An aerosol-generating device having a component to detect insertion and / or extraction of an aerosol-generating article to and / or from the aerosol-generating device

Abstract

The present disclosure relates to an aerosol-generating device having components for detecting insertion and / or extraction of an aerosol-generating article into and / or from the aerosol-generating device. The device comprises a cavity for removably receiving at least a portion of an aerosol-generating article, wherein the article comprises an aerosol-forming substrate and an inductively heatable susceptor for heating the substrate. The device further comprises a DC power supply and an induction heating device configured to generate an alternating magnetic field within the cavity for inductively heating the susceptor of the article when received in the cavity. The device further comprises a control circuit configured to generate a probe power pulse for intermittently powering the induction heating device and to detect a change in at least one property of the induction heating device due to the susceptor being present within or not present within the cavity upon insertion or extraction of an aerosol-generating article into or from the cavity, and in response, to detect insertion of an article into the cavity and / or extraction of an article from the cavity.

Description

[0001] This invention relates to an aerosol generation apparatus, comprising a cavity and a component for detecting the insertion or extraction of an aerosol-generated article into or from the cavity. The invention also relates to an aerosol generation system including such an apparatus and a method for operating such an apparatus.

[0002] Aerosol generating devices for generating inhalable aerosols by heating an aerosol forming matrix are generally known from the prior art. Such devices typically include a cavity for removably receiving at least a portion of an aerosol-generating article comprising the aerosol-forming matrix to be heated. To heat the matrix, the device may include an induction heating device, powered by a battery, and configured to generate an alternating magnetic field within the cavity for inductively heating a sensor that is in thermal proximity or direct physical contact with the matrix during device use. The sensor may be an integral part of the aerosol-generating article. Such devices may also include components for detecting the insertion or removal of the aerosol-generating article into or from the receiving cavity to enable or disable the heating process. Such detection can be achieved by a separate sensor component that continuously monitors the presence or absence of the article in the cavity. However, a separate sensor component typically requires additional assembly space within the device. Furthermore, continuous operation of the sensor is energy-intensive and can therefore significantly reduce the device's operating time.

[0003] Therefore, there will be a need for an aerosol generating apparatus that has the advantages of existing technological solutions without their limitations. In particular, it is desirable to have an aerosol generating apparatus that provides improved components for detecting the insertion or extraction of the aerosol-generated article into or from the receiving cavity of the apparatus.

[0004] According to one aspect of the present invention, an aerosol generating apparatus is provided for heating an aerosol forming matrix, the aerosol forming matrix being capable of forming an inhalable aerosol upon heating, the apparatus comprising:

[0005] - A cavity for removably receiving at least a portion of an aerosol-generating article, the article comprising the aerosol-forming matrix and a heat-sensitive sensor for heating the matrix;

[0006] -DC power supply;

[0007] - An induction heating device, which is connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating a sensor of the article during heating operation when the article is received in the cavity;

[0008] - A control circuit configured to supply power from the DC power supply to the heating device for powering the induction heating device, and to detect a change in at least one characteristic of the induction heating device caused by the presence or absence of the sensor in the cavity when the aerosol-generating article is inserted into or withdrawn from the cavity, and in response to detect the insertion of the article into the cavity and / or the withdrawal of the article from the cavity.

[0009] According to another aspect of the present invention, an aerosol generating apparatus is provided for heating an aerosol forming matrix, the aerosol forming matrix being capable of forming an inhalable aerosol upon heating, the apparatus comprising:

[0010] - A cavity for removably receiving at least a portion of an aerosol-generating article, the article comprising the aerosol-forming matrix and a heat-sensitive sensor for heating the matrix;

[0011] -DC power supply;

[0012] - An induction heating device, which is connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating a sensor of the article during heating operation when the article is received in the cavity;

[0013] - A control circuit configured to generate power pulses for intermittently energizing the induction heating device, and to detect changes in at least one characteristic of the induction heating device caused by the presence or absence of the sensor in the cavity when the aerosol-generating article is inserted into or withdrawn from the cavity, and in response to detect the insertion of the article into the cavity and / or the withdrawal of the article from the cavity.

[0014] According to the present invention, it has been found that the induction heating device can be used not only for heating a substrate, but also for detecting the insertion and / or extraction of articles into and / or from cavities. Therefore, the induction heating device can be used for multiple purposes. Advantageously, this avoids the need for additional assembly space for a separate sensor component.

[0015] Furthermore, it has been found that operating the induction heating device in pulse mode for product inspection purposes advantageously reduces power consumption and thus increases the overall operating time of the device compared to other solutions.

[0016] According to the present invention, the detection of article insertion or article extraction is based on the fact that article insertion into and article extraction from the cavity modify at least one characteristic, particularly at least one electrical and / or magnetic characteristic of the induction heating device due to the presence or absence of a sensor in the vicinity of the induction heating device. The change in at least one characteristic caused by the presence or absence of a sensor may be due to the interaction between the field of the induction heating device and the sensor.

[0017] At least one characteristic of the induction heating device can be any characteristic with an associated parameter that has a different value when the sensor is present compared to when the sensor is absent. For example, at least one characteristic can be the current, voltage, resistance, frequency, phase shift, magnetic flux, and inductance of the induction heating device.

[0018] Preferably, the characteristic is at least one of the equivalent resistance or inductance of the induction heating device. As used herein, the term "equivalent resistance" refers to the real part of a complex impedance, defined as the ratio of the AC voltage supplied to the induction heating device to the measured AC current. Therefore, "equivalent resistance" can also be expressed as the resistive load of the induction heating device. Similarly, as used herein, the term "inductance" refers to the imaginary part of a complex impedance, defined as the ratio of the supplied AC voltage to the measured AC current. Generally, inductance has circuit characteristics that are susceptible to external electromagnetic influences.

[0019] A variation in at least one characteristic of the induction heating device can be attributed to a specific permeability and / or resistivity of the sensor. That is, the sensor within the aerosol-generating article may comprise a material having a specific permeability and / or resistivity. Preferably, the sensor comprises a conductive material. For example, the sensor may comprise a metallic material. The metallic material may be, for example, aluminum, nickel, iron, or alloys thereof, such as carbon steel or ferritic stainless steel. Aluminum has a resistivity of about 2.65 × 10⁻⁸ ohm-meters and a permeability of about 1.256 × 10⁻⁶ Henry / meter when measured at room temperature (20°C). Similarly, ferritic stainless steel has a resistivity of about 6.9 × 10⁻⁷ ohm-meters and a permeability in the range of 1.26 × 10⁻⁶ Henry / meter to 2.26 × 10⁻⁶ Henry / meter when measured at room temperature (20°C).

[0020] Generally, the control circuit can be configured to detect at least one of the following: inserting the aerosol-generating article into the cavity to initiate heating operation; removing the aerosol-generating article from the cavity after heating operation to allow heating operation to restart; or removing the aerosol-generating article from the cavity during heating operation to stop heating operation. In the first and second cases, the aerosol-generating device is not in heating operation but in a specific article detection mode, specifically an article insertion detection mode or an article removal detection mode, respectively. In the third case, the aerosol-generating device is in heating operation, i.e., in heating mode. However, in heating mode, the control circuit can detect the removal of the aerosol-generating article from the cavity by detecting a change in at least one characteristic of the inductive heating device caused by the absence of a sensor in the cavity when the article is removed.

[0021] In both the first and second cases, i.e., when the device is in the article detection mode, particularly in the article insertion detection mode and the article extraction detection mode, the power pulse generated by the control circuit is specifically designed to detect the insertion of the aerosol-generated article into or out of the cavity. Therefore, during the article detection mode, particularly in the article insertion detection mode and the article extraction detection mode, the generated power pulse for article detection can be represented as a probe power pulse. Thus, the control circuit can be configured to generate the probe power pulse.

[0022] In the third case, i.e., when the device is in heating mode, the power pulse generated by the control circuit can be intended to heat the aerosol-forming matrix by pulse heating. Therefore, the power pulse generated during heating operation, particularly during heating mode, can be represented as a heating power pulse. Additionally, during heating operation, i.e., in heating mode, the power pulse can also be used to monitor the device for withdrawing the aerosol-forming article from the cavity in order to stop the heating operation. That is, the power pulse during heating mode can also be used to detect the withdrawal of the aerosol-forming article from the cavity by detecting a change in at least one characteristic of the induction heating device caused by the sensor not being in the cavity when the article is withdrawn.

[0023] Generally, the power pulses in the in-process insertion detection mode and the in-process removal detection mode can be the same. However, at least one characteristic of the power pulses in these modes can also differ, such as the amplitude, duration, and time interval between two consecutive power pulses. Similarly, the power pulses in the in-process insertion / removal detection mode and the heating mode can be the same. However, the power pulses in the insertion / removal detection mode and the heating mode, i.e., the probe power pulse and the heating power pulse, can differ in at least one characteristic, such as the amplitude, duration, and time interval between two consecutive power pulses. Specifically, the amplitude of the heating power pulse can be greater than the amplitude of the probe power pulse. Furthermore, the probe power pulse can have a fixed pulse pattern, particularly a fixed period. In contrast, the heating power pulse can have a non-fixed, specifically variable pulse pattern, for example, in the case of pulse width modulation of the heating power.

[0024] The control circuit can be configured to disable the heating operation of the induction heating device in response to detecting the removal of an article from the cavity during heating operation. Similarly, the control circuit can be configured to disable the heating operation of the induction heating device after a previous heating operation until after the removal of an article from the cavity is detected. Advantageously, this prevents the user of the device from starting a new heating operation with depleted aerosol-generated articles. That is, it prevents the user from reusing aerosol-generated articles that have already been used in a previous user experience. Otherwise, reheating used aerosol-generated articles could lead to an unsatisfactory user experience, as used aerosol-generated articles may not generate aerosols at the same level as unused aerosol-generated articles. Therefore, user convenience of the device is improved, since reheating used aerosol-generated articles could also lead to an unsatisfactory user experience. Furthermore, safety can be improved, as reheating used aerosol-generated articles could damage the heating device.

[0025] Once the removal of the article is detected, the heating operation should be stopped. Therefore, the control circuit can be configured to activate the heating operation of the induction heating device in response to detecting the removal of the article from the cavity during heating operation and after the heating operation has been disabled. Similarly, the control circuit can be configured to activate the heating operation of the induction heating device after a previous heating operation and in response to detecting the removal of the article from the cavity.

[0026] Generally, the heating operation of an induction heating device can be manually activated, i.e., activated by user input. Alternatively or additionally, the activation of the heating operation can be event-driven, i.e., it can occur in response to the detection of a specific event. Preferably, the control circuitry is configured to initiate the heating operation of the induction heating device in response to the detection of an article being inserted into the cavity. Advantageously, this enhances user convenience because the heating operation begins automatically when the article is inserted into the cavity, without requiring any further user input. In particular, the user experience begins immediately, as is known from conventional cigarettes.

[0027] The control circuit may also include a motion sensor for detecting movement of the aerosol generating device. Advantageously, the motion sensor enables the monitoring of device movement and, for example, the detection of user handling of the device. That is, if the motion sensor detects movement of the aerosol generating device, it means that the user is holding the device and may therefore be about to remove the aerosol-generated article from the cavity or insert the article into the cavity and thus begin a new user experience. For example, the motion sensor can detect movement of the aerosol generating device when it has been removed from the charging unit. 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 the charging unit or idle on a table.

[0028] As an example, a motion sensor may include at least one of an accelerometer for measuring acceleration or a gyroscope for measuring the angular orientation or angular velocity of the device. That is, a 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 user operation of the device.

[0029] To avoid generating unnecessary pulses during idle periods, i.e., times when the aerosol generating device is not in use, the control circuit can also be configured to begin generating a detection power pulse in response to the detection of movement of the aerosol generating device. Specifically, the control circuit can be configured to begin generating a power pulse only in response to the detection of movement of the aerosol generating device. Therefore, when the user is about to use the device, the detection of device movement triggers the article detection mode. Advantageously, this allows for power savings and thus increases the overall operating time of the aerosol generating device.

[0030] Preferably, the control circuit is configured to begin generating a power pulse, particularly a detection power pulse, in response to detecting that movement of the device has reached or exceeded a predetermined motion threshold. The predetermined motion threshold can be defined by an acceleration value, an angle value, or an angular velocity value. The predetermined acceleration threshold can be in the range of 0.5g to 1.5g, particularly between 0.7g and 1.3g, where g represents 9.80665 m / s² as defined by a standard. 2The standard acceleration caused by gravity in meters per second squared.

[0031] The control circuit can be configured to stop generating power pulses, particularly detection power pulses, after a predetermined time following the detection that the movement of the device has reached or exceeded a predetermined movement threshold. The control circuit can also be configured to stop generating power pulses, particularly detection power pulses, in response to detecting that the movement of the device has not reached the predetermined movement threshold within a predetermined idle time, or in response to detecting no movement within a predetermined idle time. Advantageously, this procedure also helps to reduce power consumption, thus increasing the overall operating time of the device.

[0032] To further reduce power consumption, the control circuit can be configured to reduce the number of power pulses, particularly detection power pulses, per unit time to, for example, one-half or one-third, in response to detecting that the movement of the device has not reached a predetermined motion threshold during a predetermined idle time or in response to detecting that there has been no movement during a predetermined idle time. The idle time can be between 10 seconds and 90 seconds, particularly between 15 seconds and 60 seconds, preferably between 15 seconds and 40 seconds.

