RU2851054C1 - Aerosol generating device and aerosol generating system (variations) - Google Patents

Abstract

FIELD: tobacco industry.

SUBSTANCE: group of inventions relating to the tobacco industry, in particular to systems that simulate the process of smoking tobacco. An aerosol-generating device is claimed for alternative use with different types of induction-heated aerosol-generating products containing a susceptor device. The device contains a socket designed to accommodate at least part of the aerosol-generating product, which can be removed. The induction heating device is designed to generate an alternating magnetic field for induction heating of the susceptor device of the aerosol-generating product when placed in the socket of the aerosol-generating product. The controller is functionally connected to the induction heating device and is designed to determine a first value and a second value of the electrical property of the susceptor device of the product. The electrical property is achieved during heating of the susceptor device when the device is used with the aerosol-generating product placed in the socket. The controller is designed to determine the difference between the first value and the second value and to identify the type of aerosol-generating product placed in the slot based on the determined difference. Two variants of the aerosol-generating system are claimed.

EFFECT: improved efficiency of recognising the type of aerosol-generating product placed in the aerosol-generating device.

15 cl, 8 dwg

Description

The present invention relates to an aerosol-generating device with means for identifying the type of aerosol-generating article used with the device. The present invention also relates to an aerosol-generating system comprising such a device, as well as to at least one type of aerosol-generating article for use with the device. Furthermore, the present invention relates to a method for identifying the type of aerosol-generating article placed in such a device.

Aerosol-generating devices for generating inhalable aerosols by electrically heating aerosol-forming substrates are generally known in the prior art. Such devices may comprise a receptacle for retrievably receiving at least a portion of an aerosol-generating article, which contains an aerosol-forming substrate to be heated. The devices further comprise an electric heating device designed to heat the substrate when the article is positioned within the cavity. In particular, the heating device may be an induction heating device configured to generate an alternating magnetic field for inductively heating a susceptor within the aerosol-generating article when the article is positioned within the receptacle of the device.

Document RU 2647805 C2 describes a heating control device for an electronic smoking product and a system and method related thereto. A method for controlling the heating of an aerosol precursor of an electronic smoking article, according to which power is directed from an energy source to turn on a heating device for heating the aerosol precursor and proportionally initiating a heating time period with a periodic frequency until the expiration of the heating time period, a sliding window of measurements of the instantaneous actual power directed to the heating device is determined, wherein each measurement of the measurement window is defined as the product of the voltage on the heating device and the electric current through the heating device, a simple sliding average power directed to the heating device is calculated based on the sliding window of measurements of the instantaneous actual power, the simple sliding average power is compared with a selected predetermined power value associated with the energy source, and the power directed from the energy source is adjusted to turn off or turn on the heating device with a periodic frequency in each case, in which the simple sliding average power is respectively higher or lower than the selected predetermined power value. The technical result is the creation of a smoking article that uses heat generated by electrical energy to create the sensation of smoking a cigarette, cigar or pipe, which is accomplished without burning the tobacco to any significant degree, without the need for a combustion-based heat source and without the mandatory delivery of significant quantities of incomplete combustion and pyrolysis products.

In general, such aerosol-generating devices can be designed for use with either a single type of aerosol-generating article or for alternate use with two or more different types of aerosol-generating articles. To detect the type of aerosol-generating article currently inserted into the receptacle, the article may include means for identifying the type of aerosol-generating article used with the device. This type of detection can be implemented using separate means in the form of sensors within the device that respond to specific markers on the article indicating the article type. However, having separate means in the form of device-side sensors and specific markers on the article requires significant engineering effort and increased manufacturing costs for both the device and the article.

It would therefore be desirable to have an aerosol-generating device and a method for identifying the type of aerosol-generating article used with the aerosol-generating device, which would incorporate the advantages of the prior art while simultaneously eliminating its drawbacks. In particular, it would be desirable to have an aerosol-generating device, an aerosol-generating system, and a method that would allow for the identification of the article type in a technically simple manner.

According to the present invention, an aerosol-generating device is provided for use with an aerosol-generating article comprising a susceptor device. The aerosol-generating device comprises a receptacle configured to removably accommodate at least a portion of the aerosol-generating article. The device further comprises an inductive heating device configured to generate an alternating magnetic field for inductively heating the susceptor device of the aerosol-generating article when the aerosol-generating article is placed in the receptacle. In addition, the aerosol-generating device comprises a controller operatively connected to the induction heating device and configured to determine whether the electrical property of the current-receiving (suspender) device has reached a first value and a second value, in particular an initial value and a limit value, during heating of the current-receiving (suspender) device during use of the device, when the aerosol-generating article is placed in the socket. The controller is further configured to determine the difference between the first value and the second value, in particular between the initial value and the limit value, and to identify the type of the aerosol-generating article placed in the socket, based on the determined difference.

According to the present invention, it has been discovered that separate means in the form of a device-side sensor and specific markers on the product side can be omitted for identifying the product type in favor of aerosol-generating systems with inductive heating by utilizing existing system components, i.e., a controller in combination with an inductive heating device and a susceptor device. Specifically, it has been discovered that if the susceptor device of an aerosol-generating product has at least one electrical property that passes through characteristic values during heating, namely from a first value to a second value, in particular from an initial value to a limit value, then the difference between the first value and the second value can be characteristic and thus indicative of a specific product type. On the device side, the first value and the second value of the electrical property can be easily detected by the controller in combination with the inductive heating device. For example, if the first value and the second value of the electrical property represent values indicative of the electrical conductivity of the current-receiving (suspending) device, these values may be accompanied by a corresponding first and second value, in particular, a corresponding initial and limit value of the supply current received by the induction heating device during heating of the current-receiving (suspending) device. Accordingly, the controller may be easily configured to determine the corresponding first and second signal values, which indicate the first and second values of the supply current received by the induction heating device. In addition, the controller may be configured to determine the difference between the determined values and to identify the type of aerosol-generating article placed in the receptacle based on the determined difference.

In general, the device may be designed for use with at least one type of aerosol-generating product. In particular, the device may be designed for use with a single type of aerosol-generating product.

An aerosol-generating article, in particular an aerosol-generating article of at least one type or a single type, may comprise an aerosol-forming substrate capable of forming an inhalable aerosol upon heating, and an inductively heated current-receiving (suspender) device for heating the substrate. The material composition of the current-receiving (suspender) device of the aerosol-generating article, in particular of at least one type of article or a single type of article, may be such that, with increasing temperature, the value of the electrical property of the current-receiving (suspender) device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value. The current-collecting (suspender) device of an aerosol-generating article, in particular of at least one type of article or a single type of article, respectively, may have a characteristic difference between the first value and the second value, in particular between the initial value and the limit value, wherein the difference indicates the type of article.

Similarly, the device may be configured for use with at least two different types of aerosol-generating articles. For example, the aerosol-generating device may be configured for alternative use with an aerosol-generating article comprising a gel-like aerosol-forming substrate and an aerosol-generating article comprising a solid aerosol-forming substrate. Each type of article may comprise an aerosol-forming substrate capable of forming an inhalable aerosol upon heating, and an inductively heated current-receiving device for heating the substrate. The material composition of the current-receiving device of each type of article may be such that, with increasing temperature, the electrical property of the current-receiving device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limiting value. The current collecting device of each type of product may have a characteristic difference between the corresponding first value and the corresponding second value, in particular the corresponding initial value and the corresponding limit value, whereby the difference indicates the corresponding type of product.

In other words, according to the present invention, an aerosol generating device may be provided for alternative use with at least a first type and a second type of inductively heated aerosol generating articles, wherein the article of each type comprises an aerosol generating substrate capable of forming an inhalable aerosol when heated, and a current collecting device for heating the substrate, wherein the device comprises

a socket configured to removably receive at least a portion of a first type or a second type of aerosol-generating article,

an induction heating device configured to generate an alternating magnetic field for inductively heating a current-receiving device of a first or second type of an aerosol-generating article when the aerosol-generating article is placed in the socket, and

a controller operatively connected to the induction heating device and configured to:

determining a first value and a second value of an electrical property of a current-receiving device of the first type or of a second type of product, wherein the electrical property is achieved during heating of the current-receiving device during use of the device, when an aerosol-generating product of the first or second type is placed in the socket,

determining the difference between the first value and the second value, and

identification of the type of aerosol generating product placed in the socket based on a determined difference.

For each type of product, the first and second values of the electrical property may be the initial value and the limit value, respectively, as will be described in more detail below. Specifically, the material composition of the current-receiving device may be selected such that, with increasing temperature during heating, the electrical property of the current-receiving device changes, in particular, increases or decreases, from the initial value to the limit value, and the change in the electrical property from the initial value to the limit value indicates the type of aerosol-generating product. That is, the current-receiving device of each type of product may have a characteristic difference between the corresponding first value and the corresponding second value, in particular the corresponding initial value and the corresponding limit value, wherein the difference indicates the corresponding type of product. Accordingly, the controller may be configured to determine whether an initial value and a limit value of an electrical property of the current-receiving device have been reached during heating when the device is in use, when a product of one type or another is placed in the socket, to determine the difference between the determined initial value and the determined limit value, and to identify the type of product of the corresponding product placed in the socket based on the determined difference.

In particular, the current-receiving devices of at least two different types of aerosol-generating articles may differ from one another by at least one of a corresponding first value and a corresponding second value, in particular a corresponding initial value and a corresponding limit value of the electrical property. Thus, the current-receiving device of each type of article has a characteristic difference between the corresponding first value and the corresponding second value, which differs from the difference between the corresponding first value and the corresponding second value of all other types of articles. In particular, the current-receiving devices of at least two different types of articles may differ from one another by at least one of a corresponding first value and a corresponding second value of the electrical property due to at least one of the different material compositions of the corresponding current-receiving devices or different dimensions of the corresponding current-receiving devices.

The first and second electrical property values represent corresponding electrical property values that arise or are achieved at different points in time during heating, i.e., during the heating operation of the heating device, in particular at different temperatures of the current-collecting device. Over time, the second value is preferably achieved later than the first value during heating. In particular, the second value may preferably be achieved or arise at a higher temperature than the first value.

In general, the first value may differ from the second value. Specifically, the electrical property may increase from the first value to the second value. Similarly, the electrical property may decrease from the first value to the second value.

