is provided a method of operating an aerosol generating device or an aerosol delivery system according to the present invention and as described herein, the method comprising: heating the aerosol-forming substrate at a first temperature level in an aerosol-emitting mode; and in response to the pause signal, heating the aerosol-forming substrate at a second temperature level below the first temperature level in the pause mode.

[0062] As further described above with respect to the aerosol generating device according to the present invention, the second temperature level is preferably selected to be sufficiently low to minimize depletion of the substrate during the pause mode, and at the same time sufficiently high to avoid condensation of vapor within the device, which could otherwise affect the quality of the undepleted aerosol-forming substrate.

[0063] As a result, the second temperature level may be at least 150 degrees Celsius, specifically at least 175 degrees Celsius, preferably at least 185 degrees Celsius, and more preferably at least 195 degrees Celsius. Conversely, the second temperature level may be up to 220 degrees Celsius, specifically up to 225 degrees Celsius, preferably up to 215 degrees Celsius, and more preferably at least 205 degrees Celsius. Similarly, the second temperature level is preferably in the range of 175 degrees Celsius to 225 degrees Celsius, specifically 185 degrees Celsius to 215 degrees Celsius, and more specifically 195 degrees Celsius to 205 degrees Celsius.

[0064] Relatively, the second temperature level may be at least 50 degrees Celsius, particularly at least 75 degrees Celsius, more particularly at least 100 degrees Celsius lower than the first temperature level.

[0065] The first temperature level may be in the range of 325 degrees Celsius to 385 degrees Celsius, specifically 340 degrees Celsius to 370 degrees Celsius, and more specifically 350 degrees Celsius to 360 degrees Celsius.

[0066] The method may further comprise heating the aerosol-forming substrate to return to the first temperature level after a predetermined maximum dwell time has elapsed or in response to an activity signal. As further described above with respect to the aerosol-generating device according to the invention, the predetermined maximum dwell time may be in the range of 1 minute to 15 minutes, particularly 2 minutes to 14 minutes, more particularly 3 minutes to 5 minutes, or 7 minutes to 12 minutes.

[0067] Also, as further described above with respect to the aerosol generating device according to the present invention, the method comprises: A predetermined number of puffs; the passage of a predetermined operating time in the aerosol emission mode; and the passage of a predetermined operating time in the pause mode; and ceasing heating after at least one of a predetermined weighted cumulative operating time in the aerosol emission mode and a predetermined weighted cumulative operating time in the pause mode.

[0068] To change from the aerosol-emitting mode to the pause mode in response to a pause signal, heating may be stopped until a second temperature level is reached, followed by heating the aerosol-forming substrate at the second temperature level. Similarly, in response to a pause signal, the aerosol-forming substrate may be heated at a reduced heating power or in a pulsed mode until the second temperature level is reached, followed by heating the aerosol-forming substrate at the second temperature level. The change from heating at a first temperature level in the aerosol-emitting mode to heating at a second temperature level in the pause mode in response to a pause signal may be referred to as a cooling mode.

[0069] Further features and advantages of the method according to the invention have been described with respect to the aerosol generating device and the aerosol generating system and apply equally.

[0070] The present invention is defined in the claims. However, the following provides a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein. [Example]

[0071] Example Ex1: An aerosol generating device comprising an electric heating arrangement for heating an aerosol-forming substrate to generate an aerosol, wherein the heating arrangement is configured to heat the aerosol-forming substrate at a first temperature level in an aerosol emission mode, and to heat the aerosol-forming substrate at a second temperature level below the first temperature level in a pause mode in response to a pause signal.

[0072] Embodiment Ex2: The aerosol generating device according to embodiment Ex1, wherein the first temperature level is in the range of 325 degrees Celsius to 385 degrees Celsius, specifically 340 degrees Celsius to 370 degrees Celsius, more specifically 350 degrees Celsius to 360 degrees Celsius.

[0073] Example Ex3: An aerosol generating device according to any of the preceding examples, wherein the second temperature level is in the range of 175 degrees Celsius to 225 degrees Celsius, specifically 185 degrees Celsius to 215 degrees Celsius, more specifically 195 degrees Celsius to 205 degrees Celsius.

