Aerosol generation device

Abstract

Provided is an inhalation device (100) that generates aerosol by heating an aerosol source through induction-heating of a susceptor (Su), to which the aerosol source is provided in a manner enabling heating thereof, the inhalation device (100) comprising: a resonant circuit (80) that includes a resonant coil (81) and a resonant capacitor (82) and that induction-heats the susceptor (Su) by being supplied with electric power; a detection coil (91) that is disposed at a position where the detection coil (91) can be magnetically coupled with the resonant coil (81); and an MCU (30) as a control unit that is configured to be capable of acquiring a value related to the voltage of the detection coil (91) and that controls electric power supplied to the resonant circuit (80) on the basis of the value related to the voltage of the detection coil (91).

Description

Aerosol Generator

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

[0002] Conventionally, there have been known aerosol generating devices that generate aerosols containing, for example, flavor components and allow a user to inhale the generated aerosols. Typically, such aerosol generating devices generate the aerosol by heating an aerosol source with a heating unit that is an electric resistance heater or an induction heater.

[0003] The following Patent Documents 1 and 2 disclose techniques for determining apparent ohmic resistance from the DC power supply voltage and DC current of a DC power supply during operation, and determining the temperature of a susceptor of an aerosol-forming substrate from the apparent ohmic resistance.

[0004] Furthermore, Patent Document 3 listed below discloses a technology for controlling the heating of a susceptor of an aerosol generating device, in which the temperature of a susceptor inductively heated by an oscillator circuit is determined based on the resonant frequency or resonant capacitor voltage of the oscillator circuit driven by an inverter, and the output voltage transmitted from the boost converter to the inverter is set based on the determined temperature.

[0005] Japanese Patent Publication No. 2017-516269 Japanese Patent Publication No. 2020-038842 Japanese Patent Publication No. 2024-505975

[0006] However, the conventional technology has room for improvement in terms of enabling the susceptor to be appropriately induction heated with a simple configuration.

[0007] The present disclosure provides an aerosol generating device that has a simple configuration and is capable of appropriately inductively heating a susceptor.

[0008] One aspect of the present disclosure is an aerosol generating device that generates an aerosol by inductively heating a susceptor that is configured to be able to heat an aerosol source, the aerosol generating device comprising: a resonant circuit having a first coil and a first capacitor, which inductively heats the susceptor when power is supplied; a second coil positioned so that it can be magnetically coupled to the first coil; and a control unit configured to be able to acquire a value related to the voltage of the second coil, and which controls the power supplied to the resonant circuit based on the acquired value related to the voltage of the second coil.

[0009] According to the present disclosure, it is possible to provide an aerosol generating device that has a simple configuration and is capable of appropriately heating an aerosol source using a susceptor.

[0010] FIG. 1 is a schematic diagram showing a first configuration example of the inhalation device 100. FIG. 2 is a schematic diagram showing a second configuration example of the inhalation device 100. FIG. 3 is a diagram showing a first example of the circuit configuration of the inhalation device 100. FIG. 4 is a diagram showing a second example of the circuit configuration of the inhalation device 100. FIG. 5 is a diagram showing an example of a heating profile. FIG. 6 is a diagram showing an example of processing performed by the MCU 30 in each control cycle in a smoking session.

[0011] Hereinafter, one embodiment of the aerosol generating device of the present disclosure will be described in detail with reference to the drawings. The drawings should be read in the direction of the reference symbols. Note that not all elements described in the following embodiment are necessarily essential. Also, two or more elements described in the following embodiment can be arbitrarily combined. Hereinafter, identical or similar elements will be assigned identical or similar reference symbols, and their description may be omitted or simplified as appropriate.

[0012] 1. Configuration Example of Inhalation Device An inhalation device, which is an example of an aerosol generating device according to the present disclosure, 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.

[0013] (1-1. First Configuration Example of Inhalation Device) FIG. 1 is a schematic diagram showing a first configuration example of an inhalation device 100. As shown in FIG. 1, the inhalation device 100A of this configuration example includes a power supply unit 110, a cartridge 120, and a flavor imparting cartridge 130. The power supply unit 110 includes a power supply section 111A, a sensor section 112A, a notification section 113A, a memory section 114A, a communication section 115A, and a control section 116A. The cartridge 120 includes a heating section 121A, a liquid guiding section 122, and a liquid storage section 123. The flavor imparting cartridge 130 includes a flavor source 131 and a mouthpiece 124. An air flow path 180 is formed in the cartridge 120 and the flavor imparting cartridge 130.

[0014] The power supply unit 111A stores power. The power supply unit 111A supplies power to each component of the suction device 100A under the control of the control unit 116A. The power supply unit 111A may be configured to be rechargeable with power received from an external power source. Examples of the external power source include an AC (Alternating Current) adapter, a mobile charger, and a PC (Personal Computer). The power supply unit 111A is implemented by a rechargeable battery such as a lithium-ion secondary battery.

[0015] The sensor unit 112A acquires various types of information related to the suction device 100A. The sensor unit 112A is configured with, for example, a pressure sensor such as a condenser microphone, a flow rate sensor, or a temperature sensor, and acquires values ​​associated with the suction by the user.

[0016] As one example, sensor unit 112A may include a pressure sensor (also referred to as a "puff sensor") that detects a change in pressure (hereinafter also referred to as an "internal pressure") inside suction device 100A caused by the user's inhalation. As another example, sensor unit 112A may include a flow rate sensor that detects a flow rate (hereinafter also simply referred to as a "flow rate") caused by the user's inhalation. As another example, sensor unit 112A may include a temperature sensor (also referred to as a "puff thermistor") that detects the temperature of heating unit 121A or the vicinity of heating unit 121A.

[0017] The sensor unit 112A may also include an operation detection unit that detects user operations. In other words, the sensor unit 112A may also function as an input unit that accepts information input from the user. In this case, the sensor unit 112A may be configured to include an operation button, an operation switch, a motion sensor, a hall sensor, or the like.

[0018] The notification unit 113A notifies the user of information. The notification unit 113A may be configured, for example, by a light-emitting device that emits light, a display device that displays images, a sound output device that outputs sound, or a vibration device that vibrates. Here, the light-emitting device may be realized, for example, by a light-emitting element such as an LED (Light-Emitting Diode). The display device may be, for example, a liquid crystal display or an OLED display (OLED: Organic Light Emitting Diode). The sound output device may be, for example, a speaker. The vibration device may be, for example, a vibrator configured to include a motor and an eccentric weight attached to the rotation shaft of the motor.

[0019] The storage unit 114A stores various types of information (for example, programs and data) for the operation of the suction device 100 A. The storage unit 114A can be configured, for example, by a non-volatile storage medium such as a flash memory.

[0020] The communication unit 115A is a communication interface capable of performing communication in accordance with 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).

[0021] The control unit 116A functions as an arithmetic processing unit and a control unit, and controls the overall operation of the suction device 100A in accordance with programs stored in the memory unit 114A, etc. For example, the control unit 116A controls the supply of power from the power supply unit 111A to each component (e.g., the heating unit 121A described below) and the charging of the power supply unit 111A with power received from an external power source. The control unit 116A can be configured, for example, by an electronic circuit or the like including a CPU (Central Processing Unit) or a microprocessor (hereinafter also referred to as an "MCU (Micro Controller Unit)").

[0022] The liquid reservoir 123 stores an aerosol source. The aerosol source is atomized to generate an aerosol. The aerosol source is a liquid, such as a polyhydric alcohol, such as glycerin or propylene glycol, or water. The aerosol source may contain a tobacco-derived or non-tobacco-derived flavor component. When the inhalation device 100A is a medical inhaler, such as a nebulizer, the aerosol source may contain a drug.

[0023] The liquid guide portion 122 guides and holds the aerosol source, which is a liquid stored in the liquid storage portion 123, from the liquid storage portion 123. The liquid guide portion 122 is, for example, a wick formed by twisting a fiber material such as glass fiber or a porous material such as porous ceramic. In this case, the aerosol source stored in the liquid storage portion 123 is guided by the capillary effect of the wick.

[0024] The heating unit 121A generates an aerosol by, for example, heating the aerosol source to atomize the aerosol source. The heating unit 121A is configured in any shape, such as a coil, film, or blade, and is made of any material, such as metal or polyimide. In the example shown in FIG. 1 , the heating unit 121A is configured as a coil wound with a heating resistor, such as nichrome or stainless steel, and is wound around the liquid guiding unit 122. When the heating unit 121A generates heat, the aerosol source held in the liquid guiding unit 122 is heated and atomized, generating an aerosol. The heating unit 121A generates heat when power is supplied from the power supply unit 111A (hereinafter also referred to as "power supply").

[0025] As an example, power supply from power supply unit 111A to heating unit 121A may be performed when sensor unit 112A detects that the user has started inhaling and / or that predetermined information has been input. Then, when sensor unit 112A detects that the user has stopped inhaling and / or that predetermined information has been input, power supply to heating unit 121A may be stopped.

