Aerosol generation device

Abstract

An inhalation device (100) comprises: a first DC / DC converter (40) that generates, from a battery voltage, a power system voltage different from the battery voltage; a second DC / DC converter (50) that generates, from the battery voltage, a second system voltage different from the battery voltage and the power system voltage; a resonance circuit (80) that inductively heats a susceptor (Su) by being supplied with electrical power; and a drive circuit (70) that has a field effect transistor such as a first FET (71) and controls the electrical power supply to the resonance circuit (80) by turning on and off the field effect transistor. The electrical power based on the power system voltage is supplied to the resonance circuit (80). However, a drive voltage based on the second system voltage is supplied to the field effect transistor of the drive circuit (70).

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 Document 1 discloses a technology in which an AC current is supplied to an LC circuit by controlling the timing of supplying a switching potential to each field effect transistor provided in a driver device connected to the LC circuit including an induction element (e.g., a coil) that inductively heats a susceptor.

[0004] Japan Special Table No. 2021-506248

[0005] However, in the conventional technology, there is room for improvement in terms of appropriately inductively heating the susceptor by the resonant circuit while suppressing an increase in the size of the coil of the resonant circuit and, consequently, an increase in the size of the aerosol generating device.

[0006] The present disclosure provides an aerosol generation device that can appropriately inductively heat a susceptor using a resonant circuit while suppressing an increase in the size of the coil of the resonant circuit and, consequently, an increase in the size of the aerosol generation device.

[0007] One aspect of the present disclosure is an aerosol generation device that generates an aerosol by inductively heating a susceptor that is configured to be able to heat an aerosol source, thereby heating the aerosol source, the aerosol generation device comprising: a battery; a first converter that generates a first voltage from a battery voltage that is an output voltage of the battery, the first voltage being different from the battery voltage; a second converter that generates a second voltage from the battery voltage, the second voltage being different from the battery voltage and the first voltage; a resonant circuit that has a coil and a first capacitor and inductively heats the susceptor when power is supplied; and a drive circuit that has one or more field effect transistors and controls the power supply to the resonant circuit by turning the field effect transistors on and off, wherein the resonant circuit is supplied with power based on the first voltage, and the field effect transistor is supplied with a drive voltage based on the second voltage.

[0008] According to the present disclosure, it is possible to provide an aerosol generation device that can appropriately inductively heat a susceptor using a resonant circuit while suppressing an increase in the size of the coil of the resonant circuit and therefore an increase in the size of the aerosol generation device.

[0009] 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. FIG. 7 is a diagram showing an example of the outline of the circuit configuration of the inhalation device 100 of a first modified example. FIG. 8 is a diagram showing a portion of the circuit configuration of the inhalation device 100 of a second modified example.

[0010] Hereinafter, embodiments 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 embodiments are necessarily essential. Furthermore, two or more elements described in the following embodiments can be arbitrarily combined. Hereinafter, identical or similar elements will be denoted by identical or similar reference symbols, and their description may be omitted or simplified as appropriate.

[0011] 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.

[0012] (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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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).

[0020] 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)").

[0021] 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.

[0022] 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.

[0023] 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").

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] (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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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."

[0047] 2. Circuit Configuration of Suction Device Next, the circuit configuration of the suction device 100 will be described.

[0048] (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.

[0049] 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, a detection circuit 90, and a voltage divider circuit 95.

[0050] 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.

[0051] 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 outputs the battery voltage Vbat to these.

[0052] 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.

[0053] 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.

[0054] 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 is configured to be able to acquire values ​​related to the state of the resonant circuit 80, and performs processing to control the power supply to the resonant circuit 80 via the drive circuit 70 based on the acquired values ​​related to the state of the resonant circuit 80.

[0055] Here, the value relating to the state of the resonant circuit 80 may be a value representing the heating state of the susceptor Su by the resonant circuit 80, and may be, for example, a value relating to the voltage and / or current generated in the resonant circuit 80. As an example, in this embodiment, the MCU 30 acquires a value relating to the voltage of a detection capacitor 91 (hereinafter also referred to as a "detection capacitor voltage VC"), which will be described later, as the value relating to the state of the resonant circuit 80.

[0056] Here, the value related to the detection capacitor voltage VC may be the detection capacitor voltage VC itself, or a value correlated with the detection capacitor voltage VC, in other words, a value that enables the detection capacitor voltage VC to be derived. An example of a value that enables the detection capacitor voltage VC to be derived is a voltage divided by a voltage divider circuit 95, which will be described later.

[0057] Furthermore, as an example of a process for controlling the power supply to the resonant circuit 80, the MCU 30 may perform a process of outputting a predetermined control signal (in other words, an instruction) to a gate driver 60 that drives a switch included in the drive circuit 70 described below.

[0058] 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).

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Furthermore, the power system voltage Vheat may be variable. In a case where the power system voltage Vheat is variable, for example, the MCU 30 is connected to the first DC / DC converter 40 and configured to be able to control the first DC / DC converter 40. The first DC / DC converter 40 generates the power system voltage Vheat, which is a voltage instructed by the MCU 30. As an example, if the instruction value from the MCU 30 is 4.0 [V], the first DC / DC converter 40 may generate 4.0 [V] as the power system voltage Vheat. As another example, if the instruction value from the MCU 30 is 5.0 [V], the first DC / DC converter 40 may generate 5.0 [V] as the power system voltage Vheat. In this way, even when the power system voltage Vheat is variable, it is preferable to set the upper limit voltage that the power system voltage Vheat can take to, for example, 5.0 V, so that the power system voltage Vheat is a voltage lower than the second system voltage Vsys2.

[0064] However, it should be noted that the power system voltage Vheat does not need to be constantly maintained at a voltage lower than the second system voltage Vsys2. As an example, during a single smoking session, the power system voltage Vheat may be lower than the second system voltage Vsys2 in some cases and higher than the second system voltage Vsys2 in other cases. In other words, during a specific period included in a single smoking session, the power system voltage Vheat may be temporarily higher than the second system voltage Vsys2. Alternatively, the power system voltage Vheat may be lower than the second system voltage Vsys2 throughout the entire single smoking session.

[0065] In this specification, a smoking session refers to a period of time during which heating control is performed to consume the aerosol source contained in one article (e.g., one stick-shaped substrate 150 stored in the storage unit 140). In other words, a smoking session can also be referred to as a heating period during which the aerosol source is heated by the heating unit 121, and can be, for example, a period during which heating control is performed based on the heating profile 500 described below.

[0066] 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.

[0067] When an aerosol source is heated by induction heating to generate aerosol, a higher-output inverter circuit may be required compared to when an aerosol source is heated by a resistance heater to generate aerosol. Such a high-output inverter circuit may use a high-voltage field-effect transistor. To drive such a high-voltage field-effect transistor, a relatively high voltage may be required as the voltage applied to the gate terminal (i.e., gate voltage). Therefore, during the period when heating control for generating aerosol is being performed (i.e., the smoking session), the second system voltage Vsys2 is preferably maintained at a relatively high voltage capable of driving the field-effect transistors (e.g., the first FET 71 and the second FET 72 described below) of the inverter circuit.