[0074] Example Ex4: An aerosol generating device according to any one of the preceding examples, wherein the second temperature level is at least 50 degrees Celsius, particularly at least 75 degrees Celsius, more particularly at least 100 degrees Celsius lower than the first temperature level.

[0075] Embodiment Ex5: An aerosol generating device according to any one of the preceding embodiments, wherein the second temperature level is at least 150 degrees Celsius, particularly at least 175 degrees Celsius, preferably at least 185 degrees Celsius, more preferably at least 195 degrees Celsius.

[0076] Embodiment Ex6: An aerosol generating device according to any one of the preceding embodiments, wherein the second temperature level is at most 220 degrees Celsius, in particular at most 225 degrees Celsius, preferably at most 215 degrees Celsius, more preferably at least 205 degrees Celsius.

[0077] Example Ex7: An aerosol generating device according to any one of the preceding examples, further comprising at least one sensor configured to output a sensor signal indicating that the device is being operated by a user or that operation is suspended.

[0078] Example Ex8: An aerosol generating device according to example Ex7, wherein the at least one sensor comprises one of a puff sensor for detecting a puff by the user, a motion sensor for detecting movement of the device, and an orientation sensor for detecting the orientation of the device.

[0079] Example Ex9: An aerosol generating device according to any one of the preceding examples, further comprising a user switch that allows a user of the device to initiate at least one of operation or pausing of operation of the device.

[0080] Example Ex10: An aerosol generating device according to any one of Examples Ex7 to Ex9, further comprising a controller configured to generate a pause signal in response to a sensor signal indicating a pause in operation and / or in response to a user initiating a pause in operation via a user switch.

[0081] Example Ex11: An aerosol generating device according to example Ex10, wherein the controller is configured to generate an activity signal in response to a sensor signal indicative of operation of the device and / or in response to a user initiating operation of the device via a user switch.

[0082] Example Ex12: An aerosol generating device according to any of the preceding examples, wherein the heating arrangement is configured to change from the pause mode to the aerosol emission mode after a predetermined maximum pause time has elapsed or in response to an activity signal.

[0083] Example Ex13: An aerosol generating apparatus according to example Ex12, wherein the predetermined maximum pause time is in the range of 1 minute to 15 minutes, specifically 2 minutes to 14 minutes, more specifically 3 minutes to 5 minutes, or 7 minutes to 12 minutes.

[0084] Example Ex14: The heating arrangement is A predetermined number of puffs; the passage of a predetermined operating time in the aerosol emission mode; and the passage of a predetermined operating time in the pause mode; An aerosol generating device according to any of the preceding embodiments, configured to stop the heating operation after at least one of: a predetermined weighted cumulative operating time in the aerosol emission mode and a predetermined weighted cumulative operating time in the pause mode.

[0085] Example Ex15: The aerosol generator according to example Ex14, wherein the predetermined operating time in the aerosol emission mode is in the range of 1 minute to 12 minutes, specifically 2 minutes to 10 minutes, more specifically 3 minutes to 8 minutes, for example 6 minutes.

[0086] Example Ex16: An aerosol generating device according to any one of examples Ex14 or Ex15, wherein the predetermined operating time in the pause mode is in the range of 1 minute to 15 minutes, particularly 2 minutes to 14 minutes, more particularly 5 minutes to 13 minutes, for example 12 minutes.

[0087] Example Ex17: An aerosol generating device according to any one of Examples Ex14 to Ex16, wherein the predetermined weighted cumulative operating time in the aerosol emission mode and the pause mode is in the range of 1 minute to 12 minutes, specifically 2 minutes to 10 minutes, more specifically 3 minutes to 8 minutes, for example 6 minutes.

[0088] Example Ex18: An aerosol generating device according to any of the preceding examples, wherein the heating arrangement is configured to change from heating at a first temperature level in the aerosol emission mode to heating at a second temperature level in the pause mode in response to a pause signal by stopping heating of the aerosol-forming substrate until the second temperature level is reached, or by heating the aerosol-forming substrate at a reduced heating power or in pulsed mode until the second temperature level is reached.