[0026] The heating unit 121A may be configured to generate aerosol by vibration or induction heating. When the aerosol is generated by vibration, the suction device 100A includes a vibration unit as the heating unit 121A. The vibration unit is configured, for example, by a plate-shaped member including piezoelectric ceramics that functions as an ultrasonic vibrator. When the vibration unit vibrates, the aerosol source guided to the surface of the vibration unit by the liquid guide unit 122 is atomized by ultrasonic waves generated by the vibration of the vibration unit, thereby generating the aerosol.

[0027] Furthermore, when aerosol generation is performed by induction heating, the suction device 100A includes a susceptor and an electromagnetic induction source as the heating unit 121A. The susceptor is made of a conductive material such as metal and generates heat through electromagnetic induction. The susceptor is disposed adjacent to the liquid guide unit 122. As an example, the susceptor is made of a metal conductor and is wound around the liquid guide unit 122. The electromagnetic induction source heats the susceptor through electromagnetic induction. The electromagnetic induction source is made of, for example, a coiled conductor and generates a magnetic field when an alternating current is supplied from the power supply unit 111A. When the magnetic field is generated, an eddy current is generated in the susceptor, generating Joule heat. The aerosol source held in the liquid guide unit 122 is heated and atomized by this Joule heat, generating the aerosol.

[0028] The flavor source 131 is a component for imparting flavor components to the aerosol. The flavor source 131 includes tobacco-derived or non-tobacco-derived flavor components. For example, the flavor source 131 may be a tobacco-derived product, such as a processed product obtained by molding shredded tobacco or tobacco raw materials into granules, sheets, or powder. The flavor source 131 may also include a non-tobacco-derived product made from plants other than tobacco (e.g., mint and herbs). For example, the flavor source 131 may include a flavor component such as menthol. The flavor source 131 may also be a stick-shaped member. When the inhalation device 100A is a medical inhaler, the flavor source 131 may include a medication for inhalation by the patient. Note that the flavor source 131 is not limited to a solid, but may also be a liquid containing flavor components such as polyhydric alcohols such as glycerin and propylene glycol, and water. The flavor source 131 may also be disposed inside a container such as a capsule.

[0029] The air flow path 180 is a path for air inhaled by the user. The air flow path 180 has a tubular structure with an air inlet 181, which is an entrance for air into the air flow path 180, and an air outlet 182, which is an exit for air from the air flow path 180, at both ends. A liquid guide section 122 is disposed on the upstream side (closer to the air inlet 181) of the air flow path 180, and a flavor source 131 is disposed on the downstream side (closer to the air outlet 182). Air flowing in through the air inlet 181 as the user inhales is mixed with the aerosol generated by the heating section 121A and, as shown by arrow 190, is transported through the flavor source 131 to the air outlet 182. When the mixed fluid of the aerosol and air passes through the flavor source 131, flavor components contained in the flavor source 131 are imparted to the aerosol.

[0030] Mouthpiece 124 is a member that is held in the mouth by the user when inhaling. Air outlet holes 182 are arranged in mouthpiece 124. By holding mouthpiece 124 in the mouth and inhaling, the user can take in the mixed fluid of the aerosol and air into the oral cavity.

[0031] The above describes an example of the configuration of the suction device 100A. Of course, the configuration of the suction device 100A is not limited to the above, and various configurations such as those exemplified below may be used.

[0032] As an example, the inhalation device 100A may not include the flavoring cartridge 130. In that case, the cartridge 120 is provided with the mouthpiece 124.

[0033] As another example, the inhalation device 100A may further include a flavor source heating unit (not shown) that heats the flavor source 131. The flavor source heating unit may be, for example, in the form of a film and arranged to cover the outer periphery of the flavor source 131. The flavor source heating unit generates heat when power is supplied from the power supply unit 111A, thereby heating the flavor source 131 from the outer periphery. The flavor source heating unit may be, for example, in the form of a blade that pierces the flavor source 131 and heats the flavor source 131 from the inside. The flavor source heating unit may also be configured to heat the flavor source 131 by vibration or induction heating. By providing such a flavor source heating unit, the temperature of the flavor source 131 can be increased compared to when a flavor source heating unit is not provided, thereby enabling an increase in the amount of flavor components imparted to the aerosol.

[0034] As another example, the inhalation device 100A may include multiple types of aerosol sources. Multiple types of aerosols generated from the multiple types of aerosol sources may be mixed in the air flow path 180 and undergo a chemical reaction to generate additional types of aerosols.

[0035] Furthermore, the means for atomizing the aerosol source is not limited to heating by the heating unit 121 A. For example, the means for atomizing the aerosol source may be vibration atomization or induction heating.

[0036] (1-2. Second Configuration Example of Suction Device) Fig. 2 is a schematic diagram showing a second configuration example of the suction device 100. As shown in Fig. 2, the suction device 100B of this configuration example includes a power supply unit 111B, a sensor unit 112B, a notification unit 113B, a memory unit 114B, a communication unit 115B, a control unit 116B, a heating unit 121B, a storage unit 140, and a heat insulating unit 144.

[0037] Each of the power supply unit 111B, sensor unit 112B, notification unit 113B, memory unit 114B, communication unit 115B, and control unit 116B is substantially the same as the corresponding component included in the suction device 100A described above.

[0038] 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.

[0039] 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 100B 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.

[0040] 2, the heating unit 121B is configured as a film heater with conductive tracks made of heating resistors whose electrical resistance value correlates with temperature, and is arranged to cover the outer periphery of the housing unit 140. When the heating unit 121B generates heat, the substrate unit 151 of the stick-shaped substrate 150 is heated from the outer periphery, generating an aerosol. Note that the heating resistor of the heating unit 121B can be the same as the heating resistor of the heating unit 121A described above.

[0041] The heat insulating section 144 prevents heat transfer from the heating section 121B to other components. For example, the heat insulating section 144 is made of a vacuum heat insulating material, an aerogel heat insulating material, or the like.

[0042] The above is a description of an example of the configuration of the suction device 100B. Of course, the configuration of the suction device 100B is not limited to the above, and various configurations such as those exemplified below may be used.

[0043] As one example, the heating unit 121B may be configured in a blade shape and disposed so as to protrude from the bottom 143 of the storage unit 140 into the internal space 141. In this case, the blade-shaped heating unit 121B is inserted into the substrate 151 of the stick-shaped substrate 150 and heats the substrate 151 of the stick-shaped substrate 150 from the inside. As another example, the heating unit 121B may be disposed so as to cover the bottom 143 of the storage unit 140. Furthermore, the heating unit 121B may be configured as a combination of two or more of a first heating unit covering the outer periphery of the storage unit 140, a blade-shaped second heating unit, and a third heating unit covering the bottom 143 of the storage unit 140.

[0044] As another example, the accommodation unit 140 may include an opening / closing mechanism such as a hinge that opens and closes a portion of the outer shell that forms the internal space 141. The accommodation unit 140 may then open and close the outer shell to accommodate the stick-shaped substrate 150 inserted into the internal space 141 while clamping it. In this case, the heating unit 121B may be provided at the clamping location in the accommodation unit 140 and heat the stick-shaped substrate 150 while pressing it.

[0045] Furthermore, the means for atomizing the aerosol source is not limited to heating by the heating unit 121B. For example, the means for atomizing the aerosol source may be induction heating. In that case, the suction device 100B has at least an electromagnetic induction source such as a coil that generates a magnetic field, instead of the heating unit 121B. A susceptor that generates heat by induction heating may be provided in the suction device 100B, or may be included in the stick-shaped substrate 150.

[0046] Furthermore, the suction device 100B may further include the heating unit 121A, the liquid guide unit 122, the liquid storage unit 123, and the air flow path 180 according to the first configuration example, and the air flow path 180 may supply air to the internal space 141. In this case, the mixed fluid of the aerosol and air generated by the heating unit 121A flows into the internal space 141 and is further mixed with the aerosol generated by the heating unit 121B, and reaches the oral cavity of the user.

[0047] In the following description, the suction device 100A and the suction device 100B will be referred to as the "suction device 100" without distinction. Similarly, the power supply unit 111A and the power supply unit 111B may be referred to as the "power supply unit 111," the sensor unit 112A and the sensor unit 112B as the "sensor unit 112," the notification unit 113A and the notification unit 113B as the "notification unit 113," the memory unit 114A and the memory unit 114B as the "memory unit 114," the communication unit 115A and the communication unit 115B as the "communication unit 115," the control unit 116A and the control unit 116B as the "control unit 116," and the heating unit 121A and the heating unit 121B as the "heating unit 121."

[0048] 2. Circuit Configuration of Suction Device Next, the circuit configuration of the suction device 100 will be described.

[0049] (2-1. First Example of Circuit Configuration of Suction Device) FIG. 3 is a diagram showing a first example of the circuit configuration of the suction device 100. The example shown in FIG. 3 is an example in which the suction device 100 is the suction device 100B shown in FIG. 2, and aerosol is generated by induction heating a susceptor Su that is provided so as to be able to heat an aerosol source. Here, the susceptor Su is realized, for example, by a plate- or rod-shaped metal that extends along the longitudinal direction of the stick-shaped substrate 150 and is arranged inside the stick-shaped substrate 150 (more specifically, inside the substrate portion 151). Furthermore, the susceptor Su may be realized, for example, by a metal that is arranged so as to cover at least a portion of the outer periphery of the accommodation portion 140.