As noted above, the first value may represent an initial value of the electrical property, and the second value may preferably represent a limit value, in particular a local limit value, of the electrical property. The limit value may be a minimum value or a maximum value. In particular, the limit value may be a local minimum value or a local maximum value. In the context of this document, the term "local limit value" of an electrical property should be understood from a mathematical analytical perspective. That is, the term "local limit value" refers to either the highest or lowest value of the electrical property, depending on the temperature, within a given temperature range, in particular a temperature subrange to which the current collector device may be exposed. In particular, the lowest value of an electrical property as a function of temperature within a given temperature range, in particular a temperature subrange, to which the current-receiving device may be exposed, is the "local minimum value," while the highest value of an electrical property as a function of temperature within a given temperature range, in particular a temperature subrange, to which the current-receiving device may be exposed, is the "local maximum value" of the electrical property. A limit value may also be a global limit value or an absolute limit value, in particular a global or absolute minimum value, or a global or absolute maximum value. In the context of this document, the term "global limit value" or "absolute limit value" of an electrical property should also be understood from the standpoint of mathematical analytics. That is, the term "global limit value" or "absolute limit value" refers to either the highest or the lowest absolute value(s) of an electrical property (depending on temperature) over the entire temperature range. In particular, the lowest absolute value(s) of an electrical property (depending on temperature) over the entire temperature range may represent the "global minimum value" or the "absolute minimum value" of the electrical property, while the highest absolute value(s) of an electrical property (depending on temperature) over the entire temperature range represents the "local maximum value" or the "absolute maximum value" of the electrical property. In the case of a minimum, the electrical property may decrease from an initial value to a minimum value. In the case of a maximum, the electrical property may increase from an initial value to a maximum value.

The first value, in particular the initial value, may occur or be reached during heating of the current-receiving device and the aerosol-forming substrate, i.e., during heating of the current-receiving device and the aerosol-forming substrate from an initial temperature, such as the ambient temperature, to an operating temperature. The operating temperature may be the temperature required for evaporation of volatiles from the aerosol-forming substrate. Similarly, the second value, in particular the limiting value, may occur or be reached during heating of the current-receiving device and the aerosol-forming substrate. In other words, a change from the first value to the second value of the electrical property, in particular a change from the initial value to the limiting value of the electrical property, may occur during heating of the current-receiving device and the aerosol-forming substrate. In particular, the value of the electrical property of the current-receiving device may change, in particular decrease or increase, from the first value to the second value, in particular from the initial value to the limiting value, with increasing temperature.

More specifically, the first value, in particular the initial value, may occur or be reached at the onset of heating of the current-collecting device, in particular at the initial temperature of the current-collecting device, such as the ambient temperature. The second value, in particular the limiting value, may occur or be reached at a temperature of the current-collecting device corresponding to the Curie temperature of the current-collecting device material. The current-collecting device may comprise one or more materials, in particular at least two different materials.

Accordingly, the controller of the aerosol-generating device is preferably configured to determine a first value and a second value, in particular an initial value and a limit value, of the electrical property of the current-receiving device of the aerosol-generating article, which is placed in the socket during the heating of the current-receiving device, and the aerosol-generating substrate, during use of the device, in particular during the heating operation of the induction heating device. Similarly, the controller is preferably configured to determine a difference and identify the type of the article based on the determined difference also during the heating of the current-receiving device and the aerosol-generating substrate, during use of the device, in particular during the heating operation of the induction heating device.

According to the present invention, there may be provided an aerosol generating device for use with an aerosol generating article, wherein the article comprises an aerosol generating substrate capable of forming an inhalable aerosol upon heating, and a current receiving device for heating the substrate, wherein the material composition of the current receiving device is selected such that with an increase in temperature during heating, an electrical property of the current receiving device changes, in particular decreases or increases, from an initial value to a local limit value, and wherein the current receiving device has a characteristic difference between the initial value and the limit value, wherein the difference indicates the corresponding type of article (i.e., a change in the electrical property from the initial value to the local limit value indicates the type of the aerosol generating article), wherein the aerosol generating device comprises:

a socket configured to removably receive at least a portion of the aerosol-generating article,

an induction heating device configured to generate an alternating magnetic field for inductively heating a current-receiving device of an aerosol-generating article when the aerosol-generating article is placed in the socket, and

a controller operatively connected to the induction heating device and configured to

determining the achievement of the initial value and the local limit value of the electrical property of the current-receiving device during heating of the current-receiving device when using the device, when the aerosol-generating product is placed in the socket,

determining the difference between the initial value and the local limit value, and

identification of the type of aerosol generating product placed in the nest based on a determined difference.

As described, the first value and the second value of the electrical property, in particular the initial value and the limit value of the electrical property, may be values indicative of the electrical conductivity of the susceptor. Similarly, the first value and the second value, in particular the initial value and the limit value, of the electrical property may be values indicative of the supply current received by the induction heating device when heating the susceptor. In one example, the supply current received by the induction heating device is constant when heating the susceptor. In this document, the electrical conductivity of the susceptor is directly proportional to the supply current received by the induction heating device when heating the susceptor. Thus, by determining a value indicative of the supply current received by the induction heating device when heating the susceptor, the controller can also determine a value indicative of the electrical conductivity of the susceptor. The same applies to the apparent electrical resistance of the current-collecting device, which is inversely proportional to the supply current received by the induction heating device when it is heated. Therefore, it may be sufficient to determine the corresponding first and second values, indicating the supply current received by the induction heating device.

Power for the induction heating device may be provided by a power supply unit of the aerosol generating device. Accordingly, the aerosol generating device may comprise a power supply unit operatively connected to the induction heating device and a controller, configured to supply power. In particular, the power supply unit may be a DC power supply unit configured to supply a DC supply voltage and a DC supply current. Preferably, the power supply unit is a battery, such as a lithium iron phosphate battery. Alternatively, the power supply unit may be another type of charge storage device, such as a capacitor. The power supply unit may require recharging, i.e., the power supply unit may be rechargeable. The power supply unit may have a capacity that allows for the accumulation of sufficient energy for one or more user use sessions. For example, the power supply unit may have sufficient capacity to ensure continuous aerosol generation for a period of approximately six minutes, or for a period of multiples of six minutes. In another example, the power supply may have a capacity sufficient to enable a specified number of puffs or individual activations of the induction source.

Therefore, to determine the supply current received by the induction heating device, the controller may be configured to determine the supply current received from the power supply unit and to determine the difference between the first value of the electrical property and the second value of the electrical property of the current receiving device based on the change in the supply current received from the power supply unit over time.

In particular, if the voltage supplied by the power supply decreases over time, it may be necessary to determine both the supply current and the supply voltage received from the power supply. Therefore, the controller may be configured to determine the supply current and supply voltage received from the power supply and to determine the difference between the first value of the electrical property and the second value of the electrical property of the current-receiving device based on the change in the supply current and supply voltage received from the power supply over time. In particular, the controller may be configured to determine the difference between the first value of the electrical property and the second value of the electrical property of the current-receiving device based on the change in the ratio of the supply current to the supply voltage received from the power supply over time. This applies, in particular, to those cases where the first value and the second value of the electrical property may be values indicating the electrical conductivity or the electrical apparent resistance of the current-receiving device. This is due to the fact that the electrical conductivity of the current-collecting device is directly proportional to the ratio of the supply current to the supply voltage received from the power supply, and the electrical apparent resistance of the current-collecting device is inversely proportional to the ratio of the supply current to the supply voltage received from the power supply.

The difference between the first and second values of the electrical property of the current-receiving device may depend on the actual rated power of the aerosol-generating device. Although it represents the same type, the actual rated power may differ for different aerosol-generating devices due to manufacturing tolerances. Accordingly, the induction heating device of each device may have a slightly different rated power used to generate the alternating magnetic field. This change in the maximum available power may result in the electrical property values defined for different articles of the same type also varying. This change in certain values, in turn, may interfere with proper product identification, as will be further described below. This applies in particular to cases where product identification is performed during heating of the aerosol-generating substrate, when the induction heating device is typically used at maximum power. This is because at maximum power, there is no available power buffer that could be used to equalize the power of the induction heating device. To reduce the impact of the change in maximum power, the controller may be configured to normalize the determined difference between the first value and the second value of the electrical property using the estimated power of the induction heating device used to generate the alternating magnetic field. Specifically, the controller may be configured to normalize the determined difference between the first value and the second value of the electrical property according to the following equation:

Delta_Norm=k *(Power_Norm - Power) + Delta,

where Delta_Norm is the normalized difference between the first value and the second value of the electrical property, Delta is the determined difference between the first value and the second value of the electrical property, Power_Norm is the design power factor, k is the normalization factor experimentally determined for a plurality of aerosol-generating devices, and Power is the design power of the existing induction heating device. Like the normalization factor, k, the design power factor, Power_Norm, can be determined from the average design power of a plurality of aerosol-generating devices. The design power of the induction heating device can be determined and encoded into the controller during device manufacturing using a calibration article, including a calibration susceptor. Similarly, the design power factor Power_Norm and the normalization factor k can be encoded into the controller during device manufacturing.

This type of normalization advantageously improves identification accuracy, particularly when the device is designed for use with at least two different types of aerosol-generating articles. This is because power normalization results in the distribution of the differences between the first value and the second value, determined for multiple articles of the same type, to produce a reduced standard deviation, as in the absence of power normalization. Consequently, the respective distributions of differences determined for articles of different types can be better distinguished from one another, and thus, an article of one type is less likely to be misidentified as an article of another type. Otherwise, misidentification may occur, particularly if the difference between the first value and the second value, indicating one article type, is close to the difference between the first value and the second value, indicating a different article type.

To identify the product type, the controller may be configured to compare a determined difference between a first value and a second value of the electrical property of the current-receiving device with one or more reference values or reference difference ranges stored on the device, wherein each reference value or reference range indicates a specific product type. A reference range may be a range with a minimum end point and a maximum end point, or an open range with either a minimum end point or a maximum end point. In the latter two cases, the minimum end point and maximum end point of the open range may be an upper threshold or a lower threshold of the difference, which—when crossed by the determined difference—indicates a specific product type.

The controller may be configured to control the heating of the induction heating device in response to the identified article type. Specifically, the controller may be configured to control the heating of the induction heating device according to one or more predetermined heating profiles, each associated with a specific article type. For example, a heating profile associated with an aerosol-generating article containing a solid aerosol-forming substrate may have an operating temperature lower than the operating temperature of a heating profile associated with an aerosol-generating article containing a gel-forming aerosol-forming substrate.

For this purpose, it may be advantageous for the controller of the aerosol-generating device to be configured to determine a first value and a second value of the electrical property of the current-receiving device during the heating of the aerosol-forming substrate during use of the device, in particular during the heating operation of the induction heating device. Furthermore, the controller may be configured to determine the difference between the first value and the second value and to identify the type of the article, preferably also during the heating of the aerosol-forming substrate, for example during the heating operation of the induction heating device. This enables the controller to promptly identify the type of the article, enabling the control of subsequent heating operation of the induction heating device in response to the identified type of the article, in particular the timely selection of a predetermined heating profile before the actual generation of the aerosol.

If the device is designed for use with a single type of article, the controller may be configured to allow heating of the substrate in the article only if the controller identifies that the type of article currently placed in the receptacle is compatible with that single type of article. Otherwise, the controller may be configured to identify the type of article currently placed in the receptacle as unsuitable or incompatible for use with the device. In the latter case, the controller may be configured to stop or disable the operation of the heating device, in particular, to stop or disable the heating of the substrate in the article. This may apply not only to devices designed for use with a single type of aerosol-generating article, but also to devices designed for use with at least one type of aerosol-generating article, or at least two different types of aerosol-generating articles.