[0033] According to another configuration, the control circuit can be configured to reduce the number of power pulses, particularly detection power pulses, per unit time to, for example, one-half or one-third, in response to detecting that the movement of the device has not reached a predetermined acceleration threshold during a predetermined first idle time, or in response to detecting that the device has not moved during the predetermined first idle time. Subsequently, in response to detecting that the movement of the device has not reached the predetermined acceleration threshold during a predetermined second idle time starting after the first idle time, or in response to detecting that the device has not moved during the predetermined second idle time starting after the first idle time, the generation of power pulses, particularly detection power pulses, is stopped. Advantageously, this configuration further reduces power consumption, thus increasing the overall operating time of the device. The first idle time can be between 5 and 60 seconds, particularly between 10 and 30 seconds, preferably between 15 and 25 seconds. Similarly, the second idle time can be between 10 and 90 seconds, particularly between 15 and 60 seconds, preferably between 15 and 30 seconds.

[0034] Alternatively, or in addition to triggering the article detection mode by movement of the monitoring device, the article detection mode can also be triggered by other events. For example, the article detection mode can be triggered by removing the aerosol generating device from the charging unit used to recharge the device's DC power supply. For this purpose, the control circuit can be configured to detect the removal of the aerosol generating device from the charging unit. Furthermore, the control circuit can be configured to begin generating a power pulse, specifically a probe power pulse, in response to the detection of the removal of the aerosol generating device from the charging unit. This procedure proves advantageous for the automatic initiation of article insertion detection. In particular, this procedure enhances user convenience because the user does not need to actively initiate the article detection mode when recharging the aerosol generating device.

[0035] Similarly, the control circuit can be configured to detect the insertion of the aerosol generating device into the charging unit. Based on this, the control circuit can also be configured to stop generating power pulses, specifically detecting power pulses, in response to the detection of the aerosol generating device being inserted into the charging unit. Again, this procedure allows for the avoidance of unnecessary power consumption and enhances user convenience, as the user does not need to actively stop the product detection mode before recharging the DC power supply.

[0036] The control circuit can be configured to stop the heating operation of the device under various constraints. Specifically, the control circuit can be configured to stop the heating operation of the device in response to at least one of detecting a predetermined number of suctions, detecting that a predetermined heating time has elapsed, or receiving user input.

[0037] Advantageously, any of these conditions can then initiate the detection of the aerosol-generated article being extracted from the cavity. Therefore, the control circuit can be configured to begin generating a power pulse, specifically a probe power pulse, in response to the detection of the cessation of heating operation of the device, for detecting the extraction of the article. As mentioned above, this procedure also enhances user convenience, as the user does not need to actively initiate the article detection mode at the end of the user experience.

[0038] The control circuit can also be configured to stop the heating operation of the induction heating device in response to detecting the removal of the article from the cavity. Advantageously, for example, this configuration can be used to abort the heating operation if the aerosol-generating article has been prematurely removed, for example, before the predetermined heating time has expired, before the predetermined number of aspirations have expired, or before user input. In this regard, detecting the removal of the article from the cavity can be considered another condition triggering the cessation of the heating operation. Similarly, the heating operation may also stop solely in response to detecting the removal of the article from the cavity.

[0039] The control circuit can be configured to generate at least one verification power pulse within a predetermined time period after the first detection of a change in at least one characteristic of the induction heating device, and to verify the insertion of the article into or extraction from the cavity by re-detecting a change in at least one characteristic of the induction heating device.

[0040] To generate power pulses for intermittently energizing the induction heating device, the control circuitry may include a switch configured and arranged to control the supply of power from a DC power source to the induction heating device. For this purpose, the switch may intermittently close and open, for example, intermittently energizing the induction heating device to detect the insertion of an aerosol-generating article into the cavity to initiate heating operation, withdrawing the aerosol-generating article from the cavity after heating operation to restart heating operation, or withdrawing the aerosol-generating article from the cavity during heating operation to stop heating operation, at least one of these methods.

[0041] As described above, the first two scenarios involve detecting the insertion and removal of aerosol-generated articles from the cavity during the article detection mode or operation of the aerosol generation apparatus, specifically the article insertion detection mode and the article removal detection mode, respectively. In contrast, the third scenario involves detecting the removal of aerosol-generated articles from the cavity during the heating operation or heating mode of the apparatus. In this case, the switch can also be used to intermittently energize the induction heating device during the heating mode of the apparatus to generate power pulses for pulsed heating of the aerosol-forming matrix. Therefore, this mode can be referred to as a pulsed heating mode. In this mode, the power pulses can also be used to monitor the removal of the aerosol-generated article from the cavity to stop the heating operation.

[0042] During the heating operation of the aerosol generating apparatus, the switch may be permanently closed to continuously apply the DC voltage of the DC power supply to the induction heating device. Therefore, this mode can be referred to as a continuous heating mode. In continuous heating mode, the control circuit is also able to detect the removal of the article from the cavity by detecting a change in at least one characteristic of the induction heating device caused by the sensor being outside the cavity, similar to when the aerosol-generated article is removed from the cavity in a pulsating mode.

[0043] Changes in characteristics can be observed by measuring changes in the parameters of the induction heating device. These parameters can be measured directly or indirectly. The presence or absence of a sensor in the cavity, and therefore the presence or absence of an article, can be determined by measuring the parameter and observing its different value in the presence of a sensor compared to the value in the absence of a sensor. Preferably, the parameter can be current. Therefore, the control circuit may include a measuring device for measuring a current indicating at least one characteristic of the induction heating device. Specifically, the parameter may be DC current supplied from a DC power source to the induction heating device. Therefore, the control circuit may include a measuring device arranged and configured to measure the DC current supplied from the DC power source to the induction heating device. For this purpose, the measuring device may include a DC current measuring device arranged in series between the DC power source and the induction heating device. For example, the measuring device may include a resistor and a shunt amplifier. Therefore, when an aerosol-generating article is inserted into the cavity of the aerosol-generating device, the presence of a sensor in the cavity increases the equivalent resistance due to the added resistive load. This, in turn, reduces the DC current fed to the induction heating device. The decrease in DC current is detected by a current measuring device in the control circuit, which can then activate the heating operation of the induction heating device for heating the substrate. Similarly, when the aerosol-generated article is withdrawn from the cavity of the aerosol generating device, the sensor is no longer present in the cavity, thus reducing the equivalent resistance due to the reduced resistive load. This, in turn, causes an increase in the DC current feeding the induction heating device. This increase in DC current is detected by a current measuring device in the control circuit, which can then initiate the next heating operation.

[0044] Generally, the pulse duration and the time interval between two consecutive power pulses, especially the probe pulse, should be selected for article detection, particularly for detecting article insertion into or removal from a cavity, to balance energy consumption and user experience performance. The probe pulse duration should be as short as possible, but long enough to provide reliable measurement of the current pulse. Similarly, the longer the time interval between two consecutive power pulses, especially the probe pulse, the lower the energy consumption. However, the time interval between two consecutive power pulses, especially the probe pulse, should not be too long; otherwise, the user may have to wait too long to begin the user experience.

[0045] Taking these factors into account, the power pulse, especially the detection power pulse, can have a pulse duration in the range of 1 microsecond to 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds.

[0046] As used herein, the term "pulse duration" refers to the time interval during which the heating device is energized, and in particular the time interval during which the aforementioned switch is closed.

[0047] The time interval between two consecutive power pulses, especially the detection power pulse, can be between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, and preferably between 500 milliseconds and 1 second.

[0048] The sum of the pulse duration and the time interval between two consecutive power pulses can be expressed as the polling time, which is the time difference between the start of one pulse and the start of the next. The polling time can be between 50 milliseconds and 2.5 seconds, particularly between 51 milliseconds and 2.5 milliseconds, more specifically between 100 milliseconds and 2 seconds, and preferably within the range of 500 milliseconds and 1 second.

[0049] Preferably, for article detection, a power pulse is generated within a predetermined time period, particularly a detection power pulse. That is, the detection mode can continue for a limited predetermined time period. If article insertion or removal is not detected within the predetermined time period, the detection mode can be stopped; that is, the generation of power pulses can be turned off for safe use of electricity, as described above. Similarly, if article insertion or removal is detected within the predetermined time period, the detection mode can be stopped, particularly in immediate response to the detection of article insertion or removal.

[0050] As further described above, during heating operation, power pulses may be generated for a predetermined number of suction cycles or a predetermined heating time, or until input is received from a switch, particularly a user input. Specifically, the heating mode may include pulse width modulation of the heating power pulses used to control the heating temperature.

[0051] Generally, the detection mode (detection operation) and the heating mode (heating operation) can differ from each other in at least one characteristic of the power pulse, particularly in at least one of the time period or pulse pattern. For example, the detection mode may include a power pulse, particularly a fixed pulse pattern for detecting power pulses. In contrast, the heating mode may include, for example, a non-fixed, specifically variable pulse pattern of the power pulse in the case of pulse width modulation of the power pulse, particularly a heating power pulse.

[0052] The induction heating device can be configured to generate a high-frequency alternating magnetic field. As mentioned herein, the high-frequency alternating magnetic field can range from 500 kHz to 30 MHz, particularly from 5 MHz to 15 MHz, and preferably between 5 MHz and 10 MHz.

[0053] To generate an alternating magnetic field, the induction heating device may include a DC / AC converter connected to a DC power supply. The DC / AC converter may include an LC network. For example, the DC / AC converter may include a Class C power amplifier, a Class D power amplifier, or a Class E power amplifier. Specifically, the DC / AC converter may include a transistor switch and transistor switch drive circuitry, as well as an LC network. The LC network may include a series connection of capacitors and inductors, wherein the inductors are configured and arranged to generate an alternating magnetic field within the cavity, particularly for inductively heating the inductor and for article detection. The LC network may also include a shunt capacitor connected in parallel with the transistor switch. Additionally, the DC / AC converter may include a choke inductor for supplying a DC power supply voltage +V_DC from the DC power supply.

[0054] The inductor used to generate an alternating magnetic field within the cavity for inductive heating of the sensor and for article detection may include at least one induction coil, particularly a single induction coil or multiple induction coils. The number of induction coils may depend on the size and / or number of the sensor. One or more induction coils may have a shape that matches the shape of one or more sensors in the aerosol-generating article. Similarly, one or more induction coils may have a shape that conforms to the shape of the housing of the aerosol-generating device.

[0055] At least one induction coil can be a helical coil or a planar coil, particularly a disc coil or a bent planar coil. The use of flat helical coils allows for robust and inexpensive compact designs. The use of helical induction coils advantageously allows for the generation of a uniform alternating electromagnetic field. As used herein, "flat helical coil" refers to a generally planar coil in which the axis of the coil winding is perpendicular to the surface on which the coil lies. Flat helical induction coils can have any desired shape within the plane of the coil. For example, a flat helical coil can have a circular shape, or it can have a generally oblong or rectangular shape. However, when used herein, the term "flat helical coil" encompasses both planar coils and flat helical coils shaped to conform to a bent surface. For example, the induction coil can be a "bent" planar coil arranged around the circumference of a preferably cylindrical coil support (e.g., a ferrite core). Furthermore, a flat helical coil can comprise, for example, two layers of four-turn flat helical coils or a single layer of four-turn flat helical coils.

[0056] At least one induction coil may be held within the housing of the heating device or the body or housing of the aerosol generating device that includes the heating device. At least one induction coil may be wound around a coil support, preferably cylindrical, such as a ferrite core.

[0057] The induction heating device can be configured to continuously generate an alternating magnetic field after the system is activated or intermittently, for example, on a per-port suction basis.

[0058] The control circuit can also be configured to control the overall operation of the aerosol generating device. At least a portion of the control circuit and the induction heating device can be part of the overall circuitry of the aerosol generating device.

[0059] The control circuit may include a microprocessor, such as a programmable microprocessor, a microcontroller, or an application-specific integrated circuit (ASIC), or other electronic circuitry capable of providing control. The control circuit may include at least one of a transimpedance amplifier for current-to-voltage conversion, an inverting signal amplifier, a single-ended differential converter, an analog-to-digital converter, and a microcontroller.

[0060] The microprocessor can be configured to: control a switch for generating power pulses to intermittently power on the induction heating device, read a measuring device for measuring the current supplied from a DC power source to the induction heating device, and control a transistor switch driver circuit for the induction heating device.

[0061] The control circuit can be the main controller of the aerosol generating device or a part of the main controller of the aerosol generating device.

[0062] The controller and at least a portion of the sensing source, particularly the sensing source other than the inductor, can be arranged on a common printed circuit board. This has proven particularly advantageous for the compact design of the heating device.

[0063] Preferably, the DC power supply includes at least one battery, such as a lithium iron phosphate battery. Alternatively, the power supply may include another form of charge storage device, such as a capacitor. The power supply may require charging; that is, the power supply may be rechargeable. The power supply may have a capacity that allows sufficient energy to be stored for one or more user experiences. For example, the power supply may have sufficient capacity to allow continuous aerosol generation in time intervals of approximately six minutes or multiples of six minutes. In another instance, the power supply may have sufficient capacity to allow for a predetermined number of suctions or discontinuous activation of the sensing source. The power supply may be the overall power supply for the aerosol generation apparatus according to the invention.

[0064] The receiving cavity may include an insertion opening through which an aerosol-generating article is inserted. As used herein, the direction of insertion of the aerosol-generating article is referred to as the insertion direction. Preferably, the insertion direction corresponds to the extension of the length axis, and in particular, the extension of the central axis of the receiving cavity.

[0065] After insertion into the receiving cavity, at least a portion of the aerosol-generating article can still extend outward through the insertion opening. Preferably, the outwardly extending portion is provided for interaction with the user, particularly for reaching the user's mouth. Thus, during use of the device, the insertion opening can be close to the mouth. Therefore, as used herein, when using the device, the segment near the insertion opening or near the user's mouth is indicated by the prefix "proximal". Segments arranged further away are indicated by the prefix "distal".

[0066] In contrast to this convention, the receiving cavity may be arranged in or located in the proximal portion of the aerosol generating device. The insertion opening may be arranged in or located at the proximal end of the aerosol generating device, particularly at the proximal end of the receiving cavity.

