Aerosol generation system

Abstract

[Problem] To provide a mechanism capable of further improving the quality of a user's experiences using an induction heating-type inhalation device. [Solution] An aerosol generation system is provided with a storage unit in which a base material containing an aerosol source is accommodated, a resonance circuit which includes an electromagnetic induction source for inductively heating a susceptor disposed in thermal proximity to an aerosol source of the base material accommodated in the storage unit, and a control unit for controlling operation of the resonance circuit so as to execute a process for generating an aerosol using the base material. The control unit repeatedly switches the operation mode of the resonance circuit to a first operation mode or a second operation mode during the process for generating the aerosol using the base material, wherein the first operation mode includes operating the resonance circuit at a frequency included in a first frequency band, the second operation mode includes operating the resonance circuit at a frequency included in a second frequency band, and the first frequency band and the second frequency band are separated from each other.

Description

Aerosol Generation System

[0001] The present disclosure relates to an aerosol generating system.

[0002] Inhalation devices that generate substances to be inhaled by users are widely used. For example, inhalation devices generate aerosols imparted with flavor components using a substrate containing an aerosol source for generating aerosols and a flavor source for imparting flavor components to the generated aerosol. Users can enjoy the flavor by inhaling the aerosols imparted with flavor components generated by the inhalation device. The action of a user inhaling the aerosol is hereinafter also referred to as a puff or puffing action. Examples of devices classified as inhalation devices include electronic cigarettes and heated tobacco products, which are used as alternatives to cigarettes, as well as nebulizers used for medical purposes. Note that an electronic cigarette is an inhalation device that generates an aerosol by atomizing a liquid aerosol source. A heated tobacco product is an inhalation device that generates an aerosol by heating a solid containing an aerosol source.

[0003] In recent years, an induction heating type suction device has been developed that generates an aerosol by inductively heating a susceptor and heating an aerosol source via the susceptor. For example, Patent Document 1 listed below discloses a technology for estimating the temperature of a susceptor based on frequency characteristics during induction heating.

[0004] Special Publication No. 2020-516014

[0005] However, the technology disclosed in the above-mentioned Patent Document 1 has only recently been developed, and there is still room for improvement in various respects.

[0006] Therefore, the present disclosure has been made in consideration of the above problems, and the purpose of the present disclosure is to provide a mechanism that can further improve the quality of the user experience when using an induction heating type suction device.

[0007] In order to solve the above problem, according to one aspect of the present invention, there is provided an aerosol generation system comprising: a storage unit that stores a substrate containing an aerosol source; a resonant circuit including an electromagnetic induction source that inductively heats a susceptor arranged in thermal proximity to the aerosol source of the substrate stored in the storage unit; and a control unit that controls the operation of the resonant circuit to perform a process of generating an aerosol using the substrate, wherein the control unit repeatedly switches the operation mode of the resonant circuit between a first operation mode and a second operation mode in the process of generating an aerosol using the substrate, wherein the first operation mode includes operating the resonant circuit at a frequency included in a first frequency band, and the second operation mode includes operating the resonant circuit at a frequency included in a second frequency band, and the first frequency band and the second frequency band are separated from each other.

[0008] The second frequency band may include a resonant frequency of the resonant circuit when the temperature of the susceptor is at the highest temperature expected in a process of generating an aerosol using the substrate.

[0009] The second frequency band may include a resonant frequency of the resonant circuit when the temperature of the susceptor is at the lowest temperature expected in a process of generating an aerosol using the substrate.

[0010] The first frequency band may be a higher or lower frequency band than the second frequency band.

[0011] The control unit may use one fixed frequency included in the first frequency band in the first operation mode.

[0012] The control unit may use one fixed frequency included in the second frequency band in the second operation mode.

[0013] The control unit may switch the first frequency band to a frequency band higher or lower than the second frequency band based on the electrical characteristics of the resonant circuit acquired in the first operation mode.

[0014] The control unit may control the operation of the resonant circuit in the second operation mode based on the electrical characteristics of the resonant circuit acquired in the first operation mode.

[0015] The resonant circuit may further include a capacitor, and the control unit may control the operation of the resonant circuit in the second operation mode based on the voltage of the capacitor obtained in the first operation mode.

[0016] The control unit may estimate the temperature of the susceptor based on the voltage of the capacitor acquired in the first operating mode, and control the operation of the resonant circuit in the second operating mode based on the estimated temperature of the susceptor and a predetermined target temperature of the susceptor.

[0017] The control unit may control a duty ratio of a voltage applied to the resonant circuit in the second operation mode.

[0018] The power supplied to the resonant circuit in the first operating mode may be less than the power supplied to the resonant circuit in the second operating mode.

[0019] The duration of the first mode of operation may be shorter than the duration of the second mode of operation.

[0020] The control unit may variably set the duration of the second operation mode.

[0021] The aerosol generating system may further include the substrate, and the substrate may further contain the susceptor.

[0022] As described above, the present disclosure provides a mechanism that can further improve the quality of the user experience when using an induction heating suction device.

[0023] 1 is a schematic diagram showing an example of the configuration of a suction device; FIG. 2 is a diagram showing an example of a resonant circuit included in the suction device according to the present embodiment; FIG. 3 is a diagram for explaining an example of switching of operation modes of the suction device according to the present embodiment; FIG. 4 is a graph showing the relationship between the capacitor voltage and the drive frequency in a resonant circuit having a resonant frequency in the 300 to 400 kHz band; FIG. 5 is a graph showing the relationship between the capacitor voltage and the susceptor temperature when a resonant circuit having a resonant frequency in the 300 to 400 kHz band is operated at the resonant frequency or a frequency deviating from the resonant frequency; FIG. 6 is a graph showing the relationship between the capacitor voltage and the drive frequency in a resonant circuit having a resonant frequency in the 1000 to 1100 kHz band; FIG. 7 is a graph showing the relationship between the capacitor voltage and the susceptor temperature when a resonant circuit having a resonant frequency in the 1000 to 1100 kHz band is operated at the resonant frequency or a frequency deviating from the resonant frequency; and FIG. 8 is a flowchart showing an example of the flow of processing executed by the suction device according to the present embodiment.

[0024] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0025] 1. Configuration Example of Inhalation Device The inhalation device is a device that generates a substance to be inhaled by a user. In the following description, the substance generated by the inhalation device is described as an aerosol. Alternatively, the substance generated by the inhalation device may be a gas.

[0026] 1 is a schematic diagram showing an example of the configuration of a suction device. As shown in FIG. 1, a suction device 100 according to this example configuration includes a power supply unit 111, a sensor unit 112, a notification unit 113, a storage unit 114, a communication unit 115, a control unit 116, a storage unit 140, and an electromagnetic induction source 162.