Therefore, regardless of the intended use of the device, the controller may be configured to identify the type of product currently placed in the receptacle as unsuitable or incompatible for use with the device, particularly if a defined difference does not meet a certain reference value or reference difference range. Additionally, the controller may be configured to stop or disable the heating device if the type of product currently placed in the receptacle is identified as unsuitable or incompatible for use with the device.

In addition, the controller may be configured to identify an abnormal deviation in at least one of the first value and the second value of the electrical property. An abnormal deviation may occur, in particular, if one of the devices or articles is impacted during a critical time interval between the determination of the first value and the determination of the second value, for example, during the heating operation of an induction heating device. For example, if the user displaces the aerosol-generating article relative to the aerosol-generating device during a critical time interval by pushing the article further into the receptacle (for example, because the article was not fully inserted into the receptacle), the determined difference between the first value and the second value of the electrical property may be increased or decreased, since each push may provoke a sharp drop or increase in the electrical property. Conversely, if the article is partially removed from the receptacle by pulling, the determined difference between the first value and the second value of the electrical property may be increased or decreased, since each pull may provoke a sharp rise or drop in the electrical property.

If the controller is configured to identify an abnormal deviation, the controller may be further configured to control the heating operation of the induction heating device according to a safe heating profile in response to identifying an abnormal deviation in at least one of the first value or the second value of the electrical property. The safe heating profile may correspond to the heating profile from the plurality of stored heating profiles that has the lowest operating temperature. Otherwise, overheating of the aerosol-generating substrate may occur if the aerosol-generating article is erroneously identified as an article whose associated heating profile has an operating temperature higher than the calculated operating temperature of the article actually placed in the socket. For example, the aerosol-generating device may be configured for use with an aerosol-generating article containing a gel-like aerosol-generating substrate, as well as for use with an aerosol-generating article containing a solid aerosol-generating substrate. The operating temperature of the heating profile associated with the aerosol-generating article containing a gel-like aerosol-forming substrate may be, for example, higher than the operating temperature of the heating profile associated with the aerosol-generating article containing a solid aerosol-forming substrate. In this example, in response to identifying an abnormal deviation in at least one of the first value or the second value of the electrical property, the controller may control the heating operation of the induction heating device according to the heating profile associated with the aerosol-generating article containing the solid aerosol-forming substrate.

Alternatively or additionally, the controller may be configured to stop and then resume the process of determining the first value and the second value, determining the difference between the first value and the second value, and identifying the type of product.

The controller may be configured to check the identification of the type of the article, in particular to check the first value and the second value determined in the first measurement, or also to identify an abnormal deviation of at least one of the first value or the second value of the electrical property determined in the first measurement, by repeating the process of determining the first value and the second value in the second measurement and comparing at least one of the first value determined in the first measurement with the first value determined in the second measurement and the second value determined in the first measurement with the second value determined in the second measurement. For both the first measurement and the second measurement, the heating device may be configured to heat the current-receiving device until the electrical property of the current-receiving device reaches or crosses the limit value, in particular the local limit value at which the second values are determined. Between the first measurement and the second measurement, the current-collecting device may be allowed to cool until the electrical property is again below or above a second value, in particular a limit value, depending on whether the second value, in particular the limit value, is a maximum value or a minimum value. For this purpose, the heating device may be configured to stop heating between the first measurement and the second measurement, or to reduce the heating power between the first measurement and the second measurement, or to reduce the duty cycle of the heating process between the first measurement and the second measurement.

Moreover, the controller may be configured to determine the time for the first measurement and the second measurement required for the electrical property of the current-collecting device to reach the corresponding limit value at which the corresponding second value is determined, i.e. the time interval between the determination of the first value and the determination of the second value.

In particular, the controller may be configured to identify an abnormal deviation by comparing the second value determined in the first measurement with the second value determined in the second measurement, and by determining that the second value determined in the first measurement deviates from the second value determined in the second measurement by a certain amount, for example, by more than 5 percent, or more than 10 percent, or more than 20 percent. If this is the case, it is likely that the product was partially removed from the socket by pulling during the first measurement, thereby causing a sharp increase or decrease in the electrical property, i.e., an inherent limit value, which was erroneously identified as a limit value by the controller, which led to the adoption of the second value at an incorrect, in particular too low, temperature during the first measurement. Conversely, the controller may be configured to verify the identification of the type of article by comparing the second value determined in the first measurement with the second value determined in the second measurement, and by determining that the second value determined in the first measurement deviates from the second value determined in the second measurement by at least 5 percent or at least 10 percent.

Additionally or alternatively, the controller may be configured to identify an abnormal deviation by comparing the time required for the electrical property of the current-receiving device to reach the corresponding limit value for the first measurement with the time required for the electrical property of the current-receiving device to reach the corresponding limit value during the second measurement, and by determining that the time required during the first measurement is shorter, in particular less than 90 percent or less than 75 percent, than the time required during the second measurement. If this is the case, it is also likely that the product was partially removed from the socket by pulling during the first measurement, thereby leading to an intrinsic limit value at a lower temperature, as described above. As a consequence, the time for the first measurement will be shorter than expected to reach the actual limit value at the correct (higher) temperature. In other words, the controller may be configured to check the identification of the type of product by comparing the time required for the electrical property of the current-receiving device to reach the corresponding limit value for the first measurement with the time required for the electrical property of the current-receiving device to reach the corresponding limit value during the second measurement, and by determining that the time required during the first measurement deviates from the time required during the second measurement by at least 5 percent or at least 10 percent.

Both criteria, i.e., "the second value determined in the first measurement deviates from the second value determined in the second measurement by at least 5 percent or at least 10 percent" and "the time required during the first measurement deviates from the time required during the second measurement by at least 5 percent or at least 10 percent," can be applied alternatively or in combination. That is, the controller can be configured to verify the identification of the product type if one or at least one of the two criteria is met, or only if both criteria are met. An erroneous identification can also occur if the susceptor is at an elevated temperature level when the product type is subject to identification by the controller, in particular at the beginning of a use session. This can occur, for example, when the user interrupts a use session by stopping the heating device and only shortly thereafter resumes a new use session with the same product. Similarly, such a situation can occur if the product has already been heated by another device or an oven before being placed in the device. As a result, the first value of the electrical property determined at an elevated temperature, such as after a "hot" restart, may differ from what it would have been if it had been determined at a lower temperature, such as the ambient temperature of the device. To prevent erroneous identification under such circumstances, the controller may be configured to block the start of operation of the induction heating device for a predetermined pause time after the previous operation of the induction heating device. The predetermined pause time may range from 0.5 seconds to 120 seconds, in particular from 1 second to 60 seconds, and preferably from 5 seconds to 30 seconds. Pause times in these ranges may allow for sufficient cooling of the current-collecting device.

The device may comprise a user interface capable of indicating the identified product type. For this purpose, the user interface may comprise, for example, a display or one or more light sources, such as one or more LEDs (light-emitting diodes).

Furthermore, the device may comprise a cavity for retrievably receiving at least a portion of an aerosol-generating article, at least one type of article, at least two types of articles, or a single type of article, respectively. In particular, the cavity may implement at least a portion of the device's receptacle. Alternatively, the cavity may be implemented at least partially by the device's receptacle. The cavity may comprise an insertion opening through which a corresponding aerosol-generating article can be inserted into the cavity. In the context of this document, the direction in which the aerosol-generating article is inserted is referred to as the insertion direction. Preferably, the insertion direction corresponds to the extension of the length axis, in particular the central axis of the cavity.

After insertion into the cavity, at least a portion of the aerosol-generating article may continue to extend outward through the insertion opening. The outwardly extending portion of the aerosol-generating article is preferably designed for interaction with the user, in particular for placement in the user's mouth. Therefore, during use of the device, the insertion opening may be located near the mouth. Accordingly, in the context of this document, sections located near the insertion opening or near the user's mouth during use of the device are respectively designated by the term "proximal." Sections located further away are designated by the term "distal."

The cavity may have any suitable cross-section when viewed in a plane perpendicular to the axis of the cavity's length or perpendicular to the direction of insertion of the article. In particular, the cross-section of the cavity may correspond to the shape of the corresponding aerosol-generating article(s) received therein. Preferably, the cavity has a substantially circular cross-section. Alternatively, the 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.

The induction heating device may comprise an induction source comprising an induction coil for generating a variable, in particular alternating, magnetic field. When using the device, the variable magnetic field is preferably generated at the location of the aerosol-forming substrate, in particular in a cavity, as described above. The variable magnetic field may be a high-frequency variable magnetic field. The variable magnetic field may be in the range of 500 kHz (kilohertz) to 30 MHz (megahertz), in particular from 5 MHz to 15 MHz, preferably from 5 MHz to 10 MHz. The variable magnetic field is used for inductive heating of the current-collecting device of the aerosol-generating article, via at least one of eddy currents or hysteresis losses, depending on the electrical and magnetic properties of the current-collecting material(s).

At least one induction coil may be a helical coil or a flat planar coil, in particular a disk coil or a curved planar coil. At least one induction coil may be retained within one of the main portions or the housing of the aerosol-generating device. The induction coil may be arranged to surround at least a portion of the receptacle. In particular, the induction coil may be arranged to surround at least a portion of the cavity of the device or, respectively, at least a portion of the inner surface of such a cavity. For example, the induction coil may be a helical coil arranged within the side wall of the cavity.

The induction source may comprise an alternating current (AC) generator. The AC generator may be powered by a power supply unit of the aerosol generating device. The AC generator is operatively connected to at least one induction coil. In particular, the at least one induction coil may be an integral part of the AC generator. The AC generator is configured to generate a high-frequency oscillating current to pass through the at least one induction coil to generate an alternating magnetic field. The alternating current may be supplied to the at least one induction coil continuously after activation of the system or may be supplied intermittently, for example, from puff to puff.

Preferably, the induction source comprises a DC-to-AC converter connected to a DC power supply comprising an LC circuit, wherein the LC circuit comprises a series connection of a capacitor and an inductor. Furthermore, the induction source may comprise a matching network for impedance matching. In particular, the induction source may comprise a power amplifier, such as a class C power amplifier, a class D power amplifier, or a class E power amplifier.

The aerosol-generating device may further comprise a flow concentrator located around at least a portion of the induction coil and configured to distort the alternating magnetic field of at least one induction source toward the receptacle, for example, toward the cavity. Thus, when the article is placed in the receptacle, the alternating magnetic field is distorted toward the article's current-receiving device. Preferably, the flow concentrator comprises a flow concentrator foil, in particular a multilayer flow concentrator foil.

