Aerosol generating device

Abstract

The present disclosure provides an inhalation device (100) comprising: a first voltage system (10) configured to be able to supply a first voltage generated on the basis of an output voltage of a power supply section (111) to a resistor (Rheat) as a heating unit; a second voltage system (20) configured so as to be able to supply a second voltage generated on the basis of the output voltage of the power supply unit (111) to the resistor (Rheat); and an MCU (50) as a control unit. The first voltage is lower than the second voltage. The MCU (50) acquires the temperature of the resistor (Rheat) on the basis of the resistance of the resistor (Rheat) acquired by supplying the first voltage to the resistor (Rheat), and controls the supply of the second voltage to the resistor (Rheat) on the basis of the temperature.

Description

Technical Field

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

[0002] Conventionally, for example, aerosol generating devices are known that generate an aerosol having flavor components and deliver the generated aerosol to a user in an inhalable manner. Such aerosol generating devices typically generate an aerosol by heating a substrate that typically contains an aerosol source with a heating unit (also referred to as a "heating element"), which is a resistive heater or an inductive heater.

[0003] For example, the following PTL 1 discloses a feature in which, at a stage of controlling the temperature of a heating element, the resistivity of the heating element is measured, and an actual operating temperature value of the heating element is derived from the measurement result of the resistivity, and the electric energy to be supplied to the heating element is adjusted so as to maintain the actual operating temperature of the heating element at a specified maximum operating temperature or lower than the specified maximum operating temperature.

[0004] Citation List

[0005] Patent Literature

[0006] [PTL 1] Published Japanese translation of PCT international publication of Patent Application 2011-515093 Summary of the Invention

[0007] Technical Problem

[0008] However, with conventional techniques, there is room for improvement from the perspective of reducing power consumption when obtaining the temperature of a heating unit based on the resistance of the heating unit.

[0009] The present disclosure provides an aerosol generating device that can reduce power consumption when obtaining the temperature of a heating unit based on the resistance of the heating unit.

[0010] Solution to the Problem

[0011] One aspect of the present disclosure is an aerosol generating device, comprising:

[0012] a power source;

[0013] a heating unit including a heating resistor having an association between resistance and temperature, and configured to be able to heat an aerosol source by being supplied with electric power;

[0014] a first voltage system provided between the power source and the heating unit, and configured to be able to supply a first voltage generated based on an output voltage of the power source to the heating unit;

[0015] A second voltage system, which is disposed between the power supply and the heating unit and is configured to supply a second voltage generated based on the output voltage of the power supply to the heating unit; and

[0016] A control unit, which is configured to control the supply of the first voltage to the heating unit by the first voltage system and the supply of the second voltage to the heating unit by the second voltage system, wherein

[0017] the first voltage is lower than the second voltage, and

[0018] the control unit obtains the temperature of the heating unit based on the resistance of the heating unit and controls the supply of the second voltage to the heating unit based on the temperature, and obtains the resistance by supplying the first voltage to the heating unit.

[0019] Advantageous effects of the present invention

[0020] According to the present disclosure, an aerosol generating device can be provided, which can reduce power consumption when obtaining the temperature of a heating unit based on the resistance of the heating unit. Description of the drawings

[0021] Figure 1A is a schematic diagram schematically showing a first configuration example of an inhalation device.

[0022] Figure 1B is a schematic diagram schematically showing a second configuration example of an inhalation device.

[0023] Figure 2 is a view showing a first example of the circuit configuration of the inhalation device 100.

[0024] Figure 3 is a view showing a control example of the MCU 50 for each control target during temperature detection control.

[0025] Figure 4 is a view showing a control example of the MCU 50 for each control target during heating control.

[0026] Figure 5 is a view showing a second example of the circuit configuration of the inhalation device 100.

[0027] Figure 6 is a view showing a third example of the circuit configuration of the inhalation device 100.

[0028] Figure 7 is a view showing a fourth example of the circuit configuration of the inhalation device 100. ​​​​​​​​Detailed implementation manners

[0029] An embodiment of the aerosol generating device of the present disclosure will be described in detail below with reference to the accompanying drawings. The embodiment described below is an example of applying the aerosol generating device of the present disclosure to an inhalation device. It should be noted that the drawings should be viewed in accordance with the orientation of the reference numerals. In addition, in the following, the same or similar reference numerals may be provided for the same or similar elements, and the description thereof may be appropriately omitted or simplified.

[0030] [1. Configuration example of inhalation device]

[0031] An inhalation device as an example of the aerosol generating device of the present disclosure is a device for generating a substance to be inhaled by a user. Hereinafter, the substance generated by the inhalation device is described as an aerosol. Alternatively, the substance generated by the inhalation device may be a gas.

[0032] <1-1. First configuration example of inhalation device>

[0033] Figure 1A is a schematic diagram schematically showing a first configuration example of the inhalation device. As Figure 1A shown, the inhalation device 100A of this configuration example includes a power supply unit 110, a cartridge 120, and a flavor cartridge 130. The power supply unit 110 includes a power supply part 111A, a sensor unit 112A, a notification unit 113A, a memory unit 114A, a communication unit 115A, and a control unit 116A. The cartridge 120 includes a heating unit 121A, a liquid guiding part 122, and a liquid storage part 123. The flavor 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 cartridge 130.

[0034] The power supply part 111A stores electric power. The power supply part 111A then supplies electric power to each component of the inhalation device 100A according to the control executed by the control unit 116A. The power supply part 111A may be configured by, for example, a rechargeable battery (such as a lithium-ion secondary battery).

[0035] The sensor unit 112A acquires various types of information related to the inhalation device 100A. The sensor unit 112A is configured by, for example, a pressure sensor (such as a condenser microphone, a flow rate sensor, or a temperature sensor, etc.), and acquires a value associated with the user's inhalation.

[0036] For example, the sensor unit 112A may include a pressure sensor (also referred to as a "suction sensor") that detects a change in the pressure (hereinafter also referred to as "internal pressure") in the inhalation device 100A caused by a user's inhalation. As another example, the sensor unit 112A may include a flow sensor for detecting the flow rate (hereinafter simply referred to as "flow rate") caused by a user's inhalation. Further, as another example, the sensor unit 112A may include a temperature sensor (also referred to as a "suction thermistor") that detects the temperature of the heating unit 121A or the temperature around the heating unit 121A.