[0067] Similarly, the receiving cavity can be formed as a cavity, particularly as an elongated cavity, including a distal portion and a proximal portion. If present, an insertion opening can be disposed at the proximal end of the receiving cavity. At the distal end, the receiving cavity may include a bottom opposite the insertion opening.

[0068] The aerosol generating apparatus may include an air path extending from at least one air inlet into a receiving cavity. That is, the aerosol generating apparatus may include at least one air inlet in fluid communication with the receiving cavity. When the aerosol-generating article is inserted into the cavity, the air path may further extend through the aerosol-forming matrix within the article and the mouthpiece of the article to enter the user's mouth. Preferably, the air inlet is realized at an insertion opening in the receiving cavity for inserting the article into the cavity. Thus, when the article is received in the cavity, air may be drawn into the receiving cavity at the edge of the insertion opening and further through an airflow passage formed between at least one or more portions of the outer circumference of the aerosol-generating article and the inner surface of the receiving cavity.

[0069] Generally, the receiving cavity can have any suitable shape. Specifically, the shape of the receiving cavity may correspond to the shape of the aerosol-generating article to be received therein. Preferably, the receiving cavity may have a substantially cylindrical or conical shape, such as a substantially conical or substantially truncated conical shape.

[0070] Similarly, the receiving cavity may have any suitable cross-section, as seen in a plane perpendicular to the length axis of the receiving cavity or perpendicular to the insertion direction of the article. Specifically, the cross-section of the receiving cavity may correspond to the shape of the aerosol-generated article to be received therein. Preferably, the receiving cavity has a substantially circular cross-section. Alternatively, the receiving cavity may have a substantially elliptical cross-section, or a substantially oval cross-section, or a substantially square cross-section, or a substantially rectangular cross-section, or a substantially triangular cross-section, or a substantially polygonal cross-section. As used herein, the above shapes and cross-sections preferably refer to the shape or cross-section of the receiving cavity, without regard to any protrusions at the inner surface of the receiving cavity.

[0071] The inductor can be arranged, for example, around at least a portion of the receiving cavity or at least a portion of the inner surface of the receiving cavity. For example, the inductor can be a helical coil arranged within the sidewall of the receiving cavity. Specifically, the inductor can be integrated into the wall defining the receiving cavity. For example, the inductor can be integrated into the sidewall of the receiving cavity, particularly so as to surround at least a portion of the interior of the receiving cavity.

[0072] The receiving cavity may include a plurality of protrusions extending within the cavity. Preferably, the protrusions are spaced apart from each other, such that an airflow passage is formed between adjacent protrusions, i.e., through the gap (free space) between adjacent protrusions. Additionally, the protrusions may be configured to contact at least a portion of the aerosol-generating article to retain the aerosol-generating article within the receiving cavity. The protrusions may include ribs or may be formed as ribs. Preferably, one or more ribs extend along the length axis of the receiving cavity, particularly the direction of the central axis. Preferably, the length axis of the receiving cavity corresponds to an insertion direction along which the aerosol-generating article can be inserted into the receiving cavity.

[0073] The aerosol generating apparatus may also include optical or tactile indicators for indicating the detection of at least one of the following: removal of an article from the cavity, insertion of an article into the cavity, or disabling or enabling of heating operation of the induction heating device. Advantageously, such indicators can enhance usability and user convenience.

[0074] The present invention also relates to an aerosol generation system comprising an aerosol generation apparatus according to the invention and as described herein. The system further comprises an aerosol generation article, wherein at least a portion of the article is removably receivable or removably received in a receiving cavity of the apparatus. The article comprises at least one aerosol forming matrix and a heat-sensitive sensor for heating the matrix when the article is received in the cavity.

[0075] Aerosol-generating articles can be consumables, particularly intended for single use. Aerosol-generating articles can be tobacco products. Specifically, the articles can be rod-shaped, preferably cylindrical, and can resemble conventional cigarettes.

[0076] The article may include one or more of the following elements: a first support element, a matrix element, a second support element, a cooling element, and a filter element. Preferably, the aerosol-generating article includes at least a first support element, a second support element, and a matrix element located between the first support element and the second support element.

[0077] All the aforementioned elements can be arranged sequentially along the length axis of the article in the order described above, wherein the first support element is preferably located at the distal end of the article, and the filter element is preferably located at the proximal end of the article. Each of the aforementioned elements can be substantially cylindrical. Specifically, all elements can have the same external cross-sectional shape. Furthermore, the elements can be surrounded by an outer packaging to hold the elements together and maintain the desired circular cross-sectional shape of the rod-shaped article. Preferably, the packaging is made of paper.

[0078] As used herein, the term "aerosol-forming matrix" refers to a matrix capable of releasing volatile compounds that can form aerosols upon heating. An aerosol-forming matrix can be a solid aerosol-forming matrix, a liquid aerosol-forming matrix, or a gel-like aerosol-forming matrix. An aerosol-forming matrix may include tobacco-containing materials containing volatile tobacco flavor compounds that are released from the matrix upon heating. Alternatively or additionally, an aerosol-forming matrix may include non-tobacco materials. An aerosol-forming matrix may also include aerosol-forming agents. Examples of suitable aerosol-forming agents are glycerol and propylene glycol. An aerosol-forming matrix may also include other additives and ingredients, such as nicotine or flavoring substances. Specifically, a liquid aerosol-forming matrix may include water, solvents, ethanol, plant extracts, and natural or artificial flavorings. The aerosol forming matrix can also be a paste-like material, a porous material pouch containing the aerosol forming matrix, or loose tobacco mixed with a gelling agent or adhesive, which may include common aerosol forming agents such as glycerol, and is then compressed or molded into rods.

[0079] The matrix element preferably comprises at least one aerosol-forming matrix to be heated. The matrix element may also include a sensor that is in thermal contact or thermal proximity to the aerosol-forming matrix. As used herein, the term "sensor" refers to an element comprising a material capable of being inductively heated within an alternating electromagnetic field. This can be a result of at least one of hysteresis losses or eddy currents induced in the sensor, depending on the electrical and magnetic properties of the sensor material.

[0080] Receptors can include various geometric configurations. A receptor can be a granular receptor, or a receptor filament, or a receptor mesh, or a receptor core, or a receptor pin, or a receptor rod, or a receptor blade, or a receptor strip, or a receptor sleeve, or a receptor cup, or a cylindrical receptor, or a planar receptor. For example, a receptor can be an elongated receptor strip with a length ranging from 8 mm to 16 mm, particularly from 10 mm to 14 mm, preferably 12 mm. The width of the receptor strip can, for example, range from 2 mm to 6 mm, particularly from 4 mm to 5 mm. The thickness of the receptor strip is preferably in the range of 0.03 mm to 0.15 mm, more preferably in the range of 0.05 mm to 0.09 mm.

[0081] The sensor can be a multilayer sensor, such as a multilayer sensor strip. Specifically, a multilayer sensor may include a first sensor material and a second sensor material. The first sensor material is preferably optimized in terms of heat loss and therefore heating efficiency. For example, the first sensor material may be aluminum, or an iron-containing material, such as stainless steel. In contrast, the second sensor material is preferably used as a temperature marker. For this purpose, the second sensor material is selected to have a Curie temperature corresponding to a predefined heating temperature of the sensor assembly. At its Curie temperature, the magnetic properties of the second sensor change from ferromagnetic to paramagnetic, accompanied by a temporary change in its resistance. Therefore, by monitoring the corresponding change in the current absorbed by the sensing source, it is possible to detect when the second sensor material reaches its Curie temperature, and therefore when it reaches the predefined heating temperature. The Curie temperature of the second sensor material is preferably below the ignition point of the aerosol-forming substrate, i.e., preferably below 500 degrees Celsius. Suitable materials for the second sensor material may include nickel and certain nickel alloys.

[0082] At least one of the first and second support elements may include a central air passage. Preferably, at least one of the first and second support elements may include a hollow cellulose acetate tube. Alternatively, the first support element may be used to cover and protect the distal end of the matrix element.

[0083] Aerosol cooling elements are components with a large surface area and low suction resistance (e.g., 15 mmWG to 20 mmWG). In use, an aerosol formed by volatile compounds released from the matrix element is drawn through the aerosol cooling element before being delivered to the proximal end of the aerosol-generating article.

[0084] The filter element is preferably used as a mouthpiece, or as part of a mouthpiece together with an aerosol cooling element. As used herein, the term "mouthpiece" refers to a portion of an article through which aerosol exits to form the article.

[0085] Further features and advantages of the aerosol generation system and aerosol generation articles according to the invention have been described above with respect to the aerosol generation apparatus according to the invention and are equally applicable.

[0086] The present invention also relates to aerosol generating articles of the aerosol generating system according to the invention, or aerosol generating articles used in conjunction with the aerosol generating apparatus according to the invention. The aerosol generating articles include an aerosol forming matrix and a heat-sensitive sensor for heating the matrix. Further features and advantages of the aerosol generating articles have been described above with respect to the aerosol generating apparatus and aerosol generating system according to the invention and are equally applicable.

[0087] The present invention also relates to a method of operating an aerosol generating apparatus for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating. The apparatus includes a DC power supply and a cavity for removably receiving at least a portion of an aerosol generating article, the aerosol generating article including the aerosol forming matrix and a heat-sensitive sensor for heating the matrix. The apparatus further includes an induction heating device connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating the sensor of the article during heating operation when the article is received in the cavity. Specifically, the aerosol generating apparatus may be an aerosol generating apparatus according to the present invention as described above. The method includes:

[0088] - Operate the device in the work-in-process extraction detection mode as described below.

[0089] - Generate power pulses, particularly detect power pulses, to intermittently power the induction heating device;

[0090] - For each power pulse, at least one characteristic of the induction heating device is measured, the at least one characteristic of the induction heating device being affected in response to the extraction of an aerosol-generating article from the cavity of the device while the sensor is not in the cavity, and it is detected whether at least one characteristic of the induction heating device has changed compared to one or more previous power pulses, thus indicating that the aerosol-generating article has been extracted from the cavity; and

[0091] - The device is stopped in the article extraction detection mode in response to the detection of a change in at least one characteristic of the induction heating device.

[0092] The method may further include:

[0093] - Operate the device in the work-in-process insertion detection mode as described below.

[0094] - Generate power pulses, particularly detect power pulses, to intermittently power the induction heating device;

[0095] - For each power pulse, at least one characteristic of the induction heating device is measured, the at least one characteristic of the induction heating device being affected by the insertion of an aerosol-generating article into the cavity of the device while the sensor is present in the cavity, and it is detected whether at least one characteristic of the induction heating device has changed compared to one or more previous power pulses, thus indicating that the aerosol-generating article has been inserted into the cavity; and

[0096] - Stop operating the device in the article insertion detection mode in response to detecting a change in at least one characteristic of the induction heating device;

[0097] - The device is operated in heating mode by activating the heating operation of the induction heating device to heat the substrate.

[0098] Typically, the device is operated before or after the product extraction detection mode, or both before and after the product extraction detection mode, in the product insertion detection mode, and in the heating mode. In other words, the method can include a cycle of operating the device in the product insertion detection mode, operating the device in the heating mode, and operating the device in the product extraction detection mode.

[0099] As mentioned above regarding the aerosol generating apparatus according to the invention, the power pulse, particularly the detection power pulse, can have a predetermined pulse duration and a predetermined time interval between two consecutive power pulses, particularly the detection power pulse. The predetermined pulse duration can be between 1 microsecond and 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds. The time interval between two consecutive power pulses, particularly the detection power pulse, can be between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, preferably between 500 milliseconds and 1 second.

[0100] As further mentioned above regarding the aerosol generating apparatus according to the invention, at least one characteristic is preferably at least one of the equivalent resistances of the induction heating device. The equivalent resistance can be measured by the DC current supplied from the DC power supply to the induction heating device.

[0101] Therefore, operating the device in the work-in-process extraction detection mode or operating the device in the work-in-process insertion detection mode includes at least one of the following:

[0102] - For each pulse, the equivalent resistance of the induction heating device is measured by measuring the DC current supplied from the DC power supply to the induction heating device, and by detecting whether the DC current has changed compared to the previous pulse, and therefore whether the equivalent resistance of the induction heating device has changed, it indicates whether the aerosol-generated article is being withdrawn from the cavity or inserted into the cavity, respectively; and

[0103] - In response to the detection of a change in DC current and thus a change in the equivalent resistance of the induction heating device, operation of the device is stopped in the work-in-process extraction detection mode or in the work-in-process insertion detection mode, respectively.

[0104] Preferably, the article extraction detection mode can be triggered by stopping the previous heating operation of the induction heating device.

[0105] To prevent users from reusing aerosol-generated articles previously used in heating operations, operation of the device in heating mode can be disabled during operation of the in-process extraction detection device. Similarly, operation of the device in heating mode can be enabled in response to stopping operation of the in-process extraction detection device.

[0106] To reduce power consumption and thus increase the overall operating time of the device, the method may further include operating the device in standby mode by means of the following: after stopping the generation of power pulses, particularly the detection power pulse, or after starting the generation of power pulses, particularly the detection power pulse, in the article extraction detection mode or the article insertion detection mode, respectively:

[0107] - Monitor the movement of the device; and

[0108] - In response to detecting movement of the device or the movement of the device reaching or exceeding a predetermined acceleration threshold, the device is started to operate in the article extraction detection mode or the article insertion detection mode, respectively.

[0109] The standby mode can be stopped in response to the detection that a device has been inserted into the charging unit.

[0110] In addition, to avoid unnecessary power consumption, the method may further include:

[0111] - During at least one of operating the device in the work-in-process extraction detection mode or the work-in-process insertion detection mode, the device is operated in the idle state monitoring mode by the following:

[0112] - Monitor the movement of the device; and

[0113] - In response to the determination that the device has not moved during a predetermined idle time, the operation of the device is stopped in the article extraction detection mode or the article insertion detection mode, respectively.