An aerosol-generating device may comprise a main portion, which preferably comprises at least one of a heating element, a controller, a power supply unit, and at least a portion of a cavity, if present. In addition to the main portion, the aerosol-generating device may further comprise a mouthpiece, particularly if the aerosol-generating article to be used with the device does not comprise a mouthpiece. The mouthpiece may be mounted on the main portion of the device. In the context of this document, the term "mouthpiece" refers to the part of the article through which the aerosol exits the device. The mouthpiece may be designed to close the receiving cavity after the mouthpiece is mounted on the main portion. If the device does not comprise a mouthpiece, the aerosol-generating article to be used with the aerosol-generating device may comprise a mouthpiece, such as a filter plug.

The aerosol generating device may comprise at least one air outlet, such as an air outlet in a mouthpiece (if present).

Preferably, the aerosol-generating device comprises an air path extending from at least one air inlet through the cavity and optionally further to an air outlet in the mouthpiece, if present. Preferably, the aerosol-generating device comprises at least one air inlet in fluid communication with the cavity. Preferably, the aerosol-generating device, in combination with an aerosol-generating article placed in the device, may comprise an air path extending from at least one air inlet into the cavity and optionally further through the aerosol-forming substrate within the article and the mouthpiece into the user's mouth.

Preferably, the aerosol-generating device is a puff-generating device that generates an aerosol directly inhaled by the user through the user's mouth. In particular, the aerosol-generating device is a hand-held aerosol-generating device.

The present invention also provides an aerosol-generating system comprising an aerosol-generating device according to the present invention and as described herein. The system further comprises at least one type of aerosol-generating article, or at least two aerosol-generating articles of different types, for use with which the device is adapted, in particular for use exclusively with them. Each type of article, i.e., at least one type or at least two different types, comprises an aerosol-generating substrate capable of forming an inhalable aerosol upon heating, and an inductively heated susceptor device for heating the substrate.

As described above with respect to the aerosol generating device, the material composition of the current-receiving device of each type of product may be such that, with an increase in temperature, the electrical property of the current-receiving device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current-receiving device of each type of product has a characteristic difference between the corresponding first value and the corresponding second value, wherein the difference indicates the type of product.

As further described above with respect to the aerosol generating device, the current-receiving devices of different types of articles may differ in at least one of the size of the corresponding current-receiving device or the material composition of the corresponding current-receiving device.

According to the present invention, there is also provided an aerosol generating system comprising an aerosol generating device according to the present invention and as described herein, and at least one aerosol generating article of a particular type, wherein the device is adapted for use with it, in particular for use exclusively with it.

A specific type of article may comprise an aerosol-forming substrate capable of forming an inhalable aerosol upon heating, and an inductively heated current-collecting device for heating the substrate. The material composition of the current-collecting device may be selected such that, with increasing temperature, the electrical property of the current-collecting device changes, in particular decreasing or increasing, from a first value to a second value, in particular from an initial value to a limit value. The current-collecting device exhibits a characteristic difference between the first value and the second value, with this difference indicating the specific type of article.

With respect to both systems, the current-receiving device may be located in thermal proximity to the aerosol-forming substrate or in thermal contact with it, as a result of which, during use, the substrate is heated by the current-receiving device when the product is placed in the device's socket.

In the context of this document, the term "susceptor" refers to an element containing one or more materials capable of inductively heating within an alternating magnetic field. This may result from at least one of hysteresis losses or eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the respective susceptor material.

As used herein, the term "aerosol-forming substrate" means a substrate formed from or containing an aerosol-forming material that is capable of releasing volatile compounds upon heating to generate an aerosol. The aerosol-forming substrate is designed to be heated, rather than combusted, to release the volatile compounds that form the aerosol. The aerosol-forming substrate may be a solid aerosol-forming substrate, a liquid aerosol-forming substrate, a gel-like aerosol-forming substrate, or any combination thereof. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively or additionally, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise an aerosol-forming agent. Examples of suitable aerosol-forming substances include glycerin and propylene glycol. The aerosol-forming substrate may also contain other additives and ingredients, such as nicotine or flavorings. The aerosol-forming substrate may also be a paste-like material, a pouch of porous material containing the aerosol-forming substrate, or, for example, loose tobacco mixed with a gelling agent or adhesive, which may contain a conventional aerosol-forming substance such as glycerin and which is compressed or molded into a rod.

As used herein, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate that, when heated, releases volatile compounds that can form an aerosol. Preferably, the aerosol-generating article is a heatable aerosol-generating article. That is, an aerosol-generating article that comprises at least one aerosol-forming substrate that is designed to be heated, rather than combusted, to release volatile compounds that can form an aerosol. The aerosol-generating article may be a consumable, in particular a consumable that is discarded after a single use. The article may be a cartridge containing a liquid aerosol-forming substrate that can be heated. Similarly, the article may be a rod-shaped article, in particular a tobacco article resembling conventional cigarettes.

By way of example, each type of aerosol-generating article, i.e., an article of a single type, an article of at least one type, or articles of at least two different types, may comprise one or more of the following elements: a first support element, an element in the form of a substrate, a second support element, a cooling element, and a filter element. Preferably, the aerosol-generating article comprises at least a first support element, a second support element, and an element in the form of a substrate located between the first support element and the second support element.

The substrate element preferably comprises at least one substrate that forms an aerosol to be heated and a current-receiving device in thermal contact or thermal proximity to the aerosol-forming substrate.

At least one of the first support element and the second support element may comprise a central air passage. Preferably, at least one of the first support element and the second support element may comprise a hollow tube made of cellulose acetate. Alternatively, the first support element may be used to cover and protect the distal front end of the substrate element.

The aerosol cooling element is an element with a large surface area and low suction resistance, for example, from 15 mm H2O to 20 mm H2O. In use, the aerosol formed by volatile compounds released from the element as a substrate is drawn through the aerosol cooling element before moving to the proximal end of the aerosol-generating article.

The filter element preferably serves as a mouthpiece or as part of a mouthpiece along with an aerosol cooling element. As used herein, the term "mouthpiece" refers to the portion of the product through which the aerosol exits the aerosol-generating product.

All of the aforementioned elements may be arranged sequentially along the length axis of the article in the order described above, with the first support element preferably located at the distal end of the article, and the filter element preferably located at the proximal end of the article. Each of the aforementioned elements may be substantially cylindrical. In particular, all elements may have the same outer cross-sectional shape. Additionally, the elements may be surrounded by an outer wrapper to hold the elements together and maintain the desired cross-sectional shape of the rod-shaped article. The wrapper is preferably made of paper. The wrapper may further comprise an adhesive that adheres the overlapping free ends of the wrapper to each other.

Additional features and advantages of the aerosol generating systems of the present invention have been described with respect to the aerosol generating device and are equally applicable.

According to the present invention, a method is proposed for identifying the type of an aerosol-generating article placed in an induction heating device generating an aerosol, in particular in an aerosol-generating device according to the present invention and as described herein. The article comprises an aerosol-generating substrate capable of forming an inhalable aerosol upon heating, and a current-receiving device configured to be inductively heated by the induction heating device of the device for heating the substrate. The material composition of the current-receiving device is such that with an increase in temperature, the value of the electrical property of the current-receiving device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current-receiving device, according to the type of the article, has a characteristic difference between the first value and the second value, wherein the difference indicates the type of the article. The method includes:

- heating an aerosol-forming substrate, an aerosol-generating article placed in an aerosol-generating induction heating device, using a device,

- determination during heating of the first value and the second value of the electrical property of the current-collecting device,

- determining the difference between the first value and the second value of the electrical property, and

- identification of the type of aerosol generating product based on a certain difference.

As already described above with respect to the aerosol-generating device according to the present invention, the first value may be an initial value of the electrical property, and the second value may be a limiting value of the electrical property. The limiting value may be a minimum value or a maximum value. In the case of a minimum, the electrical property may decrease from the initial value to the minimum value. In the case of a maximum, the electrical property may increase from the initial value to the maximum value. The first value, in particular the initial value, may occur or may be reached during heating of the susceptor and the aerosol-forming substrate, i.e., during heating of the susceptor and the aerosol-forming substrate from an initial temperature, such as the ambient temperature, to the operating temperature. The operating temperature may be the temperature required for evaporation of volatiles from the aerosol-forming substrate. Similarly, the second value, in particular the limiting value, may occur or may be reached during heating of the susceptor and the aerosol-forming substrate. In other words, a change from a first value to a second value of an electrical property, in particular a change from an initial value to a limiting value of an electrical property, may occur during heating of the current-receiving device and the aerosol-forming substrate.

More specifically, the first value, in particular the initial value, may occur or be reached at the onset of heating of the current-collecting device, in particular at the initial temperature of the current-collecting device, such as the ambient temperature. The second value, in particular the limiting value, may occur or be reached at a temperature of the current-collecting device corresponding to the Curie temperature of the current-collecting device material. The current-collecting device may comprise one or more materials, in particular at least two different materials.

As described above with respect to the aerosol-generating device according to the present invention, the method may include normalizing the determined difference between the first value and the second value of the electrical property using the calculated power of the induction heating device used to generate the alternating magnetic field. Advantageously, normalization can help compensate for the effects caused by changes in the calculated power.

In particular, a certain difference between the first value and the second value of an electrical property can be normalized according to the following equation:

Delta_Norm=k *(Power_Norm - Power) + Delta,

where Delta_Norm is the normalized difference, Delta is the determined difference, Power_Norm is the design power factor, k is the normalization factor experimentally determined for a set of aerosol-generating devices, and Power is the design power of the induction heating device. The design power factor, Power_Norm, can be determined from the average design power of the aerosol-generating devices.

As further described above with respect to the aerosol generating device according to the present invention, identifying the type of article may include comparing the determined difference between the first value and the second value of the electrical property with one or more stored reference values of the difference, wherein each reference value or reference range indicates a specific type of article.

Furthermore, the method may include controlling the heating operation of the induction heating device in response to the identified type of product. In particular, the heating operation of the induction heating device (particularly after heating) may be controlled according to one or more predetermined heating profiles, each associated with a specific type of product.

The method may further include identifying an abnormal deviation in at least one of the first value or the second value of the electrical property. By doing so, the heating operation of the induction heating device (in particular after heating) can be controlled according to a safe heating profile in response to identifying the abnormal deviation in at least one of the first value or the second value of the electrical property.

The method may further include indicating the identified product type to the user. This primarily improves usability.

As further described above with respect to the aerosol-generating device according to the present invention, the method may include blocking the start of operation of the induction heating device for a predetermined pause time after the previous operation of the induction heating device. This may help prevent misidentification if the user interrupts a usage session and only shortly thereafter wishes to resume a new usage session with the same product. The predetermined pause time may range from 0.5 seconds to 120 seconds, in particular from 1 second to 60 seconds, and preferably from 5 seconds to 30 seconds.

The first value and second value of the electrical property may represent values indicating the conductivity of the current-collecting device. In particular, the first value and second value of the electrical property may represent values indicating the supply current received by the induction heating device when heating the current-collecting device.