[0089] Example Ex19: An aerosol generating device according to any of the preceding examples, wherein the heating arrangement is a resistive heating arrangement or an inductive heating arrangement.

[0090] Example Ex20: An aerosol generating device according to any of the preceding examples, wherein the heating arrangement is configured to modify at least one of the first temperature level or the second temperature level based on environmental data.

[0091] Example Ex21: An aerosol generating device according to any of the preceding examples, further comprising an environmental data sensor, in particular at least one of a humidity sensor for measuring humidity in an environment of the device, or a temperature sensor for measuring temperature in an environment of the device.

[0092] Example Ex22: An aerosol generating device according to any of the preceding examples, further comprising a user interface, in particular a display such as one or more LEDs (light emitting diodes) or one or more light sources.

[0093] Example Ex23: An aerosol-generating system comprising an aerosol-generating device according to any of the preceding examples and an aerosol-generating article for use with the device, the article comprising a heated aerosol-forming substrate.

[0094] Example Ex24: An aerosol-generating system according to Example Ex23, wherein the second temperature level is selected to maintain the usefulness of the aerosol-emitting substrate for an extended period of time, more specifically by reducing the formation of aerosol by at least 50 percent and / or by avoiding condensation of material in the aerosol-forming substrate.

[0095] Example Ex25: A method of operating an aerosol generating device according to any of Examples Ex1-Ex22 or an aerosol delivery system according to any of Examples Ex23-Ex24, comprising: heating the aerosol-forming substrate at a first temperature level in an aerosol-emitting mode; and in response to the pause signal, heating the aerosol-forming substrate at a second temperature level below the first temperature level in a pause mode.

[0096] Example Ex26: The method according to example Ex25, further comprising heating the aerosol-forming substrate back to the first temperature level after a predetermined maximum pause time or in response to an activity signal.

[0097] Example Ex27: The method according to example Ex26, wherein the predetermined maximum pause time is in the range of 1 minute to 15 minutes, specifically 2 minutes to 14 minutes, more specifically 3 minutes to 5 minutes, or 7 minutes to 12 minutes.

[0098] Example Ex28: A predetermined number of puffs; the passage of a predetermined operating time in the aerosol emission mode; and the passage of a predetermined operating time in the pause mode; The method according to any one of embodiments Ex25 to Ex27, further comprising ceasing heating after at least one of: a predetermined weighted cumulative operating time in the aerosol emission mode and a predetermined weighted cumulative operating time in the pause mode.

[0099] Example Ex29: The method according to example Ex28, wherein the predetermined operating time in the aerosol emission mode is in the range of 1 minute to 12 minutes, particularly 2 minutes to 10 minutes, more particularly 3 minutes to 8 minutes, for example 6 minutes.

[0100] Example Ex30: The method according to any one of examples Ex28 or Ex29, wherein the predetermined operating time in the pause mode is in the range of 1 minute to 15 minutes, particularly 2 minutes to 14 minutes, more particularly 5 minutes to 13 minutes, for example 12 minutes.

[0101] Example Ex31: The method according to any one of Examples Ex28 to Ex30, wherein the predetermined weighted cumulative operating time in the aerosol emission mode and the pause mode is in the range of 1 minute to 12 minutes, particularly 2 minutes to 10 minutes, more particularly 3 minutes to 8 minutes, for example 6 minutes.

[0102] Example Ex32: The method according to any one of examples Ex25 to Ex31, wherein in response to a pause signal, heating is stopped until a second temperature level is reached, followed by heating the aerosol-forming substrate at the second temperature level.

[0103] Example Ex33: A method according to any one of examples Ex25 to Ex31, wherein in response to a pause signal, the aerosol-forming substrate is heated at reduced heating power or in pulsed mode until a second temperature level is reached, followed by heating the aerosol-forming substrate at the second temperature level.