[0050] As shown in FIG. 3 , the suction device 100 includes, for example, a battery 10 which is an example of a power supply unit 111, an LDO 20 (LDO: Low Drop Out), an MCU 30 which is an example of a control unit 116, a first DC / DC converter 40 (DC: Direct Current), a second DC / DC converter 50, a gate driver 60, a drive circuit 70, a resonance circuit 80, and a detection circuit 90.

[0051] Here, the MCU 30, the first DC / DC converter 40, the second DC / DC converter 50, and the gate driver 60 are each realized by an integrated circuit (IC) that integrates a plurality of electronic components, such as resistors, capacitors, and transistors. Furthermore, the ground terminals (e.g., low-potential power supply terminals) of the ICs that realize the MCU 30, the first DC / DC converter 40, the second DC / DC converter 50, and the gate driver 60 are electrically connected (hereinafter simply referred to as "connected") to a ground GND having a predetermined reference potential. This allows the MCU 30, the first DC / DC converter 40, the second DC / DC converter 50, and the gate driver 60 to operate based on the reference potential of the ground GND (in other words, a common reference potential), and the reference potential of the ground GND can be treated as 0 V, for example.

[0052] The battery 10 is a DC power supply that outputs a predetermined voltage, and is realized by, for example, a lithium-ion secondary battery. Hereinafter, the output voltage of the battery 10 will also be referred to as the "battery voltage Vbat." The battery voltage Vbat can be set to, for example, 3.5 to 4.0 V. The battery 10 is connected to each of the LDO 20, the first DC / DC converter 40, and the second DC / DC converter 50, and supplies the battery voltage Vbat to these.

[0053] The LDO regulator 20 is a linear regulator that receives the battery voltage Vbat, generates a constant voltage lower than the battery voltage Vbat, and outputs the generated constant voltage. Hereinafter, the output voltage of the LDO regulator 20 will also be referred to as the "first system voltage Vsys1." The first system voltage Vsys1 may be, for example, 3.3 V, which is suitable as a power supply voltage for the MCU 30. The LDO regulator 20 is connected to the MCU 30 and supplies the first system voltage Vsys1 to the MCU 30. This allows a stable first system voltage Vsys1 to be supplied to the MCU 30, thereby stabilizing the operation of the MCU 30.

[0054] Note that a step-up / step-down circuit (e.g., a step-up / step-down DC / DC converter) may be provided instead of the LDO regulator 20. In this case, the step-up / step-down circuit generates the first system voltage Vsys1 by boosting the battery voltage Vbat if the supplied battery voltage Vbat is lower than a voltage (e.g., 3.3 V) suitable for use as a power supply voltage for the MCU 30. On the other hand, the step-up / step-down circuit generates the first system voltage Vsys1 by lowering the battery voltage Vbat if the battery voltage Vbat is higher than the suitable power supply voltage for the MCU 30. In this way, an appropriate first system voltage Vsys1 can be supplied to the MCU 30, regardless of whether the battery voltage Vbat is higher or lower than the suitable power supply voltage for the MCU 30, thereby stabilizing the operation of the MCU 30.

[0055] The MCU 30 is a controller (i.e., a computer) that operates when the first system voltage Vsys1 is supplied as a power supply voltage and performs predetermined processing. As will be described in detail later, the MCU 30, for example, acquires a value related to a detection coil voltage VL2, which is the voltage across both ends of a detection coil 91 included in the detection circuit 90, and performs processing to control the power supplied to the resonance circuit 80 based on the acquired value related to the detection coil voltage VL2. As an example of processing to control the power supplied to the resonance circuit 80, the MCU 30 may output a predetermined control signal (i.e., an instruction) to a gate driver 60 that drives a switch included in a drive circuit 70 (described later).

[0056] The first DC / DC converter 40 is a switching regulator that receives the battery voltage Vbat, generates a predetermined voltage different from the battery voltage Vbat, and outputs the generated predetermined voltage. The first DC / DC converter 40 may be used in combination with a power inductor (not shown). Hereinafter, the output voltage of the first DC / DC converter 40 is also referred to as a "power system voltage Vheat." The power system voltage Vheat may be, for example, a voltage lower than a second system voltage Vsys2 (described later).

[0057] The first DC / DC converter 40 is connected to the drive circuit 70 that supplies power to the resonant circuit 80, or to the resonant circuit 80 itself, and supplies the power system voltage Vheat to the connected drive circuit 70 or the resonant circuit 80. For example, as shown in FIG. 3 , when the first DC / DC converter 40 is connected to the drive circuit 70, the first DC / DC converter 40 supplies the power system voltage Vheat to the drive circuit 70.

[0058] The first DC / DC converter 40 generates a stable (for example, constant) power system voltage Vheat from the battery voltage Vbat, which may fluctuate depending on the remaining charge of the battery 10, and outputs the power system voltage Vheat. As a result, even if the battery voltage Vbat fluctuates, the stable power system voltage Vheat can be supplied to the resonant circuit 80, and the resonant circuit 80 can appropriately perform induction heating of the susceptor Su.

[0059] As an example, the first DC / DC converter 40 generates a power system voltage Vheat having a voltage value higher than the battery voltage Vbat by boosting the supplied battery voltage Vbat. In this case, the power system voltage Vheat may be set to, for example, 5.0 V. In this way, when the power system voltage Vheat is set higher than the battery voltage Vbat, the temperature of the susceptor Su can be increased more quickly than when the power system voltage Vheat is set lower than the battery voltage Vbat.

[0060] As another example, the first DC / DC converter 40 may generate a power system voltage Vheat having a voltage value lower than the battery voltage Vbat by stepping down the supplied battery voltage Vbat. In this case, the power system voltage Vheat may be set to, for example, 3.0 V. In this manner, when the power system voltage Vheat is set lower than the battery voltage Vbat, it is possible to reduce the power consumption by the resonant circuit 80 when inductively heating the susceptor Su compared to when the power system voltage Vheat is set higher than the battery voltage Vbat.

[0061] The second DC / DC converter 50 is a switching regulator that receives the battery voltage Vbat, generates a predetermined voltage different from the battery voltage Vbat, and outputs the generated predetermined voltage. The second DC / DC converter 50 may be used in combination with a power inductor (not shown). Hereinafter, the output voltage of the second DC / DC converter 50 is also referred to as a "second system voltage Vsys2." The second system voltage Vsys2 may be, for example, a voltage higher than the first system voltage Vsys1 and the power system voltage Vheat. The second DC / DC converter 50 is connected to the gate driver 60 and supplies the second system voltage Vsys2 to the gate driver 60.

[0062] The second DC / DC converter 50 generates a stable second system voltage Vsys2 from the fluctuating battery voltage Vbat, similar to the first DC / DC converter 40, and outputs the second system voltage Vsys2. As a result, even if the battery voltage Vbat fluctuates, the stable second system voltage Vsys2 can be supplied to the gate driver 60, allowing the gate driver 60 to operate appropriately.

[0063] As an example, the second DC / DC converter 50 boosts the supplied battery voltage Vbat to generate a second system voltage Vsys2 having a voltage value higher than the battery voltage Vbat. In this case, the second system voltage Vsys2 may be set to, for example, 5.8 V, which is suitable as a power supply voltage for the gate driver 60. However, the present invention is not limited to this, and the second DC / DC converter 50 may also generate a second system voltage Vsys2 having a voltage value lower than the battery voltage Vbat.

[0064] The gate driver 60 is an IC that drives a switch included in the drive circuit 70 based on an instruction (in other words, a control signal) from the MCU 30. The switch included in the drive circuit 70 may be, for example, a switch that turns on and off the power supply to the resonant circuit 80. In other words, the drive circuit 70 may be a circuit that has a switch that turns on and off the power supply to the resonant circuit 80 based on an instruction from the MCU 30. An example of the switch included in the drive circuit 70 is a field-effect transistor. In other words, the drive circuit 70 may be a circuit that has one or more field-effect transistors and controls the power supply to the resonant circuit 80 by turning these field-effect transistors on and off.

[0065] 3, the drive circuit 70 is configured as a half-bridge inverter circuit having a first FET (FET: Field Effect Transistor) 71 as a high-side switch and a second FET 72 as a low-side switch. Here, the first FET 71 and the second FET 72 are described as N-channel MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), but they may be other types of switching elements (for example, P-channel MOSFETs).

[0066] The first FET 71, which is a high-side switch, has a drain terminal connected to the first DC / DC converter 40 and a source terminal connected to the drain terminal of the second FET 72. The source terminal of the second FET 72, which is a low-side switch, is connected to ground GND. The gate terminals of the first FET 71 and the second FET 72 are each connected to the gate driver 60. In addition, a connection point 70a, which is connected to the resonant circuit 80, is provided between the first FET 71 (more specifically, the source terminal of the first FET 71) and the second FET 72 (more specifically, the drain terminal of the second FET 72) in the drive circuit 70.