[0068] The gate driver 60 is an IC that drives the switches of the drive circuit 70 based on instructions (in other words, control signals) from the MCU 30. The switches of the drive circuit 70 are, for example, one or more field-effect transistors. That is, the drive circuit 70 can 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.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] The detection circuit 90 is a circuit having a detection capacitor 91, which is a capacitor connected to the resonant capacitor 82 via a rectifying element. For example, as shown in FIG. 3 , the detection capacitor 91 is connected to a connection point 80a provided between the resonant coil 81 and the resonant capacitor 82 in the resonant circuit 80 via a diode D functioning as a rectifying element. More specifically, in this case, the anode terminal of the diode D is connected to the connection point 80a, and the cathode terminal is connected to one end of the detection capacitor 91. The other end of the detection capacitor 91 is connected to ground GND. Note that the detection circuit 90 may be configured to further include other elements, such as an operational amplifier, in addition to the detection capacitor 91 and diode D described herein.

[0078] The detection capacitor voltage VC, which is the voltage across the detection capacitor 91 connected to the resonant capacitor 82 via the diode D that functions as a rectifying element, correlates with the resonant capacitor voltage, which is the voltage across the resonant capacitor 82. More specifically, when power is supplied to the resonant circuit 80, the detection capacitor voltage VC takes on a voltage value corresponding to the peak value (in other words, the maximum positive value) of the resonant capacitor voltage, which fluctuates periodically with a predetermined amplitude.

[0079] Furthermore, the resonant capacitor voltage is correlated with the susceptor temperature, which is the temperature of the susceptor Su. Therefore, the detection capacitor voltage VC, which is correlated with the resonant capacitor voltage, is also correlated with the susceptor temperature. As an example, in this embodiment, the detection capacitor voltage VC and the susceptor temperature are positively correlated, and the higher the susceptor temperature, the higher the detection capacitor voltage VC. 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.

[0080] It is preferable to use a capacitor with a relatively small capacitance as the detection capacitor 91. For example, the capacitance of the detection capacitor 91 is preferably smaller than the capacitance of the resonant capacitor 82. By using a capacitor with a small capacitance as the detection capacitor 91 in this way, the influence of the detection capacitor 91 on the resonant circuit 80 can be reduced compared to when a capacitor with a large capacitance is used as the detection capacitor 91, and it is possible to prevent a situation in which the detection capacitor voltage VC does not increase appropriately when power is supplied to the resonant circuit 80.

[0081] The detection circuit 90 also includes, for example, a reset circuit 92. The reset circuit 92 is a circuit that discharges the detection capacitor 91 based on an instruction from the MCU 30. For example, as shown in FIG. 3 , the reset circuit 92 includes a resistor 93 and an FET 94. The resistor 93 has a predetermined electrical resistance and is connected in parallel with the detection capacitor 91. The FET 94 is connected between the resistor 93 and ground GND and is a switch that opens and closes based on an instruction from the MCU 30. The FET 94 is implemented, for example, by an N-channel MOSFET. Note that the FET 94 is not limited to an N-channel MOSFET and may be another type of switching element.

[0082] When the FET 94 of the reset circuit 92 is turned on, one end of the detection capacitor 91 is connected to the ground GND via the resistor 93 of the reset circuit 92. This allows the detection capacitor 91 to be discharged. The reset circuit 92 is not an essential component and may be omitted.

[0083] The voltage divider circuit 95 is provided in parallel with the detection capacitor 91 and divides the detection capacitor voltage VC. For example, as shown in FIG. 3 , the voltage divider circuit 95 includes resistors 96 and 97 connected in series. Here, the resistors 96 and 97 are resistors each having a predetermined electrical resistance value. One end of the resistor 96 is connected to one end of the detection capacitor 91. The other end of the resistor 96 is connected to one end of the resistor 97. The other end of the resistor 97 is connected to ground GND. In the voltage divider circuit 95, a connection point 95a provided between the resistors 96 and 97 is connected to the MCU 30.

[0084] In this case, the voltage obtained by dividing the detection capacitor voltage VC using resistors 96 and 97 of the voltage-dividing circuit 95 is input to the MCU 30. This allows the MCU 30 to obtain the voltage divided by the voltage-dividing circuit 95 as a value related to the detection capacitor voltage VC. The electrical resistance values ​​of resistors 96 and 97 are known. Therefore, the MCU 30 can derive (i.e., obtain) the detection capacitor voltage VC from the voltage divided by the voltage-dividing circuit 95 and the electrical resistance values ​​of resistors 96 and 97.

[0085] As described above, the detection capacitor voltage VC and the susceptor temperature are correlated. Therefore, for example, by preparing information (e.g., a table) or a calculation formula that indicates the correlation between the detection capacitor voltage VC and the susceptor temperature in advance, the MCU 30 can derive the susceptor temperature based on the detection capacitor voltage VC.

[0086] The voltage divider circuit 95 is not an essential component and may be omitted. For example, if there is no problem with the hardware of the MCU 30 even if the detection capacitor voltage VC is input directly to the MCU 30, the voltage divider circuit 95 may be omitted and the detection capacitor voltage VC may be input directly to the MCU 30.

[0087] (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.

[0088] 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.

[0089] More specifically, in the second example shown in Fig. 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 parallel-connected resonant coil 81 and the resonant capacitor 82, 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. In this case, the detection capacitor 91 of the detection circuit 90 is connected via a diode D to a connection point 70b provided between the resonant circuit 80 (more specifically, the connection point 80c) and the second FET 72.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] When the MCU 30 detects a request for generating an aerosol, the MCU 30 generates the aerosol, for example, by inductively heating the susceptor Su. As an example, the MCU 30 controls the power supplied to the resonant circuit 80 so that the detection capacitor voltage VC or the susceptor temperature derived based on the detection capacitor voltage VC changes in a predetermined manner during a period from the time the request for generating an aerosol is detected until a predetermined time (e.g., 300 seconds) has elapsed or a predetermined number of suctions (e.g., 15 times) have been performed, thereby inductively heating the susceptor Su and generating the aerosol.

[0096] Here, the period during which aerosol is generated in this manner, i.e., the period from when a request for aerosol generation is detected until a predetermined time has elapsed or a predetermined number of puffs have been taken, corresponds to the smoking session. Information indicating how the detection capacitor voltage VC or the susceptor temperature changes during a 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 the user inhales the aerosol generated by the inhalation device 100. Therefore, by generating aerosol based on the heating profile, the flavor experienced by the user can be optimized, providing the user with a high-quality smoking experience.