[0104] Embodiment Ex34: The method according to any one of embodiments Ex25 to Ex33, wherein the first temperature level is in the range of 325 degrees Celsius to 385 degrees Celsius, specifically 340 degrees Celsius to 370 degrees Celsius, more specifically 350 degrees Celsius to 360 degrees Celsius.

[0105] Embodiment Ex35: The method according to any one of embodiments Ex25 to Ex34, wherein the second temperature level is in the range of 175 degrees Celsius to 225 degrees Celsius, specifically 185 degrees Celsius to 215 degrees Celsius, more specifically 195 degrees Celsius to 205 degrees Celsius.

[0106] Embodiment Ex36: The method according to any one of embodiments Ex25 to Ex35, wherein the second temperature level is at least 50 degrees Celsius, specifically at least 75 degrees Celsius, more specifically at least 100 degrees Celsius lower than the first temperature level.

[0107] Example Ex37: The method according to any one of examples Ex25 to Ex36, wherein the second temperature level is at least 150 degrees Celsius, particularly at least 175 degrees Celsius, preferably at least 185 degrees Celsius, more preferably at least 195 degrees Celsius.

[0108] Example Ex38: The method according to any one of examples Ex25 to Ex37, wherein the second temperature level is at most 220 degrees Celsius, in particular at most 225 degrees Celsius, preferably at most 215 degrees Celsius, more preferably at least 205 degrees Celsius.

[0109] The embodiments will now be further described with reference to the following figures: [Brief explanation of the drawings]

[0110] [Figure 1] FIG. 1 illustrates schematically an aerosol generation system according to an exemplary embodiment of the invention, including an aerosol generating device and an aerosol-generating article for use with the device. [Figure 2] FIG. 2 shows an exemplary embodiment of a method for operating an aerosol generating device according to FIG. [Figure 3] FIG. 3 shows the current versus temperature profile of the aerosol generating device according to FIG.

[0111] 1 illustrates schematically an exemplary embodiment of an aerosol-generating system 1 according to the present invention, capable of generating an inhalable aerosol by heating an aerosol-forming substrate. The system 1 comprises an aerosol-generating article 10 including an aerosol-forming substrate 21 to be heated, and an aerosol-generating device 100 for inductively heating the substrate upon engagement of the article 10 with the device 100.

[0112] The aerosol-generating article 10 has a substantially rod-shaped configuration resembling that of a conventional cigarette. In this embodiment, the article 10 comprises four elements sequentially arranged in a coaxial arrangement: a substrate element 20 disposed at the distal end of the article 10; a support element 40 having a central air passage; an aerosol-cooling element 50; and a filter element 60 disposed at the proximal end of the article 10, which functions as a mouthpiece. The substrate element 20 includes not only the aerosol-forming substrate 21 to be heated, but also a susceptor 30 that is in direct physical contact with the substrate 21 and is used to inductively heat the substrate 21, as described in more detail below. The four elements have a substantially cylindrical shape with substantially the same diameter. Additionally, the four elements are surrounded by an outer wrapper 70 that holds the elements together and maintains the desired circular cross-sectional shape of the article 10. The wrapper 70 is preferably made of paper. Further details of article 10, in particular the four elements, are disclosed, for example, in WO 2015 / 176898 A1.

[0113] The elongated aerosol-generating device 100 comprises two sections: a proximal section 102 and a distal section 101. In the proximal section 102, the device 100 comprises a cavity 103 for removably receiving at least a portion of the aerosol-generating article 10. In the distal section 101, the device 100 comprises a DC power source 150, such as a rechargeable battery, for powering the operating parts of the device, as well as a controller 160 for controlling the operation of the device 100. To heat the substrate 21 within the article 10, the device 100 comprises an electric heating arrangement 110 operably coupled to the controller 160. In this embodiment, the heating arrangement 110 is an induction heating arrangement including an electric circuit 115 for generating an alternating magnetic field, in particular a high-frequency magnetic field, within the cavity 103, and an induction coil 118. As can be seen in FIG. 1 , the induction coil 118 is a helical coil disposed within the proximal section 102 of the device so as to circumferentially surround the cylindrical receiving cavity 103. Thus, the susceptor 30 of the aerosol-generating article 10 experiences an electromagnetic field upon engagement of the article 10 with the apparatus 100, thus enabling inductive heating of the susceptor 30 within the article 10. As a result, upon insertion of the article 10 into the cavity 103 of the apparatus 100 (as shown in FIG. 1 ) and activation of the heating arrangement 110, the alternating electromagnetic field within the cavity 103 induces eddy currents and / or hysteresis losses within the susceptor 30, depending on the magnetic and electrical properties of the susceptor material. As a result, the susceptor 30 is heated to a temperature sufficient to vaporize the aerosol-forming substrate 21 surrounding the susceptor 30 within the article 10.