[0037] In addition, the sensor unit 112A may further include an input device (such as an operation button or switch) for receiving information input from the user. As an example, the sensor unit 112A may include an operation button as the input device for receiving an input of a heating start operation described later.

[0038] The notification unit 113A notifies the user of information. For example, the notification unit 113A may be configured by a light-emitting device that emits light, a display device that displays an image, a sound output device that outputs sound, or a vibration device that can vibrate, etc.

[0039] The memory unit 114A stores various information (e.g., programs and data) for the operation of the inhalation device 100A. The memory unit 114A is configured by a non-volatile storage medium (such as a flash memory), for example.

[0040] The communication unit 115A is a communication interface capable of performing communication according to any wired or wireless communication standard. Examples of communication standards that can be used include standards employing Wi-Fi (registered trademark), Bluetooth (registered trademark), Bluetooth Low Energy (BLE) (registered trademark), Near Field Communication (NFC), or Low Power Wide Area (LPWA), etc.

[0041] The control unit 116A serves as an arithmetic processing device and a control device, and controls the overall operation within the inhalation device 100A according to various programs stored in the memory unit 114A. For example, the control unit 116A is implemented by a central processing unit (CPU) or an electronic circuit such as a microprocessor. As an example, the control unit 116A may be implemented by the MCU 50 (MCU: microcontroller unit) described later.

[0042] The liquid storage section 123 stores an aerosol source. The aerosol source is atomized to generate an aerosol. For example, the aerosol source is a polyol (such as glycerol or propylene glycol) or a liquid (such as water). The aerosol source may include tobacco-derived or non-tobacco-derived flavor components. If the inhalation device 100A is a medical inhaler (such as a nebulizer), the aerosol source may include a drug.

[0043] The liquid guiding portion 122 guides the aerosol source from the liquid storage portion 123 and holds the aerosol source, which is the liquid stored in the liquid storage portion 123. The liquid guiding portion 122 is, for example, a wicking member formed by twisting fibrous materials such as glass fibers or porous materials such as porous ceramics. In this case, the aerosol source stored in the liquid storage portion 123 is guided by the capillary action of the wicking member.

[0044] The heating unit 121A includes a heating resistor having a correlation between resistance and temperature. As an example, a member having PTC characteristics (PTC: positive temperature coefficient, where the resistance increases as the temperature rises) is used for the heating resistor of the heating unit 121A. The heating resistor having PTC characteristics can be constituted by, for example, nickel-chromium alloy (NiCr), stainless steel, or tungsten. In addition, a member having NTC characteristics (NTC: negative temperature coefficient, where the resistance decreases as the temperature rises) can be used for the heating resistor of the heating unit 121A.

[0045] The heating unit 121A heats the aerosol source to atomize the aerosol source, thereby generating an aerosol. Figure 1A In the illustrated example, the heating unit 121A is configured as a coil wound around the heating resistor and wound around the liquid guiding portion 122. When the heating unit 121A generates heat, the aerosol source held in the liquid guiding portion 122 is then heated and atomized, thereby generating an aerosol. The heating unit 121A generates heat when power is supplied from the power supply unit 111A.

[0046] For example, when the sensor unit 112A detects that the user has started inhaling and / or has input specified information, power supply to the heating unit 121A can be executed. Then, when the sensor unit 112A detects that the user has completed inhaling and / or has input specified information, power supply to the heating unit 121A can be stopped.

[0047] The flavor source 131 is a component for imparting flavor components to the aerosol. The flavor source 131 can include tobacco-derived or non-tobacco-derived flavor components.

[0048] The air flow path 180 is a flow path for air to be inhaled by a user. The air flow path 180 has a tubular structure having an air inlet hole 181 and an air outlet hole 182. The air inlet hole is an entrance for air to enter the air flow path 180, and the air outlet hole is an exit for air to leave the air flow path 180, thus forming two ends. Inside the air flow path 180, a liquid guiding portion 122 is provided upstream (closer to the air inlet hole 181), and a flavor source 131 is provided downstream (closer to the air outlet hole 182). The air flowing in through the air inlet hole 181 during user inhalation is mixed with the aerosol generated by the heating unit 121A and is conveyed through the flavor source 131 to the air outlet hole 182, as shown by the arrow 190. When the mixed fluid of aerosol and air passes through the flavor source 131, the flavor components contained in the flavor source 131 are applied to the aerosol.

[0049] The mouthpiece 124 is a member that is held in the user's mouth during inhalation. The air outlet hole 182 is provided in the mouthpiece 124. The user holds the mouthpiece 124 in their mouth so that the mixed fluid of aerosol and air can be suctioned into the oral cavity.

[0050] The configuration example of the inhalation device 100A has been described above. Of course, the inhalation device 100A is not limited to the above configuration and can adopt various configurations, such as those shown as examples below.

[0051] As an example, the inhalation device 100A does not need to include a flavor cartridge 130. In this case, the cartridge 120 is provided with a mouthpiece 124.

[0052] As another example, the inhalation device 100A can include multiple types of aerosol sources. By mixing multiple types of aerosols generated from multiple types of aerosol sources in the air flow path 180 to cause a chemical reaction, other types of aerosols can be produced.

[0053] In addition, the means for atomizing the aerosol source is not limited to the heating provided by the heating unit 121A. For example, the means for atomizing the aerosol source can be vibration atomization or induction heating.

[0054] <1-2. Second Configuration Example of Inhalation Device>

[0055] Figure 1B is a schematic diagram schematically showing a second configuration example of the inhalation device. As Figure 1BAs shown, the inhalation device 100B according to the present 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 housing portion 140, and a heat insulation portion 144.

[0056] The power supply unit 111B, the sensor unit 112B, the notification unit 113B, the memory unit 114B, the communication unit 115B, and the control unit 116B are all substantially the same as the corresponding components included in the inhalation device 100A described above.