[0097] 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 capacitor voltage VC [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.

[0098] 5, in the heating profile 500, the target voltage of the detection capacitor voltage VC in the section S1 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 capacitor voltage VC in the section S2 from t1 [s] to t2 [s] (where t2>t1) is Vtgt4 [mV]. The target voltage of the detection capacitor voltage VC in the section S3 from t2 [s] to t3 [s] (where t3>t2) is Vtgt0 [mV]. The target voltage of the detection capacitor voltage VC in the section S4 from t3 [s] to t4 [s] (where t4>t3) is Vtgt2 [mV].

[0099] In addition, in the heating profile 500, the target voltage of the detection capacitor voltage VC in the section S5, where the elapsed time from the start of the smoking session is from t4 [s] to t5 [s] (where t5 > t4), is Vtgt4 [mV]. The target voltage of the detection capacitor voltage VC in the section S6, where t5 [s] to t6 [s] (where t6 > t5) is Vtgt0 [mV]. The target voltage of the detection capacitor voltage VC in the section S7, where t6 [s] to t7 [s] (where t7 > t6) is Vtgt3 [mV]. The target voltage of the detection capacitor voltage VC in the section S8, where t7 [s] to t8 [s] (where t8 > t7) is Vtgt1 [mV]. The magnitude relationship between the target voltages is, for example, Vtgt0<Vtgt1<Vtgt2<Vtgt3<Vtgt4, as shown in FIG.

[0100] 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 capacitor voltage VC is Vtgt2 [mV] during the period from 0 [s] to t1 [s] after the start of the smoking session (i.e., the period corresponding to section S1). The MCU 30 also controls the power supplied to the resonant circuit 80 so that the detection capacitor voltage VC is Vtgt2 [mV] during the period from t1 [s] to t2 [s] after the start of the smoking session (i.e., the period corresponding to section S2). 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 capacitor voltage VC corresponding to each period.

[0101] Furthermore, the MCU 30 may change the power system voltage Vheat generated by the first DC / DC converter 40 in each of the sections S1 to S8 defined by the heating profile 500. That is, the MCU 30 may instruct the first DC / DC converter 40 to set the power system voltage Vheat to a voltage corresponding to each of the sections S1 to S8 defined by the heating profile 500.

[0102] For example, the MCU 30 may instruct the first DC / DC converter 40 to set the power system voltage Vheat to 5.0 [V] in sections where the susceptor Su is heated (e.g., sections S1, S2, S4, S5, S7), while instructing the first DC / DC converter 40 to set the power system voltage Vheat to 4.0 [V] in sections where the susceptor Su is kept warm or cooled (e.g., sections S3, S6, S8).

[0103] In other words, if the sections defined by the heating profile 500 include a first section (e.g., section S2) and a second section (e.g., section S3) immediately following the first section, and the target voltage in the second section is equal to or lower than the target voltage in the first section, the MCU 30 may instruct the first DC / DC converter 40 to make the power system voltage Vheat in the second section lower than the power system voltage Vheat in the first section. The voltage as the power system voltage Vheat in each section is determined in advance by, for example, the manufacturer of the suction device 100.

[0104] Furthermore, the MCU 30 may instruct the first DC / DC converter 40 to make the power system voltage Vheat higher than the second system voltage Vsys2 (for example, 6.0 V) during the period in which the temperature of the susceptor Su is increased. In other words, a single smoking session may include a case in which the power system voltage Vheat is higher than the second system voltage Vsys2 and a case in which the power system voltage Vheat is lower than the second system voltage Vsys2.

[0105] In order to control the detection capacitor voltage VC (or susceptor temperature) to change in a predetermined manner, the MCU 30 needs to periodically acquire the detection capacitor voltage VC during the smoking session. Therefore, the MCU 30 performs a VC check process to acquire the detection capacitor voltage VC 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 capacitor voltage VC (mV). Note that the following description of FIG. 6 is based on an example in which the detection capacitor voltage VC and the susceptor temperature have a positive correlation (i.e., the higher the susceptor temperature, the higher the detection capacitor voltage VC).

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

[0108] First, an example of the VC check process will be described. In the VC check process, the MCU 30, for example, first discharges the detection capacitor 91 using the reset circuit 92. More specifically, the MCU 30 discharges the detection capacitor 91 by turning on the FET 94 of the reset circuit 92 for a predetermined time. Here, the predetermined time is determined in advance by the manufacturer of the suction device 100, taking into consideration, for example, the time required to completely discharge the detection capacitor 91.

[0109] When the discharge of the detection capacitor 91 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 VC check process. An example of the first duty is 10% in consideration of this situation. Furthermore, the first time is preferably relatively short in order to prevent the susceptor temperature from rising due to the power supply to the resonant circuit 80 in the VC check process. An example of the first time is 8 ms in consideration of this situation. 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 voltage divider circuit 95 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 capacitor voltage VC for the current VC 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 capacitor voltage VC for the current VC 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 capacitor voltage VC for the current VC check process.

[0113] Next, an example of the heating process will be described. In the heating process, the MCU 30 determines the time for which power is supplied to the resonant circuit 80 in the current heating process (hereinafter also referred to as the "heating time") based on, for example, the detection capacitor voltage VC obtained in a VC check process performed in the same control cycle as the heating process (in other words, the VC 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 capacitor voltage VC obtained by the VC 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 capacitor voltage VC obtained by the VC 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 capacitor voltage VC and the heating time when the target voltage is higher than the detection capacitor voltage VC 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 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. For example, a series resonant circuit has maximum efficiency when the duty is 50%. In consideration of this, an example of the second duty is 50%, but is not limited to this.

[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 of the detection capacitor voltage VC during a smoking session, the present invention is not limited to this. For example, the heating profile 500 may define a target temperature of the susceptor during a smoking session instead of the target voltage of the detection capacitor voltage VC. In this case, the MCU 30 derives the susceptor temperature from the detection capacitor voltage VC 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 the battery 10, the first DC / DC converter 40 that generates the power system voltage Vheat from the battery voltage Vbat, the second DC / DC converter 50 that generates the second system voltage Vsys2 from the battery voltage Vbat, the resonant circuit 80 that inductively heats the susceptor Su when power is supplied thereto, and the drive circuit 70 that has one or more field effect transistors (e.g., the first FET 71 and / or the second FET 72) and controls the power supply to the resonant circuit 80 by turning these on and off.

[0120] Here, the power system voltage Vheat is higher than the battery voltage Vbat, and the second system voltage Vsys2 is higher than the battery voltage Vbat and different from the power system voltage Vheat. Power based on the power system voltage Vheat is supplied to the resonant circuit 80. Meanwhile, a drive voltage based on the second system voltage Vsys2 is supplied to the field-effect transistor of the drive circuit 70.