[0027] The power supply unit 111 stores electric power. The power supply unit 111 supplies electric power to each component of the suction device 100 based on the control of the control unit 116. The power supply unit 111 may be configured, for example, by a rechargeable battery such as a lithium-ion secondary battery. The power supply unit 111 may supply direct current to the other components. Alternatively, the power supply unit 111 may supply alternating current converted by an inverter circuit to the other components.

[0028] The sensor unit 112 acquires various types of information related to the suction device 100. As one example, the sensor unit 112 is configured with a pressure sensor such as a condenser microphone, a flow rate sensor, a temperature sensor, or the like, and acquires values ​​associated with suction by the user. As another example, the sensor unit 112 is configured with an input device such as a button or a switch that accepts information input from the user.

[0029] The notification unit 113 notifies the user of information. The notification unit 113 is configured by, for example, a light emitting device that emits light, a display device that displays an image, a sound output device that outputs sound, or a vibration device that vibrates.

[0030] The storage unit 114 stores various types of information for the operation of the suction device 100. The storage unit 114 is configured by a non-volatile storage medium such as a flash memory, for example.

[0031] The communication unit 115 is a communication interface capable of performing communication conforming to any wired or wireless communication standard, such as Wi-Fi (registered trademark), Bluetooth (registered trademark), BLE (Bluetooth Low Energy (registered trademark)), NFC (Near Field Communication), or LPWA (Low Power Wide Area).

[0032] The control unit 116 functions as an arithmetic processing unit and a control unit, and controls the overall operation of the suction device 100 in accordance with various programs. The control unit 116 is realized by an electronic circuit such as a CPU (Central Processing Unit) or a microprocessor.

[0033] The storage unit 140 has an internal space 141 and holds the stick-shaped substrate 150 while accommodating a portion of the stick-shaped substrate 150 in the internal space 141. The storage unit 140 has an opening 142 that connects the internal space 141 to the outside and accommodates the stick-shaped substrate 150 inserted into the internal space 141 through the opening 142. For example, the storage unit 140 is a cylindrical body with the opening 142 and a bottom 143 as its bottom surface, and defines a columnar internal space 141. An air flow path that supplies air to the internal space 141 is connected to the storage unit 140. An air inlet, which is an air inlet to the air flow path, is arranged, for example, on a side surface of the suction device 100. An air outlet, which is an air outlet from the air flow path to the internal space 141, is arranged, for example, on the bottom 143.

[0034] The stick-shaped substrate 150 includes a substrate portion 151 and a mouthpiece portion 152. The substrate portion 151 includes an aerosol source. The aerosol source includes a tobacco-derived or non-tobacco-derived flavor component. When the inhalation device 100 is a medical inhaler such as a nebulizer, the aerosol source may include a medicament. The aerosol source may be, for example, a liquid such as a polyhydric alcohol, such as glycerin or propylene glycol, or water, containing a tobacco-derived or non-tobacco-derived flavor component, or a solid containing a tobacco-derived or non-tobacco-derived flavor component. When the stick-shaped substrate 150 is held in the storage portion 140, at least a portion of the substrate portion 151 is housed in the internal space 141, and at least a portion of the mouthpiece portion 152 protrudes from the opening 142. When a user holds the mouthpiece portion 152 protruding from the opening 142 in their mouth and inhales, air flows into the internal space 141 via an air flow path (not shown) and reaches the user's mouth along with the aerosol generated from the substrate portion 151.

[0035] The stick-shaped substrate 150 further includes a susceptor 161. The susceptor 161 generates heat by electromagnetic induction. The susceptor 161 is made of a conductive material such as metal. Furthermore, the susceptor 161 is preferably magnetic. As an example, the susceptor 161 may be configured as a metal plate or a metal rod. The susceptor 161 is disposed in thermal proximity to the aerosol source. That is, the susceptor 161 is disposed at a position where heat generated in the susceptor 161 is transferred to the aerosol source. In the example shown in FIG. 1 , the susceptor 161 is included in the substrate portion 151 of the stick-shaped substrate 150. Note that the susceptor 161 may be inaccessible from the outside of the stick-shaped substrate 150. For example, the susceptor 161 may be distributed in the central portion of the stick-shaped substrate 150 and not distributed near the periphery.

[0036] The electromagnetic induction source 162 inductively heats the susceptor 161. When an alternating current is applied to the electromagnetic induction source 162, the electromagnetic induction source 162 generates a fluctuating magnetic field (more specifically, an alternating magnetic field). The electromagnetic induction source 162 is disposed at a position where the generated fluctuating magnetic field is superimposed on the internal space 141 of the accommodation unit 140, more specifically, at a position where the generated fluctuating magnetic field is superimposed on the susceptor 161 of the stick-shaped substrate 150 accommodated in the accommodation unit 140. For example, the electromagnetic induction source 162 is formed of a coil-shaped conductor and disposed so as to be wound around the outer periphery of the accommodation unit 140. Therefore, when a fluctuating magnetic field is generated with the stick-shaped substrate 150 accommodated in the accommodation unit 140, the fluctuating magnetic field generated from the electromagnetic induction source 162 penetrates the susceptor 161 located in the internal space 141 of the accommodation unit 140 and inductively heats the susceptor 161. Specifically, eddy current loss occurs in the susceptor 161, and if the susceptor 161 is magnetic, magnetic hysteresis loss also occurs in the susceptor 161, causing the temperature of the susceptor 161 to rise. The aerosol source included in the stick-shaped substrate 150 is heated and atomized by the induction-heated susceptor 161, thereby generating an aerosol. As an example, when the sensor unit 112 detects that the user has started inhaling and / or that predetermined information has been input, power supply to the electromagnetic induction source 162 may be started. When the sensor unit 112 detects that the user has stopped inhaling and / or that predetermined information has been input, power supply to the electromagnetic induction source 162 may be stopped.

[0037] The above describes an example of the configuration of the suction device 100. Of course, the configuration of the suction device 100 is not limited to the above, and various configurations such as those exemplified below may be used.