If the device comprises a power supply unit configured to provide a supply current and operatively connected to an induction heating device and a controller, the method may include determining the supply current received from the power supply unit of the aerosol-generating device. In doing so, the difference between the first value of the electrical property and the second value of the electrical property of the current-receiving device may be determined based on the change in the supply current received from the power supply unit over time. Similarly, the method may include determining the supply current and supply voltage received from the power supply unit of the aerosol-generating device, and further determining the difference between the first value of the electrical property and the second value of the electrical property of the current-receiving device based on the change in the supply current and supply voltage received from the power supply unit over time, in particular based on the change in the ratio of the supply current to the supply voltage received from the power supply unit over time.

The method may further include identifying the type of article currently placed in the aerosol-generating device as unsuitable or incompatible for use with the device, particularly if the determined difference does not meet a reference value or reference difference range. Additionally, the method may include stopping or disabling the operation of the heating device if the type of article currently placed in the device is identified as unsuitable or incompatible for use with the device.

Additional features and advantages of the method according to the present invention have been described in relation to the aerosol generating device and aerosol generating systems and are equally applicable.

The present 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.

Example Ex1: An aerosol generating device for use with an aerosol generating article comprising a current collecting device, wherein the aerosol generating device comprises:

a socket configured to removably receive at least a portion of the aerosol-generating article,

an induction heating device configured to generate an alternating magnetic field for inductively heating a current-receiving device of an aerosol-generating article when the aerosol-generating article is placed in the socket, and

a controller operatively connected to the induction heating device and configured to

determining the first value and the second value of the electrical property of the current-receiving device, achieved during heating of the current-receiving device during use of the device, when the aerosol-generating product is placed in the socket,

determining the difference between the first value and the second value, and

identification of the type of aerosol generating product placed in the socket based on a determined difference.

Example Ex1a. An aerosol-generating device according to example Ex1, wherein the material composition of the current-collecting device is such that, with increasing temperature, the value of the electrical property of the current-collecting device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current-collecting device has a characteristic difference between the first value and the second value, wherein the difference indicates the type of the product.

Example Ex2: An aerosol generating device according to example Ex1, wherein the device is designed for use with at least one type of aerosol generating article, wherein the aerosol generating article comprises an aerosol generating substrate capable of forming an inhalable aerosol when heated, and an inductively heated current collecting device for heating the substrate.

Example Ex2a. An aerosol generating device according to example Ex2a, wherein the material composition of the current-receiving device of at least one type of article is such that with an increase in temperature, the value of the electrical property of the current-receiving device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current-receiving device of at least one type of article has a characteristic difference between the first value and the second value, wherein the difference indicates the type of article.

Example Ex3: An aerosol generating device according to example Ex1, wherein the device is designed for use with a single type of aerosol generating article, wherein the aerosol generating article comprises an aerosol generating substrate capable of forming an inhalable aerosol when heated, and an inductively heated current collecting device for heating the substrate.

Example Ex3a. An aerosol generating device according to example Ex3, wherein the material composition of the current-collecting device of a single type of product is such that, with an increase in temperature, the value of the electrical property of the current-collecting device changes from a first value to a second value, in particular, decreases or increases from the first value to the second value, in particular from an initial value to a limit value, and wherein the current-collecting device of a single type of product has a characteristic difference between the first value and the second value, wherein the difference indicates a single type of product.

Example Ex4: An aerosol generating device according to example Ex3 or example Ex3a, wherein the controller is configured to activate heating of the substrate in the article only if the controller identifies that the type of article currently placed in the socket corresponds to a single type of article.

Example Ex5: An aerosol generating device according to example Ex1, wherein the device is designed for use with at least two different types of aerosol generating articles, in particular for alternative use with at least a first type and a second type of inductively heated aerosol generating articles, wherein the article of each type comprises an aerosol generating substrate capable of forming an inhalable aerosol when heated, and an inductively heated current collecting device for heating the substrate.

Example Ex5a. An aerosol-generating device according to example Ex5, wherein the material composition of the current-receiving device of each type of product is such that, with an increase in temperature, the value of the electrical property of the current-receiving device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current-receiving device of each type of product has a characteristic difference between the corresponding first value and the corresponding second value, wherein the difference indicates the type of product of the aerosol-generating device.

Example Ex6: An aerosol generating device according to any of the previous examples, wherein the first value is an initial value of an electrical property and the second value is a limit value, in particular a minimum value or a maximum value, of the electrical property.

Example Ex6a. An aerosol generating device according to any of the previous examples, wherein the first value, in particular the initial value, occurs or is reached during heating of the current-collecting device, in particular from an initial temperature, such as the ambient temperature, to the operating temperature.

Example Ex6b. An aerosol generating device according to example Ex6a, wherein the second value, in particular the limiting value, occurs or is reached during heating of the current collecting device, in particular from an initial temperature, such as the ambient temperature, to the operating temperature.

Example Ex6c. An aerosol generating device according to any of the previous examples, wherein the first value, in particular the initial value, occurs or is reached at the start of heating of the current-receiving device, in particular at an initial temperature of the current-receiving device, such as the ambient temperature.

Example Ex6d. An aerosol generating device according to example Ex6c, wherein the second value, in particular the limiting value, occurs or is reached at a temperature of the current-collecting device corresponding to the Curie temperature of the material of the current-collecting device.

Example Ex7: An aerosol generating device according to any of the previous examples, wherein the controller is configured to identify the type of article currently placed in the receptacle as unsuitable or incompatible for use with the device.

Example Ex7a. An aerosol generating device according to example Ex7, wherein the controller is configured to stop or block the operation of the heating device if the type of product currently placed in the receptacle is identified as unsuitable or incompatible for use with the device.

Example Ex8: An aerosol generating device according to any of the previous examples, wherein the first value and the second value of the electrical property are values indicating the electrical conductivity of the current collecting device.

Example Ex9: An aerosol generating device according to any of the previous examples, wherein the first value and the second value of the electrical property are values indicative of the supply current received by the induction heating device when heating the current-collecting device.

Example Ex10: An aerosol generating device according to any of the previous examples, wherein the device comprises a power supply unit configured to provide a supply current and operatively connected to an induction heating device and a controller.

Example Ex11: An aerosol generating device according to example Ex10, wherein the controller is configured to determine a supply current received from a power supply unit and to determine a difference between a first value of an electrical property and a second value of an electrical property of a current-receiving device based on a change in the supply current received from the power supply unit over time.

Example Ex12: An aerosol generating device according to example Ex10 or Ex11, wherein the controller is configured to determine the supply current and supply voltage received from the power supply unit and to determine the difference between the first value of the electrical property and the second value of the electrical property of the current-receiving device based on the change in the supply current and supply voltage received from the power supply unit over time.

Example Ex13: An aerosol generating device according to any of the examples Ex 10-Ex12, wherein the controller is configured to determine the supply current and supply voltage received from the power supply unit and to determine the difference between the first value of the electrical property and the second value of the electrical property of the current receiving device based on the change in the ratio of the supply current to the supply voltage received from the power supply unit over time.

Example Ex14: An aerosol generating device according to any of examples Ex10-Ex13, wherein the power supply is a DC power supply.

Example Ex15: An aerosol generating device according to any of the previous examples, wherein the controller is configured to normalize the determined difference between the first value and the second value of the electrical property using the calculated power of the induction heating device used to generate the alternating magnetic field.

Example Ex16: An aerosol generating device according to any of the previous examples, wherein the controller is configured to normalize the determined difference between the first value and the second value according to the following equation:

Delta_Norm=k *(Power_Norm - Power) + Delta,

where Delta_Norm is the normalized difference, Delta is the determined difference, Power_Norm is the design power factor, k is the normalization factor experimentally determined for a variety of aerosol generating devices, and Power is the design power of the induction heating device.

Example Ex17: An aerosol generating device according to example Ex16, wherein the design power factor, Power_Norm, is determined from the average design power of the aerosol generating devices.

Example Ex18: An aerosol generating device according to any of the previous examples, wherein to identify the type of product, the controller is configured to compare the determined difference between the first value and the second value of the electrical property of the current-receiving device with one or more stored reference values or reference ranges of the difference.

Example Ex19: An aerosol generating device according to any of the previous examples, wherein the controller is configured to control the heating operation of the induction heating device in response to the identified type of article.

Example Ex20: An aerosol generating device according to any of the previous examples, wherein the controller is configured to control the heating operation of the induction heating device according to a corresponding one or more predetermined heating profiles, each of which is associated with a specific type of article.

Example Ex21: An aerosol generating device according to any of the previous examples, wherein the controller is configured to identify an abnormal deviation of at least one of the first value or the second value of the electrical property.

Example Ex21a. An aerosol generating device according to any of the previous examples, wherein the controller is configured to check the identification of the type of article, in particular to check the first value and the second value determined in the first measurement, or also to identify an abnormal deviation of at least one of the first value or the second value of the electrical property, by repeating the process of determining the first value and the second value in the second measurement and comparing at least one of the first value determined in the first measurement with the first value determined in the second measurement, and the second value determined in the first measurement with the second value determined in the second measurement.

Example Ex 21b. An aerosol generating device according to example Ex21a, wherein for both the first measurement and the second measurement the heating device is configured to heat the current collecting device until the electrical property of the current collecting device reaches or crosses a limit value, in particular a local limit value at which the second values are determined.

Example Ex21c. An aerosol generating device according to example Ex21a or example Ex21b, wherein the heating device is configured to stop heating between the first measurement and the second measurement, or to reduce the heating power between the first measurement and the second measurement, or to reduce the duty cycle of the heating process between the first measurement and the second measurement in order to allow the current collecting device to cool between the first measurement and the second measurement until the electrical property is again below or above the second value, in particular the limit value, depending on whether the second value, in particular the limit value, is a maximum value or a minimum value.

Example Ex21d. An aerosol generating device according to any of examples Ex21a-Ex21c, wherein the controller is configured to identify an abnormal deviation by comparing the second value determined in the first measurement with the second value determined in the second measurement, and by determining that the second value determined in the first measurement deviates from the second value determined in the second measurement by a certain amount, for example, by more than 5 percent or more than 10 percent, or more than 20 percent.

Example Ex21e. An aerosol generating device according to any of examples Ex21a-Ex21d, wherein the controller is configured to check the identification of the type of article by comparing the second value determined in the first measurement with the second value determined in the second measurement, and by determining that the second value determined in the first measurement deviates from the second value determined in the second measurement by at least 5 percent or at least 10 percent.

Example Ex21f. An aerosol generating device according to any of the examples Ex21a-Ex21e, wherein the controller is configured to determine the time for the first measurement and the second measurement required for the electrical property of the current collecting device to reach the corresponding limit value at which the corresponding second value is determined, in particular the time interval between the determination of the first value and the determination of the second value.