[0067] In the example shown in Figure 3, the MCU 30 is configured to be able to output, for example, a control signal as an instruction regarding the switching of the first FET 71 and a control signal as an instruction regarding the switching of the second FET 72 to the gate driver 60 independently. Then, the MCU 30 instructs the gate driver 60 to, for example, alternately place the first FET 71 and the second FET 72 in a conductive state. In accordance with this instruction, the gate driver 60 controls the gate voltages applied to the gate terminals of the first FET 71 and the second FET 72, respectively, to drive the first FET 71 and the second FET 72 so that the first FET 71 and the second FET 72 alternately place the first FET 71 and the second FET 72 in a conductive state. As a result, in the example shown in Figure 3, AC power can be generated by the drive circuit 70 configured as an inverter circuit, and this AC power can be supplied to the resonant circuit 80.

[0068] When driving the first FET 71 and the second FET 72, a drive voltage based on the second system voltage Vsys2 can be supplied to these gate terminals. That is, the gate driver 60 can drive the first FET 71 and the second FET 72 by supplying the second system voltage Vsys2 generated by the second DC / DC converter 50 to the gate terminals of the first FET 71 and the second FET 72. By supplying the drive voltage based on the second system voltage Vsys2 to the first FET 71 and the second FET 72, it becomes possible to apply a voltage sufficiently exceeding a so-called "threshold voltage Vth" between the gate terminal and source terminal of the first FET 71 and the second FET 72, and it becomes possible to appropriately drive the first FET 71 and the second FET 72.

[0069] The resonant circuit 80 is a circuit that inductively heats the susceptor Su when power is supplied to it. That is, when power is supplied to the resonant circuit 80, it functions as an electromagnetic induction source and causes the susceptor Su to generate heat through electromagnetic induction.

[0070] 3, the resonant circuit 80 has a resonant coil 81 and a resonant capacitor 82 connected in series to form an LC series resonant circuit. In this case, one end of the resonant coil 81 is connected to the connection point 70a of the drive circuit 70, and the other end is connected to one end of the resonant capacitor 82. The other end of the resonant capacitor 82 is connected to ground GND.

[0071] The resonance coil 81 is realized by, for example, a coil-shaped (e.g., spiral) conducting wire wound around the outer periphery of the housing portion 140, and generates a magnetic field when an alternating current is supplied. When the magnetic field is generated, an eddy current is generated in the susceptor Su, generating Joule heat. This Joule heat heats the aerosol source of the stick-shaped substrate 150 housed in the housing portion 140, generating an aerosol.

[0072] The resonant frequency varies depending on the inductance of the resonant coil 81 and the capacitance of the resonant capacitor 82 that constitute the resonant circuit 80. A relatively large current may flow through the resonant capacitor 82, which is prone to heat generation. For this reason, the resonant capacitor 82 is preferably configured as a temperature-compensating capacitor. Here, a temperature-compensating capacitor is a capacitor whose capacitance changes less with temperature than a high-dielectric-constant capacitor. More specifically, it may be a capacitor that meets the "Class 1" requirements defined by JIS (Japanese Industrial Standards) and EIA (Energy Information Administration). By configuring the resonant capacitor 82 as a temperature-compensating capacitor, it is possible to suppress changes in the resonant frequency (i.e., the resonance point) of the resonant circuit 80 due to changes in the capacitance of the resonant capacitor 82, even if the resonant capacitor 82 generates heat. Therefore, even if the resonant capacitor 82 generates heat, the susceptor Su can be appropriately inductively heated.

[0073] The detection circuit 90 is a circuit that has a detection coil 91, which is a coil that is arranged in a position that allows it to be magnetically coupled to the resonance coil 81. The detection circuit 90 also has, for example, a diode D as an example of a rectifying element, and a detection capacitor 92 that is connected to the detection coil 91 via the diode D.

[0074] In this case, one end of the detection coil 91 is connected to ground GND, and the other end is connected to the anode terminal of the diode D. One end of the detection capacitor 92 is connected to the cathode terminal of the diode D and the MCU 30, and the other end is connected to ground GND. This allows the voltage across the detection capacitor 92 (hereinafter also referred to as the "detection capacitor voltage VC") to be input to the MCU 30. In other words, the MCU 30 can acquire the detection capacitor voltage VC.

[0075] The detection coil 91 is realized by, for example, a coiled conductor wound around the outer periphery of the housing 140 in the same manner as the resonance coil 81, and is magnetically coupled to the resonance coil 81 when power is supplied to the resonance circuit 80. The detection coil 91 generates an AC voltage according to the voltage across the resonance coil 81 (hereinafter also referred to as the "resonance coil voltage VL1"), the primary number of turns n1 which is the number of turns of the resonance coil 81, and the secondary number of turns n2 which is the number of turns of the detection coil 91.

[0076] The AC voltage generated by the detection coil 91 is also referred to hereinafter as the "detection coil voltage VL2." The detection coil voltage VL2 decreases as the secondary winding number n2 (i.e., the number of windings of the detection coil 91) decreases relative to the primary winding number n1 (i.e., the number of windings of the resonant coil 81). Therefore, by adjusting the secondary winding number n2, the manufacturer of the suction device 100 can obtain the desired detection coil voltage VL2 without changing the resonant coil voltage VL1 or the primary winding number n1, that is, without changing the characteristics of the induction heating coil. In other words, the manufacturer of the suction device 100 can appropriately determine the voltage range that the detection coil voltage VL2 can take by adjusting the secondary winding number n2.

[0077] The primary winding number n1 (i.e., the number of windings of the resonance coil 81) and the secondary winding number n2 (i.e., the number of windings of the detection coil 91) may be equal to or different from each other, which allows the primary winding number n1 and the secondary winding number n2 to be set to appropriate numbers of windings taking into account the roles of the resonance coil 81 and the detection coil 91, respectively.

[0078] For example, if the number of secondary turns n2 is made smaller than the number of primary turns n1, the size of the detection coil 91 can be reduced, making it possible to easily install the detection coil 91 while preventing the suction device 100 from becoming larger. Furthermore, by making the number of secondary turns n2 smaller than the number of primary turns n1, the voltage value input to the MCU 30 as the value related to the detection coil voltage VL2 can be reduced without providing a voltage divider circuit or the like in the circuit portion that inputs the value related to the detection coil voltage VL2 to the MCU 30 (for example, between the detection capacitor 92 described below and the MCU 30). Therefore, the configuration of the suction device 100 can be simplified.

[0079] Furthermore, because the resonance coil 81 is a coil for induction heating, it is difficult to properly inductively heat the susceptor Su unless a certain large current flows through it. In contrast, because the detection coil 91 is not a coil for induction heating, it is not a problem if a larger current flows through it than through the resonance coil 81. Therefore, the conductors constituting the detection coil 91 may be thinner than those constituting the resonance coil 81. In other words, the diameter of the conductors constituting the detection coil 91 may be smaller than the diameter of the conductors constituting the resonance coil 81. In this way, by making the conductors constituting the detection coil 91 thinner than those constituting the resonance coil 81, the detection coil 91 can be made smaller, which makes it possible to easily install the detection coil 91 while preventing the suction device 100 from becoming larger.

[0080] Furthermore, in suction device 100, a configuration is also conceivable in which MCU 30 acquires a detection value relating to detection coil voltage VL2 via an A / D converter or the like. In such a configuration, the manufacturer of suction device 100 may determine the voltage range of detection coil voltage VL2 (i.e., the number of secondary turns n2) taking into consideration a reference value used by the A / D converter for A / D conversion of the detection value. For example, by adjusting the voltage range of detection coil voltage VL2 so that the reference value of the A / D converter and the peak value that detection coil voltage VL2 can take are somewhat close, it is possible to improve the resolution when A / D converting the detection value relating to detection coil voltage VL2.

[0081] Furthermore, if the primary winding number n1 (i.e., the number of windings of the resonant coil 81) and the secondary winding number n2 (i.e., the number of windings of the detection coil 91) were the same, the peak value of the detection coil voltage VL2 might be smaller than the reference value of the A / D converter. In such a case, it is preferable to make the secondary winding number n2 larger than the primary winding number n1. By making the secondary winding number n2 larger than the primary winding number n1, the value of the detection coil voltage VL2 can be increased without an amplifier such as an operational amplifier, compared to when the secondary winding number n2 is the same as the primary winding number n1. In this way, by adjusting the voltage range of the detection coil voltage VL2 so that the reference value of the A / D converter and the peak value of the detection coil voltage VL2 are somewhat close, it is possible to reduce the size of the suction device 100 with a simple configuration that does not require an amplifier, and improve the resolution when A / D converting the detection value related to the detection coil voltage VL2.