[0038] The susceptor 161 may be provided in the suction device 100 instead of being included in the stick-shaped substrate 150. As an example, the suction device 100 may have a susceptor 161 arranged outside the internal space 141. Specifically, the accommodation unit 140 may be made of a conductive and magnetic material and function as the susceptor 161. The accommodation unit 140 serving as the susceptor 161 contacts the outer periphery of the substrate 151, and thus can be thermally close to the aerosol source contained in the substrate 151. As another example, the suction device 100 may have a susceptor 161 arranged inside the internal space 141. Specifically, the blade-shaped susceptor 161 may be arranged so as to protrude from the bottom 143 of the accommodation unit 140 into the internal space 141. When the stick-shaped substrate 150 is inserted into the internal space 141 of the storage section 140, the blade-shaped susceptor 161 is inserted into the inside of the stick-shaped substrate 150 so as to pierce the substrate portion 151 of the stick-shaped substrate 150. This allows the blade-shaped susceptor 161 to be thermally close to the aerosol source contained in the substrate portion 151.

[0039] 2. Technical Features (1) Configuration of Resonant Circuit Fig. 2 is a diagram schematically illustrating an example of a resonant circuit included in the suction device 100 according to this embodiment. As shown in Fig. 2, the suction device 100 according to this embodiment has a resonant circuit 160 including an electromagnetic induction source 162 and a capacitor 163.

[0040] In the example shown in Fig. 2, the resonant circuit 160 is a series resonant circuit in which an electromagnetic induction source 162 and a capacitor 163 are connected in series. The electromagnetic induction source 162 is a so-called induction coil. As shown in Fig. 2, the resonant circuit 160 may be an LC resonant circuit including the electromagnetic induction source 162 and the capacitor 163. However, when the stick-shaped substrate 150 containing the susceptor 161 is housed in the housing portion 140, the susceptor 161 essentially functions as a resistor in the resonant circuit 160 when it is inductively heated by the electromagnetic induction source 162. Therefore, the resonant circuit 160 can also be considered to constitute an RLC resonant circuit including the susceptor 161.

[0041] As shown in FIG. 2 , the resonant circuit 160 includes an inverter circuit 164. The inverter circuit 164 is a half-bridge inverter including two FETs (Field Effect Transistors) 165 (165A and 165B). For example, the FET 165A is a P-channel FET, and the FET 165B is an N-channel FET. The inverter circuit 164 converts a supplied direct current into an alternating current by repeatedly switching the ON / OFF states of the two FETs 165. The alternating current converted by the inverter circuit 164 is supplied to the electromagnetic induction source 162 and the capacitor 163.

[0042] 2 , the two FETs 165 are switched ON / OFF based on the control of an IC (Integrated Circuit) corresponding to the control unit 116. The control unit 116 controls the ON / OFF states of the two FETs 165, thereby controlling the drive frequency of the resonant circuit 160, i.e., the frequency of the AC current supplied to the electromagnetic induction source 162 and the capacitor 163.

[0043] The drive frequency of the resonant circuit 160 may be, for example, 100 kHz or more and 7000 kHz or less. Preferably, the drive frequency of the resonant circuit 160 may be 300 kHz or more and 2000 kHz or less, and more preferably, 500 kHz or more and 1000 kHz or less. The resonant frequency of the resonant circuit 160 is preferably within the range of the drive frequency of the resonant circuit 160.

[0044] (2) Heating Profile The control unit 116 controls the operation of the resonant circuit 160 based on the heating profile as a process for generating an aerosol using one stick-shaped substrate 150. The heating profile is control information for controlling the temperature at which the aerosol source is heated. The heating profile may be control information for controlling the temperature of the susceptor 161. As an example, the heating profile may include a target value for the temperature of the susceptor 161 (hereinafter also referred to as the target temperature). The target temperature may change depending on the elapsed time from the start of heating, in which case the heating profile includes information specifying the time series progression of the target temperature.

[0045] The control unit 116 controls the operation of the resonant circuit 160 so that the actual temperature of the susceptor 161 (hereinafter also referred to as the actual temperature) changes over time in the same manner as the target temperature defined in the heating profile. This allows the aerosol to be generated as planned by the heating profile. The heating profile is typically designed to optimize the flavor that the user experiences when inhaling the aerosol generated from the stick-shaped substrate 150. Therefore, by controlling the operation of the resonant circuit 160 based on the heating profile, the flavor that the user experiences can be optimized.

[0046] The heating profile may include one or more combinations of the elapsed time since the start of heating and the target temperature to be reached at that elapsed time. The control unit 116 controls the temperature of the susceptor 161 based on the difference between the target temperature in the heating profile corresponding to the elapsed time since the start of the current heating and the current actual temperature. The temperature control of the susceptor 161 can be achieved, for example, by known feedback control. In feedback control, the control unit 116 controls the operation of the resonant circuit 160 based on the difference between the actual temperature and the target temperature, etc.

[0047] The feedback control may be, for example, a proportional-integral-differential (PID) control. The control unit 116 may supply power from the power supply unit 111 to the resonant circuit 160 in the form of pulses obtained by pulse width modulation (PWM) or pulse frequency modulation (PFM). In this case, the control unit 116 may control the temperature of the susceptor 161 by adjusting the duty ratio of the power pulses in the feedback control. Alternatively, the control unit 116 may perform simple ON-OFF control. For example, the control unit 116 may supply power to the resonant circuit 160 until the actual temperature of the susceptor 161 reaches a target temperature, and may stop supplying power to the resonant circuit 160 when the actual temperature reaches the target temperature.

[0048] The period from the start to the end of the process of generating aerosol using the stick-shaped substrate 150 is also referred to as a heating session hereinafter. In other words, a heating session is a period during which the operation of the resonant circuit 160 is controlled based on the heating profile. The start of a heating session is the timing when heating based on the heating profile starts. The end of a heating session is the timing when a sufficient amount of aerosol is no longer generated. A heating session includes a pre-heating period and a puffable period following the pre-heating period. The puffable period is a period during which a sufficient amount of aerosol is expected to be generated. The pre-heating period is the period from the start of heating to the start of the puffable period. Heating performed during the pre-heating period is also referred to as pre-heating.

[0049] (3) Switching of Operation Modes During the process of generating an aerosol using the stick-shaped substrate 150, i.e., during the heating process based on the heating profile, the control unit 116 repeatedly switches the operation mode of the resonant circuit 160 between the temperature estimation mode and the heating mode. The temperature estimation mode is an operation mode in which the temperature of the susceptor 161 is estimated and is an example of a first operation mode. The heating mode is an operation mode in which the susceptor 161 is heated and is an example of a second operation mode. This configuration makes it possible to control the temperature of the susceptor 161 while monitoring it.

[0050] The control unit 116 controls the operation of the resonant circuit 160 in the heating mode based on the electrical characteristics of the resonant circuit 160 acquired in the temperature estimation mode. Here, the electrical characteristics of the resonant circuit 160 are electrical characteristics corresponding to the temperature of the susceptor 161. With this configuration, it is possible to control the temperature of the susceptor 161 while monitoring the temperature of the susceptor 161.