[0057] The housing portion 140 has an internal space 141 and holds the rod-shaped substrate 150, while accommodating a part of the rod-shaped substrate 150 in the internal space 141. The housing portion 140 has an opening 142 to allow the internal space 141 to communicate with the outside, and the housing portion accommodates the rod-shaped substrate 150 inserted into the internal space 141 from the opening 142. For example, the housing portion 140 is a cylindrical body that includes the opening 142 and a bottom portion 143 serving as a bottom surface, and defines a columnar internal space 141. An air flow path for supplying air to the internal space 141 is connected to the housing portion 140. For example, an air inlet hole is provided in the side surface of the inhalation device 100, and the air inlet hole is an entrance for air to enter the air flow path. For example, an air outlet hole is provided in the bottom portion 143, and the air outlet hole serves as an outlet for air to flow from the air flow path to the internal space 141.

[0058] The rod-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 tobacco-derived or non-tobacco-derived flavor components. If the inhalation device 100B is a medical inhaler (such as a nebulizer), the aerosol source may include a drug. For example, the aerosol source may be a liquid including tobacco-derived or non-tobacco-derived flavor components such as water and polyols (such as glycerol and propylene glycol), or may be a solid including tobacco-derived or non-tobacco-derived flavor components. In a state where the rod-shaped substrate 150 is held in the housing portion 140, at least a part of the substrate portion 151 is accommodated in the internal space 141, and at least a part of the mouthpiece portion 152 protrudes from the opening 142. Thus, when the 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 in the figure and reaches the inside of the user's mouth together with the aerosol generated from the substrate portion 151.

[0059] In Figure 1BIn the illustrated example, the heating unit 121B is configured as a film heater having conductive tracks made of a heating resistor having an association between resistance and temperature, and is arranged to cover the outer peripheral edge of the housing portion 140. Then, when the heating unit 121B generates heat, the matrix portion 151 of the rod-shaped matrix 150 is heated from the outer periphery, thereby generating an aerosol. It should be noted that the same heating resistor as that of the heating resistor of the aforementioned heating unit 121A can be used as the heating resistor of the heating unit 121B.

[0060] The heat insulation portion 144 prevents heat from being transferred from the heating unit 121B to other components. For example, the heat insulation portion 144 is configured of a vacuum heat insulation material or an aerogel heat insulation material or the like.

[0061] The configuration example of the inhalation device 100B has been described above. The inhalation device 100B is of course not limited to the above configuration, and various configurations can be adopted, such as the examples shown below.

[0062] As an example, the heating unit 121B can have a blade shape and can be arranged to protrude from the bottom portion 143 of the accommodation portion 140 into the internal space 141. In this case, the blade-shaped heating unit 121B is inserted into the matrix portion 151 of the rod-shaped matrix 150 and heats it from the inside of the matrix portion 151 of the rod-shaped matrix 150. As another example, the heating unit 121B can be arranged to cover the bottom portion 143 of the accommodation portion 140. In addition, the heating unit 121B can be configured by a combination of two or more of a first heating unit covering the outer peripheral edge of the accommodation portion 140, a blade-shaped second heating unit, and a third heating unit covering the bottom portion 143 of the accommodation portion 140.

[0063] As another example, the accommodation portion 140 can include an opening / closing mechanism (such as a hinge) for opening / closing a part of the outer shell forming the internal space 141. By opening / closing the outer shell, the accommodation portion 140 can then receive and hold the rod-shaped matrix 150 that has been inserted into the internal space 141. In this case, the heating unit 121B can be provided on the holding portion of the accommodation portion 140, and can heat the rod-shaped matrix while pressing the rod-shaped matrix 150.

[0064] In addition, the means for atomizing the aerosol source is not limited to the heating provided by the heating unit 121B. For example, the means for atomizing the aerosol source can be induction heating. In this case, the inhalation device 100B includes at least an electromagnetic induction source (such as a coil) for generating a magnetic field, rather than the heating unit 121B. A receptor for generating heat by induction heating can be provided in the inhalation device 100B, or can be contained in the rod-shaped matrix 150.

[0065] The inhalation device 100B may further include a heating unit 121A, a liquid guiding part 122, a liquid storage part 123, and an 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 further mixes with the aerosol generated by the heating unit 121B and reaches the user's mouth.

[0066] Note that hereinafter, unless otherwise specified, the inhalation device of this embodiment is described as Figure 1B the inhalation device 100B shown, but the present invention is not limited thereto, and when the inhalation device 100 of this embodiment is Figure 1A the inhalation device 100A shown, it is also applicable.

[0067] [2. Circuit Configuration of Inhalation Device]

[0068] Next, the circuit configuration of the inhalation device 100 will be described. Note that hereinafter, for the sake of simplifying the explanation, the focus of the explanation will be on the parts of the circuit of the inhalation device 100 related to supplying power to the heating unit 121 (for example, the heating unit 121B), and the descriptions and explanations of other parts should be omitted or simplified as appropriate.

[0069] Figure 2 is a view showing a first example of the circuit configuration of the inhalation device 100. In Figure 2 it, the wiring indicated by the symbol Ln is the wiring having a reference potential in the circuit of the inhalation device 100. Hereinafter, the wiring Ln will also be referred to as the "ground wire Ln", and the potential of the ground wire Ln will be 0 V. Additionally, hereinafter, unless otherwise specified, each of the following voltages should represent the potential difference from the ground wire Ln (i.e., 0 V).

[0070] As Figure 2 shown, the inhalation device 100 includes a power supply unit 111 (for example, the power supply unit 111B) which is a rechargeable battery (such as a lithium-ion rechargeable battery), a resistor Rheat serving as a heating resistor of the heating unit 121 (for example, the heating unit 121B), and an MCU 50 serving as a microprocessor for implementing the control unit 116 (for example, the control unit 116B). In addition, the inhalation device 100 further includes a first voltage system 10, a second voltage system 20, and a temperature detection circuit 30.

[0071] For example, the power supply unit 111 is configured to be able to output approximately 4 V as the voltage on the positive terminal and the negative terminal. Hereinafter, the output voltage of the power supply unit 111 is also referred to as the "power supply voltage Vbat". The positive terminal of the power supply unit 111 is connected to the power supply voltage line Lbat. The negative terminal of the power supply unit 111 is connected to the ground line Ln.

[0072] <2-1. First voltage system>

[0073] The first voltage system 10 is provided between the power supply unit 111 and the resistor Rheat (i.e., the heating unit 121), and is configured to be able to supply a first voltage generated based on the power supply voltage Vbat to the resistor Rheat.