[0082] However, it should be noted that the present invention is not limited to the examples described here, and a voltage divider circuit may be provided in the circuit portion that inputs the value related to the detection coil voltage VL2 to the MCU 30, or an amplifier may be provided that amplifies the value related to the detection coil voltage VL2. In other words, the voltage divider circuit and / or amplifier may be provided in the suction device 100 (e.g., the detection circuit 90) as needed.

[0083] In this embodiment, the MCU 30 acquires the detection capacitor voltage VC of the detection capacitor 92 connected to the detection coil 91 as a value related to the detection coil voltage VL2. That is, when power is supplied to the resonant circuit 80, the detection coil voltage VL2 periodically fluctuates with a predetermined amplitude, similar to the resonant coil voltage VL1. The detection capacitor voltage VC then takes on a voltage value corresponding to the peak value (in other words, the maximum positive value) of the detection coil voltage VL2, which periodically fluctuates with the predetermined amplitude.

[0084] Therefore, the MCU 30 can obtain the peak value of the detection coil voltage VL2 based on the obtained detection capacitor voltage VC. As an example, if the voltage value of the detection capacitor voltage VC is approximately the same as the peak value of the detection coil voltage VL2, the MCU 30 may obtain the detection capacitor voltage VC as the peak value of the detection coil voltage VL2.

[0085] As another example, information (e.g., a table) or a formula that can derive the peak value of the detection coil voltage VL2 from the voltage value of the detection capacitor voltage VC may be prepared in advance, and the MCU 30 may derive the peak value of the detection coil voltage VL2 based on this information or formula and the acquired detection capacitor voltage VC. In this way, even if the voltage value of the detection capacitor voltage VC deviates slightly from the peak value of the detection coil voltage VL2, the MCU 30 can accurately obtain the peak value of the detection coil voltage VL2 based on the acquired detection capacitor voltage VC.

[0086] It is preferable to use a capacitor with a relatively small capacitance as the detection capacitor 92. For example, the capacitance of the detection capacitor 92 is preferably smaller than the capacitance of the resonant capacitor 82. In this way, by using a capacitor with a small capacitance as the detection capacitor 92, it is possible to prevent the detection capacitor voltage VC from not rising appropriately when power is supplied to the resonant circuit 80, compared to when a capacitor with a large capacitance is used as the detection capacitor 92. Therefore, the MCU 30 can easily and accurately obtain the peak value of the detection coil voltage VL2 based on the obtained detection capacitor voltage VC.

[0087] The resonant coil voltage VL1 (e.g., the peak value of the resonant coil voltage VL1) correlates with the susceptor temperature, which is the temperature of the susceptor Su. The detection coil voltage VL2 also correlates with the resonant coil voltage VL1. Therefore, the detection coil voltage VL2 also correlates with the susceptor temperature. As an example, in this embodiment, the peak value of the detection coil voltage VL2 and the susceptor temperature are positively correlated, and the higher the peak value of the detection coil voltage VL2, the higher the susceptor temperature. However, this is not limiting, and the suction device 100 may be configured so that the detection capacitor voltage VC and the susceptor temperature are negatively correlated.

[0088] In this way, since the detection coil voltage VL2 is correlated with the susceptor temperature, the MCU 30 can perform induction heating taking into account the susceptor temperature by controlling the power supplied to the resonant circuit 80 based on the peak value of the detection coil voltage VL2.

[0089] Furthermore, for example, if information (e.g., a table) or a calculation formula showing the correlation between the peak value of the detection coil voltage VL2 and the susceptor temperature is prepared in advance, the MCU 30 can derive the susceptor temperature from the peak value of the detection coil voltage VL2. Therefore, in this case, the MCU 30 can control the power supplied to the resonant circuit 80 based on the susceptor temperature derived from the detection coil voltage VL2, and induction heating can be performed taking the susceptor temperature into consideration.

[0090] The detection circuit 90 also includes, for example, a reset circuit 93. The reset circuit 93 is a circuit that discharges the detection capacitor 92 based on an instruction from the MCU 30. For example, as shown in FIG. 3 , the reset circuit 93 includes a resistor 94 and an FET 95. The resistor 94 has a predetermined electrical resistance and is connected in parallel with the detection capacitor 92. The FET 95 is connected between the resistor 94 and ground GND and is a switch that opens and closes based on an instruction from the MCU 30. The FET 95 is implemented, for example, by an N-channel MOSFET. Note that the FET 95 is not limited to an N-channel MOSFET and may be another type of switching element.

[0091] When the FET 95 of the reset circuit 93 is turned on, one end of the detection capacitor 92 is connected to the ground GND via the resistor 94 of the reset circuit 93. This allows the detection capacitor 92 to be discharged. The reset circuit 93 is not an essential component and may be omitted.

[0092] (2-2. Second Example of Circuit Configuration of Suction Device) Next, a second example of the circuit configuration of the suction device 100 will be described. In the following, for the sake of brevity, the description will focus on the differences from the first example shown in Figure 3, and the description of the same parts as in the first example shown in Figure 3 will be appropriately simplified or omitted.

[0093] Fig. 4 is a diagram showing a second example of the circuit configuration of the suction device 100. As shown in Fig. 4, this second example differs from the first example shown in Fig. 3 in the configurations of the drive circuit 70 and the resonant circuit 80.

[0094] 4 , the resonant circuit 80 is configured as an LC parallel resonant circuit in which a resonant coil 81 and a resonant capacitor 82 are connected in parallel. The drive circuit 70 also has a second FET 72 as a low-side switch that turns on and off the power supply to the resonant circuit 80. Of the connection points between the resonant coil 81 and the resonant capacitor 82 connected in parallel, one connection point 80b is connected to the first DC / DC converter 40, and the other connection point 80c is connected to ground GND via the second FET 72.

[0095] In the second example of the suction device 100 shown in FIG. 4 , the MCU 30 instructs the gate driver 60 to, for example, turn on and off the second FET 72 at a predetermined duty. The gate driver 60 repeatedly turns on and off the second FET 72 in accordance with this instruction. In this way, in the case of the second example shown in FIG. 4 , when the second FET 72 is repeatedly turned on and off, an alternating current flows through the resonant circuit 80, generating a magnetic field. When a magnetic field is generated, an eddy current is generated in the susceptor Su, generating Joule heat. This Joule heat heats the aerosol source of the stick-shaped substrate 150, generating an aerosol.

[0096] Note that, although the inhalation device 100 has been described herein as the inhalation device 100B shown in Fig. 2, this is not limiting. For example, the same can be applied to the case where the inhalation device 100 is the inhalation device 100A shown in Fig. 1. In this case, the susceptor Su is provided so as to be able to heat, for example, the aerosol source stored in the liquid storage unit 123 or the aerosol source held by the liquid guide unit 122. Alternatively or additionally, the susceptor Su may be provided so as to be able to heat the flavor source 131.

[0097] 3 and 4 are merely examples, and the present invention is not limited to these. For example, the resonant circuit 80 may be any circuit capable of inductively heating the susceptor Su, and is not limited to the configurations shown in Fig. 3 or 4. Similarly, the drive circuit 70 may be any circuit capable of supplying power to the resonant circuit 80 based on instructions from the MCU 30, and is not limited to the configurations shown in Fig. 3 or 4.

[0098] 3. Specific Examples of Control by MCU Next, a description will be given of specific examples of control by the MCU 30. The MCU 30, which is an example of the control unit 116, causes the inhalation device 100 to generate an aerosol in response to a request for aerosol generation from a user.

[0099] Here, the aerosol generation request can be, for example, an operation to instruct the start of heating (hereinafter also referred to as a "heating start operation"). As an example, the heating start operation can be pressing a predetermined operation button (not shown) provided on the suction device 100. Furthermore, the heating start operation is not limited to pressing an operation button, and can also be inserting the stick-shaped substrate 150 into the storage unit 140, suctioning into the suction device 100, receiving predetermined information from another device such as a smartphone, or the like. The MCU 30 can detect the aerosol generation request based on information acquired by, for example, the sensor unit 112 or the communication unit 115.

[0100] When the MCU 30 detects a request for aerosol generation, it generates aerosol, for example, by inductively heating the susceptor Su. For example, during a period (hereinafter also referred to as a "smoking session") from the time the request for aerosol generation is detected until a predetermined time (e.g., 300 seconds) has elapsed or a predetermined number of inhalations (e.g., 15 inhalations) have been performed, the MCU 30 inductively heats the susceptor Su and generates aerosol by controlling the power supplied to the resonant circuit 80 so that the detection coil voltage VL2 (e.g., the peak value of the detection coil voltage VL2) or the susceptor temperature derived based on the detection coil voltage VL2 changes in a predetermined manner. Information indicating how the detection coil voltage VL2 or the susceptor temperature changes during the smoking session is pre-stored in the MCU 30 as, for example, a "heating profile." The heating profile is typically designed to optimize the flavor experienced by the user when inhaling the aerosol generated by the inhalation device 100. Therefore, by generating aerosol based on a heating profile, the flavor enjoyed by the user can be optimized, providing the user with a high-quality smoking experience.