[0051] The control unit 116 controls the operation of the resonant circuit 160 in the heating mode based on the voltage of the capacitor 163 acquired in the temperature estimation mode. Specifically, the control unit 116 estimates the temperature of the susceptor 161 based on the voltage of the capacitor 163 acquired in the temperature estimation mode. The control unit 116 then controls the operation of the resonant circuit 160 in the heating mode based on the estimated temperature of the susceptor 161. As will be described later, the voltage of the capacitor 163 (particularly the maximum value of the AC voltage) according to this embodiment has a high correlation with the temperature of the susceptor 161. Therefore, the control unit 116 estimates the temperature of the susceptor 161 by referring to a lookup table that defines a correspondence relationship between the voltage of the capacitor 163 and an estimated temperature value of the susceptor 161. This lookup table is stored in the storage unit 114. This configuration makes it possible to control the temperature of the susceptor 161 while estimating the temperature of the susceptor 161 with high accuracy.

[0052] Being able to estimate the temperature of the susceptor 161 based on the voltage of the capacitor 163 means that the temperature of the susceptor 161 can be estimated without providing a separate temperature sensor or the like that comes into contact with the susceptor 161. This effect is particularly effective in a configuration in which it is difficult to measure the temperature of the susceptor 161 by bringing a temperature sensor into contact with the susceptor 161, such as when the susceptor 161 is built into the stick-shaped substrate 150.

[0053] The control unit 116 controls the operation of the resonant circuit 160 in the heating mode based on the estimated temperature of the susceptor 161 and a predetermined target temperature of the susceptor 161. With this configuration, the control unit 116 can change the temperature of the susceptor 161 as specified in the heating profile. As a result, the quality of the user experience can be improved.

[0054] In the heating mode, the control unit 116 may control the duty ratio of the voltage applied to the resonant circuit 160. More specifically, in the heating mode, the control unit 116 may control the duty ratio of the voltage applied to the electromagnetic induction source 162. For example, the control unit 116 controls the induction heating of the susceptor 161 by controlling the duty ratio of the voltage applied to the inverter circuit 164 in feedback control according to the difference between the estimated temperature of the susceptor 161 and the target temperature. With this configuration, it is possible to appropriately control the temperature of the susceptor 161.

[0055] Here, an example of the relationship between switching of the operation mode and the temperature transition of the susceptor 161 will be described with reference to FIG. 3 . FIG. 3 is a diagram for explaining an example of switching of the operation mode of the suction device 100 according to this embodiment. The vertical axis of graph 10 shown in FIG. 3 represents the temperature of the susceptor 161, and the horizontal axis represents time. As shown in FIG. 3 , the control unit 116 repeatedly switches between the temperature estimation mode and the heating mode as time passes. Then, based on the temperature of the susceptor 161 estimated in the temperature estimation mode, the control unit 116 increases, decreases, or maintains the temperature of the susceptor 161 in the subsequent heating mode.

[0056] The power supplied to the resonant circuit 160 in the temperature estimation mode may be smaller than the power supplied to the resonant circuit 160 in the heating mode. As an example, the voltage applied to the resonant circuit 160 in the temperature estimation mode may be lower than the voltage applied to the resonant circuit 160 in the heating mode. This configuration can reduce adverse effects of the temperature estimation process on the temperature of the susceptor 161, such as an unintended increase in the temperature of the susceptor 161 when a voltage is applied to the resonant circuit 160 to estimate the temperature of the susceptor 161. As a result, it is possible to more accurately control the temperature of the susceptor 161.

[0057] However, since the power supplied to the resonant circuit 160 in the temperature estimation mode is small, the temperature of the susceptor 161 may decrease in the temperature estimation mode, as shown in graph 10. Therefore, as shown in FIG. 3, it is desirable that the duration of the temperature estimation mode is shorter than the duration of the heating mode. With this configuration, the extent of decrease in the temperature of the susceptor 161 in the temperature estimation mode can be reduced. This makes it possible to appropriately increase the temperature of the susceptor 161 at the timing when the temperature of the susceptor 161 should be increased. In particular, this enables the temperature of the susceptor 161 to be rapidly increased in the preheating period, thereby shortening the preheating period.

[0058] The control unit 116 may variably set the duration of the heating mode. As an example, the control unit 116 may set the duration of the heating mode longer as the difference between the estimated temperature of the susceptor 161 and the target temperature increases. This makes it possible to quickly eliminate the difference between the estimated temperature of the susceptor 161 and the target temperature. As another example, the control unit 116 may set the duration of the heating mode shorter as the difference between the estimated temperature of the susceptor 161 and the target temperature decreases. This increases the frequency of estimating the temperature of the susceptor 161, making it possible to gradually bring the estimated temperature of the susceptor 161 closer to the target temperature. In this way, with this configuration, it becomes possible to more accurately control the temperature of the susceptor 161.

[0059] (4) Control of Drive Frequency The present inventor conducted an experiment to investigate the relationship between the drive frequency of the resonant circuit 160 and the estimation accuracy of the temperature of the susceptor 161. Specifically, the inventor placed a susceptor 161 equipped with a heater in the same position as the susceptor 161 when the stick-shaped substrate 150 is housed in the housing section 140. After heating the susceptor 161 to a predetermined temperature using the heater, the inventor measured the voltage of the capacitor 163 using an oscilloscope connected to both sides of the capacitor 163 while changing the drive frequency of the resonant circuit 160 in 2 kHz increments. The inventor used two types of resonant circuits 160 with different resonant frequencies. These resonant circuits 160 had different capacitances of the capacitor 163. The experimental results will be described in detail below with reference to FIGS. 4 to 7 .

[0060] Experimental Results for the −300 to 400 kHz Band FIG. 4 is a graph showing the relationship between the voltage of the capacitor 163 and the drive frequency in the resonant circuit 160 whose resonant frequency is in the 300 to 400 kHz band. The vertical axis of graph 20 represents the voltage of the capacitor 163, which increases from bottom to top. The voltage here refers to the maximum value of the AC voltage in the capacitor 163. The horizontal axis of graph 30 represents the drive frequency of the resonant circuit 160, which increases from left to right. Line 21 represents the relationship between the voltage of the capacitor 163 and the drive frequency of the resonant circuit 160 when the temperature of the susceptor 161 is room temperature. Line 22 represents the relationship between the voltage of the capacitor 163 and the drive frequency of the resonant circuit 160 when the temperature of the susceptor 161 is approximately 100°C. Line 23 represents the relationship between the voltage of the capacitor 163 and the drive frequency of the resonant circuit 160 when the temperature of the susceptor 161 is approximately 200°C. Line 24 shows the relationship between the voltage of capacitor 163 and the drive frequency of resonant circuit 160 when the temperature of susceptor 161 is about 280°C.