[0114] For the same reason, according to another configuration, the method may include:

[0115] - During at least one of operating the device in the work-in-process extraction detection mode or the work-in-process insertion detection mode, the device is operated in the idle state monitoring mode by the following:

[0116] - Monitor the movement of the device; and

[0117] - In response to detecting that the device movement does not reach a predetermined acceleration threshold during a predetermined idle time or in response to detecting that there is no movement during a predetermined idle time, the number of power pulses per unit time, in particular the number of detection power pulses, is reduced to, for example, one-half or one-third.

[0118] The idle time can be between 10 and 90 seconds, especially between 15 and 60 seconds, preferably between 15 and 40 seconds.

[0119] According to another alternative configuration, the method may include:

[0120] - During at least one of operating the device in the work-in-process extraction detection mode or the work-in-process insertion detection mode, the device is operated in the idle state monitoring mode by the following:

[0121] -Measure the movement of the device;

[0122] - In response to the detection that the device movement has not reached a predetermined acceleration threshold during a predetermined first idle time or in response to the detection that there has been no movement during the predetermined first idle time, the number of power pulses, particularly the detection power pulses, per unit time is reduced to, for example, one-half or one-third. Subsequently, in response to the detection that the device movement has not reached the predetermined acceleration threshold during a predetermined second idle time starting after the first idle time or in response to the detection that there has been no movement during the predetermined second idle time starting after the first idle time, the generation of power pulses, particularly the detection power pulses, is stopped.

[0123] The first idle time can be between 5 and 60 seconds, particularly between 10 and 30 seconds, and preferably between 15 and 25 seconds. Similarly, the second idle time can be between 10 and 90 seconds, particularly between 15 and 60 seconds, and preferably between 15 and 30 seconds.

[0124] The article detection mode can be triggered by removing the aerosol generating device from the charging unit. Advantageously, this procedure enhances user convenience because the user does not need to actively activate the article detection mode when recharging the aerosol generating device.

[0125] According to another aspect of the present invention, an aerosol generating apparatus is provided for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating. The apparatus includes a cavity for removably receiving at least a portion of an aerosol-generating article, wherein the article includes the aerosol-generating matrix and a heat-sensitive sensor for heating the matrix. The apparatus further includes a DC power supply and an induction heating device connected to the DC power supply and configured to generate an alternating magnetic field within the cavity to inductively heat the sensor of the article when it is received in the cavity. The apparatus further includes control circuitry configured to generate power pulses for intermittently energizing the induction heating device and to detect changes in at least one characteristic of the induction heating device due to the presence of the sensor when the aerosol-generating article is received in the cavity, thereby enabling detection of insertion of the article into the cavity.

[0126] According to the present invention, it has been recognized that the induction heating device can be used not only for heating a substrate, but also for detecting the insertion of aerosol-generated articles into the receiving cavity of the device. Therefore, the induction heating device can be used for multiple purposes. Advantageously, this avoids the need for additional assembly space for separate sensor components. Furthermore, it has been recognized that, for the purpose of article detection, operating the induction heating device in pulse mode advantageously reduces power consumption, and thus increases the overall operating time of the device compared to other solutions.

[0127] According to the present invention, the article insertion detection is based on the fact that the insertion of the article into the cavity modifies at least one characteristic, particularly at least one electrical and / or magnetic characteristic of the induction heating device due to the presence of a sensor near the induction heating device. The change in at least one characteristic caused by the presence of the sensor can be attributed to the interaction between the field of the induction heating device and the sensor.

[0128] At least one characteristic of the induction heating device can be any characteristic with an associated parameter that has a different value when the sensor is present compared to when the sensor is absent. For example, at least one characteristic can be the current, voltage, resistance, frequency, phase shift, magnetic flux, and inductance of the induction heating device.

[0129] Preferably, the characteristic is at least one of the equivalent resistance or inductance of the induction heating device. As used herein, the term "equivalent resistance" refers to the real part of a complex impedance, defined as the ratio of the supplied AC voltage to the measured AC current. Therefore, "equivalent resistance" can also be expressed as the resistive load of the induction heating device. Similarly, as used herein, the term "inductance" refers to the imaginary part of a complex impedance, defined as the ratio of the supplied AC voltage to the measured AC current. Generally, inductance has circuit characteristics that are susceptible to external electromagnetic influences.

[0130] A variation in at least one characteristic of the induction heating device can be attributed to a specific permeability and / or resistivity of the sensor. That is, the sensor within the aerosol-generating article may comprise a material having a specific permeability and / or resistivity. Preferably, the sensor comprises a conductive material. For example, the sensor may comprise a metallic material. The metallic material may be, for example, aluminum, nickel, iron, or alloys thereof, such as carbon steel or ferritic stainless steel. Aluminum has a resistivity of about 2.65 × 10⁻⁸ ohm-meters and a permeability of about 1.256 × 10⁻⁶ Henry / meter when measured at room temperature (20°C). Similarly, ferritic stainless steel has a resistivity of about 6.9 × 10⁻⁷ ohm-meters and a permeability in the range of 1.26 × 10⁻⁶ Henry / meter to 2.26 × 10⁻⁶ Henry / meter when measured at room temperature (20°C).

[0131] Preferably, the control circuit is also configured to (automatically) activate the heating operation of the induction heating device to heat the matrix upon detection of article insertion into the cavity. Because of this, the user of the device advantageously does not need to perform any additional action to initiate the heating process when the aerosol-generating article is inserted into the cavity of the device. For example, the user of the device does not need to operate the user interface, such as pressing a button. Instead, the user experience begins immediately and irreversibly, as is known from conventional cigarettes.

[0132] To generate power pulses for intermittently energizing the induction heating device, the control circuitry may include a switch configured and arranged to control the supply of power from a DC power source to the induction heating device. For this purpose, the switch can be intermittently closed and opened, for example, intermittently energizing the induction heating device for article detection, particularly for detecting article insertion into a cavity, i.e., during the article detection mode of the aerosol generation device. In contrast, during the heating mode of the aerosol generation device, the switch can be permanently closed to continuously apply the DC voltage of the DC power source to the induction heating device. Therefore, this mode can be represented as a continuous heating mode. Alternatively, the switch can be intermittently closed and opened during the heating mode of the aerosol generation device, for example, to generate power pulses for pulsed heating of the aerosol-forming matrix. Therefore, this mode can be represented as a pulsed heating mode.

[0133] The power pulse generated for article inspection, particularly the power pulse used to detect article insertion into a cavity, can be represented as a probe power pulse. Similarly, the power pulse generated for pulsed heating of the aerosol-forming matrix can be represented as a heating power pulse.

[0134] Changes in characteristics can be observed by measuring changes in the parameters of the induction heating device. These parameters can be measured directly or indirectly. The presence of a sensor can be determined by measuring the parameter and observing that the parameter has a different value compared to when the sensor is absent, thus determining the presence of the article. Preferably, the parameter can be current. Therefore, the control circuit may include a measuring device for measuring a current indicating at least one characteristic of the induction heating device. Specifically, the parameter can be DC current supplied from a DC power source to the induction heating device. Therefore, the control circuit may include a measuring device arranged and configured to measure the DC current supplied from the DC power source to the induction heating device. That is, the measuring device may include a DC current measuring device arranged in series between the DC power source and the induction heating device. For example, the measuring device may include a resistor and a shunt amplifier. Therefore, when the aerosol-generated article is inserted into the cavity of the aerosol-generating device, the presence of the sensor increases the equivalent resistance due to the increased resistive load. This, in turn, reduces the DC current fed to the induction heating device. The reduction in DC current is detected by the current measuring device of the control circuit, which activates the heating operation of the induction heating device for heating the substrate.

[0135] Generally, the pulse duration and the time interval between two consecutive power pulses should be selected for article inspection, particularly for detecting article insertion into the cavity, to balance energy consumption and user experience performance. The pulse duration should be as short as possible, yet still long enough to provide reliable measurement of the current pulse. Similarly, a longer time interval between two consecutive power pulses results in lower energy consumption. However, the time interval between two consecutive power pulses should not be too long; otherwise, the user may have to wait too long to begin the user experience.

[0136] Taking these factors into consideration, the power pulse used for product inspection, i.e., the probe power pulse, can have a pulse duration between 1 microsecond and 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds. As used herein, the term "pulse duration" refers to the time interval during which the heating device is energized, particularly the time interval during which the aforementioned switch is closed.

[0137] The time interval between two consecutive power pulses used for product detection, i.e., the time interval between two consecutive detection pulses, can be between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, and preferably between 500 milliseconds and 1 second.

[0138] Preferably, for article detection, a detection power pulse is generated within a predetermined time period. That is, the detection mode can continue for a limited predetermined time period. If no article insertion is detected within the predetermined time period, the detection mode can be stopped; that is, the generation of the power pulse can be turned off to ensure safe power supply. Similarly, if article insertion is detected within the predetermined time period, the detection mode can be stopped in response to the detection of article insertion, specifically, it can be stopped immediately.

[0139] The heating power pulses can be generated for a predetermined number of suctions or a predetermined heating time, or until an input is received from a switch, particularly a user input. Specifically, the heating mode may include pulse width modulation of the heating power pulses used to control the heating temperature.

[0140] Generally, the detection mode and the heating mode may differ from each other in at least one characteristic of the power pulse, particularly in at least one of the time intervals or pulse patterns. For example, the detection mode may include a fixed pulse pattern for detecting the power pulse. In contrast, the heating mode may include a non-fixed, particularly variable pulse pattern for heating the power pulse, for example, in the case of pulse width modulation of the heating power pulse.

[0141] The induction heating device can be configured to generate a high-frequency alternating magnetic field. As mentioned herein, the high-frequency alternating magnetic field can range from 500 kHz to 30 MHz, particularly from 5 MHz to 15 MHz, and preferably between 5 MHz and 10 MHz.

[0142] To generate an alternating magnetic field, the induction heating device may include a DC / AC converter connected to a DC power supply. The DC / AC inverter may include a Class C, Class D, or Class E power amplifier. Specifically, the DC / AC converter may include a transistor switch, a transistor switch drive circuit, and an LC network. The LC network may include a series connection of a capacitor and an inductor, wherein the inductor is configured and arranged to generate an alternating magnetic field within a cavity for inductively heating the inductor. The LC network may also include a shunt capacitor connected in parallel with the transistor switch. Additionally, the DC / AC converter may include a choke inductor for supplying a DC power supply voltage +V_DC from the DC power supply.

[0143] The inductor used to generate an alternating magnetic field within the cavity for inductive heating of the sensor may include at least one induction coil, particularly a single induction coil or multiple induction coils. The number of induction coils may depend on the size and / or number of the sensor. One or more induction coils may have a shape that matches the shape of one or more sensors in the aerosol generating article. Similarly, one or more induction coils may have a shape that conforms to the shape of the housing of the aerosol generating device.

[0144] At least one induction coil can be a helical coil or a planar coil, particularly a disc coil or a bent planar coil. The use of flat helical coils allows for robust and inexpensive compact designs. The use of helical induction coils advantageously allows for the generation of a uniform alternating electromagnetic field. As used herein, "flat helical coil" refers to a generally planar coil in which the axis of the coil winding is perpendicular to the surface on which the coil lies. Flat helical induction coils can have any desired shape within the plane of the coil. For example, a flat helical coil can have a circular shape, or it can have a generally oblong or rectangular shape. However, when used herein, the term "flat helical coil" encompasses both planar coils and flat helical coils shaped to conform to a bent surface. For example, the induction coil can be a "bent" planar coil arranged around the circumference of a preferably cylindrical coil support (e.g., a ferrite core). Furthermore, a flat helical coil can comprise, for example, two layers of four-turn flat helical coils or a single layer of four-turn flat helical coils.

[0145] At least one induction coil may be held within the housing of the heating device or the body or housing of the aerosol generating device that includes the heating device. At least one induction coil may be wound around a coil support, preferably cylindrical, such as a ferrite core.

[0146] The induction heating device can be configured to continuously generate an alternating magnetic field after the system is activated or intermittently, for example, on a per-port suction basis.

[0147] The control circuit can also be configured to detect the removal of the aerosol generating device from the charging unit, and automatically start generating the power pulse when the removal of the aerosol generating device from the charging unit is detected.

[0148] The control circuit can also be configured to control the overall operation of the aerosol generating device. At least a portion of the control circuit and the induction heating device can be part of the overall circuitry of the aerosol generating device.

[0149] The control circuit may include a microprocessor, such as a programmable microprocessor, a microcontroller, or an application-specific integrated circuit (ASIC), or other electronic circuitry capable of providing control. The control circuit may include at least one of a transimpedance amplifier for current-to-voltage conversion, an inverting signal amplifier, a single-ended differential converter, an analog-to-digital converter, and a microcontroller.

[0150] The microprocessor can be configured to: control a switch for generating power pulses to intermittently power on the induction heating device, read a measuring device for measuring the current supplied from a DC power source to the induction heating device, and control a transistor switch driver circuit for the induction heating device.

[0151] The control circuit can be the main controller of the aerosol generating device or a part of the main controller of the aerosol generating device.

[0152] The controller and at least a portion of the sensing source, particularly the sensing source other than the inductor, can be arranged on a common printed circuit board. This has proven particularly advantageous for the compact design of the heating device.

[0153] Preferably, the DC power supply includes at least one battery, such as a lithium iron phosphate battery. Alternatively, the power supply may include another form of charge storage device, such as a capacitor. The power supply may require charging; that is, the power supply may be rechargeable. The power supply may have a capacity that allows sufficient energy to be stored for one or more user experiences. For example, the power supply may have sufficient capacity to allow continuous aerosol generation in time intervals of approximately six minutes or multiples of six minutes. In another instance, the power supply may have sufficient capacity to allow for a predetermined number of suctions or discontinuous activation of the sensing source. The power supply may be the overall power supply for the aerosol generation apparatus according to the invention.