[0121] That is, the voltage suitable for the resonant circuit 80 to appropriately inductively heat the susceptor Su may differ from the voltage suitable as a drive voltage for the field-effect transistors of the drive circuit 70, such as the first FET 71 and the second FET 72. For example, a relatively high voltage is required to appropriately drive the first FET 71 and the second FET 72. On the other hand, if such a high voltage is also supplied to the resonant circuit 80, an overcurrent may occur in the resonant circuit 80. Although increasing the number of turns of the resonant coil 81 may potentially suppress such an overcurrent, this would result in an increase in the size of the resonant coil 81 and, ultimately, the size of the suction device 100.

[0122] Therefore, the suction device 100 is provided with a first DC / DC converter 40 that generates a power system voltage Vheat from the battery voltage Vbat and a second DC / DC converter 50 that generates a second system voltage Vsys2 from the battery voltage Vbat. The resonant circuit 80 is supplied with power based on the power system voltage Vheat, and the field-effect transistor of the drive circuit 70 is supplied with a drive voltage based on the second system voltage Vsys2. This makes it possible to supply appropriate voltages to the resonant circuit 80 and the field-effect transistor of the drive circuit 70. Therefore, it is possible to appropriately inductively heat the susceptor Su by the resonant circuit 80 while suppressing an increase in the size of the resonant coil 81 and, consequently, the size of the suction device 100.

[0123] Furthermore, the power system voltage Vheat is preferably lower than the second system voltage Vsys2. That is, during a single smoking session, the power system voltage Vheat may be lower than the second system voltage Vsys2. In this manner, the field-effect transistors of the drive circuit 70 can be supplied with the relatively high second system voltage Vsys2 as a drive voltage, thereby enabling the field-effect transistors of the drive circuit 70 to be appropriately driven. Meanwhile, the resonant circuit 80 can be supplied with power based on the power system voltage Vheat, which is lower than the second system voltage Vsys2, thereby preventing overcurrent from occurring in the resonant circuit 80 without increasing the number of turns of the resonant coil 81. Therefore, the resonant circuit 80 can appropriately inductively heat the susceptor Su while preventing the resonant coil 81 and, consequently, the inhaler 100 from becoming larger.

[0124] Furthermore, the power system voltage Vheat may be maintained lower than the second system voltage Vsys2 throughout a single smoking session. This makes it possible to prevent overcurrent from occurring in the resonant circuit 80. Alternatively, the power system voltage Vheat may be set higher than the second system voltage Vsys2 only during a specific period included in a single smoking session, and may be set lower than the second system voltage Vsys2 during the remaining periods. This allows the voltage supplied to the resonant circuit 80 to be flexibly changed during a smoking session, thereby enabling the resonant circuit 80 to appropriately inductively heat the susceptor Su.

[0125] The second system voltage Vsys2 may be higher than the battery voltage Vbat, so that even if the field-effect transistor of the drive circuit 70 requires a drive voltage higher than the battery voltage Vbat, the field-effect transistor can be appropriately driven.

[0126] The power system voltage Vheat may be variable, which allows the voltage supplied to the resonant circuit 80 to be flexibly changed, thereby enabling the resonant circuit 80 to appropriately inductively heat the susceptor Su.

[0127] The suction device 100 may further include an MCU 30 as a control unit configured to control the first DC / DC converter 40 and the drive circuit 70. In this case, the first DC / DC converter 40 may generate a power system voltage Vheat, which is a voltage instructed by the MCU 30. The MCU 30 may also be configured to acquire a value related to the state of the resonant circuit 80 (e.g., a detection capacitor voltage VC) and control the power supply to the resonant circuit 80 via the drive circuit 70 based on the acquired value related to the state of the resonant circuit 80. In this manner, the MCU 30 can control the power supply to the resonant circuit 80 in consideration of the power system voltage Vheat generated by the first DC / DC converter 40 (i.e., the voltage instructed by the MCU 30 itself). Therefore, the susceptor Su can be appropriately induction-heated by the resonant circuit 80 while simplifying the configuration of the suction device 100 and reducing the processing load on the MCU 30.

[0128] On the other hand, if the power system voltage Vheat is not based on an instruction from the MCU 30, in order for the MCU 30 to control the power supply to the resonant circuit 80 taking the power system voltage Vheat into consideration, it would be necessary to provide the suction device 100 with a voltage sensor or the like for measuring the power system voltage Vheat, or for the MCU 30 to determine the power system voltage Vheat by calculation. Therefore, in this case, there is a risk that the configuration of the suction device 100 will become complicated and the processing load on the MCU 30 will increase.

[0129] Furthermore, the MCU 30 may acquire a value relating to the state of the resonant circuit 80 at a predetermined period and control the power supply to the resonant circuit 80 via the drive circuit 70 so that the value relating to the state of the resonant circuit 80 changes in a predetermined manner (for example, a manner defined by the heating profile 500 shown in FIG. 5 ). In this way, the flavor experienced by a user inhaling the aerosol generated by the inhalation device 100 can be optimized, thereby providing the user with a high-quality smoking experience.

[0130] The predetermined aspect may also include target values ​​(e.g., Vtgt0 to Vtgt4 [mV] shown in FIG. 5) for values ​​relating to the state of the resonant circuit 80 for each interval (e.g., intervals S1 to S8 shown in FIG. 5) defined by the elapsed time since the aerosol generation request was made, and the MCU 30 may instruct the first DC / DC converter 40 to set the power system voltage Vheat to a voltage corresponding to the interval. In this way, the power system voltage Vheat (i.e., the voltage supplied to the resonant circuit 80) can be flexibly changed according to the interval defined by the elapsed time since the aerosol generation request was made, thereby enabling the resonant circuit 80 to appropriately inductively heat the susceptor Su.

[0131] Furthermore, the above-mentioned intervals include a first interval (e.g., interval S2 shown in FIG. 5 ) and a second interval (e.g., interval S3 shown in FIG. 5 ) immediately following the first interval, and when a target value for a value related to the state of the resonant circuit 80 in the second interval is equal to or lower than the target value in the first interval, the MCU 30 may instruct the first DC / DC converter 40 to make the power system voltage Vheat in the second interval lower than the power system voltage Vheat in the first interval. In this way, the power system voltage Vheat (i.e., the voltage supplied to the resonant circuit 80) can be appropriately lowered in consideration of the target value in each interval, thereby making it possible to reduce power consumption in the suction device 100 while appropriately inductively heating the susceptor Su by the resonant circuit 80.