[0061] Referring to region 25 of graph 20, it can be seen that when the drive frequency of resonant circuit 160 is close to the resonant frequency F1 kHz, the voltage of capacitor 163 does not vary substantially even if the temperature of susceptor 161 varies. On the other hand, referring to region 26 of graph 20, it can be seen that when the drive frequency of resonant circuit 160 is F2 kHz, which is deviated from the resonant frequency F1 kHz, the voltage of capacitor 163 varies greatly depending on the temperature of susceptor 161. In other words, it can be said that when resonant circuit 160 is operated at a frequency deviated from the resonant frequency, the voltage of capacitor 163 can clearly reflect the temperature of susceptor 161.

[0062] 5 is a graph showing the relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161 when the resonant circuit 160, whose resonant frequency is in the 300 to 400 kHz band, is operated at the resonant frequency or at a frequency outside the resonant frequency. The vertical axis of graph 30 represents the voltage of the capacitor 163, which increases from bottom to top. The voltage here refers to the maximum value of the AC voltage in the capacitor 163. The horizontal axis of graph 30 represents the temperature of the susceptor 161. Plot 31 shows the relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161 when the resonant circuit 160 is operated at the resonant frequency of F1 kHz. Plot 32 shows the relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161 when the resonant circuit 160 is operated at a frequency of F2 kHz, which is outside the resonant frequency. Line 33 is a regression line of the relationship between the voltage of capacitor 163 and the temperature of susceptor 161 when resonant circuit 160 is operated at F2 kHz, which is a frequency that is different from the resonant frequency.

[0063] As shown in plot 31 of graph 30, when the resonant circuit 160 is operated at the resonant frequency, the voltage of the capacitor 163 may be the same even if the temperature of the susceptor 161 is different. Therefore, it can be said that it is difficult to estimate the temperature of the susceptor 161 based on the voltage of the capacitor 163. On the other hand, as shown in plot 32 and line 33 of graph 30, when the resonant circuit 160 is operated at a frequency other than the resonant frequency, it can be said that there is a linear relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161. More specifically, the higher the temperature of the susceptor 161, the higher the voltage of the capacitor 163. From the above, when the resonant circuit 160 is operated at a frequency other than the resonant frequency, it is possible to accurately estimate the temperature of the susceptor 161 based on a lookup table that defines such a linear relationship.

[0064] Experimental Results for the −1000 to 1100 kHz Band FIG. 6 is a graph showing the relationship between the voltage of the capacitor 163 and the drive frequency in a resonant circuit 160 having a resonant frequency in the 1000 to 1100 kHz band. The vertical axis of graph 40 represents the voltage of the capacitor 163, which increases from bottom to top. The voltage here refers to the maximum value of the AC voltage in the capacitor 163. The horizontal axis of graph 40 represents the drive frequency of the resonant circuit 160, which increases from left to right. Line 41 represents the relationship between the voltage of the capacitor 163 and the drive frequency of the resonant circuit 160 when the temperature of the susceptor 161 is room temperature. Line 42 represents the relationship between the voltage of the capacitor 163 and the drive frequency of the resonant circuit 160 when the temperature of the susceptor 161 is approximately 100°C. Line 43 represents the relationship between the voltage of the capacitor 163 and the drive frequency of the resonant circuit 160 when the temperature of the susceptor 161 is approximately 200°C. Line 44 shows the relationship between the voltage of capacitor 163 and the drive frequency of resonant circuit 160 when the temperature of susceptor 161 is about 280°C.

[0065] Referring to region 45 of graph 40, it can be seen that when the drive frequency of resonant circuit 160 is close to the resonant frequency of F3 kHz, the voltage of capacitor 163 does not vary substantially even when the temperature of susceptor 161 varies. On the other hand, referring to region 46 of graph 40, it can be seen that when the drive frequency of resonant circuit 160 is F4 kHz, which is deviated from the resonant frequency of F3 kHz, the voltage of capacitor 163 varies greatly depending on the temperature of susceptor 161. In other words, it can be said that when resonant circuit 160 is operated at a frequency deviating from the resonant frequency, the voltage of capacitor 163 can clearly reflect the temperature of susceptor 161.

[0066] 7 is a graph showing the relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161 when the resonant circuit 160, whose resonant frequency is in the 1000 to 1100 kHz band, is operated at the resonant frequency or at a frequency outside the resonant frequency. The vertical axis of graph 50 represents the voltage of the capacitor 163, which increases from bottom to top. The voltage here refers to the maximum value of the AC voltage in the capacitor 163. The horizontal axis of graph 50 represents the temperature of the susceptor 161. Plot 51 shows the relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161 when the resonant circuit 160 is operated at the resonant frequency of F3 kHz. Plot 52 shows the relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161 when the resonant circuit 160 is operated at a frequency of F4 kHz, which is outside the resonant frequency. Line 53 is a regression line of the relationship between the voltage of capacitor 163 and the temperature of susceptor 161 when resonant circuit 160 is operated at F4 kHz, which is a frequency that is different from the resonant frequency.

[0067] As shown in plot 51 of graph 50, when the resonant circuit 160 is operated at the resonant frequency, a stable relationship is not observed between the temperature of the susceptor 161 and the voltage of the capacitor 163. Therefore, it can be said that it is difficult to estimate the temperature of the susceptor 161 based on the voltage of the capacitor 163. On the other hand, as shown in plot 52 and line 53 of graph 50, when the resonant circuit 160 is operated at a frequency other than the resonant frequency, it can be said that there is a linear relationship between the voltage of the capacitor 163 and the temperature of the susceptor 161. More specifically, the higher the temperature of the susceptor 161, the higher the voltage of the capacitor 163. From the above, when the resonant circuit 160 is operated at a frequency other than the resonant frequency, it is possible to accurately estimate the temperature of the susceptor 161 based on a lookup table that defines such a linear relationship.