[0154] The receiving cavity may include an insertion opening through which an aerosol-generating article is inserted. As used herein, the direction of insertion of the aerosol-generating article is referred to as the insertion direction. Preferably, the insertion direction corresponds to the extension of the length axis, and in particular, the extension of the central axis of the receiving cavity.

[0155] After insertion into the receiving cavity, at least a portion of the aerosol-generating article can still extend outward through the insertion opening. Preferably, the outwardly extending portion is provided for interaction with the user, particularly for reaching the user's mouth. Thus, during use of the device, the insertion opening can be close to the mouth. Therefore, as used herein, when using the device, the segment near the insertion opening or near the user's mouth is indicated by the prefix "proximal". Segments arranged further away are indicated by the prefix "distal".

[0156] In contrast to this convention, the receiving cavity may be arranged in or located in the proximal portion of the aerosol generating device. The insertion opening may be arranged in or located at the proximal end of the aerosol generating device, particularly at the proximal end of the receiving cavity.

[0157] Similarly, the receiving cavity can be formed as a cavity, particularly as an elongated cavity, including a distal portion and a proximal portion. If present, an insertion opening can be disposed at the proximal end of the receiving cavity. At the distal end, the receiving cavity may include a bottom opposite the insertion opening.

[0158] The aerosol generating apparatus may include an air path extending from at least one air inlet into a receiving cavity. That is, the aerosol generating apparatus may include at least one air inlet in fluid communication with the receiving cavity. When the aerosol-generating article is inserted into the cavity, the air path may further extend through the aerosol-forming matrix within the article and the mouthpiece of the article to enter the user's mouth. Preferably, the air inlet is realized at an insertion opening in the receiving cavity for inserting the article into the cavity. Thus, when the article is received in the cavity, air may be drawn into the receiving cavity at the edge of the insertion opening and further through an airflow passage formed between at least one or more portions of the outer circumference of the aerosol-generating article and the inner surface of the receiving cavity.

[0159] Generally, the receiving cavity can have any suitable shape. Specifically, the shape of the receiving cavity may correspond to the shape of the aerosol-generating article to be received therein. Preferably, the receiving cavity may have a substantially cylindrical or conical shape, such as a substantially conical or substantially truncated conical shape.

[0160] Similarly, the receiving cavity may have any suitable cross-section, as seen in a plane perpendicular to the length axis of the receiving cavity or perpendicular to the insertion direction of the article. Specifically, the cross-section of the receiving cavity may correspond to the shape of the aerosol-generated article to be received therein. Preferably, the receiving cavity has a substantially circular cross-section. Alternatively, the receiving cavity may have a substantially elliptical cross-section, or a substantially oval cross-section, or a substantially square cross-section, or a substantially rectangular cross-section, or a substantially triangular cross-section, or a substantially polygonal cross-section. As used herein, the above shapes and cross-sections preferably refer to the shape or cross-section of the receiving cavity, without regard to any protrusions at the inner surface of the receiving cavity.

[0161] The inductor can be arranged, for example, around at least a portion of the receiving cavity or at least a portion of the inner surface of the receiving cavity. For example, the inductor can be a helical coil arranged within the sidewall of the receiving cavity. Specifically, the inductor can be integrated into the wall defining the receiving cavity. For example, the inductor can be integrated into the sidewall of the receiving cavity, particularly around at least a portion of the interior of the receiving cavity.

[0162] The receiving cavity may include a plurality of protrusions extending within the cavity. Preferably, the protrusions are spaced apart from each other, such that an airflow passage is formed between adjacent protrusions, i.e., through the gap (free space) between adjacent protrusions. Additionally, the protrusions may be configured to contact at least a portion of the aerosol-generating article to retain the aerosol-generating article within the receiving cavity. The protrusions may include ribs or may be formed as ribs. Preferably, one or more ribs extend along the length axis of the receiving cavity, particularly the direction of the central axis. Preferably, the length axis of the receiving cavity corresponds to an insertion direction along which the aerosol-generating article can be inserted into the receiving cavity.

[0163] The present invention also relates to an aerosol generation system comprising an aerosol generation apparatus according to the invention and as described herein. The system further comprises an aerosol generation article, wherein at least a portion of the article is removably receivable or removably received in a receiving cavity of the apparatus. The article comprises at least one aerosol forming matrix and a heat-sensitive sensor for heating the matrix when the article is received in the cavity.

[0164] Aerosol-generating articles can be consumables, particularly intended for single use. Aerosol-generating articles can be tobacco products. Specifically, the articles can be rod-shaped, preferably cylindrical, and can resemble conventional cigarettes.

[0165] The article may include one or more of the following elements: a first support element, a matrix element, a second support element, a cooling element, and a filter element. Preferably, the aerosol-generating article includes at least a first support element, a second support element, and a matrix element located between the first support element and the second support element.

[0166] All the aforementioned elements can be arranged sequentially along the length axis of the article in the order described above, wherein the first support element is preferably located at the distal end of the article, and the filter element is preferably located at the proximal end of the article. Each of the aforementioned elements can be substantially cylindrical. Specifically, all elements can have the same external cross-sectional shape. Furthermore, the elements can be surrounded by an outer packaging to hold the elements together and maintain the desired circular cross-sectional shape of the rod-shaped article. Preferably, the packaging is made of paper.

[0167] As used herein, the term "aerosol forming matrix" refers to a matrix capable of releasing volatile compounds that can form aerosols upon heating. An aerosol forming matrix can be a solid or liquid aerosol forming matrix. An aerosol forming matrix may include tobacco-containing material containing volatile tobacco flavor compounds that are released from the matrix upon heating. Alternatively or additionally, an aerosol forming matrix may include non-tobacco materials. An aerosol forming matrix may also include an aerosol forming agent. Examples of suitable aerosol forming agents are glycerol and propylene glycol. An aerosol forming matrix may also include other additives and ingredients, such as nicotine or flavoring substances. Specifically, a liquid aerosol forming matrix may include water, solvents, ethanol, plant extracts, and natural or artificial flavorings. An aerosol forming matrix may also be a paste material, a porous material pouch containing an aerosol forming matrix, or loose tobacco mixed with a gelling agent or adhesive, which may include common aerosol forming agents such as glycerol, and is subsequently compressed or molded into rods.

[0168] The matrix element preferably comprises at least one aerosol-forming matrix to be heated. The matrix element may also include a sensor that is in thermal contact or thermal proximity to the aerosol-forming matrix. As used herein, the term "sensor" refers to an element comprising a material capable of being inductively heated within an alternating electromagnetic field. This can be a result of at least one of hysteresis losses or eddy currents induced in the sensor, depending on the electrical and magnetic properties of the sensor material.

[0169] Receptors can include various geometric configurations. A receptor can be a granular receptor, or a receptor filament, or a receptor mesh, or a receptor core, or a receptor pin, or a receptor rod, or a receptor blade, or a receptor strip, or a receptor sleeve, or a receptor cup, or a cylindrical receptor, or a planar receptor. For example, a receptor can be an elongated receptor strip with a length ranging from 8 mm to 16 mm, particularly from 10 mm to 14 mm, preferably 12 mm. The width of the receptor strip can, for example, range from 2 mm to 6 mm, particularly from 4 mm to 5 mm. The thickness of the receptor strip is preferably in the range of 0.03 mm to 0.15 mm, more preferably in the range of 0.05 mm to 0.09 mm.

[0170] The sensor can be a multilayer sensor, such as a multilayer sensor strip. Specifically, a multilayer sensor may include a first sensor material and a second sensor material. The first sensor material is preferably optimized in terms of heat loss and therefore heating efficiency. For example, the first sensor material may be aluminum, or an iron-containing material, such as stainless steel. In contrast, the second sensor material is preferably used as a temperature marker. For this purpose, the second sensor material is selected to have a Curie temperature corresponding to a predefined heating temperature of the sensor assembly. At its Curie temperature, the magnetic properties of the second sensor change from ferromagnetic to paramagnetic, accompanied by a temporary change in its resistance. Therefore, by monitoring the corresponding change in the current absorbed by the sensing source, it is possible to detect when the second sensor material reaches its Curie temperature, and therefore when it reaches the predefined heating temperature. The Curie temperature of the second sensor material is preferably below the ignition point of the aerosol-forming substrate, i.e., preferably below 500 degrees Celsius. Suitable materials for the second sensor material may include nickel and certain nickel alloys.

[0171] The first support element can be used to cover and protect the distal front portion. At least one of the first and second support elements may include a central air passage. Preferably, at least one of the first and second support elements may include a hollow cellulose acetate tube. Alternatively, the end of the matrix element.

[0172] Aerosol cooling elements are components with a large surface area and low suction resistance (e.g., 15 mmWG to 20 mmWG). In use, an aerosol formed by volatile compounds released from the matrix element is drawn through the aerosol cooling element before being delivered to the proximal end of the aerosol-generating article.

[0173] The filter element is preferably used as a mouthpiece, or as part of a mouthpiece together with an aerosol cooling element. As used herein, the term "mouthpiece" refers to a portion of an article through which aerosol exits to form the article.

[0174] Further features and advantages of the aerosol generation system and aerosol generation articles according to the present invention have been described above with respect to the aerosol generation apparatus and are equally applicable.

[0175] The present invention also relates to a method for operating an aerosol generating apparatus according to the invention and as described herein. The method includes:

[0176] - Operate the device in the work-in-process inspection mode as described below.

[0177] - Generate power pulses, especially detect power pulses, to intermittently power the induction heating device;

[0178] - For each pulse, at least one characteristic of the induction heating device is measured, the at least one characteristic of the induction heating device being affected by the presence of a sensor when the aerosol-generating article is inserted into the cavity of the device, and it is detected whether at least one characteristic of the induction heating device has changed compared to a previous pulse, thus indicating that the aerosol-generating article is inserted into the cavity; and

[0179] - Stop operating the device in the product detection mode when at least one characteristic change of the induction heating device is detected;

[0180] - The device is operated in heating mode by activating the heating operation of the induction heating device to heat the substrate.

[0181] In the in-process inspection mode, power pulses can be generated using a switch. The switch can be positioned between the DC power supply and the induction heating element of the aerosol generation device, and can be intermittently closed and opened to intermittently power the induction heating element. In contrast, in the heating mode, the switch is permanently closed to continuously apply the DC voltage from the DC power supply to the induction heating element.

[0182] As mentioned above regarding the aerosol generating apparatus according to the invention, the power pulse, particularly the detection power pulse, can have a predetermined pulse duration and a predetermined time interval between two consecutive power pulses, particularly the detection power pulse. The predetermined pulse duration can be between 1 microsecond and 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds. The time interval between two consecutive power pulses, particularly the detection power pulse, can be between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, preferably between 500 milliseconds and 1 second.

[0183] As mentioned above regarding the aerosol generating apparatus according to the invention, the aforementioned characteristic is preferably at least one of the equivalent resistances of the induction heating device. The equivalent resistance can be measured by the DC current supplied from the DC power supply to the induction heating device.

[0184] Therefore, the operating device in the work-in-process inspection mode preferably includes:

[0185] - For each pulse, the equivalent resistance [resistive load] of the induction heating device is measured by measuring the DC current supplied from the DC power supply to the induction heating device, and it is detected whether the DC current has changed compared to the previous pulse, and therefore whether the equivalent resistance of the induction heating device has changed, thereby indicating that the aerosol-generating article is inserted into the cavity; and

[0186] - Stop operating the device in the article detection mode when a change in DC current is detected and therefore a change in the equivalent resistance of the induction heating device is detected.

[0187] The product detection mode can be triggered by extracting the aerosol generating device from the charging unit.

[0188] Further features and advantages of the method according to the invention have been described with respect to the aerosol generation system and are equally applicable.

[0189] The invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0190] Example Ex1: An aerosol generating apparatus for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating, the apparatus comprising:

[0191] - A cavity for removably receiving at least a portion of an aerosol-generating article, the article comprising the aerosol-forming matrix and a heat-sensitive sensor for heating the matrix;

[0192] -DC power supply;

[0193] - An induction heating device, which is connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating a sensor of the article during heating operation when the article is received in the cavity;

[0194] - A control circuit configured to supply power from the DC power supply to the heating device for powering the induction heating device, and to detect a change in at least one characteristic of the induction heating device caused by the presence or absence of the sensor in the cavity when the aerosol-generating article is inserted into or withdrawn from the cavity, and in response to detect the insertion of the article into the cavity and / or the withdrawal of the article from the cavity.

[0195] Example Ex2: An aerosol generating apparatus for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating, the apparatus comprising:

[0196] A cavity for removably receiving at least a portion of an aerosol-generating article, the article comprising the aerosol-forming matrix and a heat-sensitive sensor for heating the matrix;

[0197] -DC power supply;

[0198] - An induction heating device, which is connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating a sensor of the article during heating operation when the article is received in the cavity;

[0199] - A control circuit configured to generate power pulses for intermittently energizing the induction heating device, and to detect changes in at least one characteristic of the induction heating device caused by the presence or absence of the sensor in the cavity when the aerosol-generating article is inserted into or withdrawn from the cavity, and in response to detect the insertion of the article into the cavity and / or the withdrawal of the article from the cavity.

[0200] Example Ex3: An aerosol generating apparatus according to Example Ex2, wherein the control circuit is configured to disable the heating operation of the induction heating device under the following conditions:

[0201] - In response to detecting the removal of an article from the cavity during heating operation; or

[0202] - After the previous heating operation, and until the article is detected to have been removed from the cavity.