[0101] 5 is a diagram showing an example of a heating profile. In FIG. 5, the horizontal axis represents time [s] elapsed from the start of a smoking session. The vertical axis represents the detection coil voltage VL2 [mV]. For example, the MCU 30 controls the power supplied to the resonant circuit 80 during a smoking session based on the heating profile 500 shown in FIG. 5.

[0102] 5, in the heating profile 500, the target voltage of the detection coil voltage VL2 during the period from 0 [s] to t1 [s] (where t1>0) after the start of the smoking session is Vtgt2 [mV]. The target voltage of the detection coil voltage VL2 during the period from t1 [s] to t2 [s] (where t2>t1) is Vtgt4 [mV]. The target voltage of the detection coil voltage VL2 during the period from t2 [s] to t3 [s] (where t3>t2) is Vtgt0 [mV]. The target voltage of the detection coil voltage VL2 during the period from t3 [s] to t4 [s] (where t4>t3) is Vtgt2 [mV].

[0103] In addition, in the heating profile 500, the target voltage of the detection coil voltage VL2 during the period from t4 [s] to t5 [s] (where t5 > t4) after the start of the smoking session is set to Vtgt4 [mV]. The target voltage of the detection coil voltage VL2 during the period from t5 [s] to t6 [s] (where t6 > t5) is set to Vtgt0 [mV]. The target voltage of the detection coil voltage VL2 during the period from t6 [s] to t7 [s] (where t7 > t6) is set to Vtgt3 [mV]. The target voltage of the detection coil voltage VL2 during the period from t7 [s] to t8 [s] (where t8 > t7) is set to Vtgt1 [mV]. The magnitude relationship between the target voltages is, for example, Vtgt0<Vtgt1<Vtgt2<Vtgt3<Vtgt4, as shown in FIG.

[0104] When the susceptor Su is induction heated based on this heating profile 500, the MCU 30 controls the power supplied to the resonant circuit 80 so that the detection coil voltage VL2 is Vtgt2 [mV] during the period from 0 [s] to t1 [s] after the start of the smoking session. The MCU 30 also controls the power supplied to the resonant circuit 80 so that the detection coil voltage VL2 is Vtgt2 [mV] during the period from t1 [s] to t2 [s] after the start of the smoking session. Similarly, in the following periods, the MCU 30 controls the power supplied to the resonant circuit 80 based on the target voltage of the detection coil voltage VL2 corresponding to each period.

[0105] To achieve this control, the MCU 30 needs to periodically acquire the detection coil voltage VL2 during the smoking session. Therefore, the MCU 30 performs a VL2 check process to acquire the detection coil voltage VL2 at a predetermined control period during the smoking session.

[0106] FIG. 6 is a diagram showing an example of processing performed by the MCU 30 at each control period during a smoking session. In FIG. 6, the horizontal axis represents time (ms) elapsed since the start of the smoking session. The vertical axis represents the detection coil voltage VL2 (mV). Note that the following description of FIG. 6 is based on an example in which the detection coil voltage VL2 and the susceptor temperature have a positive correlation (i.e., the higher the susceptor temperature, the higher the detection coil voltage VL2).

[0107] 6, during a smoking session, the MCU 30 performs a VL2 check process and a heating process in each control period, for example, 50 ms. An example of the VL2 check process and the heating process will be described in detail below.

[0108] First, an example of the VL2 check process will be described. In the VL2 check process, the MCU 30, for example, first discharges the detection capacitor 92 using the reset circuit 93. More specifically, the MCU 30 discharges the detection capacitor 92 by turning on the FET 95 of the reset circuit 93 for a predetermined time. Here, the predetermined time is determined in advance by the manufacturer of the suction device 100, taking into account, for example, the time required to completely discharge the detection capacitor 92.

[0109] When the discharge of the detection capacitor 92 is completed, the MCU 30 drives the switch of the drive circuit 70 via the gate driver 60 at a first duty for a first time (see the time indicated by symbol T1 in Figure 6), thereby supplying power to the resonant circuit 80 for the first time.

[0110] Here, the first duty is preferably smaller than the second duty used in the heating process described below in order to prevent the susceptor temperature from rising due to the power supply to the resonant circuit 80 in the VL2 check process. An example of the first duty, taking these circumstances into consideration, is 10%. Furthermore, the first time is preferably set to a relatively short time in order to prevent the susceptor temperature from rising due to the power supply to the resonant circuit 80 in the VL2 check process. An example of the first time, taking these circumstances into consideration, is 8 ms. The first duty and the first time are each determined in advance by, for example, the manufacturer of the suction device 100.

[0111] While the switch of the drive circuit 70 is being driven at the first duty, the MCU 30 monitors the detection capacitor voltage VC during this period based on the voltage input from the detection capacitor 92 to the MCU 30. Then, the MCU 30 acquires, for example, the highest value of the detection capacitor voltage VC during this period as the detection coil voltage VL2 for the current VL2 check process (in other words, for the current control cycle).

[0112] Here, the MCU 30 acquires the highest value of the detection capacitor voltage VC while the switch of the drive circuit 70 is being driven at the first duty as the detection coil voltage VL2 for the current VL2 check process, but this is not limited to this. For example, after a second time (e.g., 2 ms) shorter than the first time has elapsed since the switch of the drive circuit 70 began to be driven at the first duty, the MCU 30 may acquire the average value of the detection capacitor voltage VC from the time the switch of the drive circuit 70 began to be driven at the first duty until the first time has elapsed as the detection coil voltage VL2 for the current VL2 check process.

[0113] Next, an example of a heating process will be described. In the heating process, the MCU 30 determines the time for supplying power to the resonant circuit 80 in the current heating process (hereinafter also referred to as the "heating time") based on, for example, the detection coil voltage VL2 acquired by a VL2 check process performed in the same control cycle as the heating process (in other words, the VL2 check process performed immediately before) and the target voltage determined by the heating profile 500.

[0114] For example, if the target voltage corresponding to the period during which the current heating control is performed in heating profile 500 is lower than the detection coil voltage VL2 obtained by the VL2 check process performed immediately before the heating process, MCU 30 determines a relatively short heating time (see the time indicated by symbol T2 in FIG. 6).

[0115] On the other hand, if the target voltage corresponding to the period during which the current heating control is performed in heating profile 500 is higher than the detection coil voltage VL2 obtained by the VL2 check process performed immediately before the heating process, MCU 30 determines a relatively long heating time (see the time indicated by symbol T3 in FIG. 6).

[0116] The heating time when the target voltage is lower than the detection coil voltage VL2 and the heating time when the target voltage is higher than the detection coil voltage VL2 are each determined in advance by, for example, the manufacturer of the suction device 100.

[0117] Once the heating time has been determined, the MCU 30 drives the switch of the drive circuit 70 at the second duty via the gate driver 60 for the heating time, thereby supplying power to the resonant circuit 80 for the heating time. More specifically, the MCU 30 drives the switch of the drive circuit 70 at the second duty from a time equal to the heating time before the end of the current control cycle until the end of the current control cycle, thereby supplying power to the resonant circuit 80 for the heating time. Note that the second duty is preferably set to a relatively large value so that the susceptor temperature can be quickly increased by the power supply to the resonant circuit 80 during the heating process. Taking these circumstances into consideration, an example of the second duty is 50%.

[0118] Although the example described here is one in which the MCU 30 performs the heating process based on the heating profile 500 that defines the target voltage for the detection coil voltage VL2 during a smoking session, the present invention is not limited to this. For example, the heating profile 500 may define a target temperature for the susceptor during a smoking session instead of the target voltage for the detection coil voltage VL2. In this case, the MCU 30 derives the susceptor temperature from the detection coil voltage VL2 acquired in each control cycle and supplies power to the resonant circuit 80 for a heating time corresponding to the susceptor temperature.

[0119] 4. Effects of the Present Embodiment As described above, the suction device 100 of the present embodiment includes a resonance circuit 80 that has a resonance coil 81 and a resonance capacitor 82 and that inductively heats the susceptor Su when power is supplied thereto, a detection coil 91 that is disposed in a position that allows magnetic coupling with the resonance coil 81, and an MCU 30 as an example of a control unit 116. The MCU 30 is configured to be able to acquire a value related to a detection coil voltage VL2 that is the voltage of the detection coil 91, and controls the power supplied to the resonance circuit 80 based on the acquired value related to the detection coil voltage VL2. This allows the susceptor Su to be inductively heated with a simple configuration, taking into account the susceptor temperature that is the temperature of the susceptor Su, and enables the aerosol source to be appropriately heated by the susceptor Su.

[0120] Furthermore, the primary number of turns n1, which is the number of turns of the resonance coil 81, and the secondary number of turns n2, which is the number of turns of the detection coil 91, may be different from each other. In this way, the primary number of turns n1 and the secondary number of turns n2 can be set to appropriate numbers of turns taking into account the roles of the resonance coil 81 and the detection coil 91, respectively.