[0132] The resonant circuit 80 may include a resonant coil 81 and a resonant capacitor 82, and the suction device 100 may further include a detection capacitor 91 connected to the resonant capacitor 82 via a diode D serving as a rectifying element. In this case, the MCU 30 may be configured to acquire a value related to the detection capacitor voltage VC, which is the voltage of the detection capacitor 91, as a value related to the state of the resonant circuit 80, and may control the power supply to the resonant circuit 80 based on the acquired value related to the detection capacitor voltage VC. This allows the MCU 30 to acquire, with a simple configuration, a value related to the detection capacitor voltage VC, which is correlated with the susceptor temperature, which is the temperature of the susceptor Su, as a value related to the state of the resonant circuit 80. The MCU 30 controls the power supply to the resonant circuit 80 based on the acquired value related to the detection capacitor voltage VC, thereby controlling the power supply to the resonant circuit 80 in consideration of the susceptor temperature. Therefore, the configuration of the suction device 100 can be simplified while the resonant circuit 80 can appropriately inductively heat the susceptor Su.

[0133] The suction device 100 may further include a gate driver 60 configured to be able to supply the second system voltage Vsys2 as a drive voltage to the field effect transistors of the drive circuit 70. In this case, the MCU 30 may be configured to be able to control the gate driver 60 and control the drive circuit 70 via the gate driver 60. In this way, even if the MCU 30 cannot directly drive the field effect transistors of the drive circuit 70 due to hardware factors or the like, it is possible to appropriately drive the field effect transistors of the drive circuit 70.

[0134] The suction device 100 may further include an LDO regulator 20 that generates a first system voltage Vsys1 from the battery voltage Vbat. Here, the first system voltage Vsys1 is a constant voltage that is lower than the battery voltage Vbat and the second system voltage Vsys2. In this case, the first system voltage Vsys1 may be supplied to the MCU 30 as a power supply voltage. In this way, a stable first system voltage Vsys1 can be supplied to the MCU 30 as a power supply voltage, thereby stabilizing the operation of the MCU 30.

[0135] 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 drive circuit 70 may be an inverter circuit having two or more field-effect transistors (for example, the first FET 71 and the second FET 72 shown in FIG. 3) that converts DC power having the power system voltage Vheat into AC power and supplies it to the resonant circuit 80. In this case, 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, it is possible to appropriately inductively heat the susceptor Su even if the voltage supplied to the resonant circuit 80 (i.e., the power system voltage Vheat) is lowered.

[0136] 4, the resonant circuit 80 may be configured as an LC parallel resonant circuit in which a resonant coil 81 and a resonant capacitor 82 are connected in parallel. In this case, the drive circuit 70 may be a circuit having a field-effect transistor (e.g., the second FET 72 shown in FIG. 4) as a switch that turns on and off the power supply to the resonant circuit 80. In this way, the number of field-effect transistors required to configure the drive circuit 70 can be reduced 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 connected in series, thereby simplifying the drive circuit 70.

[0137] Furthermore, in each control cycle, the MCU 30 may acquire a value related to the detection capacitor voltage Vc when the reset circuit 92 discharges the detection capacitor 91 and then supplies a predetermined power to the resonance circuit 80. In this way, it becomes possible to acquire a value related to the detection capacitor voltage Vc under the same conditions for each control cycle.

[0138] Furthermore, the MCU 30 may determine the power to be supplied to the resonant circuit 80 in each control cycle based on the value of the detection capacitor voltage VC 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 capacitor voltage VC acquired in that control cycle.

[0139] 5. Modifications of the Present Embodiment Next, modifications of the present embodiment will be described. Note that, for the sake of brevity, the following description will focus on differences from the previously described embodiment, and descriptions of similarities to the previously described embodiment will be appropriately simplified or omitted.

[0140] 7 is a diagram showing an example of an outline of the circuit configuration of the suction device 100 of the first modified example. In the above-described embodiment, the battery voltage Vbat is supplied to the LDO regulator 20, and the LDO regulator 20 generates the first system voltage Vsys1 from the battery voltage Vbat. However, this is not limited to this. In other words, it is sufficient that a voltage higher than the first system voltage Vsys1 generated by the LDO regulator 20 is supplied to the LDO regulator 20.

[0141] 7, the LDO regulator 20 and the second DC / DC converter 50 may be connected, the second system voltage Vsys2 generated by the second DC / DC converter 50 may be supplied to the LDO regulator 20, and the LDO regulator 20 may generate the first system voltage Vsys1 from the second system voltage Vsys2. Even in this case, the stable first system voltage Vsys1 can be supplied to the MCU 30 as a power supply voltage, thereby stabilizing the operation of the MCU 30.

[0142] Furthermore, a voltage higher than the battery voltage Vbat or the first system voltage Vsys1 may be required to operate the notification unit 113. Therefore, as shown in Fig. 7 , power based on the second system voltage Vsys2 generated by the second DC / DC converter 50 may be supplied to the notification unit 113. In this way, even when the notification unit 113 requires a voltage higher than the battery voltage Vbat or the first system voltage Vsys1 as its operating voltage, the notification unit 113 can be operated appropriately.

[0143] More specifically, the notification unit 113 may include an LED that requires a relatively high voltage as an operating voltage. In such a case, the suction device 100 may include an LDO 21 as an example of a linear regulator that generates, from the second system voltage Vsys2, a third system voltage Vsys3 that is lower than the second system voltage Vsys2 and is constant.

[0144] 7 , the LDO regulator 21 is provided between the second DC / DC converter 50 and the LED (hereinafter simply referred to as the “LED”) included in the notification unit 113. The LDO regulator 21 receives the second system voltage Vsys2 to generate a third system voltage Vsys3 and outputs the generated third system voltage Vsys3 to the LED. The third system voltage Vsys3 is higher than the battery voltage Vbat and the first system voltage Vsys1, and may be set to, for example, 5.0 V. This allows the LED to be supplied with a relatively high and stable third system voltage Vsys3, enabling the LED to operate properly.

[0145] In the example described here, LDO 21 is provided, but if the LEDs operate properly even if the second system voltage Vsys2 is supplied to them as is, LDO 21 may be omitted and the second system voltage Vsys2 may be supplied to the LEDs.

[0146] Although the example described above uses an LED as the notification unit 113 to which power based on the second system voltage Vsys2 is supplied, this is not limiting. For example, as described above, the notification unit 113 may also include a display device, a vibration device, etc., and instead of or in addition to an LED, these display devices and vibration devices may be supplied with power based on the second system voltage Vsys2. Furthermore, for example, an LED serving as the notification unit 113 with a relatively high operating voltage may be supplied with power based on the second system voltage Vsys2, and a vibration device serving as the notification unit 113 with a relatively low operating voltage may be supplied with power based on the first system voltage Vsys1.

[0147] Furthermore, by extracting the power to operate the MCU 30, etc. from a power line other than the power line that supplies power to the resonant circuit 80 (i.e., the power line to which the power system voltage Vheat is applied), the power supplied to the resonant circuit 80 can be stabilized, and the susceptor Su can be appropriately inductively heated by the resonant circuit 80.