[0074] In Figure 2 the illustrated example, the first voltage system 10 includes a first DC / DC converter 11 and a first switch circuit 12. Then, the first voltage system 10 can supply the system voltage Vcc (described later) generated by the first DC / DC converter 11 to the resistor Rheat via the first switch circuit 12 and the resistor Rref. Here, the resistor Rref is a resistor having a prescribed resistance and is connected in series with the resistor Rheat.

[0075] The first DC / DC converter 11 is used in combination with a first inductor L1 serving as a power inductor, and is an IC (integrated circuit) serving as a switching regulator for converting an input DC voltage into a prescribed DC voltage.

[0076] For example, the first DC / DC converter 11 includes a VIN terminal, a GND terminal, a VOUT terminal, an LX1 terminal, and an LX2 terminal as terminals for electrically connecting the inside and the outside of the first DC / DC converter 11.

[0077] The VIN terminal of the first DC / DC converter 11 is a power supply terminal on the high potential side of the first DC / DC converter 11, and is connected to the positive terminal of the power supply unit 111 via the power supply voltage line Lbat. The GND terminal is a ground terminal (in other words, a power supply terminal on the low potential side) of the first DC / DC converter 11 and is connected to the ground line Ln. The VOUT terminal is an output terminal for outputting the system voltage Vcc generated by the first DC / DC converter 11, and is connected to the VBAT terminal, which is a power supply terminal on the high potential side of the MCU 50, via the system voltage line Lsys1. The LX1 terminal and the LX2 terminal are used to connect the first DC / DC converter 11 and the first inductor L1.

[0078] For example, when a supply voltage Vbat is input via the VIN terminal, the first DC / DC converter 11 generates a system voltage Vcc and outputs the system voltage from the VOUT terminal. The system voltage Vcc output from the first DC / DC converter 11 can be supplied to the MCU 50 and / or the resistor Rheat via the system voltage line Lsys1. In other words, the system voltage line Lsys1 is a power line for supplying the system voltage Vcc from the first DC / DC converter 11.

[0079] The system voltage Vcc is a voltage required for the normal operation of the MCU 50 and can be, for example, 3.3 V. Hereinafter, the system voltage Vcc is described as 3.3 V, but the system voltage is not limited thereto. However, the system voltage Vcc should be set to be lower than the heating voltage Vheat, which will be described later.

[0080] The first switch circuit 12 is a circuit that operates under the control of the MCU 50 and serves as a switch for connecting or disconnecting the first voltage system 10 and the resistor Rheat (i.e., the heating unit 121). When the first switch circuit 12 is in the on state, the first voltage system 10 is electrically connected to the resistor Rheat, and when the first switch circuit 12 is in the off state, the first voltage system 10 is electrically disconnected from the resistor Rheat.

[0081] In Figure 2 the illustrated example, the first switch circuit 12 includes a BJT 12a (BJT: bipolar junction transistor), FETs 12b (FET: field effect transistor), 12c, and a resistor Ra. The BJT 12a is an NPN-type bipolar transistor. The FETs 12b and 12c are P-channel MOSFETs (metal oxide semiconductor field effect transistors). The resistor Ra is a resistor having a specified resistance.

[0082] The base of BJT 12a is connected to a specified output terminal (e.g., terminal F9 herein) of MCU 50. The emitter of BJT 12a is connected to the ground line Ln. The collector of BJT 12a is connected to the respective gates of FET 12b and FET 12c. Note that a configuration including a base resistor between the base of BJT 12a and the specified output terminal of MCU 50 can be adopted, or a configuration including a collector resistor between the collector of BJT 12a and the respective gates of FET 12b and FET 12c can be adopted, or a configuration with appropriately inserted components can be adopted. Additionally, BJT 12a is an example of a switch (first switch) for adjusting the gate potential of FET 12b and FET 12c, but this switch is not limited to an NPN bipolar transistor such as BJT 12a. For example, a switch for adjusting the gate potential of FET 12b and FET 12c can be an N-channel MOSFET. In this case, the gate of the N-channel MOSFET is connected to the specified output terminal (e.g., terminal F9) of MCU 50, the source is connected to the ground line Ln, and the drain is connected to the respective gates of FET 12b and FET 12c.

[0083] The respective sources of FET 12b and FET 12c are connected to each other and are connected to the respective gates of FET 12b and FET 12c through resistor Ra. The drain of FET 12b is connected to connection point Cp1 provided on system voltage line Lsys1. The drain of FET 12c is connected to one end of resistor Rheat through resistor Rref.

[0084] The other end of resistor Rheat is connected to the ground line Ln via, for example, FET 60, which serves as a low-side switch to turn on or off the power supply to resistor Rheat.

[0085] For example, FET 60 is an N-channel MOSFET. Additionally, the gate of FET 60 is connected to a specified output terminal (e.g., terminal K9) of MCU 50. The drain of FET 60 is connected to the other end of resistor Rheat. The source of FET 60 is connected to the ground line Ln.

[0086] <2-2. Second Voltage System>

[0087] The second voltage system 20 is provided between the power supply unit 111 and resistor Rheat (i.e., the heating unit 121) and is configured to be able to supply a second voltage generated based on the supply voltage Vbat (i.e., the output voltage of the power supply unit 111) to resistor Rheat.

[0088] In Figure 2In the illustrated example, the second voltage system 20 includes a second DC / DC converter 21 and a second switch circuit 22. Then, the second voltage system 20 can supply a heating voltage Vheat (described later) generated by the second DC / DC converter 21 to the resistor Rheat via the second switch circuit 22.

[0089] The second DC / DC converter 21 is used in combination with a second inductor L2 serving as a power inductor, and is an IC serving as a switching regulator for converting an input DC voltage into a specified DC voltage.

[0090] For example, the second DC / DC converter 21 includes a VIN terminal, a GND terminal, a VOUT terminal, a SW terminal, a BST terminal, and an EN terminal as terminals for electrically connecting the inside and outside of the second DC / DC converter 21.