[0114] During use of the system, when a user takes a puff, i.e., when negative pressure is applied to the filter element 60 of the article 10, air is drawn into the cavity 103 at the edge of the article insertion opening 105. The airflow continues through a passageway formed between the inner surface of the cylindrical cavity 103 and the outer surface of the article 10 toward the distal end of the cavity 103. At the distal end of the cavity 103, the airflow enters the aerosol-generating article 10 through the substrate element 20. From there, the airflow further passes through the support element 40, the aerosol-cooling element 50, and the filter element 60, where it finally exits the article 10. During heating, vaporized material from the aerosol-forming substrate 21 is entrained in the airflow through the substrate element 20. As it passes further through the support element 40, the cooling element 50, and the filter element 60, the airflow containing the vaporized material is cooled to form an aerosol that exits the article 10 through the filter element 60.

[0115] Typically, once initiated, the user experience continues without interruption until the aerosol-forming substrate in the article is depleted or until predetermined operating conditions are met. That is, the user typically takes multiple consecutive puffs until they sense depletion of the substrate, or until a predetermined number of puffs or a predetermined maximum operating time is reached. However, as further noted above, there is a long-felt desire to allow a user to interrupt the user experience and resume it at a later stage using the same article, still with acceptable aerosol quality.

[0116] To this end, the present invention suggests interrupting aerosol generation by changing operation of device 100 from the aerosol-emitting mode to a pause mode in which the aerosol-forming substrate is held at an intermediate temperature. The intermediate temperature is chosen to be below the temperature during the aerosol-emitting mode to minimize substrate depletion, yet still high enough to avoid condensation of vapor within cavity 103, which could adversely affect substrate 21. Thus, the user experience may be paused and resumed without sustaining an unacceptable loss of quality of the generated aerosol after resumption of the user experience.

[0117] This procedure is illustrated in FIG. 2, which illustrates an exemplary embodiment of a method for operating the aerosol-generating device according to FIG. 1 at different temperatures T during different operating modes and over time t. Starting on the left side of FIG. 2, the user experience begins at time t0, for example, by user input via the user switch 165 shown in FIG. 1 or by detecting the insertion of the aerosol-generating article 10 into the device 100. Once initiated, the heating arrangement 110 begins heating the aerosol-forming substrate 21 within the article 10 during a pre-heating mode PH from room temperature T3 until a first temperature level T1 is reached at time t1. The first temperature level T1 is sufficient to vaporize the aerosol-forming substrate 21 to form an aerosol. Depending on the substrate type, the first temperature level T1 may be in the range of 325°C to 385°C, specifically 340°C to 370°C, or more specifically 350°C to 360°C. At time t1, the operation of the heating arrangement 110 changes from the preheating mode to the aerosol-emitting mode H, in which the temperature t of the aerosol-forming substrate 21 is maintained at a first temperature level T1. At this point, the user may begin taking a certain number of puffs at their discretion, until they may decide to interrupt their user experience. In the embodiment according to FIG. 2, the user takes two puffs (represented by the dotted curve) and then decides to temporarily interrupt their user experience at time t2. This pause may be initiated, for example, by user input, preferably again via the user switch 165. Alternatively, or additionally, as shown in FIG. 1, the aerosol-generating device 100 may include a motion sensor 166 for detecting movement of the device 100. The motion sensor 166 may detect, for example, that the aerosol-generating device 100 has not been moved for a certain period of time, which may indicate that the device 100 is not being used (e.g., because the device 100 is sitting idle on a table). As a result, the motion sensor 166 may output a sensor signal indicating that the device 100 is in a suspended state of operation, i.e., suspended state of use.Thereafter, in response to a user initiating a pause in operation, i.e., a pause in use, via the user switch 165 or in response to such a sensor signal, the controller 160 may generate a pause signal that causes the heating arrangement 110 to change from the aerosol-emitting mode to the pause mode P described above. In the pause mode P, the heating arrangement 110 heats the aerosol-forming substrate 21 at a second temperature level T2 that is lower than the first temperature level T1 to minimize depletion of the substrate 21. Nevertheless, the second temperature level T2 is still sufficiently high to prevent condensation of vaporized material within the cavity 103. Depending on the particular substrate type and composition, among other things, the second temperature level may be in the range of 175°C to 225°C, specifically 185°C to 215°C, and more specifically 195°C to 205°C.