[0148] FIG. 8 is a diagram showing a portion of the circuit configuration of the suction device 100 of a second modified example. The circuit configuration of the second modified example shown in FIG. 8 differs from the circuit configuration of the first example shown in FIG. 3 in that a bootstrap circuit (described later) is provided in the suction device 100 and this bootstrap circuit is used to drive the first FET 71, which is the high-side switch of the drive circuit 70. In other respects, the circuit configuration is similar to that of the first example. Note that in this modified example, the first FET 71 is also an N-channel MOSFET. It should also be noted that FIG. 8 omits the illustration of the battery 10, LDO 20, MCU 30, first DC / DC converter 40, detection circuit 90, voltage divider circuit 95, and the like, which are shown in FIG. 3.

[0149] As shown in FIG. 8 , the gate driver 60 includes, for example, a VDD terminal (illustrated as “VDD”), an HO terminal (illustrated as “HO”), an HS terminal (illustrated as “HS”), an LO terminal (illustrated as “LO”), an HB terminal (illustrated as “HB”), a high-side drive circuit 61, and a low-side drive circuit 62.

[0150] The VDD terminal is connected to the output terminal of the second DC / DC converter 50 (i.e., the terminal from which the second system voltage Vsys2 is output). The HO terminal is connected to the gate terminal of the first FET 71 via a power line PL1. The HS terminal is connected to a connection point 70a provided between the first FET 71 and the second FET 72 via a power line PL2. The LO terminal is connected to the gate terminal of the second FET 72 via a power line PL3. The HB terminal is connected to the power line PL2 via a bootstrap capacitor 64, which will be described later.

[0151] The high-side drive circuit 61 is connected to the VDD terminal, the HB terminal, the HO terminal, and the HS terminal. The voltage between the VDD terminal or the HB terminal and the HS terminal is supplied to the high-side drive circuit 61 as a power supply voltage. When the power supply voltage is supplied to the high-side drive circuit 61, the high-side drive circuit 61 outputs the power supply voltage to the HO terminal in response to an instruction from the MCU 30 to turn on (i.e., to a conductive state) the first FET 71. This causes the output voltage from the high-side drive circuit 61 to be supplied to the gate terminal of the first FET 71, turning the first FET 71 on. Furthermore, the high-side drive circuit 61 stops outputting the power supply voltage in response to an instruction from the MCU 30 to turn off (i.e., to a non-conductive state) the first FET 71. This turns off the first FET 71.

[0152] Similarly, the low-side drive circuit 62 is connected to the VDD terminal, the LO terminal, etc. When a power supply voltage is supplied via the VDD terminal, etc., the low-side drive circuit 62 outputs the power supply voltage to the LO terminal in accordance with an instruction from the MCU 30 to turn on the second FET 72. As a result, the output voltage from the low-side drive circuit 62 is supplied to the gate terminal of the second FET 72, turning on the second FET 72. Furthermore, in accordance with an instruction from the MCU 30 to turn off the second FET 72, the low-side drive circuit 62 stops outputting the power supply voltage, turning off the second FET 72.

[0153] The suction device 100 of the second modified example further includes, for example, a first diode 63, a bootstrap capacitor 64, and a second diode 65. The first diode 63, the bootstrap capacitor 64, and the second diode 65 configure a bootstrap circuit 69.

[0154] The first diode 63 is provided, for example, inside the gate driver 60. The anode terminal of the first diode 63 is connected to the VDD terminal. The cathode terminal of the first diode 63 is connected to the high-side drive circuit 61 and is also connected to the power line PL2 via the HB terminal and the bootstrap capacitor 64. In other words, one end of the bootstrap capacitor 64 is connected to the cathode terminal of the first diode 63 and the other end is connected to the power line PL2. Here, the bootstrap capacitor 64 is a capacitor having a predetermined capacitance.

[0155] In the example shown in FIG. 8, the first diode 63 is built into the gate driver 60, but this is not limiting, and the first diode 63 may be provided outside the gate driver 60.

[0156] The second diode 65 has an anode terminal connected to the power line PL2 and a cathode terminal connected to the power line PL1. The connection point between the anode terminal of the second diode 65 and the power line PL2 is located closer to the connection point 70a than the connection point between the other end of the bootstrap capacitor 64 and the power line PL2.

[0157] In the suction device 100 of the second modified example, the second system voltage Vsys2 is supplied to the gate driver 60, and when the first FET 71, which is a high-side switch, is off and the second FET 72, which is a low-side switch, is on, the bootstrap capacitor 64 is charged.

[0158] Then, when the first FET 71 is turned on and the second FET 72 is turned off while the bootstrap capacitor 64 is charged, the gate potential of the first FET 71 becomes higher than the source potential (i.e., the potential at the connection point 70a), which is the potential of the source terminal of the first FET 71, by the voltage across the bootstrap capacitor 64. Therefore, the first FET 71 can be driven more quickly than when the suction device 100 does not include the bootstrap circuit 69. Furthermore, because the gate potential of the first FET 71 can be increased by the voltage across the bootstrap capacitor 64, the first FET 71 can be driven even if the second system voltage Vsys2 supplied to the gate driver 60 is lowered, compared to when the suction device 100 does not include the bootstrap circuit 69.

[0159] As described above, the suction device 100 may include a bootstrap circuit 69 that, when the bootstrap capacitor 64 is charged, turns on the first FET 71 and turns off the second FET 72, thereby making the gate potential of the first FET 71 higher than the source potential of the first FET 71 by the voltage across the bootstrap capacitor 64. In this way, the first FET 71 can be driven more quickly than when the suction device 100 does not include the bootstrap circuit 69. Furthermore, the first FET 71 can be driven even if the second system voltage Vsys2 supplied to the gate driver 60 is lowered.

[0160] If the suction device 100 is provided with a bootstrap circuit 69, from the viewpoint of quickly charging the gate capacitance of the first FET 71, it is preferable that the capacitance of the bootstrap capacitor 64 be equal to or greater than the gate capacitance of the first FET 71. Furthermore, if a push-pull circuit is provided in the power line connecting the connection point 70a and the resonant circuit 80, in other words, if the power line connecting the connection point 70a and the resonant circuit 80 is connected to ground GND via a predetermined resistor, it is preferable that the impedance of the resistor be made relatively small from the viewpoint of quickly charging the gate capacitance of the first FET 71.

[0161] Although the above describes various embodiments of the aerosol generating device of the present disclosure, it goes without saying that the present disclosure is not limited to such embodiments. 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 naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0162] For example, in the above-described embodiment, MCU 30 acquires a value related to detection capacitor voltage VC as a value related to the state of resonant circuit 80, and controls the power supply to resonant circuit 80 based on the acquired value related to detection capacitor voltage VC, but this is not limited to this. As an example, another coil may be provided in suction device 100, positioned so as to be magnetically coupled to resonant coil 81, and MCU 30 may acquire a value related to the voltage of that coil as a value related to the state of resonant circuit 80.