[0091] The VIN terminal of the second DC / DC converter 21 is a power supply terminal on the high potential side of the second DC / DC converter 21, and is connected to the positive terminal of the power supply unit 111 via a power supply voltage line Lbat. The GND terminal is the ground terminal of the second DC / DC converter 21 and is connected to the ground wire Ln. The VOUT terminal is an output terminal, and is connected to the connection point Cp2 between the resistor Rref and the resistor Rheat via a heating voltage line Lheat. The heating voltage Vheat generated by the second DC / DC converter 21 is output at this output terminal. The SW terminal and the BST terminal are used to connect the second DC / DC converter 21 and the second inductor L2. In addition, the EN terminal is connected to a specified output terminal (for example, the K9 terminal) of the MCU 50.

[0092] When a power supply voltage Vbat is input via the VIN terminal, in a state where a high-level voltage is input to the EN terminal, the second DC / DC converter 21 generates a heating voltage Vheat by boosting the power supply voltage Vbat, for example, and outputs the heating voltage from the VOUT terminal. The heating voltage Vheat output from the second DC / DC converter 21 can be supplied to the resistor Rheat via the heating voltage line Lheat. In other words, the heating voltage line Lheat is a power line for supplying the heating voltage Vheat from the second DC / DC converter 21.

[0093] In this embodiment, the heating voltage Vheat is set to a voltage higher than the system voltage Vcc (i.e., 3.3 V), such as 5 V, in order to efficiently and quickly generate heat in the resistor Rheat (i.e., the heating unit 121). Hereinafter, the heating voltage is described as 5 V, but the heating voltage is not limited thereto.

[0094] The second switching circuit 22 operates under the control of the MCU 50 and serves as a switch for controlling the supply of power from the second voltage system 20 to the resistor Rheat (i.e., the heating unit 121). In an embodiment, power is supplied to the heating unit 121 in the form of pulses, for example, by pulse width modulation (PWM). The second switching circuit 22 is used to adjust the duty cycle of the power pulses supplied to the heating unit 121.

[0095] In Figure 2 In the illustrated example, the second switching circuit 22 includes a BJT 22a and an FET 22b. The BJT 22a is an NPN bipolar transistor. The FET 22b is a P-channel MOSFET.

[0096] The base of the BJT 22a is connected to a predetermined output terminal of the MCU 50 (e.g., the L9 terminal herein). The emitter of the BJT 22a is connected to the ground line Ln. The collector of the BJT 22a is connected to the gate of the FET 22b. It should be noted that a configuration including a base resistor between the base of the BJT 22a and the predetermined output terminal of the MCU 50 can be adopted, or a configuration including a collector resistor between the collector of the BJT 22a and the gate of the FET 22b can be adopted, or a configuration with appropriately inserted components can be adopted. In addition, the BJT 22a is an example of a switch for adjusting the gate potential of the FET 22b, and this switch is not limited to an NPN bipolar transistor such as the BJT 22a. For example, a switch for adjusting the gate potential of the FET 22b can be used as an N-channel MOSFET. In this case, the gate of the N-channel MOSFET is connected to a predetermined output terminal of the MCU 50 (e.g., the L9 terminal), the source is connected to the ground line Ln, and the drain is connected to the gate of the FET 22b.

[0097] The FET 22b is provided on the heating voltage line Lheat. Then, the drain of the FET 22b is connected to the above connection point Cp2. The source of the FET 22b is connected to the VOUT terminal of the second DC / DC converter 21.

[0098] <2-3. Temperature Measurement Circuit>

[0099] The temperature detection circuit 30 is configured such that the MCU 50 can obtain the amount of voltage drop caused by the resistor Rheat (i.e., the heating unit 121). It should be noted that if the MCU 50 can obtain the amount of voltage drop caused by the resistor Rheat, the resistance of the resistor Rheat can be obtained based on this voltage drop amount. Additionally, if the MCU 50 can obtain the resistance of the resistor Rheat, the temperature of the resistor Rheat can be obtained based on this resistance.

[0100] InFigure 2 In the illustrated example, the temperature detection circuit 30 includes a first voltage divider circuit 31, an operational amplifier 32, and a second voltage divider circuit 33.

[0101] The first voltage divider circuit 31 includes a series connection between a resistor Rh and a resistor Rl, where each resistor has a prescribed resistance. Additionally, one end of the first voltage divider circuit 31 on the resistor Rh side is connected to a connection point Cp3 between the drain of the FET 12b and the resistor Rref. The other end of the first voltage divider circuit 31 on the resistor Rl side is connected to the ground line Ln. Furthermore, a connection point Cp4 between the resistor Rh and the resistor Rl in the first voltage divider circuit 31 is connected to a prescribed input terminal (e.g., the F1 terminal in this case) of the MCU 50.

[0102] The operational amplifier 32 is, for example, an amplifier having an IN+ terminal as a non-inverting input terminal, an IN- terminal as an inverting input terminal, and an OUT terminal as an output terminal, and this amplifier outputs from the OUT terminal the result of amplifying the potential difference between the IN+ terminal and the IN- terminal by a prescribed amplification factor (differential gain). In the present embodiment, the operational amplifier 32 is configured as an IC, and in addition to the above terminals, it further includes a VS terminal, a GND terminal, and an EN terminal.

[0103] The VS terminal of the operational amplifier 32 is a power supply terminal on the high potential side of the operational amplifier 32 and is connected to the system voltage line Lsys1. The GND terminal is a ground terminal on the operational amplifier 32 and is connected to the ground line Ln. The IN+ terminal is connected to the above connection point Cp2. The IN- terminal is connected to a connection point Cp5 between the other end of the resistor Rheat and the drain of the FET 60. The OUT terminal is connected to one end of the second voltage divider circuit 33 on the resistor Rhh side, which will be described later. The EN terminal is connected to a prescribed output terminal (e.g., the K9 terminal in this case) of the MCU 50.

[0104] For example, when a prescribed supply voltage is supplied via the VS terminal and the GND terminal, and a high-level voltage is input to the EN terminal, the operational amplifier 32 amplifies the potential difference between the IN+ terminal and the IN+ terminal and outputs the result from the OUT terminal. Note that in Figure 2 the illustrated example, the system voltage Vcc is supplied to the operational amplifier 32 as the supply voltage.