[0121] Furthermore, the number of secondary turns n2 may be smaller than the number of primary turns n1. In this way, the detection coil 91 can be made smaller than when the number of secondary turns n2 is equal to or larger than the number of primary turns n1, and therefore the detection coil 91 can be easily installed while preventing the suction device 100 from becoming larger.

[0122] Furthermore, the conductors constituting the detection coil 91 may be thinner than the conductors constituting the resonance coil 81. In this way, the detection coil 91 can be made smaller than when the conductors constituting the detection coil 91 are thicker than the conductors constituting the resonance coil 81. This makes it possible to easily install the detection coil 91 while preventing the suction device 100 from becoming larger.

[0123] Furthermore, resonance coil 81 and detection coil 91 may be configured by conductors wound around the outer periphery of storage section 140, which stores stick-shaped substrate 150 including the aerosol source. In this way, resonance coil 81 and detection coil 91 can be configured as concentric circles centered on storage section 140, allowing resonance coil 81 and detection coil 91 to be arranged by efficiently utilizing limited space, and making it possible to prevent suction device 100 from becoming larger.

[0124] 3, the resonant circuit 80 may be configured as an LC series resonant circuit in which a resonant coil 81 and a resonant capacitor 82 are connected in series. In this case, the suction device 100 may include a drive circuit 70 as an inverter circuit that converts DC power into AC power and supplies the AC power to the resonant circuit 80 based on instructions from the MCU 30. In this way, the susceptor Su can be appropriately induction-heated even if the voltage supplied to the resonant circuit 80 is lowered, compared to when the resonant circuit 80 is configured as an LC parallel resonant circuit in which the resonant coil 81 and the resonant capacitor 82 are connected in parallel (in other words, when DC power is supplied to the resonant circuit 80).

[0125] Furthermore, the drive circuit 70 as an inverter circuit may have a first FET 71 and a second FET 72 (i.e., field-effect transistors) as switches. In this case, the suction device 100 may include a gate driver 60 that drives the first FET 71 and the second FET 72 based on instructions from the MCU 30. In this way, even if the MCU 30 cannot directly drive the first FET 71 and the second FET 72 due to hardware factors or the like, it is possible to appropriately drive the first FET 71 and the second FET 72.

[0126] 4, the resonant circuit 80 may be configured as an LC parallel resonant circuit in which the resonant coil 81 and the resonant capacitor 82 are connected in parallel. In this case, the suction device 100 may include a drive circuit 70 having a second FET 72 as a switch that turns on and off the power supply to the resonant circuit 80 based on instructions from the MCU 30. This configuration reduces the number of switches (e.g., FETs) required to configure the drive circuit 70, compared to when the resonant circuit 80 is configured as an LC series resonant circuit in which the resonant coil 81 and the resonant capacitor 82 are directly connected (in other words, when AC power is supplied to the resonant circuit 80), thereby simplifying the drive circuit 70. Even in this case, the suction device 100 may include a gate driver 60 that drives the second FET 72 based on instructions from the MCU 30, thereby enabling the second FET 72 to be appropriately driven even when the MCU 30 is unable to directly drive the second FET 72 due to hardware or other factors.

[0127] The suction device 100 may further include a detection capacitor 92 connected to the detection coil 91 via a diode D serving as a rectifying element. In this case, the MCU 30 may acquire the detection capacitor voltage VC, which is the voltage of the detection capacitor 92, as a value related to the detection coil voltage VL2. This allows the MCU 30 to acquire the detection coil voltage VL2 (e.g., the peak value of the detection coil voltage VL2) that has a correlation with the susceptor temperature with a simple configuration.

[0128] The suction device 100 may also include a reset circuit 93 that discharges the detection capacitor 92 based on an instruction from the MCU 30. This prevents the detection capacitor voltage VC from remaining high due to the power supply to the resonant circuit 80. Therefore, the MCU 30 can easily and accurately obtain the detection coil voltage VL2 (e.g., the peak value of the detection coil voltage VL2) based on the obtained detection capacitor voltage VC.

[0129] The reset circuit 93 may also include a resistor 94 connected in parallel to the detection capacitor 92, and an FET 95 that serves as a switch that is connected between the ground GND and the resistor 94 and opens and closes in response to an instruction from the MCU 30. In this way, the reset circuit 93 can be realized with a simple configuration.

[0130] 5 and 6, the MCU 30 may acquire a value related to the detection coil voltage VL2 at a predetermined control period and control the power supplied to the resonant circuit 80 so that the detection coil voltage VL2 or the susceptor temperature derived based on the detection coil voltage VL2 changes in a predetermined manner. In this way, the flavor experienced by the user inhaling the aerosol generated by the inhalation device 100 can be optimized, providing the user with a high-quality smoking experience.

[0131] Furthermore, in each control cycle, the MCU 30 may obtain the detection coil voltage VL2 based on the detection capacitor voltage VC obtained when the reset circuit 93 discharges the detection capacitor 92 and then supplies a predetermined power to the resonance circuit 80. In this way, it becomes possible to obtain the detection coil voltage VL2 under the same conditions for each control cycle.

[0132] Furthermore, the MCU 30 may determine the power to be supplied to the resonant circuit 80 in each control cycle based on the detection coil voltage VL2 acquired in that control cycle. In this way, it becomes possible to supply appropriate power to the resonant circuit 80 in each control cycle, taking into account the detection coil voltage VL2 (i.e., the susceptor temperature) acquired in that control cycle.

[0133] Furthermore, for example, the detection coil 91, the detection capacitor 92, and the MCU 30 are each connected to ground GND having a predetermined reference potential, so that a common reference potential is applied to the detection coil 91, the detection capacitor 92, and the MCU 30. This eliminates the need for the MCU 30 to take into account deviations in the reference potentials of the detection coil 91, the detection capacitor 92, and the MCU 30 when acquiring the detection coil voltage VL2, making it possible to easily acquire the detection coil voltage VL2.

[0134] Furthermore, the resonant capacitor 82 is configured by, for example, a temperature compensation capacitor. This makes it possible to suppress changes in the resonant frequency of the resonant circuit 80 caused by changes in the capacitance of the resonant capacitor 82 even if the resonant capacitor 82 generates heat. Therefore, even if the resonant capacitor 82 generates heat, it is possible to appropriately inductively heat the susceptor Su.

[0135] Although one embodiment of the aerosol generating device of the present disclosure has been described above, it goes without saying that the present disclosure is not limited to such an embodiment. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiment may be combined in any manner without departing from the spirit of the invention.

[0136] As an example, in the above-described embodiment, a common reference potential is applied to each of the detection coil 91, the detection capacitor 92, and the MCU 30, but this is not limiting. For example, the reference potential applied to the MCU 30 may be different from the reference potential applied to the detection coil 91 and / or the detection capacitor 92. In this case, information or the like representing the difference between the reference potential applied to the MCU 30 and the reference potential applied to the detection coil 91 and / or the detection capacitor 92 is stored in advance in the MCU 30, and the MCU 30 determines the difference in the reference potentials based on this information or the like and acquires the detection coil voltage VL2 taking this difference into consideration.

[0137] This specification and the like describes at least the following: In parentheses, components corresponding to those in the above-described embodiments are shown as examples, but the present invention is not limited to these.

[0138] (1) An aerosol generating device (suction device 100) that generates an aerosol by inductively heating a susceptor (susceptor Su) that is provided so as to be able to heat an aerosol source, the aerosol generating device comprising: a resonant circuit (resonant circuit 80) having a first coil (resonant coil 81) and a first capacitor (resonant capacitor 82) and that inductively heats the susceptor when power is supplied; a second coil (detection coil 91) that is positioned so as to be magnetically coupled to the first coil; and a control unit (control unit 116, 116A, 116B, MCU 30) that is configured to be able to acquire a value related to the voltage of the second coil (detection coil voltage VL2), and that controls the power supplied to the resonant circuit based on the acquired value related to the voltage of the second coil.

[0139] According to (1), the susceptor can be induction heated with a simple configuration, taking into account the susceptor temperature, and the aerosol source can be appropriately heated by the susceptor.

[0140] (2) The aerosol generating device according to (1), wherein the number of turns of the first coil (number of primary turns n1) and the number of turns of the second coil (number of secondary turns n2) are different from each other.

[0141] According to (2), the number of turns of the first coil and the number of turns of the second coil can be set to an appropriate number of turns taking into consideration the role of each of the first coil and the second coil.

[0142] (3) The aerosol generating device according to (2), wherein the number of turns of the second coil is smaller than the number of turns of the first coil.

[0143] According to (3), the second coil can be made smaller than when the number of turns of the second coil is greater than or equal to the number of turns of the first coil, making it possible to easily install the second coil while preventing the aerosol generating device from becoming larger.

[0144] (4) The aerosol generating device according to (2), wherein the number of turns of the second coil is greater than the number of turns of the first coil.

[0145] According to (4), compared to when the number of turns of the first coil and the number of turns of the second coil are the same, the voltage value of the second coil can be increased without providing an amplifier such as an operational amplifier, etc. This allows the aerosol generating device to be downsized with a simple configuration that does not require an amplifier, etc., and enables the control unit to obtain a highly accurate value related to the voltage of the second coil.