[0203] Example Ex4: An aerosol generating apparatus according to Example Ex2 or Ex3, wherein the control circuit is configured to activate the heating operation of the induction heating device under the following conditions:

[0204] - In response to detecting the removal of an article from the cavity during heating operation, and after disabling the heating operation; or

[0205] - After a previous heating operation, and in response to the detection of the article being withdrawn from the cavity.

[0206] Example Ex5: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit is configured to verify that an article is inserted into or removed from the cavity by generating at least one verification power pulse for a predetermined time period after the first detection of at least one characteristic change of the induction heating device and by re-detecting a change of at least one characteristic of the induction heating device.

[0207] Example Ex6: An aerosol-generated article according to Example Ex5, wherein the predetermined time period is in the range of 0.5 seconds to 3 seconds.

[0208] Example Ex7: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit is configured to initiate the heating operation of the induction heating device in response to detecting that the article is inserted into the cavity.

[0209] Example Ex8: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit further includes a motion sensor for detecting movement of the apparatus.

[0210] Example Ex9: An aerosol-generated article according to Example Ex8, wherein the motion sensor includes at least one of an accelerometer or a gyroscope.

[0211] Example Ex10: An aerosol generating article according to Example Ex8 or Ex9, wherein the control circuit is configured to start generating a power pulse, particularly a detection power pulse, in response to detecting movement of the device.

[0212] Example Ex11: An aerosol generating apparatus according to any of Examples Ex8 to Ex10, wherein the control circuit is configured to start generating a power pulse, in particular a detection power pulse, in response to detecting that the movement of the apparatus reaches or exceeds a predetermined motion threshold.

[0213] Example Ex12: An aerosol generating article according to any of Examples Ex8 to Ex11, wherein the control circuit is configured to stop generating power pulses, particularly detecting power pulses, in response to detecting that the movement of the device has not reached a predetermined motion threshold during a predetermined idle time or in response to detecting that there has been no movement during a predetermined idle time.

[0214] Example Ex13: An aerosol generating article according to any of Examples Ex8 to Ex11, wherein the control circuit is configured to reduce the number of power pulses per unit time, particularly the number of detection power pulses, in response to detecting that the movement of the device has not reached a predetermined motion threshold during a predetermined idle time or in response to detecting that there has been no movement during a predetermined idle time.

[0215] Example Ex14: An aerosol-generated article according to Example Ex12 or Ex13, wherein the idle time is between 10 seconds and 90 seconds, particularly between 15 seconds and 60 seconds, preferably between 15 seconds and 40 seconds.

[0216] Example Ex15: An aerosol generating article according to any of Examples Ex8 to Ex11, wherein the control circuit is configured to reduce the number of power pulses per unit time, particularly the number of detection power pulses, in response to detecting that the movement of the device has not reached a predetermined movement threshold during a predetermined first idle time or in response to detecting that there has been no movement during the predetermined first idle time; and subsequently, in response to detecting that the movement of the device has not reached the predetermined movement threshold during a predetermined second idle time starting after the predetermined first idle time or in response to detecting that there has been no movement during the predetermined second idle time starting after the predetermined first idle time, to stop generating power pulses, particularly detection power pulses.

[0217] Example Ex16: An aerosol-generated article according to Example Ex15, wherein the first idle time is between 5 seconds and 60 seconds, particularly between 10 seconds and 30 seconds, preferably between 15 seconds and 25 seconds.

[0218] Example Ex17: An aerosol-generated article according to Example Ex15 or Ex16, wherein the second idle time is between 10 seconds and 90 seconds, particularly between 15 seconds and 60 seconds, preferably between 15 seconds and 30 seconds.

[0219] Example Ex18: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit is configured to detect that the aerosol generating apparatus is withdrawn from the charging unit.

[0220] Example Ex19: An aerosol generating article according to Example Ex18, wherein the control circuit is configured to start generating a power pulse, particularly a detection power pulse, in response to detecting the aerosol generating device being withdrawn from the charging unit.

[0221] Example Ex20: An aerosol generating article according to Example Ex18, wherein the control circuit is configured to start generating a power pulse, particularly a detection power pulse, in response to detecting the aerosol generating device being withdrawn from the charging unit, for detecting the article being inserted into the cavity.

[0222] Example Ex21: An aerosol generating device according to any of the foregoing examples, wherein the control circuit is configured to detect that the aerosol generating device is inserted into the charging unit.

[0223] Example Ex22: An aerosol generating article according to Example Ex21, wherein the control circuit is configured to stop generating power pulses, particularly detecting power pulses, in response to detecting that the aerosol generating device is inserted into the charging unit.

[0224] Example Ex23: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit is configured to stop the heating operation of the apparatus in response to at least one of detecting a predetermined number of suctions, detecting that a predetermined heating time has elapsed, or receiving user input.

[0225] Example Ex24: An aerosol-generated article according to any of the foregoing examples, wherein the control circuit is configured to start generating a probe power pulse for detecting the extraction of the article in response to the cessation of the heating operation of the device, particularly in response to the detection of the cessation of the heating operation of the device.

[0226] Example Ex25: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit is configured to stop the heating operation of the induction heating device in response to detecting the article being extracted from the cavity.

[0227] Example Ex26: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuitry includes a switch configured and arranged to control the power supply from the DC power source to the induction heating device.

[0228] Example Ex27: An aerosol generating apparatus according to any of the foregoing examples, wherein the control circuit includes a measuring device for measuring a current indicating at least one characteristic of the induction heating apparatus.

[0229] Example Ex28: An aerosol generating apparatus according to any of the foregoing examples, wherein the power pulse, particularly the detection power pulse, has a pulse duration in the range of 1 microsecond to 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds.

[0230] Example Ex29: An aerosol generating apparatus according to any of the preceding examples, wherein the time interval between two consecutive power pulses, particularly the detection power pulse, is between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, preferably within the range of 500 milliseconds and 1 second.

[0231] Example Ex30: An aerosol generating apparatus according to any of the foregoing examples, wherein the induction heating device includes a DC / AC converter connected to the DC power supply and includes an LC network, wherein the LC network includes a series connection of a capacitor and an inductor, and wherein the inductor is configured and arranged to generate an alternating magnetic field within the cavity for inductively heating the sensor.

[0232] Example Ex31: An aerosol generating apparatus according to any of the foregoing examples, wherein at least one characteristic is the equivalent resistance of the induction heating device or the inductance of the induction heating device.

[0233] Example Ex32: An aerosol generating apparatus according to any of the foregoing examples further includes an optical or tactile indicating component for indicating at least one of the following: the detection of an article being withdrawn from the cavity, the article being inserted into the cavity, or the heating operation of the induction heating device being disabled or enabled.

[0234] Example Ex33: An aerosol generation system comprising an aerosol generation apparatus according to any of the foregoing examples, and an aerosol generation article removably received in a cavity of the apparatus, wherein the aerosol generation article comprises an aerosol forming matrix and a heat-sensitive sensor for heating the matrix.

[0235] Example Ex34: An aerosol generating article of an aerosol generating system according to Example Ex33 or an aerosol generating apparatus for use with any of Examples Ex1 to Ex32, wherein the aerosol generating article includes an aerosol forming matrix and a heat-sensitive sensor for heating the matrix.

[0236] Example Ex35: A method of operating an aerosol generating apparatus for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating, wherein the apparatus includes: a DC power supply; a cavity for removably receiving at least a portion of an aerosol generating article, the aerosol generating article including the aerosol forming matrix and a heat-sensitive sensor for heating the matrix; and an inductive heating device connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating the sensor of the article during heating operation when the article is received in the cavity, the method comprising operating the apparatus in an article extraction detection mode, the operation being performed by:

[0237] - Generate power pulses, particularly detect power pulses, to intermittently power the induction heating device;

[0238] - For each power pulse, at least one characteristic of the induction heating device is measured, the at least one characteristic of the induction heating device being affected in response to the extraction of an aerosol-generating article from the cavity of the device while the sensor is not in the cavity, and it is detected whether at least one characteristic of the induction heating device has changed compared to one or more previous power pulses, thus indicating that the aerosol-generating article has been extracted from the cavity; and

[0239] - Stop operating the device in the article extraction detection mode in response to detecting a change in at least one characteristic of the induction heating device;

[0240] Example Ex36: Based on the method of Example Ex35, it also includes:

[0241] - Operate the device in the work-in-process insertion detection mode as described below.

[0242] - Generate power pulses, particularly detect power pulses, to intermittently power the induction heating device;

[0243] - For each power pulse, at least one characteristic of the induction heating device is measured, the at least one characteristic of the induction heating device being affected by the insertion of an aerosol-generating article into the cavity of the device while the sensor is present in the cavity, and it is detected whether at least one characteristic of the induction heating device has changed compared to one or more previous power pulses, thus indicating that the aerosol-generating article has been inserted into the cavity; and

[0244] - Stop operating the device in the article insertion detection mode in response to detecting a change in at least one characteristic of the induction heating device;

[0245] - The device is operated in heating mode by activating the heating operation of the induction heating device to heat the substrate.

[0246] Example Ex37: According to the method of Example Ex36, at least one of the following occurs: operating the device in the article insertion detection mode and operating the device in the heating mode before or after operating the device in the article extraction detection mode.

[0247] Example Ex38: The method according to any one of Examples Ex35 to Ex37, wherein operating the device in a work-in-process extraction detection mode or operating the device in a work-in-process insertion detection mode comprises:

[0248] - For each power pulse, the equivalent resistance of the induction heating device is measured by measuring the DC current supplied from the DC power source to the induction heating device, and it is detected whether the DC current has changed compared to one or more previous power pulses, and therefore whether the equivalent resistance of the induction heating device has changed, thus indicating whether the aerosol-generating article is withdrawn from the cavity or inserted into the cavity, respectively; and

[0249] - In response to the detection of a change in DC current and thus a change in the equivalent resistance of the induction heating device, operation of the device is stopped in the work-in-process extraction detection mode or in the work-in-process insertion detection mode, respectively.

[0250] Example Ex39: The method according to any of Examples Ex35 to Ex38, wherein the power pulse, in particular the probe power pulse, has a predetermined pulse duration and a predetermined time interval between two consecutive power pulses, in particular the probe power pulse.

[0251] Example Ex40: According to the method of Example Ex39, the predetermined pulse duration is between 1 microsecond and 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds.

[0252] Example Ex41: The method according to any of Examples Ex39 or Ex40, wherein the time interval between two consecutive power pulses, particularly the detection power pulse, is between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, preferably within the range of 500 milliseconds and 1 second.

[0253] Example Ex42: The method according to any one of Examples Ex35 to Ex41 further includes generating at least one verification power pulse within a predetermined time period after detecting a change in at least one characteristic of the induction heating device, and verifying the insertion of the article into or extraction from the cavity by re-detecting a change in at least one characteristic of the induction heating device.

[0254] Example Ex43: According to the method of Example Ex42, the predetermined time period is in the range of 0.5 seconds to 3 seconds.

[0255] Example Ex44: According to the method of any of Examples Ex35 to Ex43, wherein the article extraction detection mode is triggered by the cessation of the previous heating operation of the induction heating device.

[0256] Example Ex45: The method according to any of Examples Ex35 to Ex44, wherein during operation of the apparatus in the work-in-process extraction detection mode, operation of the apparatus in the heating mode is disabled.

[0257] Example Ex46: The method according to any one of Examples Ex35 to Ex45, wherein the device is enabled to operate in the heating mode in response to stopping the operation of the device in the article extraction test.

[0258] Example Ex47: The method according to any one of Examples Ex35 to Ex46 further includes operating the device in an idle state monitoring mode by means of at least one of operating the device in the article extraction detection mode or operating the device in the article insertion detection mode:

[0259] - Monitor the movement of the device; and

[0260] - In response to the determination that the device has not moved during a predetermined idle time, the operation of the device is stopped in the article extraction detection mode or the article insertion detection mode, respectively.

[0261] Example Ex48: The method according to any one of Examples Ex35 to Ex46 further includes operating the device in an idle state monitoring mode by means of at least one of operating the device in the article extraction detection mode or operating the device in the article insertion detection mode:

[0262] - Monitor the movement of the device; and

[0263] - In response to the detection that the movement of the device has not reached a predetermined motion threshold during a predetermined idle time or in response to the detection that there has been no movement during a predetermined idle time, the number of power pulses per unit time, particularly the number of detection power pulses, is reduced.

[0264] Example Ex49: According to the method of Example Ex47 or Ex48, the idle time is in the range of 10 seconds to 90 seconds, particularly 15 seconds to 60 seconds, preferably 15 seconds to 40 seconds.

[0265] Example Ex50: The method according to any one of Examples Ex35 to Ex46 further includes operating the device in an idle state monitoring mode by means of at least one of operating the device in the article extraction detection mode or operating the device in the article insertion detection mode:

[0266] - Monitor the movement of the device;

[0267] - In response to detecting that the movement of the device does not reach a predetermined acceleration threshold during a predetermined first idle time or in response to detecting that there is no movement during the predetermined first idle time, the number of power pulses per unit time, particularly the number of detection power pulses, is reduced. Subsequently, in response to detecting that the movement of the device does not reach the predetermined acceleration threshold during a predetermined second idle time starting after the first idle time or in response to detecting that there is no movement during the predetermined second idle time starting after the first idle time, the generation of power pulses, particularly detection power pulses, is stopped.

[0268] Example Ex51: According to the method of Example Ex50, the first idle time is between 5 seconds and 60 seconds, particularly between 10 seconds and 30 seconds, preferably between 15 seconds and 25 seconds.

[0269] Example Ex52: The method according to any one of Examples Ex50 or Ex51, wherein the second idle time is between 10 seconds and 90 seconds, particularly between 15 seconds and 60 seconds, preferably between 15 seconds and 30 seconds.