[0105] The second voltage divider circuit 33 includes a series connection between a resistor Rhh and a resistor Rhl, where each resistor has a specified resistance. One end of the second voltage divider circuit 33 on the resistor Rhh side is connected to the OUT terminal of the operational amplifier 32. The other end of the second voltage divider circuit 33 on the resistor Rhl side is connected to the ground line Ln. In addition, the connection point Cp6 between the resistor Rhh and the resistor Rhl in the second voltage divider circuit 33 is connected to a specified input terminal (e.g., the D1 terminal here) of the MCU 50.

[0106] <2-4. MCU>

[0107] For example, the MCU 50 mainly consists of a processor that performs various calculations and controls the operation of a specified control target provided in the circuit of the inhalation device 100. Examples of the control targets controlled by the MCU 50 may include the aforementioned BJT 12a, the second DC / DC converter 21, BJT 22a (i.e., FET 22b), the operational amplifier 32, FET 60, etc.

[0108] For example, the MCU 50 includes a VBAT terminal, a GND terminal, an F9 terminal, an L9 terminal, a K9 terminal, an F1 terminal, and a D1 terminal as terminals for electrically connecting the inside and outside of the MCU 50.

[0109] The VBAT terminal of the MCU 50 is a power supply terminal on the high-potential side of the MCU 50 and is connected to the system voltage line Lsys1. The GND terminal is the ground terminal of the MCU 50 and is connected to the ground line Ln. The F9 terminal, L9 terminal, and K9 terminal are output terminals from which a specified electrical signal (i.e., voltage) is output. The F1 terminal and D1 terminal are input terminals for inputting a specified electrical signal.

[0110] For example, the MCU 50 can control the operation of the control target using the output from the F9 terminal, L9 terminal, or K9 terminal. More specifically, the MCU 50 can control the BJT 12a using the output from the F9 terminal, control BJT 22 (i.e., FET 22b) using the output from the L9 terminal, and control the second DC / DC converter 21, the operational amplifier 32, and FET 60 using the output from the K9 terminal. In addition, the MCU 50 can obtain the amount of voltage drop caused by the resistor Rheat (i.e., the heating unit 121) based on the input from the F1 terminal and D1 terminal.

[0111] Note that the MCU 50 may further include a memory device (e.g., flash memory) that implements the memory unit 114, a communication module that implements the communication unit 115, etc.

[0112] [3. Examples of the operation of the inhalation device]

[0113] Next, an operation example of the inhalation device 100 will be described. For example, the MCU 50 serving as the control unit 116 of the inhalation device 100 supplies power to the heating unit 121 (more specifically, the resistor Rheat) in response to an aerosol generation request from the user, thereby causing the heating unit 121 to generate an aerosol.

[0114] The aerosol generation request may be, for example, an operation for indicating the start of heating (hereinafter also referred to as "heating start operation"). As an example, the heating start operation may be pressing a predetermined operation button (not shown) provided on the inhalation device 100. As another example, the heating start operation may be inserting the rod-shaped substrate 150 into the inhalation device 100 or inhaling on the inhalation device 100. In addition, the aerosol generation request is not limited to directly operating on the inhalation device 100, but may, for example, receive predetermined information from another device (such as a smartphone) capable of communicating with the inhalation device 100. The MCU 50 may detect the aerosol generation request based on information obtained by, for example, the sensor unit 112 or the communication unit 115.

[0115] Then, for example, within a period of time from the detection of the aerosol generation request to the elapse of a specified time (e.g., 300 s) or the inhalation of a specified amount (e.g., 15 times), the MCU 50 repeatedly executes temperature detection control at a specified cycle (e.g., every 50 ms) to obtain the actual temperature of the heating unit 121 (hereinafter also referred to as "actual temperature"), and repeatedly executes heating control to control the temperature of the heating unit 121 so that the actual temperature obtained by the temperature detection control approaches a specified target temperature.

[0116] Note that the period of time from the detection of the aerosol generation request to the elapse of a specified time or the inhalation of a specified amount, or in other words, the period during which the temperature detection control and the heating control are repeatedly executed, is hereinafter also referred to as the "smoking period". The inhalation device 100 generates an aerosol during the smoking period, thereby allowing the user to inhale (or in other words, puff) the aerosol.

[0117] In the temperature detection control, the MCU 50 obtains, for example, the amount of voltage drop caused by the heating unit 121 (more specifically, the resistor Rheat) when a specified voltage is supplied to the heating unit 121, and obtains the resistance of the heating unit 121 based on the amount of voltage drop. In addition, the MCU 50 obtains the temperature of the heating unit 121 based on the resistance of the heating unit 121. As an example, the MCU 50 may obtain the temperature according to the resistance of the heating unit 121 by using a map, a calculation formula, etc. that define the relationship between the resistance and the temperature of the heating unit 121.

[0118] In addition, the heating control can be achieved by known feedback control. For example, the MCU 50 supplies power to the heating unit 121 in the form of pulses through pulse width modulation (PWM). In this case, the MCU 50 can perform heating control by adjusting the duty cycle of the power pulses supplied to the heating unit 121.

[0119] More specifically, the MCU 50 only needs to control the power (e.g., the duty cycle) supplied to the heating unit 121 based on the difference between the actual temperature and the target temperature, etc. In addition, the feedback control can be proportional integral derivative controller (PID) control. Alternatively, the MCU 50 can perform simple on-off control. In this case, for example, the MCU 50 can supply power to the heating unit 121 until the actual temperature reaches the target temperature, stop supplying power to the heating unit 121 when the actual temperature reaches the target temperature, and supply power to the heating unit 121 again when the actual temperature drops below the target temperature.

[0120] <3-1. Temperature Detection Control>

[0121] Next, a control example of the MCU 50 for each control target during temperature detection control is described. Figure 3 is a view showing a control example of the MCU 50 for each control target during temperature detection control. It should be noted that in this section, the focus is on the regions different from those described in Figure 2 and the regions common to those described in Figure 2 will be omitted or appropriately simplified. In addition, it is assumed below that power is supplied from the power supply unit 111 to the first DC / DC converter 11 and the second DC / DC converter 21.