[0118] During the aerosol-emitting mode or the pause mode, the heating of the substrate 21 at the respective temperature levels T1 and T2 is preferably controlled in a closed-loop configuration by the controller 160. To this end, the controller 160 may be configured to determine, from the DC supply voltage of the DC power supply 150 and from the DC current drawn from the DC power supply 150, an apparent ohmic resistance of the susceptor 30, which indicates the temperature of the susceptor 30 and, therefore, the temperature of the aerosol-forming substrate 21. It may be preferable to measure both the DC supply voltage and the DC current drawn from the DC power supply. This may be achieved using a suitable DC voltage sensor and a suitable DC current sensor (not shown in FIG. 1 ). However, in the case of a DC power supply with a constant supply voltage, temperature control may be based solely on measuring the DC current. Details of this control mechanism are disclosed, for example, in WO 2015 / 177256 A1.

[0119] To facilitate temperature control at the first temperature level T1 and the second temperature level T2, the aerosol generating system 1 according to FIG. 1 may include a susceptor 30 that includes at least two different susceptor materials. That is, the susceptor 30 may include a first susceptor material optimized for heat loss and therefore heating efficiency. In addition, the susceptor 30 may include a second susceptor material used as a temperature marker. For this purpose, the second susceptor material is selected to have a Curie temperature corresponding to a predetermined operating temperature of the susceptor assembly. That is, in this embodiment, the Curie temperature of the second susceptor material is preferably selected at approximately the first temperature level T1. When the susceptor 30 reaches the Curie temperature of the second susceptor material, the magnetic properties of this material change from ferromagnetic or ferrimagnetic to paramagnetic, accompanied by a temporary change in the apparent resistance or conductance of the susceptor 30. As mentioned above, the DC current drawn from the DC power supply 150 is proportional to the conductance and inversely proportional to the apparent resistance of the susceptor. Thus, by monitoring the corresponding change in the electrical DC current drawn by the induction heating arrangement 110, it is possible to detect when the second susceptor material has reached its Curie temperature, and therefore a predefined operating temperature. Details of this control mechanism are disclosed, for example, in WO 2015 / 177294 A1.

[0120] The basis of this mechanism is also illustrated in FIG. 3 , which shows the electrical DC current I_DC absorbed by the induction heating arrangement 110 versus the temperature T of the susceptor 30, and therefore the temperature T of the substrate. To control the heating process at the first temperature level T1 during the aerosol emission mode, the controller 160 may adjust the current I1 to the minimum 311 or to a point between the minimum 311 and the maximum 312 of the current versus temperature profile shown in FIG. 3 . To this end, the current versus temperature profile shown in FIG. 3 may be programmed into the controller 160. To control the heating process at the second temperature level T2 during the pause mode, also as shown in FIG. 3 , the controller 160 may adjust the current I2 to point 313, which corresponds to the current at the minimum 311, and a predetermined offset value in the drop to the left of the minimum 311 of the current versus temperature profile. That is, control of the heating temperature at the second temperature level T2 may be based on the principle of offset control. The heating arrangement 110 may be operated in pulsed mode to maintain the temperature at the respective temperature levels T1, T2 during the aerosol emission mode H or during the pause mode P. The principles of pulsed mode operation are described, for example, in WO 2015 / 177256 A1.