[0270] Example Ex53: The method according to any of Examples Ex35 to Ex52 further includes operating the device in a standby mode by the following description: after stopping the generation of power pulses, particularly the detection power pulse, or before starting the generation of power pulses, particularly the detection power pulse, in either the article extraction detection mode or the article insertion detection mode:

[0271] - Monitor the movement of the device; and

[0272] - In response to detecting movement of the device or the movement of the device reaching or exceeding a predetermined acceleration threshold, the device is started to operate in the article extraction detection mode or the article insertion detection mode, respectively.

[0273] Example Ex54: The method according to any of Examples Ex35 to Ex53, wherein the article insertion detection mode is triggered by withdrawing the aerosol generating device from the charging unit.

[0274] Example Ex55: An aerosol generating apparatus for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating, the apparatus comprising:

[0275] A cavity for removably receiving at least a portion of an aerosol-generating article, the article comprising the aerosol-forming matrix and a heat-sensitive sensor for heating the matrix;

[0276] -DC power supply;

[0277] - An induction heating device, which is connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating the sensor of the article when it is received in the cavity;

[0278] - A control circuit configured to generate power pulses, particularly detection power pulses, for intermittently energizing the induction heating device and detecting changes in at least one characteristic of the induction heating device due to the presence of the sensor when the aerosol-generated article is received in the cavity, thereby enabling the detection of the article being inserted into the cavity.

[0279] Example Ex56: An aerosol generating apparatus according to Example Ex55, wherein the control circuit is further configured to activate the heating operation of the induction heating device for heating the matrix when the article is detected to be inserted into the cavity.

[0280] Example Ex57: An aerosol generating apparatus according to any one of Examples Ex55 or Ex56, wherein the control circuitry includes a switch configured and arranged to control the power supply from the DC power source to the induction heating device.

[0281] Example Ex58: An aerosol generating apparatus according to any one of Examples Ex55 to Ex57, wherein the control circuitry includes a measuring device for measuring a current indicating at least one characteristic of the induction heating apparatus.

[0282] Example Ex59: An aerosol generating apparatus according to any of Examples Ex55 to Ex58, wherein the power pulse, particularly the detection power pulse, has a pulse duration in the range of 1 microsecond to 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds.

[0283] Example Ex60: An aerosol generating apparatus according to any of Examples Ex55 to Ex59, wherein the time interval between two consecutive power pulses, particularly the detection power pulse, is between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, preferably within the range of 500 milliseconds and 1 second.

[0284] Example Ex61: An aerosol generating apparatus according to any of Examples Ex55 to Ex60, wherein the induction heating device includes a DC / AC inverter connected to the DC power supply and includes an LC network, wherein the LC network includes a series connection of capacitors and inductors, and wherein the inductors are configured and arranged to generate an alternating magnetic field within the cavity for inductively heating the sensor.

[0285] Example Ex62: An aerosol generating apparatus according to any one of Examples Ex55 to Ex61, wherein at least one characteristic is the equivalent resistance of the induction heating device or the inductance of the induction heating device.

[0286] Example Ex63: An aerosol generation system comprising an aerosol generation apparatus according to any one of Examples Ex55 to Ex62, and an aerosol generation article removably received in a cavity of the apparatus, wherein the aerosol generation article comprises an aerosol forming matrix and a heat-sensitive sensor for heating the matrix.

[0287] Example Ex64: A method for operating an aerosol generating apparatus according to any one of Examples Ex55 to Ex62, the method comprising the following steps:

[0288] - Operate the device in the work-in-process inspection mode as described below.

[0289] - Generate power pulses, particularly detect power pulses, to intermittently power the induction heating device;

[0290] - For each pulse, at least one characteristic of the induction heating device is measured, the at least one characteristic of the induction heating device being affected by the presence of a sensor when the aerosol-generating article is inserted into the cavity of the device, and it is detected whether at least one characteristic of the induction heating device has changed compared to a previous pulse, thereby indicating that the aerosol-generating article has been inserted into the cavity; and

[0291] - Stop operating the device in the product detection mode when at least one characteristic change of the induction heating device is detected;

[0292] - The device is operated in heating mode by activating the heating operation of the induction heating device to heat the substrate.

[0293] Example Ex65: According to the method of Example Ex64, the steps of operating the device in the work-in-process inspection mode preferably include the following steps:

[0294] - For each pulse, the equivalent resistance of the induction heating device is measured by measuring the DC current supplied from the DC power supply to the induction heating device, and it is detected whether the DC current has changed compared to the previous pulse, and therefore whether the equivalent resistance of the induction heating device has changed, thereby indicating whether the aerosol-generating article has been inserted into the cavity; and

[0295] - The device is stopped in the product detection mode after a change in the DC current is detected, and therefore a change in the equivalent resistance of the induction heating device is detected.

[0296] Example Ex66: The method according to any of Examples Ex64 or Ex65, wherein the power pulse, in particular the probe power pulse, has a predetermined pulse duration and a predetermined time interval between two consecutive power pulses.

[0297] Example Ex67: According to the method of Example Ex66, the predetermined pulse duration is between 1 microsecond and 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds.

[0298] Example Ex68: The method according to any of Examples Ex66 or Ex67, wherein the time interval between two consecutive power pulses, particularly the detection power pulse, is between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, preferably within the range of 500 milliseconds and 1 second.

[0299] Example Ex69: The method according to any of Examples Ex64 to Ex68, wherein the article detection mode is triggered by withdrawing the aerosol generating device from the charging unit.

[0300] The invention will be further described by way of example only with reference to the accompanying drawings, in which:

[0301] Figure 1-2 An exemplary embodiment of an aerosol generation system according to the present invention, including an aerosol generation apparatus and an aerosol generation article used with the apparatus, is illustrated schematically.

[0302] Figure 3 It schematically shows the following based on Figure 1 and Figure 2 Induction heating device for aerosol generation apparatus; Figure 4-5 The operational details of the method according to the invention are illustrated schematically; and

[0303] Figure 6 It schematically shows the following based on Figure 1 Different operating modes of the aerosol generating apparatus, particularly different operating modes of the method according to the present invention.

[0304] Figure 1 and Figure 2 An exemplary embodiment of an aerosol generation system 1 according to the present invention is illustrated schematically, which is used to generate an inhalable aerosol by heating an aerosol forming matrix. System 1 includes: an aerosol generation article 10 including an aerosol forming matrix 21 to be heated; and an aerosol generation device 100 for heating the matrix when the article 10 is engaged with the device 100.

[0305] like Figure 1 As can be seen in detail, the aerosol-generating article 10 has a substantially rod-shaped form similar to that of a conventional cigarette. In this embodiment, the article 10 includes four elements arranged in a coaxial alignment sequence: a matrix 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 serves as a mouthpiece. The matrix element 20 includes an aerosol-forming matrix 21 to be heated and a receptor 30 in direct physical contact with the matrix 21 for inductively heating the matrix 21. This is described in more detail below. The four elements have a substantially cylindrical shape and have substantially the same diameter. In addition, the four elements are defined by an outer packaging 70 to hold the four elements together and maintain the desired circular cross-sectional shape of the rod-shaped article 10. The packaging 70 is preferably made of paper. Other details of the article 10, and in particular other details of the four elements, are disclosed, for example, in WO 2015 / 176898 A1.

[0306] The elongated aerosol generating apparatus 100 essentially has two parts: a proximal part 102 and a distal part 101. In the proximal part 102, the apparatus 100 includes a cavity 103 for removably receiving at least a portion of the aerosol-generated article 10. In the distal part 101, the apparatus 100 includes a power supply 150 and a controller 160 for powering the apparatus 100 and controlling its operation. To heat the substrate, the apparatus 100 includes an induction heating device 110 comprising an induction coil 118 for generating alternating, particularly high-frequency, magnetic fields within the cavity 103. In this embodiment, the induction coil 118 is a helical coil arranged in the proximal part 102 of the apparatus to circumferentially surround the cylindrical receiving cavity 103. The coil 118 is arranged such that the receptors 30 of the aerosol-generated article 10 are subjected to an electromagnetic field when the article 100 is engaged with the apparatus 10. When the article 10 is received in the cavity 103, the alternating magnetic field is used to inductively heat the sensor 30 within the aerosol-generating article 10. Therefore, when the article 10 is inserted into the cavity 103 of the device 100 (see...), the alternating magnetic field... Figure 2 When the heating device 110 is activated, the alternating magnetic field within cavity 103 induces eddy currents and / or hysteresis losses in sensor 30 based on the magnetic and electrical properties of the sensor material. As a result, sensor 30 heats up until it reaches a temperature sufficient to vaporize the aerosol-forming matrix 21 surrounding sensor 30 within article 10. In use of the system, when the user draws air in, i.e., when a negative pressure is applied at filter element 60 of article 10, air is drawn into cavity 103 at the edge of article insertion opening 105 of device 100. The airflow further extends toward the distal end of cavity 103 through a channel formed between the inner surface of cylindrical cavity 103 and the outer surface of article 10. At the distal end of cavity 103, the airflow enters aerosol-forming article 10 through matrix element 20 and further through support element 40, aerosol cooling element 50, and filter element 60, where it finally exits article 10. In matrix element 20, vaporized material from aerosol-forming matrix 21 is entrained in the airflow. Subsequently, as the airflow passes through the support element 40, cooling element 50, and filter element 60, it is cooled to form an aerosol that escapes from the article 10 through the filter element 60.

[0307] Figure 3 Further details of the induction heating device 110 for generating an alternating magnetic field within cavity 103 are shown. According to this embodiment, the induction heating device 110 includes a DC / AC inverter connected to… Figure 1 and 2The DC power supply 150 is shown. The DC / AC inverter includes a Class E power amplifier, which in turn includes: a transistor switch 111, which includes a field-effect transistor T (FET), such as a metal-oxide-semiconductor field-effect transistor (MOSFET); a transistor switch supply circuit, indicated by arrow 112, for supplying a switching signal (gate-source voltage) to the transistor switch 111; and an LC load network 113 including a shunt capacitor C1 and a capacitor C2 and an inductor L2 connected in series. The inductor L2 corresponds to... Figure 1 and 2 The induction coil 118 shown is used to generate an alternating magnetic field within the cavity 103. Additionally, a choke L1 is provided that supplies a DC power supply voltage +V_DC from a DC power supply 150. Figure 3 The diagram also shows an ohmic resistance R representing the total equivalent resistance or total resistive load 114, which, when the system is in use, i.e., when the article is inserted into the cavity 103 of the device 100, is the sum of the ohmic resistance of the inductor coil 118, marked L2, and the ohmic resistance of the inductor. Otherwise, when the article is not inserted into the cavity 103, the equivalent resistance or resistive load 114 corresponds only to the ohmic resistance of the inductor coil 118.

[0308] Further details of the induction heating device 110 according to this embodiment, particularly regarding its operating principle, are disclosed, for example, in WO 2015 / 177046A1.

[0309] For various purposes, particularly for automatically enabling or disabling the heating process and / or for preventing the user from reheating the depleted aerosol-generating article, it may be desirable to detect the insertion of the aerosol-generating article into and / or the removal of the aerosol-generating article from the receiving cavity 103. Therefore, the aerosol-generating apparatus according to this embodiment can operate in at least one of an article insertion detection mode or an article removal detection mode.

[0310] According to the invention, the insertion and / or removal detection of the article is achieved by the heating device 110 itself. Advantageously, this avoids the need for additional assembly space for a separate sensor component. The basic idea for detecting the insertion into and / or removal of the article from the cavity is to detect changes in at least one characteristic of the inductive heating device caused by the presence or removal of the sensor when the article 10 is received in or removed from the cavity 103 during aerosol generation.

[0311] In this embodiment, the total resistive load 114 of the heating device 110 serves as a characteristic of the induction heating device, indicating whether the article 10 is present or absent in the receiving cavity 103. As explained above, the value of the total equivalent resistance or total resistive load 114 depends on the presence or absence of the sensor 30 near the induction coil 118. When the article is inserted into the cavity 103 of the device 100, the total equivalent resistance 118 corresponds to the sum of the ohmic resistance of the inductor coil 118 and the ohmic resistance of the sensor 30, while when the article is not received in the cavity 103, it corresponds only to the ohmic resistance of the inductor coil 118.

[0312] This change in the equivalent resistance 118 can be detected by supplying a DC current I_DC from the DC power supply 150 to the induction heating device 110, i.e., to the LC load network 113. For this purpose, the aerosol generating apparatus includes a current measuring device 140 arranged in series between the DC power supply 150 and the LC load network 113. Therefore, when the aerosol generating article 10 is inserted into the cavity 103 of the aerosol generating apparatus 100, the presence of the sensor 30 increases the equivalent resistance 118 of the heating device due to the increased resistive load 114. This, in turn, causes a decrease in the DC current fed to the induction heating device 110. The decrease in the DC current I_DC is detected by the current measuring device 140, which can then be used as a trigger signal to activate the heating operation of the induction heating device 110 for heating the substrate 21.

[0313] Conversely, when the aerosol-generated article 10 is extracted from cavity 103, the absence of sensor 30 reduces the resistive load 114, thus decreasing the equivalent resistance 118 of the heating device. This, in turn, causes an increase in the DC current fed to the induction heating device 110.

[0314] The current measuring device 140 can detect the decrease and increase of DC current (ΔI_DC).

[0315] To reduce overall power consumption when the aerosol generation apparatus 100 is in a product detection mode (e.g., a product insertion detection mode or a product extraction detection mode), the heating components operate in a pulsed mode instead of a continuous mode. For this purpose, the aerosol generation apparatus 100 includes a switch 130 arranged and configured to control the power supply from a DC power supply 150 to the induction heating device 110. In this embodiment, the switch 130 is arranged in series between the DC power supply 150 and the LC load network 113. During the product detection mode, the switch is intermittently opened and closed, for example, to generate power pulses to intermittently power the induction heating device 130. In contrast, during the heating mode of the aerosol generation apparatus 100, the switch can be permanently closed to continuously apply the DC voltage of the DC power supply to the induction heating device 110. The switch can also be intermittently opened and closed during the heating mode of the aerosol generation apparatus to generate pulsed heating power for pulsating heating of the aerosol forming matrix. Therefore, this mode can be referred to as a pulsed heating mode.