[0068] -Configuration of the suction device 100 based on experimental results As described above, the control unit 116 repeatedly switches the operating mode of the resonant circuit 160 between the temperature estimation mode and the heating mode during heating processing based on the heating profile. Here, in the temperature estimation mode, the control unit 116 operates the resonant circuit 160 at a frequency included in the first frequency band. On the other hand, in the heating mode, the control unit 116 operates the resonant circuit 160 at a frequency included in the second frequency band. The first frequency band and the second frequency band are separated from each other. In other words, the first frequency band and the second frequency band do not overlap. With this configuration, the resonant circuit 160 can be driven at an appropriate drive frequency in each of the temperature estimation mode and the heating mode. As a result, the quality of the user experience when using the induction heating suction device 100 can be further improved.

[0069] The first frequency band does not include the resonant frequency of the resonant circuit 160. That is, in the temperature estimation mode, the control unit 116 drives the resonant circuit 160 at a frequency that is different from the resonant frequency. With this configuration, it is possible to improve the accuracy of estimating the temperature of the susceptor 161 in the temperature estimation mode.

[0070] The first frequency band may be a frequency band lower than the second frequency band. For example, if the suction apparatus 100 includes the resonant circuit 160 used in the experiments shown in FIGS. 4 and 5 , the control unit 116 may use a frequency band of approximately F2 kHz, which is lower than the resonant frequency of F1 kHz, as the first frequency band. For another example, if the suction apparatus 100 includes the resonant circuit 160 used in the experiments shown in FIGS. 6 and 7 , the control unit 116 may use a frequency band of approximately F4 kHz, which is lower than the resonant frequency of F3 kHz, as the first frequency band. With this configuration, as described above with reference to FIGS. 4 to 7 , it is possible to improve the accuracy of estimating the temperature of the susceptor 161 in the temperature estimation mode.

[0071] On the other hand, the second frequency band includes the resonant frequency of the resonant circuit 160. That is, in the heating mode, the control unit 116 drives the resonant circuit 160 at a frequency close to the resonant frequency. With this configuration, it is possible to suppress power loss in the electromagnetic induction source 162 and the capacitor 163. As a result, it is possible to efficiently inductively heat the susceptor 161 in the heating mode.

[0072] As an example, if the suction device 100 has the resonant circuit 160 used in the experiments shown in Figures 4 and 5, the control unit 116 may use a frequency band around F1 kHz, which is the resonant frequency, as the second frequency band. As another example, if the suction device 100 has the resonant circuit 160 used in the experiments shown in Figures 6 and 7, the control unit 116 may use a frequency band around F3 kHz, which is the resonant frequency, as the second frequency band.

[0073] The resonant frequency of the resonant circuit 160 may vary depending on the temperature of the susceptor 161. From this perspective, it is desirable that the second frequency band include the resonant frequency of the resonant circuit 160 when the temperature of the susceptor 161 is at a temperature expected in the heat treatment based on the heating profile. More specifically, it is desirable that the second frequency band include the resonant frequency of the resonant circuit 160 when the temperature of the susceptor 161 is at the highest temperature expected in the heat treatment based on the heating profile. For example, if the highest target temperature specified in the heating profile is 300°C, it is desirable that the second frequency band include the resonant frequency of the resonant circuit 160 when the temperature of the susceptor 161 is 300°C. It is also desirable that the second frequency band include the resonant frequency of the resonant circuit 160 when the temperature of the susceptor 161 is at the lowest temperature expected in the heat treatment based on the heating profile. More simply, it is desirable that the second frequency band include the resonant frequency of the resonant circuit 160 when the temperature of the susceptor 161 is at room temperature before the heat treatment based on the heating profile is performed. Furthermore, with regard to the first frequency band, it is desirable that the first frequency band does not include the resonant frequency of the resonant circuit 160 when the temperature of the susceptor 161 is at a temperature expected in the heating process based on the heating profile. With this configuration, it is possible to improve the accuracy of estimating the temperature of the susceptor 161 in the temperature estimation mode and improve the heating efficiency of the susceptor 161 in the heating mode at any timing during heating based on the heating profile.

[0074] In the temperature estimation mode, the control unit 116 may use a fixed frequency within the first frequency band. In particular, in the temperature estimation mode, the control unit 116 may use a fixed frequency outside the vicinity of the resonant frequency. Note that "near the resonant frequency" may be a frequency within a range of approximately 15 kHz from the resonant frequency. Preferably, "near the resonant frequency" may be a frequency within a range of approximately 10 kHz from the resonant frequency, more preferably a frequency within a range of approximately 5 kHz from the resonant frequency, and even more preferably a frequency within a range of approximately 2 kHz from the resonant frequency. Furthermore, a frequency outside the resonant frequency may be a frequency that is 5 kHz or more away from the resonant frequency, preferably 10 kHz or more away, and even more preferably 15 kHz or more away from the resonant frequency. As an example, if the suction device 100 has the resonant circuit 160 used in the experiments shown in FIGS. 4 and 5 , the control unit 116 may use F2 kHz, a frequency outside the resonant frequency, in the temperature estimation mode. As another example, if the suction device 100 has the resonant circuit 160 used in the experiments shown in Figures 6 and 7, the control unit 116 may use F4 kHz, which is a frequency that is different from the resonant frequency, in the temperature estimation mode. With this configuration, it is possible to improve the accuracy of estimating the temperature of the susceptor 161.

[0075] The control unit 116 may use a fixed frequency included in the second frequency band in the heating mode. In particular, it is desirable for the control unit 116 to use a fixed frequency near the resonant frequency or the resonant frequency itself in the heating mode. As an example, if the suction device 100 has the resonant circuit 160 used in the experiments shown in FIGS. 4 and 5 , the control unit 116 may use the resonant frequency F1 kHz in the heating mode. As another example, if the suction device 100 has the resonant circuit 160 used in the experiments shown in FIGS. 6 and 7 , the control unit 116 may use the resonant frequency F3 kHz in the heating mode. Driving the resonant circuit 160 near the resonant frequency minimizes power loss in the electromagnetic induction source 162 and the capacitor 163. As a result, the susceptor 161 can be induction-heated most efficiently in the heating mode.

[0076] The resonant frequency of the resonant circuit 160 can be obtained when the suction device 100 is shipped from the factory. The drive frequencies used in the temperature estimation mode and the heating mode can be set based on the resonant frequency obtained when the suction device 100 is shipped from the factory.

[0077] (5) Process Flow FIG. 8 is a flowchart showing an example of the process flow executed by the suction device 100 according to this embodiment.

[0078] 8 , first, the suction device 100 receives a user operation to instruct the start of heating (step S102). As one example, the control unit 116 may receive a user operation to press a predetermined button as the user operation to instruct the start of heating. As another example, the control unit 116 may receive a user operation to insert the stick-shaped substrate 150 into the storage unit 140 as the user operation to instruct the start of heating.