Example Ex21g. An aerosol generating device according to example Ex1f, wherein the controller is configured to identify an abnormal deviation by comparing the time required for the electrical property of the current-receiving device to reach the corresponding limit value for the first measurement with the time required for the electrical property of the current-receiving device to reach the corresponding limit value during the second measurement, and by determining that the time required during the first measurement is shorter, in particular less than 90 percent or less than 75 percent, than the time required during the second measurement.

Example Ex21h. An aerosol generating device according to example Ex21f or example Ex21g, wherein the controller is configured to check the identification of the type of article by comparing the time required for the electrical property of the current-receiving device to reach the corresponding limit value for the first measurement with the time required for the electrical property of the current-receiving device to reach the corresponding limit value during the second measurement, and by determining that the time required during the first measurement deviates from the time required during the second measurement by at least 5 percent or at least 10 percent.

Example Ex21i. An aerosol generating device according to example Ex21a or example Ex21h, wherein the controller is configured to check the identification of the type of article if one or at least one of the two criteria "the second value determined in the first measurement deviates from the second value determined in the second measurement by at least 5 percent or at least 10 percent" and "the time required during the first measurement deviates from the time required during the second measurement by at least 5 percent or at least 10 percent" is met.

Example Ex21j. An aerosol generating device according to example Ex21a or example Ex21h, wherein the controller is configured to check the identification of the type of article only if both of the two criteria "the second value determined in the first measurement deviates from the second value determined in the second measurement by at least 5 percent or at least 10 percent" and "the time required during the first measurement deviates from the time required during the second measurement by at least 5 percent or at least 10 percent" are met.

Example Ex22: An aerosol generating device according to any of examples Ex21-Ex21j, wherein the controller is configured to control the heating operation of the induction heating device according to a safe heating profile in response to identifying an abnormal deviation in at least one of the first value or the second value of the electrical property.

Example Ex23: An aerosol generating device according to any of the previous examples, wherein the controller is configured to block the start of operation of the induction heating device for a specified pause time after the previous operation of the induction heating device.

Example Ex24: An aerosol generating device according to example Ex23, wherein the predetermined pause time is in the range from 0.5 seconds to 120 seconds, in particular from 1 second to 60 seconds, preferably from 5 seconds to 30 seconds.

Example Ex25: An aerosol generating device according to any of the previous examples, wherein the device comprises a user interface configured to indicate the identified type of product.

Example Ex26: An aerosol generating system comprising an aerosol generating device according to any of examples Ex1-Ex25 and at least one type of aerosol generating article or at least two aerosol generating articles of different types for use with which the device is adapted, in particular for use exclusively with them, wherein the article of each type comprises an aerosol generating substrate capable of forming an inhalable aerosol when heated, and an inductively heated current collecting device for heating the substrate, wherein the material composition of the current collecting device of each type of article is such that with an increase in temperature the electrical property of the current collecting device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current collecting device of each type of article has a characteristic difference between the corresponding first value and the corresponding second value, wherein the difference indicates the type of article.

Example Ex27: An aerosol generating system according to example Ex26, wherein the current collecting devices of different types of articles differ in at least one of the size of the corresponding current collecting device or the material composition of the corresponding current collecting device.

Example Ex28: An aerosol generating system comprising an aerosol generating device according to any of examples Ex1 to Ex25 and an aerosol generating article of a particular type for use with which the device is adapted, in particular for use exclusively with it, wherein the article of a particular type comprises an aerosol generating substrate capable of forming an inhalable aerosol when heated, and an inductively heated current collecting device for heating the substrate, wherein the material composition of the current collecting device is selected such that with an increase in temperature, an electrical property of the current collecting device changes, in particular decreases or increases, from a first value to a second value, in particular from an initial value to a limit value, and wherein the current collecting device has a characteristic difference between the corresponding first value and the corresponding second value, wherein the difference is indicative of a particular type of article.

Example Ex29: A method for identifying the type of an aerosol-generating article placed in an aerosol-generating induction heating device, in particular an aerosol-generating device according to any of examples Ex1-Ex25, wherein the article comprises an aerosol-generating substrate capable of forming an inhalable aerosol upon heating, and a current-receiving device configured to be inductively heated by the induction heating device of the device for heating the substrate, wherein the material composition of the current-receiving device is such that with an increase in temperature, the value of an electrical property of the current-receiving device changes, in particular decreases or increases, from a first value to a second limiting value, in particular from an initial value to a limiting value, and wherein the current-receiving device according to the type of article has a characteristic difference between the first value and the second value, wherein the difference indicates the type of article, wherein the method includes:

heating an aerosol-generating substrate, an aerosol-generating article placed in an aerosol-generating induction heating device, using a device,

determining during heating the first value and the second value of the electrical property of the current-collecting device,

determining the difference between the first value and the second value of the electrical property, and

identification of the type of aerosol generating product based on a determined difference.

Example Ex30: The method according to example Ex29, further comprising normalizing the determined difference between the first value and the second value of the electrical property using the calculated power of the induction heating device used to generate the alternating magnetic field.

Example Ex31: The method according to example Ex30, wherein the determined difference between the first value and the second value of the electrical property can be normalized according to the following equation:

Delta_Norm=k *(Power_Norm - Power) + Delta,

where Delta_Norm is the normalized difference, Delta is the determined difference, Power_Norm is the design power factor, k is the normalization factor experimentally determined for a variety of aerosol generating devices, and Power is the design power of the induction heating device.

Example Ex32: The method according to example Ex31, wherein the design power factor, Power_Norm, is determined from the average design power of the aerosol generating devices.

Example Ex33: The method according to any of examples Ex29-Ex32, wherein identifying the type of product comprises comparing the determined difference between the first value and the second value of the electrical property with one or more stored reference values or reference ranges of the difference, wherein each reference value or reference range indicates a specific type of product.

Example Ex34: The method according to any of examples Ex29-Ex33, further comprising controlling the heating operation of the induction heating device in response to the identified type of article.

Example Ex35: The method according to example Ex34, wherein the heating operation of the induction heating device (in particular after heating the aerosol-forming substrate) is controlled according to one or more predetermined heating profiles, each of which is associated with a specific type of article.

Example Ex36: The method according to any of examples Ex29-Ex35, further comprising identifying an abnormal deviation of at least one of the first value or the second value of the electrical property.

Example Ex37: The method according to example Ex36, wherein the heating operation of the induction heating device (in particular after heating the aerosol-forming substrate) is controlled according to a safe heating profile in response to identifying an abnormal deviation in at least one of the first value or the second value of the electrical property.

Example Ex38: The method according to any of examples Ex29-Ex37, further comprising indicating the identified type of product to the user.

Example Ex39: The method according to any of examples Ex29-Ex38, further comprising blocking the start of operation of the induction heating device for a predetermined pause time after the previous operation of the induction heating device.

Example Ex40: The method according to example 39, wherein the predetermined pause time is in the range from 0.5 seconds to 120 seconds, in particular from 1 second to 60 seconds, preferably from 5 seconds to 30 seconds.

Example Ex41: The method according to any of examples Ex29-Ex40, wherein the first value and the second value of the electrical property are values indicating the electrical conductivity of the current collecting device.

Example Ex42: The method according to any of examples Ex29-Ex40, wherein the first value and the second value of the electrical property are values indicating the supply current received by the induction heating device when heating the current-collecting device.

Example Ex43: The method according to any of examples Ex29-Ex42, wherein the device comprises a power supply unit configured to provide a supply current and operatively connected to the induction heating device and the controller.

Example Ex44: A method according to any of examples Ex29-Ex43, comprising determining a supply current received from a power supply unit of an aerosol generating device, wherein the difference between a first value of an electrical property and a second value of an electrical property of the current receiving device is determined based on a change in the supply current received from the power supply unit over time.

Example Ex45: A method according to any of examples Ex29-Ex44, comprising determining a supply current and a supply voltage received from a power supply unit of an aerosol generating device, wherein the difference between a first value of an electrical property and a second value of an electrical property of the current receiving device is determined based on a change in the supply current and the supply voltage received from the power supply unit over time.

Example Ex46: The method according to example Ex45, wherein the difference between the first value of the electrical property and the second value of the electrical property of the current-receiving device is determined based on the change in the ratio of the supply current to the supply voltage received from the power supply over time.

Example Ex47: A method according to any of examples Ex29 to Ex46, comprising identifying the type of article currently placed in the aerosol generating device as unsuitable or incompatible for use with the device, in particular if the determined difference does not correspond to any reference value or reference range of difference.

Example Ex48: The method according to example Ex47, including stopping or blocking the operation of the heating device if the type of article currently placed in the device is identified as unsuitable or incompatible for use with the device.

Example Ex49: The method according to any of examples Ex29-Ex48, wherein the first value is an initial value of the electrical property and the second value is a limit value, in particular a minimum value or a maximum value, of the electrical property.

Example Ex50. A method according to any of examples Ex29-Ex49, wherein the first value, in particular the initial value, occurs or is reached during heating of the current-collecting device, in particular from an initial temperature, such as the ambient temperature, to the operating temperature.

Example Ex51. The method according to example Ex50, wherein the second value, in particular the limit value, occurs or is reached during heating of the current-collecting device, in particular from an initial temperature, such as the ambient temperature, to the operating temperature.

Example Ex52. The method according to any of the examples Ex29-Ex51, wherein the first value, in particular the initial value, occurs or is reached at the beginning of heating of the current-receiving device, in particular at the initial temperature of the current-receiving device, such as the ambient temperature.

Example Ex53. The method according to example Ex52, wherein the second value, in particular the limiting value, occurs or is reached at a temperature of the current-collecting device corresponding to the Curie temperature of the material of the current-collecting device.

Below, the examples will be further described with reference to figures in which:

Fig. 1-2 schematically illustrates an aerosol generating system according to an illustrative embodiment of the present invention, comprising an aerosol generating device and an aerosol generating article for use with the device;

Fig. 3 shows a conductivity-temperature profile for each of the components of the aerosol generating system shown in Fig. 1 and Fig. 2;

Fig. 4 shows details of the induction heating device for the articles of the aerosol generating system shown in Fig. 1 and Fig. 2;

Fig. 5 shows the distribution of the difference Delta determined for a set of products of the same type with and without normalization;

Fig. 6 schematically illustrates the corresponding distributions of the Delta difference with and without normalization for each product of the aerosol generating system shown in Fig. 1 and Fig. 2; and

Fig. 7-8 shows the conductivity-temperature relationship profile for one of the articles of the aerosol generating system shown in Fig. 1 and Fig. 2 for different situations, which may lead to misidentification of the article type.

Fig. 1 and Fig. 2 schematically illustrate an exemplary embodiment of an aerosol generating system 300 according to the present invention, which is configured to generate an inhalable aerosol by heating an aerosol-forming substrate. The system 300 comprises at least two aerosol-generating articles 100, 200 of different types, as well as an aerosol generating device 1 for alternative use with the at least two different types of articles 100, 200. While Fig. 1 shows an aerosol generating device 1 used with an aerosol generating article 100 of a first type, Fig. 2 shows an aerosol generating device 1 used with an aerosol generating article 200 of a second type.