[0316] like Figure 3 As shown, switch 130 and current measuring device 140 are both part of a control circuit, which also includes a microprocessor 160. The microprocessor 160 is configured to control switch 130 for generating power pulses to intermittently power the induction heating device 110; read measuring device 140 for measuring the current I_DC supplied from the DC power supply to the induction heating device 110; and control transistor switch driver circuitry 112 for controlling the induction heating device 110. The control circuit may be a master controller of the aerosol generating device 100 or may be part of a master controller of the aerosol generating device.

[0317] In the work-in / out detection mode, the microprocessor 160 initiates the operation of the switch 130 by closing it for a predetermined closing time interval, thereby generating a current pulse with a pulse duration T1 corresponding to the closing time interval. The pulse duration T1 can be between 1 microsecond and 500 microseconds, particularly between 10 microseconds and 300 microseconds, preferably between 15 microseconds and 120 microseconds, and most preferably between 30 microseconds and 100 microseconds. At the end of the closing time interval, the microprocessor 160 reopens the switch 130 within a predetermined opening time interval, thereby interrupting the current path to the heating device. The opening time interval corresponds to the time interval between two consecutive power pulses; for work-in-process detection, the opening time interval can be between 50 milliseconds and 2 seconds, particularly between 100 milliseconds and 2 seconds, and preferably between 500 milliseconds and 1 second. The closing and opening of the switch 130 can be performed at regular time intervals, for example, by generating periodic power pulses to periodically power the induction heating device. Therefore, the sum of the closing time interval and the opening time interval, or the sum of the pulse duration and the time interval between two consecutive power pulses, corresponds to the period of the pulse series. Generally, the time interval between two consecutive probe power pulses T2 should be selected to balance the impact of energy consumption and user experience performance. The pulse duration T1 should be kept as short as possible, but provide reliable measurement of the current pulse.

[0318] Figure 4 This is a graph illustrating the evolution of a current pulse I_DC over time t according to an exemplary embodiment of the method according to the invention. According to this embodiment, a series of current pulses are generated, with a pulse duration T1 of 100 microseconds and a time interval T2 of 1 second between two consecutive power pulses. It should be understood that these values ​​are merely exemplary and can be changed.

[0319] As long as no aerosol-generated article is inserted, the current measuring device 140 measures a current with a value I_NA (where “NA” means “no article”) for each pulse. As explained, the measured value I_NA depends on the ohmic load 114, which is equal to the ohmic resistance of inductor L2. In contrast, when the user inserts the aerosol-generated article into cavity 103, the ohmic load 114 increases because the ohmic load is now equal to the ohmic resistance of inductor L2 and the ohmic resistance of sensor 21. Due to the increase in ohmic load, the current absorbed by the heating assembly decreases. Therefore, the current measuring device 140 measures a current pulse with a value I_A (where “A” means “article inserted”), which is lower than I_NA. The difference ΔI_DC between I_NA and I_A is recorded by the microcontroller 160 that triggers the start of the heating mode.

[0320] The article insertion detection mode can be triggered, for example, by removing the aerosol generating device 100 from the charging unit. Therefore, the aerosol generating device can be configured to detect the removal of the device from the charging unit.

[0321] although Figure 4 Only the article insertion detection mode is shown, but Figure 5 Both are shown, namely the current pulse I_DC in-process insertion detection mode (see...). Figure 5 During the left half of the process and the sampling and detection mode for in-process products (see the left half of the process), Figure 5 The evolution during the right half of the process. For the evolution of the current pulse I_DC during the in-process insertion detection mode, refer to... Figure 4 The above description describes the evolution of the current pulse I_DC during the in-process removal detection mode in reverse. That is, during the in-process removal detection mode, as long as the aerosol-generated article is still received in cavity 103, the current measuring device 140 measures a current with a value of I_A for each pulse. Once the article is removed from the cavity, the ohmic load 114 decreases, which causes an increase in the current absorbed by the heating assembly. Therefore, the current measuring device 140 measures a current pulse with a value of I_NA. The difference ΔI_DC between I_A and I_NA is also recorded by the microcontroller 160, thus indicating that the article has been removed from the cavity.

[0322] Figure 6 An aerosol generating apparatus according to the invention is shown, particularly according to Figure 1 An exemplary embodiment of the method of the aerosol generation apparatus 100. In particular, Figure 6 A flowchart illustrating different operating modes of the aerosol generating apparatus according to the present invention is shown schematically.

[0323] Typically, a new user experience begins by withdrawing the aerosol generating device 100 from the charging unit, which is used to charge the device 100 via the DC power supply 150. This step is indicated by arrow 1150. During charging, as shown in box 1100, the device 100 is off or in standby mode. Advantageously, withdrawing the aerosol generating device 100 from the charging unit 1150 can trigger an article insertion detection mode—indicated by box 1200—for detecting the insertion of an aerosol-generated article into the cavity of the aerosol generating device. In article insertion detection mode 1200, a sequence of probe power pulses is generated to intermittently energize the induction heating device. Simultaneously, the characteristics of the induction heating device for each pulse, preferably the total resistive load of the heating device, are measured, and it is detected whether this characteristic has changed relative to the previous pulse, thereby indicating that the aerosol-generated article has been inserted into the cavity. In response to the detection of such a change, article insertion detection mode 1200 is stopped, and then the heating operation of the induction heating device—as indicated by box 1300—is activated to operate the device in heating mode for heating the aerosol-forming matrix. Preferably, the detection of article insertion triggers the start of heating operation 1300, as indicated by arrow 1250. The heating operation may include different heating steps, such as a preheating step and a main heating step.

[0324] The heating operation 1300 can be stopped after a predetermined number of suctions or after a predetermined heating time has elapsed. Alternatively, the heating operation 1300 can be stopped manually, for example, by receiving user input from a switch.

[0325] Once heating operation 1300 has stopped, the device operates in article extraction detection mode, as shown in block 1400. Preferably, article extraction detection mode 1400 is initiated in response to the cessation of heating operation 1300, and more particularly in response to the detection of the cessation of heating operation 1300. In article extraction detection mode 1400—as in article insertion detection mode 1200—a sequence of probe power pulses is generated to intermittently energize the induction heating device. Simultaneously, for each pulse, the characteristics of the induction heating device are measured, preferably the total resistive load of the heating device is measured again, and it is detected whether this characteristic has changed compared to the previous pulse, thus indicating the extraction of the aerosol from the cavity to form the article.

[0326] During the in-process removal detection mode 1400, activation of new heating operations is disabled to prevent the user from reheating the depleted aerosol-generated article from a previous heating operation. As indicated by arrow 1450, as soon as aerosol-generated article removal is detected, the in-process removal detection mode 1400 is stopped, and activation of new heating operations is re-enabled, allowing the user to insert a new aerosol-generated article and begin the next heating operation. Therefore, the next in-process insertion detection mode 1200 can begin in response to the detection of aerosol-generated article removal.

[0327] To reduce power consumption and thus increase the overall operating time of the device, the device can operate in standby mode before operating in the (next) article insertion detection mode, as indicated by block 1500, particularly after the article extraction detection mode 1400 has stopped, i.e., in response to the detection of the extraction of an aerosol-generated article by a previous user. In standby mode, a motion sensor, such as an accelerometer, is used to monitor the movement of the device. In response to the detection of movement of the device or the device movement reaching or exceeding a predetermined motion threshold, the (next) article insertion detection mode is initiated, such as... Figure 6 As indicated by arrow 1550. Preferably, the movement of the device is continuously monitored until movement of the device is detected or the movement of the device reaches or exceeds a predetermined motion threshold.

[0328] To reduce power consumption, the device may operate in an idle state monitoring mode during at least one of the following: operation in a work-in-process extraction detection mode or operation in a work-in-process insertion detection mode. In the idle state monitoring mode, for example in a standby mode, movement of the device is monitored using a motion sensor. The device is operated in either the work-in-process extraction detection mode or the work-in-process insertion detection mode in response to the detection that movement of the device has not reached a predetermined motion threshold or has not occurred at all during a predetermined idle time.

[0329] In another configuration of the idle state monitoring mode, detection does not stop in response to the detection that the movement of the device during a predetermined idle time has not reached a predetermined motion threshold or even that there has been no movement. Instead, for example, the number of detection power pulses per time unit can be reduced to one-half or one-third.

[0330] In another configuration of the idle state monitoring mode,

[0331] According to another alternative configuration, the number of detection power pulses per time unit can be reduced first in response to the detection that the device has not moved within a predetermined first idle time, or even has not moved at all. Figure 6 This is indicated by block 1600 for the article extraction detection mode and block 1700 for the article insertion detection mode. Only subsequently, in response to the detection that the movement of the device during a predetermined second idle time, which begins after the first idle time, has not reached a predetermined movement threshold or has not even moved, can the generation of a detection power pulse be stopped.

[0332] In any of these configurations, once the generation of probe power pulses ceases due to the device being in an idle state, as indicated by arrows 1650 and 1750, the device can switch to standby mode 1500 to monitor movement of the device, and then (re)start the operation of the device in article extraction detection mode 1400 or article insertion detection mode 1200 respectively, as indicated by arrow 1550, in response to the detection of appropriate movement.

[0333] The standby mode can be stopped in response to the detection that a device has been inserted into the charging unit.

[0334] For the purposes of this specification and the appended claims, unless otherwise stated, all figures representing quantities, quantities, percentages, etc., shall be understood to be modified by the term "about" in all cases. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges that may be specifically listed or not listed herein. Thus, in this context, the number A is understood to be A ± 5% A. In this context, the number A can be considered to include a value within the general standard error for the measurement of the attribute modified by the number A. In some cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of deviation from A does not materially affect the essential and novel features of the claimed invention. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges that may be specifically listed or not listed herein.

Claims

1. An aerosol generating apparatus for heating an aerosol forming matrix capable of forming an inhalable aerosol upon heating, the apparatus comprising: A cavity for removably receiving at least a portion of an aerosol-generating article, the article comprising the aerosol-forming matrix and a heat-sensitive sensor for heating the matrix; -DC power supply; - An induction heating device, which is connected to the DC power supply and configured to generate an alternating magnetic field within the cavity for inductively heating a sensor of the article during heating operation when the article is received in the cavity; - A control circuit configured to operate in two different modes: a heating mode in which the aerosol generating device performs a heating operation, and a detection mode in which at least one of the aerosol generating article being inserted into the cavity or the aerosol generating article being withdrawn from the cavity is detected, wherein, in the detection mode, the control circuit is configured to - Generate power pulses to intermittently power the induction heating device; - For each power pulse, measure at least one characteristic of the induction heating device; - Detect whether, compared to one or more previous power pulses, a change has occurred in at least one characteristic of the induction heating device due to the sensor becoming present or absent in the cavity when the aerosol-generating article is inserted into or withdrawn from the cavity, and - In response to detecting a change in at least one characteristic of the induction heating device, at least one of the articles being inserted into or withdrawn from the cavity is detected.

2. The aerosol generating apparatus according to claim 1, wherein the control circuit is configured to disable the heating operation of the induction heating device in the following circumstances: - In response to detecting the removal of an article from the cavity during heating operation, the heating operation shall be stopped; or - After a previous heating operation, and until the article is detected to have been removed from the cavity, to prevent the user from reheating the depleted aerosol-generated article from the previous heating operation.

3. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit is configured to activate the heating operation of the induction heating device under the following conditions: - In response to detecting the removal of an article from the cavity during heating operation, and after disabling the heating operation, to stop disabling the heating operation; or - After a previous heating operation, and in response to the detection of an article being withdrawn from the cavity, the user is allowed to insert a new aerosol-generated article and begin the next heating operation.

4. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit is configured to initiate heating operation of the induction heating device in response to detecting that the article is inserted into the cavity.

5. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit further comprises a motion sensor for detecting movement of the apparatus.

6. The aerosol generating apparatus of claim 5, wherein the control circuit is configured to initiate the generation of a power pulse in response to detecting movement of the apparatus.

7. The aerosol generating apparatus of claim 5, wherein the control circuit is configured to stop generating power pulses in response to detecting that the movement of the apparatus for a predetermined idle time has not reached a predetermined movement threshold or in response to detecting that there has been no movement for a predetermined idle time.

8. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit is configured to detect that the aerosol generating apparatus is withdrawn from the charging unit.

9. The aerosol generating apparatus of claim 8, wherein the control circuit is configured to begin generating the power pulse in response to detecting that the aerosol generating apparatus is withdrawn from the charging unit.

10. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit is configured to detect that the aerosol generating apparatus is inserted into the charging unit.

11. The aerosol generating apparatus of claim 10, wherein the control circuit is configured to stop generating the power pulse in response to detecting that the aerosol generating apparatus is inserted into the charging unit.

12. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit is configured to start generating a power pulse for detecting extraction of the article in response to detecting a cessation of heating operation of the apparatus.

13. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit is configured to stop the heating operation of the induction heating device in response to detecting the removal of the article from the cavity.

14. The aerosol generating apparatus according to claim 1 or 2, wherein the control circuit includes a measuring device for measuring a current indicating at least one characteristic of the induction heating device.

15. An aerosol generating article for use with an aerosol generating apparatus according to any one of the preceding claims, wherein the aerosol generating article is removably receivable in a cavity of the apparatus, and wherein the article comprises an aerosol forming matrix and a heat-sensitive sensor for heating the matrix.

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