[0122] As Figure 3 shown, in temperature detection control, the MCU 50 sets the output from the K9 terminal to a high level. This supplies a high-level voltage to the EN terminal of each of the second DC / DC converter 21 and the operational amplifier 32. Therefore, each of the second DC / DC converter 21 and the operational amplifier 32 is in an operable state. In addition, a high-level voltage output from the K9 terminal of the MCU 50 is also supplied to the gate of the FET 60, which is the low-side switch of the resistor Rheat. This places the FET 60 in the on state.

[0123] In addition, in temperature detection control, the MCU 50 sets the output from the F9 terminal to a high level. This supplies a drive current to the base of the BJT12a and places the BJT 12a in the on state. When the BJT 12a is on, 0 V of the ground wire Ln is supplied to the corresponding gates of the FET 12b and the FET 12c connected to the collector of the BJT12a.

[0124] Meanwhile, the current from the system voltage line Lsys1 flows through the body diode D1 of the FET 12b to the corresponding source electrodes of the FET 12b and the FET 12c, thereby generating a voltage which is the system voltage Vcc supplied (i.e., 3.3 V) minus the forward voltage of the body diode D1, so that a potential difference is generated between the corresponding source and gate electrodes of the FET 12b and the FET 12c. Therefore, both the FET 12b and the FET 12c are in the ON state. Then, when the FET 12b and the FET 12c are in the ON state, the first switch circuit 12 is in the ON state. In other words, the ON state of the first switch circuit 12 means that both the FET 12b and the FET 12c are in the ON state.

[0125] When the first switch circuit 12 is in the ON state, the system voltage Vcc is supplied to the series circuit of the resistor Rref and the resistor Rheat. Hereinafter, the voltage supplied to the series circuit of the resistor Rref and the resistor Rheat through the first switch circuit 12 entering the ON state is also referred to as "reference voltage Vtemp".

[0126] When the reference voltage Vtemp is supplied to the series circuit of the resistor Rref and the resistor Rheat, the measured voltage Vheat_temp is input to the IN+ terminal of the operational amplifier 32, and this measured voltage is the voltage obtained by dividing the reference voltage Vtemp by the resistor Rref and the resistor Rheat. At the same time, since the FET 60 is in the ON state, 0 V of the ground wire Ln is supplied to the IN- terminal of the operational amplifier 32.

[0127] Therefore, the operational amplifier 32 outputs from the OUT terminal the voltage obtained by amplifying the measured voltage Vheat_temp by a specified amplification factor. The voltage output from the OUT terminal of the operational amplifier 32 is divided by the second voltage divider circuit 33 and then input to the D1 terminal of the MCU 50. In this way, the MCU 50 obtains the voltage value of the measured voltage Vheat_temp based on the voltage input to the D1 terminal.

[0128] In addition, when the first switch circuit 12 is turned on, the voltage obtained by dividing the reference voltage Vtemp (i.e., the system voltage Vcc) by the first voltage divider circuit 31 is input to the F1 terminal of the MCU 50. In this way, the MCU 50 obtains the voltage value of the reference voltage Vtemp based on the voltage input to the F1 terminal.

[0129] Then, the MCU 50 obtains the voltage drop amount caused by the resistor Rheat (i.e., the heating unit 121) based on the corresponding voltage values of the reference voltage Vtemp and the measured voltage Vheat_temp, obtains the resistance of the resistor Rheat based on this voltage drop amount, and obtains the temperature of the resistor Rheat (in other words, the actual temperature of the heating unit 121) based on this resistance. When obtaining the resistance of the resistor Rheat, it is not necessary to obtain the reference voltage Vtemp, but the voltage drop amount caused by the resistor Rheat (i.e., the heating unit 121) can be obtained based on the voltage value of the measured voltage Vheat_temp, and the resistance of the resistor Rheat can be obtained based on this voltage drop amount.

[0130] In addition, in the temperature detection control, the MCU 50 maintains the output from the L9 terminal at a low level. For example, this places the BJT 22a (i.e., the second switching circuit 22) in the off state, and sets the duty ratio of the power pulse of the heating voltage Vheat supplied to the resistor Rheat (i.e., the heating unit 121) to 0 [%].

[0131] Note that during the temperature detection control, the MCU 50 can stop the operation of the second DC / DC converter 21 by setting the input of the EN terminal of the second DC / DC converter 21 to a low level. For example, the EN terminal of the second DC / DC converter 21 can be connected to the output terminal of the MCU 50, and the output of this output terminal is at a low level during the temperature detection control. In this way, the power consumption caused by the unnecessary operation of the second DC / DC converter 21 can be reduced.

[0132] <3-2. Heating Control>

[0133] Next, a control example of the MCU 50 for each control target during the heating control is described. Figure 4 is a view showing the control example of the MCU 50 for each control target during the heating control. Note that in this section, the focus is on the areas different from those Figure 2 or Figure 3 described, and the areas common to those Figure 2 or Figure 3 described will be omitted or appropriately simplified.

[0134] As Figure 4 shown, in the heating control, the MCU 50 uses the output from the L9 terminal to control the on / off of the BJT 22a (i.e., the second switching circuit 22), thereby adjusting the duty ratio of the power pulse of the heating voltage Vheat supplied to the resistor Rheat (i.e., the heating unit 121). This allows the MCU 50 to make the actual temperature closer to the target temperature.

[0135] In addition, as Figure 4 shown, in the heating control, the MCU 50 sets the output from the F9 terminal to a low level. This places the BJT 12a in an OFF state, which interrupts the connection between the respective gates of the FETs 12b and 12c and the ground line Ln. During the heating control, the current from the heating voltage line Lheat can flow through the body diode D2 of the FET 12c to the respective sources of the FETs 12b and 12c. However, the connection between the respective gates of the FETs 12b and 12c and the ground line Ln is interrupted, and thus the potential difference between the respective sources and gates of the FETs 12b and 12c remains below the threshold at which these FETs are driven (e.g., approximately 0 V). Accordingly, both the FETs 12b and 12c are in an OFF state, and the first switching circuit 12 is in an OFF state. This makes it possible to suppress the current flowing into the first voltage system 10 due to the potential difference between the first voltage system 10 and the second voltage system 20 when the heating voltage Vheat is supplied to the heating unit 121.