[0079] Next, the suction device 100 starts heating based on the heating profile (step S104). For example, the control unit 116 starts applying a voltage from the power supply unit 111 to the resonant circuit 160.

[0080] Next, the suction device 100 operates in a temperature estimation mode. That is, the suction device 100 sets the drive frequency of the resonant circuit 160 to a frequency included in the first frequency band and estimates the temperature of the susceptor 161 (step S106). For example, the control unit 116 drives the resonant circuit 160 at a frequency that is different from the resonant frequency, and estimates the temperature of the susceptor 161 based on the voltage of the capacitor 163.

[0081] Next, the suction device 100 operates in the heating mode. That is, the suction device 100 sets the drive frequency of the resonant circuit 160 to a frequency included in the second frequency band and controls the temperature of the susceptor 161 (step S108). For example, the control unit 116 drives the resonant circuit 160 at a frequency close to the resonant frequency and controls the duty ratio of the voltage applied to the resonant circuit 160 so as to reduce the difference between the estimated temperature and the target temperature of the susceptor 161.

[0082] Next, inhalation device 100 determines whether to end heating (step S110). As one example, control unit 116 determines to end heating when the elapsed time since the start of heating based on the heating profile reaches a predetermined threshold. As another example, control unit 116 determines to end heating when the number of puffs reaches a predetermined threshold.

[0083] If it is determined that the heating should not be terminated (step S110: NO), the process returns to step S106 again.

[0084] On the other hand, if it is determined that the heating should be terminated (step S110: YES), the suction device 100 terminates the heating based on the heating profile (step S112). For example, the control unit 116 stops the application of voltage from the power supply unit 111 to the resonant circuit 160.

[0085] 3. Supplementary Information Although preferred embodiments of the present disclosure have been described above in detail with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art to which the present disclosure pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0086] In the above embodiment, an example has been described in which the first frequency band is a frequency band lower than the second frequency band. However, the present disclosure is not limited to such an example. The first frequency band may be a frequency band higher than the second frequency band as long as it is separated from the second frequency band. Referring to FIG. 4 , it can be seen that the voltage of the capacitor 163 varies significantly depending on the temperature of the susceptor 161, not only in frequency bands lower than the resonant frequency F1 kHz but also in higher frequency bands. Similarly, referring to FIG. 6 , it can be seen that the voltage of the capacitor 163 varies significantly depending on the temperature of the susceptor 161, not only in frequency bands lower than the resonant frequency F3 kHz but also in higher frequency bands. Therefore, even when a frequency band higher than the second frequency band is used as the first frequency band, it is possible to accurately estimate the temperature of the susceptor 161 based on the voltage of the capacitor 163.

[0087] The control unit 116 may switch the first frequency band to a frequency band higher or lower than the second frequency band based on the electrical characteristics of the resonant circuit 160 acquired in the temperature estimation mode. More simply, the control unit 116 may switch the first frequency band to a frequency band higher or lower than the second frequency band based on the temperature of the susceptor 161 estimated in the temperature estimation mode. As an example, it is assumed that the resonant frequency of the resonant circuit 160 decreases as the temperature of the susceptor 161 increases. In this case, the control unit 116 may use a frequency band lower than the second frequency band as the first frequency band when the estimated temperature of the susceptor 161 is lower than a predetermined threshold, and may use a frequency band higher than the second frequency band as the first frequency band when the estimated temperature of the susceptor 161 is higher than the predetermined threshold. If it is assumed that the resonant frequency of the resonant circuit 160 increases as the temperature of the susceptor 161 increases, the control unit 116 may perform the opposite control to the above. According to this configuration, even if the resonant frequency of the resonant circuit 160 changes in response to a change in the temperature of the susceptor 161, the drive frequency of the resonant circuit 160 in the temperature estimation mode can be maintained at a frequency that is significantly different from the resonant frequency of the resonant circuit 160. As a result, it is possible to improve the accuracy of estimating the temperature of the susceptor 161 in the temperature estimation mode.

[0088] In the above embodiment, an example has been described in which the resonant circuit 160 is configured as a series resonant circuit in which the electromagnetic induction source 162 and the capacitor 163 are connected in series, but the present disclosure is not limited to such an example. The resonant circuit 160 may also be configured as a parallel resonant circuit in which the electromagnetic induction source 162 and the capacitor 163 are connected in parallel.

[0089] In the above embodiment, an example has been described in which the inverter circuit 164 is a half-bridge inverter, but the present disclosure is not limited to such an example. As an example, the inverter circuit 164 may be a full-bridge inverter. As another example, the inverter circuit 164 may be a single-ended circuit such as a class E amplifier. More specifically, the inverter circuit 164 may be a single-ended circuit that includes, for example, an N-channel FET but does not include a P-channel FET.

[0090] The inhalation device 100 described above is an example of an aerosol generation system that generates an aerosol to be inhaled by a user using a substrate containing either an aerosol source or a flavor source. The flavor source is a component that imparts a flavor component to the aerosol. The stick-shaped substrate 150 is an example of a substrate used in an aerosol generation system. The combination of the inhalation device 100 and the stick-shaped substrate 150 may be considered as an aerosol generation system.

[0091] In the above embodiment, the stick-shaped substrate 150 is given as an example of a substrate containing an aerosol source, but the shape of the substrate is arbitrary. For example, the substrate containing the aerosol source may be configured in a cup shape or a flat shape. A cup-shaped substrate is configured, for example, by filling an aerosol source into a hollow container having an arbitrary shape. A flat-shaped substrate is configured, for example, by forming the aerosol source into a thin, planar shape.

[0092] The series of processes performed by each device described herein may be implemented using software, hardware, or a combination of software and hardware. The software programs may be stored in advance on a recording medium (more specifically, a non-transitory computer-readable storage medium) internal or external to each device. Each program is then loaded into RAM and executed by a processing circuit such as a CPU when executed by a computer controlling each device described herein. The recording medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. The computer program may also be distributed over a network without using a recording medium. The computer may be an application-specific integrated circuit (ASIC), a general-purpose processor that executes functions by loading a software program, or a computer on a server used in cloud computing. The series of processes performed by each device described herein may be centrally processed by a single computer or distributed across multiple computers. Furthermore, in each of the above embodiments, two or more communication means present in a single device may be physically implemented on a single medium.

[0093] Furthermore, the processes described herein using flowcharts or sequence diagrams do not necessarily have to be performed in the order shown. Some process steps may be performed in parallel. Furthermore, additional process steps may be employed, and some process steps may be omitted.