[0121] To change the temperature of the substrate 21 from the first temperature level T1 to the second temperature level T2, the heating arrangement 110 may stop heating the aerosol-forming substrate 21 until the second temperature level T2 is reached. Alternatively, the heating arrangement 110 may heat the aerosol-forming substrate 21 at a reduced heating power or in a pulsed mode until the second temperature level T2 is reached. The change from heating at the first temperature level T1 in the aerosol emission mode H to heating at the second temperature level T2 in the pause mode P may be referred to as the cooling mode C. As illustrated in FIG. 2 , the initial part of the pause mode P may be the cooling mode C.

[0122] Upon reaching the second temperature level T2, the heating arrangement 110 may return to a normal heating mode, such as during the aerosol emission mode H, to maintain the temperature of the substrate 21 at the second temperature T2, particularly by using feedback control as described above.

[0123] When the user decides to resume the user experience, a change from pause mode P back to aerosol emission mode may be initiated, for example, by user input, preferably via user switch 165. As a result, in response to the user re-initiating operation of the device via user switch 165, controller 160 may generate an activity signal that causes heating arrangement 110 to again operate in aerosol heating mode P by increasing and then maintaining the temperature of susceptor 21 to a first temperature level T1, as shown in FIG. 2 at time t3.

[0124] Additionally or alternatively, a motion sensor 166 may be used to restart the aerosol emission mode upon detecting movement of the device 100, which may indicate that the user is (again) holding the device 100 and therefore possibly intending to resume the user experience. In doing so, the motion sensor 166 may output a sensor signal indicating that the device 100 is again in operation or is intended to be again in operation. In response to such a sensor signal, the controller 160 also generates an activity signal (as in response to activation of a user switch), which causes the heating arrangement 110 to again operate in the aerosol heating mode P by increasing the temperature of the susceptor 21 and then maintaining it at the first temperature level T1.

[0125] The heating arrangement 110 may also be configured to change from the pause mode P to the aerosol-emitting mode H after a predetermined maximum pause time has elapsed, for example, after 10 minutes. Specifically, this may occur regardless of whether the user has actively initiated a resumption of the user experience. Advantageously, this avoids keeping the device 100 in the pause mode for too long, which may result in the aerosol-forming substrate 21 eventually running out of power. Additionally, having a predetermined maximum pause time may help prevent the device 100 from running out of power.

[0126] Nevertheless, the heating arrangement 110 according to this embodiment is configured to stop the heating operation after a predetermined number of puffs or, depending on which event occurred earlier, after a predetermined weighted cumulative operating time in the aerosol-emitting mode and the pause mode. Using a weighted cumulative operating time may advantageously take into account that the aerosol-forming substrate may still be slightly depleted during the pause mode, reducing the effective operating time in the aerosol-emitting mode. As an example, the time in the aerosol-emitting mode may be weighted by a factor of 1, while the time in the pause mode may be weighted by a factor of 1 / 6. As a result, to still achieve an acceptable amount of aerosol, if the effective operating time of a given aerosol-generating article is, for example, 6 minutes, the device may operate for 6 minutes in the aerosol-emitting mode and 0 minutes in the pause mode, or for 5 minutes in the aerosol-emitting mode and 6 minutes in the pause mode, or for 4 minutes in the aerosol-emitting mode and 12 minutes in the pause mode, etc. In this embodiment, the heating operation ceases at time t4 due to reaching a predetermined maximum total number of 12 puffs available when using the aerosol-generating article shown in FIG.