[0163] Furthermore, in the above-described embodiment, a common reference potential is applied to each of the resonant capacitor 82, the detection capacitor 91, 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 resonant capacitor 82 and / or the detection capacitor 91. 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 resonant capacitor 82 and / or the detection capacitor 91 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 capacitor voltage VC taking this difference into consideration.

[0164] 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.

[0165] (1) An aerosol generating device (suction device 100, 100A, 100B) that generates an aerosol by inductively heating a susceptor (susceptor Su) that is provided so as to be able to heat an aerosol source, and thereby heating the aerosol source, comprising: a battery (battery 10, power supply unit 111); a first converter (first DC / DC converter 40) that generates, from a battery voltage that is an output voltage of the battery, a first voltage (power system voltage Vheat) that is different from the battery voltage; a second converter (second DC / DC converter 50) that generates, from the battery voltage, a second voltage (second system voltage Vsys2) that is different from the battery voltage and the first voltage; a resonant circuit (resonant circuit 80) that has a coil (resonant coil 81) and a first capacitor (resonant capacitor 82), and that inductively heats the susceptor when power is supplied; an aerosol generating device comprising: a drive circuit (drive circuit 70) having one or more field effect transistors (first FET 71, second FET 72) and controlling the power supply to the resonant circuit by turning on and off the field effect transistors; wherein the resonant circuit is supplied with power based on the first voltage, and the field effect transistor is supplied with a drive voltage based on the second voltage.

[0166] According to (1), it is possible to supply appropriate voltages to the field effect transistors of the resonant circuit and the drive circuit, respectively, and therefore it is possible to appropriately inductively heat the susceptor by the resonant circuit while suppressing an increase in the size of the coil of the resonant circuit and, consequently, an increase in the size of the aerosol generation device.

[0167] (2) The aerosol generating device according to (1), including a case in which the first voltage is lower than the second voltage during one smoking session.

[0168] According to (2), during a smoking session, a relatively high second voltage can be supplied as a drive voltage to the field-effect transistor of the drive circuit, thereby enabling the field-effect transistor of the drive circuit to be appropriately driven. Meanwhile, a first voltage lower than the second voltage can be supplied to the resonant circuit, thereby preventing overcurrent from occurring in the resonant circuit without increasing the number of turns of the resonant circuit coil. Therefore, the resonant circuit can appropriately inductively heat the susceptor while preventing the resonant circuit coil from becoming larger, thereby preventing the aerosol generation device from becoming larger.

[0169] (3) The aerosol generating device according to (2), wherein the first voltage is lower than the second voltage during the single smoking session.

[0170] According to (3), during a smoking session, the first voltage can be maintained lower than the second voltage, thereby making it possible to prevent overcurrent from occurring in the resonant circuit.

[0171] (4) The aerosol generating device according to any one of (1) to (3), wherein the second voltage is higher than the battery voltage.

[0172] According to (4), even if the field effect transistor of the drive circuit requires a drive voltage higher than the battery voltage, the field effect transistor can be driven appropriately.

[0173] (5) The aerosol generating device according to any one of (1) to (4), wherein the first voltage is variable.

[0174] According to (5), the voltage supplied to the resonant circuit can be flexibly changed, so that the susceptor can be appropriately inductively heated by the resonant circuit.

[0175] (6) The aerosol generating device according to (5), further comprising a control unit (MCU 30, control units 116, 116A, 116B) configured to be able to control the first converter and the drive circuit, wherein the first converter generates the first voltage which is a voltage instructed by the control unit, and the control unit is configured to be able to acquire a value relating to the state of the resonant circuit (detection capacitor voltage VC), and controls the power supply to the resonant circuit via the drive circuit based on the acquired value relating to the state of the resonant circuit.

[0176] According to (6), compared to when a voltage sensor or the like for measuring the first voltage is provided in the aerosol generating device or when the control unit determines the first voltage by calculation, it is possible to simplify the configuration of the aerosol generating device and reduce the processing burden on the control unit, while allowing the control unit to control the power supply to the resonant circuit taking the first voltage into consideration.

[0177] (7) The aerosol generating device according to (6), wherein the control unit acquires a value relating to the state of the resonant circuit at a predetermined period, and controls the power supply to the resonant circuit via the drive circuit so that the value relating to the state of the resonant circuit changes in a predetermined manner.

[0178] According to (7), it is possible to optimize the flavor experienced by a user who inhales the aerosol generated by the aerosol generating device, thereby providing the user with a high-quality smoking experience.

[0179] (8) The aerosol generating device according to (7), wherein the predetermined aspect includes target values ​​(Vtgt0 to Vtgt4) for values ​​relating to the state of the resonant circuit for each interval (intervals S1 to S8) defined by the elapsed time since a request for aerosol generation was made, and the control unit instructs the first converter to set the first voltage to a voltage corresponding to the interval.

[0180] According to (8), the first voltage can be flexibly changed according to the interval defined by the elapsed time from when a request for aerosol generation was made, thereby making it possible to appropriately inductively heat the susceptor using the resonant circuit.

[0181] (9) The aerosol generating device according to (8), wherein the section includes a first section and a second section immediately following the first section, and when the target value in the second section is equal to or less than the target value in the first section, the control unit instructs the first converter to make the first voltage in the second section lower than the first voltage in the first section.

[0182] According to (9), the first voltage can be appropriately lowered taking into account the target value in each section, making it possible to reduce power consumption in the aerosol generating device while appropriately inductively heating the susceptor using the resonant circuit.

[0183] (10) An aerosol generating device according to any one of (6) to (9), further comprising a second capacitor (detection capacitor 91) connected to the first capacitor via a rectifying element (diode D), and the control unit is configured to be able to acquire a value relating to the voltage of the second capacitor as a value relating to the state of the resonant circuit, and controls the power supply to the resonant circuit based on the acquired value relating to the voltage of the second capacitor.

[0184] According to (10), with a simple configuration, the control unit can acquire a value related to the voltage of the second capacitor, which is correlated with the susceptor temperature, as a value related to the state of the resonant circuit.The control unit then controls the power supply to the resonant circuit based on the acquired value related to the voltage of the second capacitor, thereby controlling the power supply to the resonant circuit in consideration of the susceptor temperature.This makes it possible to appropriately inductively heat the susceptor using the resonant circuit while simplifying the configuration of the aerosol generation device.

[0185] (11) The aerosol generating device according to any one of (6) to (10), further comprising a gate driver (gate driver 60) configured to be able to supply a driving voltage based on the second voltage to the field effect transistor, and the control unit configured to be able to control the gate driver and controls the driving circuit via the gate driver.

[0186] According to (11), even when the control unit cannot directly drive the field effect transistor of the drive circuit due to hardware factors or the like, it is possible to appropriately drive the field effect transistor of the drive circuit.