[0146] (5) The aerosol generating device according to (1), wherein the number of turns of the second coil is equal to the number of turns of the first coil.

[0147] According to (5), when the voltage supplied to the first coil is relatively close to the reference value of the A / D converter that detects the voltage of the second coil, the control unit can obtain an accurate value for the voltage of the second coil while miniaturizing the aerosol generating device with a simple configuration that does not require an amplifier, voltage divider circuit, etc.

[0148] (6) The aerosol generating device according to any one of (1) to (5), wherein the conducting wire constituting the second coil is thinner than the conducting wire constituting the first coil.

[0149] According to (6), the second coil can be made smaller than when the conducting wire constituting the second coil is made thicker than the conducting wire constituting the first coil, so that the second coil can be easily installed while preventing the aerosol generating device from becoming larger.

[0150] (7) The aerosol generating device according to any one of (1) to (6), wherein the first coil and the second coil are configured by conductive wires wound around the outer periphery of a storage section (storage section 140) that stores a substrate (stick-shaped substrate 150) including the aerosol source.

[0151] According to (7), the first coil and the second coil can be configured as concentric circles centered on the storage section, so that the first coil and the second coil can be arranged by efficiently utilizing limited space, and it is possible to prevent the aerosol generating device from becoming larger.

[0152] (8) An aerosol generating device according to any one of (1) to (7), wherein the resonant circuit is configured by connecting the first coil and the first capacitor in series, and the aerosol generating device further includes a drive circuit as an inverter circuit that converts DC power into AC power and supplies it to the resonant circuit based on an instruction from the control unit.

[0153] According to (8), compared to when the resonant circuit is an LC parallel resonant circuit in which the first coil and the first capacitor are connected in parallel, it is possible to appropriately inductively heat the susceptor even if the voltage supplied to the resonant circuit is lowered.

[0154] (9) The aerosol generating device according to (8), wherein the inverter circuit has a field effect transistor as a switch, and the aerosol generating device further includes a gate driver that drives the field effect transistor based on an instruction from the control unit.

[0155] According to (9), even when the control unit cannot directly drive the switches of the drive circuit serving as an inverter circuit due to hardware factors or the like, it is possible to appropriately drive the switches of the drive circuit.

[0156] (10) An aerosol generating device according to any one of (1) to (7), wherein the resonant circuit is configured by connecting the first coil and the first capacitor in parallel, and the aerosol generating device further includes a drive circuit having a switch that turns on and off the power supply to the resonant circuit based on an instruction from the control unit.

[0157] According to (10), compared to when the resonant circuit is an LC series resonant circuit in which the first coil and the first capacitor are directly connected, the number of switches required to configure the drive circuit can be reduced, thereby simplifying the drive circuit.

[0158] (11) The aerosol generating device according to (10), wherein the switch is configured by a field effect transistor, and the aerosol generating device further includes a gate driver that drives the field effect transistor based on an instruction from the control unit.

[0159] According to (11), even when the control unit cannot directly drive the switches of the drive circuit due to hardware factors or the like, it is possible to appropriately drive the switches of the drive circuit.

[0160] (12) The aerosol generating device according to any one of (1) to (11), further comprising a second capacitor connected to the second coil via a rectifying element, and the control unit acquires the voltage of the second capacitor as a value related to the voltage of the second coil.

[0161] According to (12), the control unit can acquire the voltage of the second coil (for example, the peak value of the voltage of the second coil) that is correlated with the temperature of the susceptor with a simple configuration.

[0162] (13) The aerosol generation device according to (12), further comprising a reset circuit that discharges the second capacitor based on an instruction from the control unit.

[0163] According to (13), it is possible to prevent the voltage of the second capacitor from remaining high due to the power supply to the resonant circuit, and therefore the control unit can easily and accurately obtain the voltage of the second coil based on the obtained voltage of the second capacitor.

[0164] (14) The aerosol generating device according to (13), wherein the reset circuit has: a resistor connected in parallel to the second capacitor; and a switch connected between ground and the resistor, which opens and closes in response to the instruction.

[0165] According to (14), the reset circuit can be realized with a simple configuration.

[0166] (15) The aerosol generating device according to any one of (12) to (14), wherein the control unit acquires the voltage of the second coil based on the voltage of the second capacitor at a predetermined control period, and controls the power supplied to the resonant circuit so that the voltage of the second coil or the temperature of the susceptor derived based on the voltage of the second coil changes in a predetermined manner.

[0167] According to (15), the flavor experienced by a user who inhales the aerosol generated by the aerosol generating device can be optimized, thereby providing the user with a high-quality smoking experience.

[0168] (16) The aerosol generating device according to (15), further comprising a reset circuit that discharges the second capacitor based on an instruction from the control unit, and in each control cycle, the aerosol generating device acquires the voltage of the second coil based on the voltage of the second capacitor when a predetermined power is supplied to the resonant circuit after the second capacitor is discharged by the reset circuit.

[0169] According to (16), it is possible to obtain the voltage of the second coil based on the voltage of the second capacitor under the same conditions for each control period.

[0170] (17) The aerosol generating device according to (16), wherein the control unit determines the power to be supplied to the resonant circuit in each control cycle based on the voltage of the second coil acquired in that control cycle.

[0171] According to (17), in each control cycle, it is possible to supply appropriate power to the resonant circuit, taking into account the voltage of the second coil acquired in that control cycle.

[0172] 30 MCU (control unit) 60 Gate driver 70 Drive circuit 71 First FET (switch) 72 Second FET (switch) 80 Resonant circuit 81 Resonant coil (first coil) 82 Resonant capacitor (first capacitor) 91 Detection coil (second coil) 92 Detection capacitor (second capacitor) 93 Reset circuit 94 Resistor 95 FET (switch) 100 Suction device 116A, 116B, 116 Control unit D Diode (rectifying element) Su Susceptor

Claims

1. An aerosol generating device that generates an aerosol by inductively heating a susceptor provided so as to be able to heat an aerosol source, the aerosol generating device comprising: a resonant circuit having a first coil and a first capacitor, which inductively heats the susceptor when power is supplied; a second coil positioned so as to be magnetically coupled to the first coil; and a control unit configured to be able to acquire a value related to the voltage of the second coil, and which controls the power supplied to the resonant circuit based on the acquired value related to the voltage of the second coil.

2. An aerosol generating device according to claim 1, wherein the number of turns of the first coil and the number of turns of the second coil are different from each other.

3. An aerosol generating device according to claim 2, wherein the number of turns of the second coil is smaller than the number of turns of the first coil.

4. An aerosol generating device according to claim 2, wherein the number of turns of the second coil is greater than the number of turns of the first coil.

5. An aerosol generating device according to claim 1, wherein the number of turns of the second coil is equal to the number of turns of the first coil.

6. An aerosol generating device according to any one of claims 1 to 4, wherein the conducting wire constituting the second coil is thinner than the conducting wire constituting the first coil.

7. An aerosol generating device according to any one of claims 1 to 5, wherein the first coil and the second coil are constituted by conductive wires wound around the outer periphery of a storage section that stores a substrate containing the aerosol source.

8. An aerosol generating device according to any one of claims 1 to 6, wherein the resonant circuit is configured by connecting the first coil and the first capacitor in series, and the aerosol generating device further comprises a drive circuit serving as an inverter circuit that converts DC power into AC power and supplies it to the resonant circuit based on instructions from the control unit.

9. An aerosol generating device according to any one of claims 1 to 6, wherein the resonant circuit is configured by connecting the first coil and the first capacitor in parallel, and the aerosol generating device further comprises a drive circuit having a switch that turns on and off the power supply to the resonant circuit based on instructions from the control unit.

10. An aerosol generating device according to any one of claims 1 to 9, further comprising a second capacitor connected to the second coil via a rectifying element, and the control unit acquires the voltage of the second capacitor as a value related to the voltage of the second coil.

11. An aerosol generating device according to claim 10, further comprising a reset circuit that discharges the second capacitor based on an instruction from the control unit.

12. An aerosol generating device according to claim 11, wherein the reset circuit comprises: a resistor connected in parallel with the second capacitor; and a switch connected between ground and the resistor, which opens and closes in response to the instruction.

13. An aerosol generating device according to any one of claims 10 to 12, wherein the control unit acquires the voltage of the second coil based on the voltage of the second capacitor at a predetermined control period, and controls the power supplied to the resonant circuit so that the voltage of the second coil or the temperature of the susceptor derived based on the voltage of the second coil changes in a predetermined manner.

14. An aerosol generating device as described in claim 13, further comprising a reset circuit that discharges the second capacitor based on instructions from the control unit, and in each control cycle, the voltage of the second coil is obtained based on the voltage of the second capacitor when a predetermined power is supplied to the resonant circuit after the second capacitor is discharged by the reset circuit.

15. An aerosol generating device according to claim 14, wherein the control unit determines the power to be supplied to the resonant circuit in each control cycle based on the voltage of the second coil acquired in that control cycle.

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