Each of the two aerosol-generating articles 100, 200 has a substantially rod-shaped form resembling the shape of a conventional cigarette. In the present embodiment, each of the two articles 100, 200 comprises four elements sequentially arranged in coaxial alignment: an element 110, 210 in the form of a substrate, located at the distal end of the corresponding article 100, 200, a support element 140, 240 with a central air passage, an element 150, 250 that cools the aerosol, and a filter element 160, 260, located at the proximal end of the corresponding article 100, 200, which performs the function of a mouthpiece. Each element 110, 210 in the form of a substrate contains an aerosol-forming substrate 120, 220 capable of forming an inhalable aerosol upon heating, as well as an inductively heated current-receiving (susceptor) device 130, 230, which is in direct physical contact with the corresponding substrate 120, 220 for heating this substrate. In the present embodiment, the aerosol-generating article 100 of the first type contains a solid aerosol-forming substrate 120, while the aerosol-generating article 200 of the second type contains a gel-like aerosol-forming substrate 220.

As shown in Fig. 1-3 , the material composition of each current-receiving (suspending) device 130, 230 of each type of article is such that with an increase in temperature, the value of the electrical property of the current-receiving (suspending) device 130, 230 changes from a first value 135, 235 to a second value 136, 236, in particular from an initial value 135, 235 to a limit value 136, 236. In the present embodiment, the material composition of each current-receiving (suspending) device 130, 230 is such that with an increase in temperature, the value of the electrical conductivity G of the corresponding current-receiving device 130, 230 decreases from the corresponding initial value 135, 235 to the limit value 136, 236, that is, the minimum value, and then increases again as the temperature further increases. This behavior is shown in Fig. 3. As can be further seen in Fig. 3, the current-collecting devices 130, 230 of the article 100 of the first type and the article 200 of the second type have different conductivity-to-temperature ratio profiles 133, 233. In particular, each current collecting (susceptor) device 130, 230 has a characteristic difference Delta 137, 237 between the corresponding initial value 135, 235 and the corresponding limit value 136, 236 of the electrical conductivity G. In general, different profiles 133, 233 of the conductivity-to-temperature ratio, in particular different values of the characteristic difference Delta 137, 237, can be caused by the fact that the current collecting devices 130, 230 differ in at least one of the size of the current collecting devices 130, 230 or the material composition of the current collecting devices 130, 230. In the present embodiment, both current collecting devices 130, 230 are current collecting devices in the form of a strip, made of the same material, but having different sizes, in particular different sizes 139, 239 width relative to the shape of the strip, as shown in Fig. 1 and Fig. 2.

In addition to the different aerosol-forming substrates 120, 220 and the different current-collecting devices 130, 230, the articles 100, 200 of both types are essentially identical, in particular with respect to the supporting elements 140, 240, the aerosol-cooling elements 150, 250 and the filter elements 160, 260. In the articles 100, 200 of both types, the corresponding four elements have a substantially cylindrical shape with a substantially identical diameter. In addition, the four elements are surrounded by an outer wrapper 170, 270 so as to hold the elements together and maintain the required circular cross-sectional shape of the article 100, 200. The wrapper 170, 270 is preferably made of paper. Further details of the article 100, 200, in particular the four elements, are disclosed, for example, in document WO 2015/176898 A1.

An elongated aerosol generating device 1 comprises two parts: a proximal part 2 and a distal part 3. In the proximal part 2, the device 1 comprises a cavity 4 which forms a receptacle 6 for removably receiving at least a portion of the corresponding aerosol generating article 100, 200. In the distal part 3, the device 1 comprises a direct current power supply unit 50, such as a rechargeable battery, for providing power for the operation of the device 1, as well as a controller 60 for controlling the operation of the device 1. For heating the substrates 120, 220 in the corresponding articles 100, 200, the device 1 comprises an induction heating device 10 operatively connected to the controller 60. The heating device 10 comprises an electrical circuit 15 and an induction coil 18 for generating an alternating, in particular high-frequency, magnetic field inside the cavity 4.

Fig. 4 shows the details of the induction heating device 10. According to the present embodiment, the induction heating device 10 comprises a DC/AC converter which is connected to the DC power supply unit 50 shown in Fig. 1 and Fig. 2. The DC/AC converter comprises a class E power amplifier which in turn comprises the following components: a transistor switch 11 comprising a field effect transistor T (FET), such as a field effect transistor with a metal-oxide-semiconductor structure (MOSFET), a transistor switch power supply circuit indicated by an arrow 12 for supplying a switching signal (gate-source voltage) to the transistor switch 11 and an LC load circuit 13 comprising a shunt capacitor C1 and a series connection of a capacitor C2 and an inductor L2. The inductor L2 corresponds to the induction coil 18 shown in Fig. 1 and Fig. 2, used to generate an alternating magnetic field inside the cavity 4. In addition, a choke coil L1 is provided for supplying a DC supply voltage +V_DC from the DC power supply unit 50. Also shown in Fig. 3 is an ohmic resistance R, representing the total equivalent resistance or total resistive load 14, which, when using the system, is the sum of the ohmic resistance of the induction coil 18, marked as L2, and the ohmic resistance of the corresponding current-collecting device 130, 230, which, in turn, is substantially inversely proportional to the electrical conductivity G of the corresponding current-collecting device 130, 230. Additional details of the induction heating device 10 according to the present invention, in particular those related to the principle of its operation, are disclosed, for example, in document WO 2015/177046 A1. The electrical circuit 15 of the electrical 10 heating device (except for the induction coil 18) is located on the printed circuit board 61 together with the main control unit 60.

As can be seen in Fig. 1 and Fig. 2, the induction coil 18 is a helical coil located in the proximal part 2 of the device 1 so that it circumferentially surrounds the cylindrical receiving cavity 4. Accordingly, when the corresponding article 100, 200 is introduced into the cavity 4 of the device 100 (as shown in Fig. 1 and Fig. 2) and the heating device 10 is activated, the corresponding current-receiving device 130, 230 is influenced by a changing magnetic field, which, in turn, induces at least one of eddy currents and hysteresis losses in the current-receiving device 130, 230, depending on the magnetic and electrical properties of the corresponding material composition of the current-receiving device 130, 230. As a result, the current-receiving device 130, 230 is heated until an operating temperature is reached that is sufficient to evaporate the corresponding substrate 120, 220, forming an aerosol surrounding the current-receiving device 130, 230 inside the article 100, 200. During this heating, the conductivity of the current-receiving device 130, 230 exhibits a process 133, 233, as explained above and illustrated in Fig. 3. When the operating temperature is reached, the system 300 is ready for use and the user can take a puff through the filter element 160, 260 of the corresponding article 100, 200 placed in the device 1. By doing this, air is drawn into the cavity 4 at the edge of the opening 5 for insertion. Then, from there, the air flow passes in the direction of the distal end of the cavity 4 through the passage formed between the inner surface of the cylindrical cavity 4 and the outer surface of the corresponding article 100, 200. At the distal end of the cavity 4, the air flow enters the article 100, 200 generating an aerosol through the corresponding element 110, 210 in the form of a substrate, and then passes through the support element 140, 240, the element 150, 250 cooling the aerosol, and the filter element 160, 260, through which it ultimately leaves the article 100, 200. During heating, the material converted into steam from the substrate 120, 220 forming an aerosol is captured by the air flow through the element 110, 210 in the form of a substrate. As the air flow containing the material converted into steam passes further through the support element 140, 240, the cooling element 150, 250 and the filter element 160, 260, it is cooled to form an aerosol that leaves the article 100, 200 through the filter element 160, 260.

Different types of aerosol-generating articles containing different aerosol-forming substrates may require different heating operations. For example, the first type of aerosol-generating article 100 according to the present embodiment, which contains a solid tobacco-containing aerosol-forming substrate, may require a lower operating temperature than the second type of aerosol-generating article 200 according to the present embodiment, which contains a gel-like aerosol-forming substrate. For this purpose, as well as to prevent the operation of device 1 with any unsuitable or incompatible articles, proper identification of the article is important. According to the present invention, it has been discovered that the difference between the initial value and the limit value of the electrical property of the current-receiving device in the article can be used as a characteristic indicator of the article type. With respect to the present embodiment, it is the difference Delta 137, 237 between the respective initial value 135, 235 and the respective minimum value 136, 236 of the electrical conductivity G of the current-receiving device 130, 230 that is characteristic of each of the articles 100, 200, as illustrated in Fig. 3, and can thus be used to identify the type of article placed in the cavity 4. For this, the controller 60 of the device 1 is configured to determine the supply current received by the heating device 10 from the power supply unit 50, and further to determine the difference between the respective initial value 135, 235 and the respective minimum value 136, 236 of the electrical conductivity G of the current-receiving device 130, 230 on the basis of the respective initial value and the respective limit value of the current received from the power supply unit 50, or also on the basis of the change in the supply current received from the power supply unit 50 over time. In order to determine the current received from the power supply unit 50, the aerosol generating device 1 according to the present embodiment comprises a current measuring device 62 operatively connected to the controller 60, as shown in Fig. 4. Measuring the current may be sufficient in the case where the voltage provided by the power supply unit 50 is constant, since in this case the conductivity G over time is essentially only a linear dependence of the current over time. In this case, the corresponding values reflecting the conductivity G may be the result of the ratio of the determined current values to the nominal supply voltage of the power supply unit 50, wherein the value of the nominal supply voltage can be stored in the controller 60. Otherwise, if the supply voltage is not constant, then the voltage must also be measured to determine the conductivity as a dependence of both the supply current and the supply voltage over time. For this, the aerosol generating device 1 may additionally comprise a voltage measuring device 63, as also shown in Fig. 4. Like the current measuring device 62, the voltage measuring device 63 is operatively connected to the controller 60, thereby allowing the controller 60 to determine both the supply current and the supply voltage received from the power supply unit 50 and to determine the difference between the corresponding initial value 135, 235 and the corresponding minimum 136, 236 of the electrical conductivity G of the current receiving devices 130, 230 based on the change in the supply current and the supply voltage received from the power supply unit 50 over time. In particular, the controller 60 can be configured to determine the difference between the corresponding initial value 135, 235 and the corresponding minimum 136, 236 of the electrical conductivity G of the current receiving device 130, 230 based on the change in the ratio of the supply current to the supply voltage received from the power supply unit 50 over time.