[0187] (12) The aerosol generating device according to any one of (6) to (11), further comprising a linear regulator (LDO 20) that generates a third voltage, which is lower than the battery voltage and the second voltage and is constant, from the battery voltage or the second voltage, and the third voltage is supplied to the control unit as a power supply voltage.

[0188] According to (12), a stable third voltage can be supplied to the control unit as a power supply voltage, thereby stabilizing the operation of the control unit.

[0189] (13) The aerosol generating device according to any one of (1) to (12), further comprising a notification unit (notification unit 113, 113A, 113B) that notifies a user of information, and power based on the second voltage is supplied to the notification unit.

[0190] According to (13), even if the notification unit requires a voltage higher than the battery voltage as the operating voltage, the notification unit can be operated appropriately.

[0191] (14) An aerosol generating device according to any one of (1) to (13), wherein the resonant circuit is configured by connecting the coil and the first capacitor in series, and the drive circuit is an inverter circuit that has two or more of the field effect transistors and converts DC power having the first voltage into AC power and supplies it to the resonant circuit.

[0192] According to (14), compared to when the resonant circuit is an LC parallel resonant circuit in which a coil and a first capacitor are connected in parallel, it is possible to appropriately inductively heat the susceptor even if the voltage supplied to the resonant circuit (i.e., the first voltage) is lowered.

[0193] (15) The aerosol generation device according to (14), wherein the drive circuit has a first field effect transistor (first FET 71) that is a high-side switch and a second field effect transistor (second FET 72) that is a low-side switch, the first field effect transistor is an N-channel field effect transistor, and the aerosol generation device further includes a bootstrap circuit (bootstrap circuit 69) that has a bootstrap capacitor (bootstrap capacitor 64), and the bootstrap circuit makes the gate potential of the first field effect transistor higher than the source potential of the first field effect transistor by the voltage across the bootstrap capacitor when the bootstrap capacitor is charged and the first field effect transistor is turned on and the second field effect transistor is turned off.

[0194] According to (15), the first field-effect transistor, which is the high-side switch of the drive circuit, can be driven more quickly than when the aerosol generating device does not include a bootstrap circuit.

[0195] (16) The aerosol generating device according to (15), wherein the capacitance of the bootstrap capacitor is equal to or greater than the gate capacitance of the first field effect transistor.

[0196] According to (16), it is possible to quickly charge the gate capacitance of the first field effect transistor.

[0197] 30 MCU (control unit) 60 Gate driver 70 Drive circuit 71 First FET (field effect transistor, first field effect transistor) 72 Second FET (field effect transistor, second field effect transistor) 80 Resonant circuit 81 Resonant coil (coil) 82 Resonant capacitor (first capacitor) 91 Detection capacitor (second capacitor) 100 Suction device (aerosol generation device) 116A, 116B, 116 Control unit D Diode (rectifying element) Su Susceptor

Claims

1. An aerosol generation device that generates an aerosol by inductively heating a susceptor provided so as to be able to heat an aerosol source, thereby heating the aerosol source, comprising: a battery; a first converter that generates a first voltage from a battery voltage that is an output voltage of the battery, the first voltage being different from the battery voltage; a second converter that generates a second voltage from the battery voltage, the second voltage being different from the battery voltage and the first voltage; a resonant circuit having a coil and a first capacitor, and inductively heating the susceptor when power is supplied; and a drive circuit having one or more field effect transistors, and controlling the power supply to the resonant circuit by turning the field effect transistors on and off, wherein the resonant circuit is supplied with power based on the first voltage, and the field effect transistors are supplied with a drive voltage based on the second voltage.

2. The aerosol generating device according to claim 1, wherein the first voltage is lower than the second voltage during a single smoking session.

3. The aerosol generating device according to claim 2, wherein the first voltage is lower than the second voltage during the single smoking session.

4. An aerosol generating device according to any one of claims 1 to 3, wherein the second voltage is higher than the battery voltage.

5. An aerosol generating device according to any one of claims 1 to 4, wherein the first voltage is variable.

6. An aerosol generating device as described in claim 5, further comprising a control unit configured to be able to control the first converter and the drive circuit, wherein the first converter generates the first voltage which is a voltage instructed by the control unit, and the control unit is configured to be able to acquire a value relating to the state of the resonant circuit, and controls the supply of power to the resonant circuit via the drive circuit based on the acquired value relating to the state of the resonant circuit.

7. An aerosol generating device according to claim 6, wherein the control unit acquires a value relating to the state of the resonant circuit at a predetermined period, and controls the supply of power to the resonant circuit via the drive circuit so that the value relating to the state of the resonant circuit changes in a predetermined manner.

8. An aerosol generating device as described in claim 7, wherein the predetermined aspect includes a target value for a value relating to the state of the resonant circuit for each interval defined by the elapsed time since a request for aerosol generation was made, and the control unit instructs the first converter to set the first voltage to a voltage corresponding to the interval.

9. An aerosol generating device according to claim 8, wherein the interval includes a first interval and a second interval immediately following the first interval, and when the target value in the second interval is equal to or less than the target value in the first interval, the control unit instructs the first converter to make the first voltage in the second interval lower than the first voltage in the first interval.

10. An aerosol generating device according to any one of claims 6 to 9, further comprising a second capacitor connected to the first capacitor via a rectifying element, and the control unit is configured to be able to acquire a value relating to the voltage of the second capacitor as a value relating to the state of the resonant circuit, and controls the supply of power to the resonant circuit based on the acquired value relating to the voltage of the second capacitor.

11. An aerosol generating device according to any one of claims 6 to 10, further comprising a linear regulator that generates a third voltage, which is lower than the battery voltage and the second voltage and is constant, from the battery voltage or the second voltage, and the control unit is supplied with the third voltage as a power supply voltage.

12. An aerosol generating device according to any one of claims 1 to 11, further comprising a notification unit that notifies a user of information, and wherein the notification unit is supplied with power based on the second voltage.

13. An aerosol generating device according to any one of claims 1 to 12, wherein the resonant circuit is configured by connecting the coil and the first capacitor in series, and the drive circuit is an inverter circuit that has two or more of the field effect transistors and converts DC power having the first voltage into AC power and supplies it to the resonant circuit.

14. An aerosol generation device according to claim 13, wherein the drive circuit has a first field effect transistor which is a high-side switch and a second field effect transistor which is a low-side switch, the first field effect transistor being an N-channel field effect transistor, and the aerosol generation device further comprises a bootstrap circuit having a bootstrap capacitor, wherein the bootstrap circuit makes the gate potential of the first field effect transistor higher than the source potential of the first field effect transistor by the voltage across the bootstrap capacitor when the bootstrap capacitor is charged and the first field effect transistor is turned on and the second field effect transistor is turned off.

15. An aerosol generating device according to claim 14, wherein the capacitance of the bootstrap capacitor is equal to or greater than the gate capacitance of the first field effect transistor.

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