[0127] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are understood to be modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A ± 5 percent of A. Within this context, the number A may be considered to include values ​​that are within the common standard error of measurement for the property it modifies. In some cases, as used in the appended claims, the number A may deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel property(ies) of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. An aerosol generating device comprising an electrical heating arrangement for heating an aerosol-forming substrate to generate an aerosol, the arrangement comprising: the device further comprising a user switch configured to allow a user of the device to initiate a pause in use of the device; the device further comprising a controller configured to generate a pause signal in response to a user initiating a pause of use of the device via the user switch; The aerosol generating device, wherein the heating arrangement is configured to heat the aerosol-forming substrate at a first temperature level in an aerosol emission mode, and in response to the pause signal, to heat the aerosol-forming substrate at a second temperature level lower than the first temperature level in a pause mode.

2. 10. The aerosol generating device of claim 1, wherein the device further comprises at least one sensor configured to output a sensor signal indicating that the device is in use by a user or is temporarily suspended from use, and the controller is further configured to generate a suspension signal in response to the sensor signal indicating that the device is temporarily suspended from use.

3. 3. The aerosol generating device according to claim 1, wherein the first temperature level is in the range of 325°C to 385°C, specifically 340°C to 370°C, more specifically 350°C to 360°C.

4. 4. The aerosol generating device according to claim 1, wherein the second temperature level is in the range of 175°C to 225°C, specifically 185°C to 215°C, more specifically 195°C to 205°C.

5. 5. An aerosol generating device according to claim 1, wherein the second temperature level is at least 50 degrees Celsius, particularly at least 75 degrees Celsius, more particularly at least 100 degrees Celsius, lower than the first temperature level.

6. An aerosol generating device as described in any one of claims 2 to 5, wherein the at least one sensor comprises one of a puff sensor for detecting a user's puff, a motion sensor for detecting movement of the device, and an orientation sensor for detecting the orientation of the device.

7. 7. An aerosol generating device according to any one of claims 2 to 6, wherein the user switch is further configured to enable a user of the device to initiate use of the device, in particular a user experience.

8. The aerosol generating device of claim 7, wherein the controller is configured to generate an activity signal in response to the sensor signal indicating that the device is being used by a user and / or in response to a user initiating use of the device, particularly a user experience via the user switch.

9. 9. The aerosol generating device of claim 8, wherein the heating arrangement is configured to change from the pause mode to the aerosol emission mode after a predetermined maximum pause time has elapsed or in response to the activation signal.

10. 10. The aerosol generating device of claim 9, wherein the predetermined maximum pause time is in the range of 1 minute to 15 minutes, specifically 2 minutes to 14 minutes, more specifically 3 minutes to 5 minutes, or 7 minutes to 12 minutes.

11. The heating arrangement comprises: A predetermined number of puffs; the passage of a predetermined operating time in the aerosol emission mode; and the passage of a predetermined operating time in the pause mode; and An aerosol generating device as described in any one of claims 1 to 10, configured to stop heating operation in both the aerosol emission mode and the pause mode after at least one of the following: and a predetermined weighted cumulative operating time has elapsed in the aerosol emission mode and the pause mode.

12. 12. The aerosol generating device of claim 11, wherein the predetermined operating time in the aerosol emission mode is in the range of 1 minute to 12 minutes, specifically 2 minutes to 10 minutes, more specifically 3 minutes to 8 minutes, for example 6 minutes.

13. 13. The aerosol generating device of claim 11 or 12, wherein the predetermined operating time in the pause mode is in the range of 1 minute to 15 minutes, particularly 2 minutes to 14 minutes, more particularly 5 minutes to 13 minutes, for example 12 minutes.

14. 14. The aerosol generating device according to claim 1, wherein the heating arrangement is configured to change from heating at the first temperature level in the aerosol emission mode to heating at the second temperature level in the pause mode in response to the pause signal by stopping heating of the aerosol-forming substrate until the second temperature level is reached, or by heating the aerosol-forming substrate with reduced heating power or in pulsed mode until the second temperature level is reached.

15. the heating arrangement is configured to modify at least one of the first temperature level or the second temperature level based on environmental data; An aerosol generating device according to any one of claims 1 to 14, wherein the device further comprises an environmental data sensor, in particular at least one of a humidity sensor for measuring humidity in the environment of the device, or a temperature sensor for measuring the temperature in the environment of the device.

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