In use, when the aerosol-generating article is inserted into the cavity 4 of the device 1, the heating device 10 begins to heat the current-receiving device in the article. At the start of the heating operation, the controller 60, in combination with the measuring devices 62, 63, determines the initial supply current and, if necessary, the corresponding supply voltage received from the power supply unit 50. As the temperature increases during the heating operation, the supply current decreases and reaches a minimum value before increasing again. This minimum value of the supply current and, if necessary, the corresponding supply voltage received from the power supply unit 50 are also determined by the controller 60. After this, the controller 60 determines the initial value and the minimum value of the electrical conductivity G based on the ratio of the determined initial supply current to the corresponding supply voltage and based on the determined minimum supply current to the corresponding supply voltage, respectively. As described above, if the supply voltage is constant over time, it may be sufficient to determine only the supply current and determine the initial value and corresponding minimum conductivity G based on the ratio of the correspondingly determined current to the nominal supply voltage of the power supply unit 50. Similarly, it is also possible to use only the supply current (instead of conductivity) as an electrical property of the current-sensing device, which exhibits a characteristic temperature change that indicates the type of product.

After determining the initial value and the minimum conductivity value, the controller 60 determines the difference between these values. The determined difference is then compared with reference values or reference ranges stored in the controller 60 for each type of article with which the device is adapted for use. Accordingly, if the determined difference corresponds to the reference value or reference difference range for the article 100 of the first type, the controller 60 identifies the article currently located in the cavity 4 as the aerosol-generating article 100 of the first type. Similarly, if the determined difference corresponds to the reference value or reference difference range for the article 200 of the second type, the controller 60 identifies the article currently located in the cavity 4 as the aerosol-generating article 200 of the second type. Otherwise, the controller 60 identifies the article currently placed in the cavity 4 as an article that is unsuitable or incompatible for use with the device 1. In the latter case, the controller 60 may stop the heating operation of the heating device 10. In other cases, the controller 60 controls the heating operation of the induction heating device 10 according to the corresponding predetermined heating profile associated with the article 100 of the first type or the article 200 of the second type, respectively.

As further described above, the actual rated power, i.e., the maximum power that can be delivered by heating device 10, may vary for different aerosol-generating devices due to manufacturing tolerances. This variation in maximum available power may, particularly if product identification is performed during heating, result in induction heating device 10 typically operating at maximum power. In order to reduce the influence of the change in the maximum power, the controller 60 according to the present embodiment is configured to normalize the determined difference Delta between the initial value 135, 235 and the limit value 136, 236 of the conductivity G using the calculated power of the induction heating device 10. For example, the controller 60 can be configured to normalize the determined difference Delta between these values 135, 235, 136, 236 according to the equation: Delta_Norm=k *(Power_Norm - Power) + Delta, where Delta_Norm is the normalized difference between the initial value and the limit value of the conductivity, Delta is the determined difference, and Power is the calculated power of the existing induction heating device 10. The calculated power of the induction heating device 10 can be determined and coded in the controller 60 during the manufacture of the device 1 using a calibration article, including a calibration susceptor. Power_Norm is the average calculated power and k is the normalization factor, each of which is determined experimentally for a plurality of aerosol generating devices in advance and coded into the controller 60 during the manufacture of the device 1. Advantageously, this type of normalization results in the distribution of the differences between the initial value and the limit value, determined for a plurality of articles of the same type, to obtain a reduced standard deviation as in the absence of power normalization. This is illustrated in Fig. 5, which shows the distribution of the differences Delta, Delta-Norm, determined for a plurality of articles of the same type with and without normalization. As a consequence, the corresponding distributions of the differences determined for articles of different types can be better distinguished from each other. This is shown in Fig. 6, which schematically illustrates the corresponding distributions of the differences Delta, Delta_Norm for article 100 of the first type and article 200 of the second type with and without normalization. Due to the normalization of the distribution, the differences Delta_Norm for article 100 of the first type and article 200 of the second type no longer overlap. This way, a product of one type is less likely to be misidentified as a product of another type.

If the user displaces the aerosol generating article relative to the aerosol generating device during the critical time interval between the measurement of the initial value and the limit value by pushing the article further into the cavity (e.g. because the article was not fully inserted into the cavity), the determined difference 237a between the initial value 235 and the limit value 236a of the conductivity may be inaccurate, since each push may cause a sudden drop in the conductivity G. This is shown in Fig. 7, which illustrates a conductivity-temperature relationship profile 233, 233a for an article 200 of the second-first type with (dashed line 233a) and without (solid line 233) repeated pushing of the article 200 further into the cavity 4 by the user. As a consequence, in the example shown in Fig. 7, the actually determined difference 237a between the initial value 235 and the limit value 236a is greater than the difference 237 determined without the presence of any displacement of the article. The controller 60 is configured to identify such an abnormal deviation of at least one of the initial value 235 or the limit value 236, 236a of conductivity and, in response to this, to control the heating operation of the induction heating device 10 according to a safe heating profile, for example according to a heating profile associated with the article 100 of the first type, which includes a lower operating temperature. In this way, overheating can be effectively prevented. An erroneous identification may also occur if the susceptor device 230 is at an elevated temperature level T1 at the beginning of the use session, as shown in Fig. 8 for the aerosol-generating article 200 of the second type. This situation can occur, for example, when the user interrupts a usage session by stopping the operation of the heating device and only shortly thereafter resumes a new usage session with the same article. Similarly, such a situation can occur if the article has already been heated by another device or an oven before being inserted into the device. Accordingly, if the susceptor 230 is at an elevated temperature level T1, then the initial conductivity value 235b determined after the "hot" resumption (start) can be lower than the initial value 235 determined at a lower temperature level T0. This is also shown in Fig. 8. As a consequence, the determined conductivity difference 237b would be too low. In order to avoid erroneous identification under such circumstances, the controller 60 is configured to block the start of a new operation of the induction heating device 10 for a predetermined pause time after the previous operation of the induction heating device, for example for 60 seconds. This pause is long enough to allow the susceptor 130, 230 to cool sufficiently.

As further shown in Fig. 1 and Fig. 2, the device 1 comprises a user interface 65 configured to indicate the identified type of article. In the present embodiment, the user interface 65 comprises two LEDs (light emitting diodes), one for indicating that the aerosol-generating article 100 of the first type is placed in the cavity 4, and the other for indicating that the aerosol-generating article 200 of the second type is placed in the cavity 4.

For the purposes of the present description and the appended claims, except where otherwise indicated, all numbers expressing quantities, amounts, percentages, etc., shall be understood as modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points and include any intermediate ranges therebetween, which may or may not be specifically listed herein. Therefore, in this context, the number A shall be understood as A ± 5 percent A. In this context, the number A may be considered to include numerical values that are within the normal standard error for the measurement of the property that the number A modifies. The number A, in some instances, when used in the appended claims, may deviate by the percentages listed above, provided that the amount by which A deviates does not materially affect the fundamental and novel property(ies) of the claimed invention. Also, all ranges include the disclosed maximum and minimum points and include any intermediate ranges therebetween, which may or may not be specifically listed herein.

Claims (27)

1. An aerosol generating device for alternative use with different types of inductively heated aerosol generating articles comprising a susceptor device, wherein the aerosol generating device comprises: a socket configured to removably receive at least a portion of the aerosol-generating article, an induction heating device capable of generating an alternating magnetic field for inductively heating the susceptor device of the aerosol-generating article when placed in the socket of the aerosol-generating article, and a controller operatively connected to the induction heating device and configured to - determining a first value and a second value of an electrical property of the susceptor device of the article, wherein the electrical property is achieved during heating of the susceptor device during use of the device when the aerosol-generating article is placed in the socket, - determining the difference between the first value and the second value, and - identification of the type of aerosol generating product placed in the socket based on a determined difference. 2. An aerosol generating device according to claim 1, characterized in that the first value and the second value of the electrical property are values indicating the electrical conductivity of the susceptor device, or values indicating the supply current received by the induction heating device when heating the susceptor device. 3. An aerosol generating device according to any one of the preceding claims, characterized in that the device comprises a power supply unit configured to provide a supply current and operatively connected to the induction heating device and the controller. 4. An aerosol generating device according to claim 3, characterized in that the controller is configured to determine the supply current received from the power supply unit and to determine the difference between the first value of the electrical property and the second value of the electrical property of the susceptor device based on a change in the supply current received from the power supply unit over time. 5. An aerosol generating device according to claim 3 or 4, characterized in that the controller is configured to determine the supply current and supply voltage received from the power supply unit and to determine the difference between the first value of the electrical property and the second value of the electrical property of the susceptor device based on the change in the supply current and supply voltage received from the power supply unit over time. 6. An aerosol generating device according to any one of the preceding claims, characterized in that the controller is configured to normalize a determined difference between the first value and the second value of the said electrical property using the calculated power of the induction heating device used to generate the alternating magnetic field. 7. An aerosol generating device according to any one of the preceding claims, characterized in that the controller is configured to normalize a certain difference between said first value and said second value according to the following equation: Delta_Norm = k *(Power_Norm - Power) + Delta, where Delta_Norm - normalized difference; Delta - a certain difference; Power_Norm - calculated power factor; k is the normalization coefficient experimentally determined for a variety of aerosol-generating devices; Power - the calculated power of the induction heating device. 8. An aerosol generating device according to any one of the preceding claims, characterized in that the controller is configured to control the heating operation of the induction heating device in response to the identified type of product. 9. An aerosol generating device according to any one of the preceding claims, characterized in that the controller is configured to control the heating operation of the induction heating device according to one or more predetermined heating profiles, each of which is associated with a specific type of product. 10. An aerosol generating device according to any one of the preceding claims, characterized in that the controller is configured to identify an abnormal deviation in at least one of said first value or said second value of the electrical property. 11. The aerosol generating device according to claim 10, wherein the controller is configured to control the heating operation of the induction heating device according to a safe heating profile in response to identifying an abnormal deviation in at least one of said first value or said second value of the electrical property. 12. An aerosol generating device according to any of the preceding paragraphs, characterized in that the controller is configured to block the start of operation of the induction heating device for a specified pause time after the previous operation of the induction heating device. 13. An aerosol generating system comprising an aerosol generating device according to any one of claims 1 to 12 and an aerosol generating article or two aerosol generating articles of different types for use with which the device is adapted, wherein the article of each type comprises an aerosol generating substrate configured to form an inhalable aerosol upon heating, and an inductively heated susceptor device for heating said substrate, wherein the material composition of the susceptor device of each type of article is designed such that with an increase in temperature, an electrical property of the susceptor device changes from a first value to a second value, and wherein the susceptor device of each type of article has a characteristic difference between the corresponding first value and the corresponding second value, wherein the difference indicates the type of article. 14. An aerosol generating system according to claim 13, characterized in that the susceptor devices of different types of articles differ in at least one of the size of the corresponding susceptor device or the material composition of the corresponding susceptor device. 15. An aerosol generating system comprising an aerosol generating device according to any one of claims 1 to 12 and an aerosol generating article of a particular type for use with which the device is adapted, wherein the article of a particular type comprises an aerosol generating substrate configured to form an inhalable aerosol upon heating, and an inductively heated susceptor device for heating the substrate, wherein the material composition of the susceptor device is selected such that with increasing temperature an electrical property of the susceptor device changes from a first value to a second value, and wherein the susceptor device has a characteristic difference between the first value and the second value, wherein the difference is indicative of a particular type of article.