[0094] Note that the following configurations also fall within the technical scope of the present disclosure. (1) An aerosol generation system comprising: a storage unit that stores a substrate containing an aerosol source; a resonant circuit including an electromagnetic induction source that inductively heats a susceptor arranged in thermal proximity to the aerosol source of the substrate stored in the storage unit; and a control unit that controls operation of the resonant circuit to perform a process of generating an aerosol using the substrate, wherein the control unit repeatedly switches the operation mode of the resonant circuit between a first operation mode and a second operation mode in the process of generating an aerosol using the substrate, wherein the first operation mode includes operating the resonant circuit at a frequency included in a first frequency band, and the second operation mode includes operating the resonant circuit at a frequency included in a second frequency band, and the first frequency band and the second frequency band are separated. (2) The aerosol generation system according to (1), wherein the second frequency band includes a resonant frequency of the resonant circuit when the temperature of the susceptor is the highest temperature expected in the process of generating an aerosol using the substrate. (3) The aerosol generating system according to (1) or (2), wherein the second frequency band includes a resonant frequency of the resonant circuit when the temperature of the susceptor is the lowest temperature expected in a process of generating an aerosol using the substrate. (4) The aerosol generating system according to any one of (1) to (3), wherein the first frequency band is a frequency band higher or lower than the second frequency band. (5) The aerosol generating system according to any one of (1) to (4), wherein the control unit uses a fixed frequency included in the first frequency band in the first operation mode. (6) The aerosol generating system according to any one of (1) to (5), wherein the control unit uses a fixed frequency included in the second frequency band in the second operation mode. (7) The aerosol generating system according to (4), wherein the control unit switches the first frequency band to a frequency band higher or lower than the second frequency band based on the electrical characteristics of the resonant circuit acquired in the first operation mode.(8) The aerosol generation system according to any one of (1) to (7), wherein the control unit controls the operation of the resonant circuit in the second operation mode based on electrical characteristics of the resonant circuit acquired in the first operation mode. (9) The aerosol generation system according to (8), wherein the resonant circuit further includes a capacitor, and the control unit controls the operation of the resonant circuit in the second operation mode based on the voltage of the capacitor acquired in the first operation mode. (10) The aerosol generation system according to (9), wherein the control unit estimates a temperature of the susceptor based on the voltage of the capacitor acquired in the first operation mode, and controls the operation of the resonant circuit in the second operation mode based on the estimated temperature of the susceptor and a predetermined target temperature of the susceptor. (11) The aerosol generation system according to any one of (8) to (10), wherein the control unit controls a duty ratio of a voltage applied to the resonant circuit in the second operation mode. (12) The aerosol generation system according to any one of (1) to (11), wherein the power supplied to the resonant circuit in the first operation mode is smaller than the power supplied to the resonant circuit in the second operation mode. (13) The aerosol generation system according to any one of (1) to (12), wherein the duration of the first operation mode is shorter than the duration of the second operation mode. (14) The aerosol generation system according to any one of (1) to (13), wherein the control unit variably sets the duration of the second operation mode. (15) The aerosol generation system according to any one of (1) to (14), further including the substrate, wherein the substrate further contains the susceptor.

[0095] REFERENCE SIGNS LIST 100 Suction device 111 Power supply unit 112 Sensor unit 113 Notification unit 114 Memory unit 115 Communication unit 116 Control unit 140 Storage unit 141 Internal space 142 Opening 143 Bottom 150 Stick-shaped substrate 151 Substrate unit 152 Suction nozzle unit 160 Resonant circuit 161 Susceptor 162 Electromagnetic induction source 163 Capacitor 164 Inverter circuit 165 FET

Claims

1. a container for containing a substrate containing an aerosol source; a resonant circuit including an electromagnetic induction source for inductively heating a susceptor disposed in thermal proximity to an aerosol source of the substrate contained in the container; a control unit that controls the operation of the resonant circuit to perform a process of generating an aerosol using the base material; Equipped with the control unit repeatedly switches the operation mode of the resonant circuit between a first operation mode and a second operation mode during the process of generating an aerosol using the base material; the first operating mode includes operating the resonant circuit at a frequency within a first frequency band; the second operating mode includes operating the resonant circuit at a frequency within a second frequency band; the first frequency band and the second frequency band are spaced apart; Aerosol generation systems.

2. the second frequency band includes a resonant frequency of the resonant circuit when the temperature of the susceptor is at a maximum temperature assumed in a process of generating an aerosol using the substrate; 10. The aerosol generating system of claim 1.

3. the second frequency band includes a resonant frequency of the resonant circuit when the temperature of the susceptor is the lowest temperature expected in a process of generating an aerosol using the substrate; 3. The aerosol generating system according to claim 1 or 2.

4. The first frequency band is a higher or lower frequency band than the second frequency band.

3. The aerosol generating system according to claim 1 or 2.

5. the control unit uses one fixed frequency included in the first frequency band in the first operation mode; 3. The aerosol generating system according to claim 1 or 2.

6. the control unit uses one fixed frequency included in the second frequency band in the second operation mode.

3. The aerosol generating system according to claim 1 or 2.

7. the control unit switches the first frequency band to a frequency band higher or lower than the second frequency band based on the electrical characteristics of the resonant circuit acquired in the first operation mode.

5. The aerosol generating system according to claim 4.

8. the control unit controls the operation of the resonant circuit in the second operation mode based on the electrical characteristics of the resonant circuit acquired in the first operation mode.

3. The aerosol generating system according to claim 1 or 2.

9. the resonant circuit further includes a capacitor; the control unit controls the operation of the resonant circuit in the second operation mode based on the voltage of the capacitor acquired in the first operation mode.

9. The aerosol generating system according to claim 8.

10. the control unit estimates a temperature of the susceptor based on the voltage of the capacitor acquired in the first operation mode, and controls the operation of the resonant circuit in the second operation mode based on the estimated temperature of the susceptor and a predetermined target temperature of the susceptor.

10. The aerosol generating system according to claim 9.

11. the control unit controls a duty ratio of a voltage applied to the resonant circuit in the second operation mode.

9. The aerosol generating system according to claim 8.

12. The power supplied to the resonant circuit in the first operating mode is less than the power supplied to the resonant circuit in the second operating mode.

3. The aerosol generating system according to claim 1 or 2.

13. the duration of the first operating mode is shorter than the duration of the second operating mode; 3. The aerosol generating system according to claim 1 or 2.

14. the control unit variably sets the duration of the second operation mode.

3. The aerosol generating system according to claim 1 or 2.

15. The aerosol generating system further comprises the substrate; The substrate further contains the susceptor.

3. The aerosol generating system according to claim 1 or 2.