[0136] As described above, the MCU 50 serving as the control unit 116 of the inhalation device 100 is configured to be able to control the supply of the first voltage (e.g., the system voltage Vcc) from the first voltage system 10 to the heating unit 121 (more specifically, the resistor Rheat) and the supply of the second voltage (e.g., the heating voltage Vheat) from the second voltage system to the heating unit 121.

[0137] More specifically, the MCU 50 can control the supply of the first voltage from the first voltage system 10 to the heating unit 121 by controlling the first switching circuit 12 of the first voltage system 10. In addition, the MCU 50 can control the supply of the second voltage from the second voltage system 20 to the heating unit 121 by controlling the second switching circuit 22 of the second voltage system 20.

[0138] Then, the MCU 50 obtains the temperature of the heating unit 121 (more specifically, the resistor Rheat) based on the resistance of the heating unit 121, and controls the supply of the second voltage to the heating unit 121 based on this temperature, obtaining the resistance by supplying the first voltage to the heating unit 121. Accordingly, it is possible to control the supply of power to the heating unit 121 while taking into account the actual temperature of the heating unit 121, which thus makes it possible to appropriately heat the aerosol source by the heating unit 121.

[0139] In addition, the first voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 is lower than the second voltage. Therefore, compared with the second voltage, the voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 can be reduced. Accordingly, the power consumption when obtaining the temperature of the heating unit 121 based on the resistance of the heating unit 121 can be reduced.

[0140] In addition, the first voltage system 10 includes a first DC / DC converter 11 that generates a system voltage Vcc based on a power supply voltage Vbat (the power supply voltage is the output voltage of the power supply unit 111), and the MCU 50 operates by being supplied with the system voltage Vcc. The first voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 is generated based on the system voltage Vcc. This enables the use of the first voltage to obtain the temperature of the heating unit 121 by obtaining the first voltage by utilizing the system voltage Vcc required to operate the MCU 50. Therefore, compared with the case where the voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 is a dedicated voltage independent of the system voltage Vcc, the configuration of the inhalation device 100 can be prevented from becoming complicated without a DC / DC converter or the like for generating a dedicated voltage.

[0141] The second voltage system 20 includes a second DC / DC converter 21 that boosts the power supply voltage Vbat (the power supply voltage is the output voltage of the power supply unit 111) to generate a heating voltage Vheat, and generates a second voltage supplied to the heating unit 121 for heating the aerosol source based on the heating voltage Vheat. This enables a voltage higher than the power supply voltage Vbat to be supplied to the heating unit 121 as the second voltage. Accordingly, the aerosol source can be efficiently heated by means of the heating unit 121.

[0142] The first voltage system 10 further includes a first switch circuit 12 that connects or disconnects the connection between the first voltage system 10 and the heating unit 121, and the first switch circuit 12 operates according to the control of the MCU 50. The MCU 50 sets the first switch circuit 12 to the on state when supplying the first voltage to the heating unit 121, and sets the first switch circuit 12 to the off state when supplying the second voltage to the heating unit 121. This enables the current caused by the potential difference between the first voltage system 10 and the second voltage system 20 to be prevented from flowing into the first voltage system 10 when the second voltage is supplied to the heating unit 121. Accordingly, the MCU 50 or the like connected to the first voltage system 10 can be protected from the current caused by the potential difference between the first voltage system 10 and the second voltage system 20.

[0143] The first switching circuit 12 includes a BJT 12a, and FETs 12b and 12c that are P-channel MOSFETs. In the BJT 12a, the base is connected to the MCU 50, the emitter is connected to the ground line Ln, and the collector is connected to the respective gates of the FETs 12b and 12c. The respective sources of the FETs 12b and 12c are connected to each other and are also connected to the respective gates of the FETs 12b and 12c through a resistor Ra having a predetermined resistance. Further, the drain of the FET 12b is connected to the system voltage line Lsys1 to which the system voltage Vcc is supplied by the first DC / DC converter 11, and the drain of the FET 12c is connected to the heating unit 121.

[0144] By configuring the first switching circuit 12 in this way, compared with the case where the first switching circuit 12 is configured as Figure 6 shown (which will be described later), the number of resistors required for the first switching circuit 12 can be reduced, and the configuration of the inhalation device 100 can be prevented from becoming complicated.

[0145] Note that when the first switching circuit 12 is configured as described above, the MCU 50 can set the BJT 12a to the on state when supplying the first voltage to the heating unit 121. When the BJT 12a is set to the on state, both the FETs 12b and 12c are set to the on state, and the first switching circuit 12 can be set to the on state. At the same time, when supplying the second voltage to the heating unit 121, the MCU 50 can set the BJT 12a to the off state. When the BJT 12a is set to the off state, both the FETs 12b and 12c are set to the off state, and the first switching circuit 12 can be set to the off state.

[0146] When the first switching circuit 12 is configured as described above, the orientation of each of the body diodes D1 of the FET 12b and the body diode D2 of the FET 12c points to the inside of the first switching circuit 12, and thus, after supplying the second voltage to the heating unit 121 (i.e., after heating control), charge may accumulate between the FET 12b and the FET 12c.

[0147] Therefore, preferably, after supplying the second voltage to the heating unit 121, the MCU 50 temporarily sets the BJT 12a to the on state at a specified timing. This allows the charge accumulated between the FET 12b and the FET 12c to escape to the ground line Ln after the second voltage is supplied to the heating unit 121. Therefore, the occurrence of a failure caused by the charge accumulated between the FET 12b and the FET 12c can be suppressed. Note that the above-mentioned specified timing may be, for example, at the end of a smoking period (i.e., when it is assumed that there will be some time before the next smoking).

[0148] In addition, the inhalation device 100 further includes an operational amplifier 32. In the operational amplifier 32, the IN+ terminal (non-inverting input terminal) is connected to one end of the heating unit 121, the IN- terminal (inverting input terminal) is connected to the other end of the heating unit 121, the output terminal is connected to the MCU 50, and the operational amplifier operates with the system voltage Vcc as the supply voltage. In addition, the MCU 50 obtains the resistance of the heating unit 121 based on the output of the operational amplifier 32, and obtains the temperature of the heating unit 121 based on the resistance. Compared with the case where the supply voltage of the operational amplifier 32 is higher than the system voltage Vcc (for example, the heating voltage Vheat), this makes it possible to further stabilize the operation of the operational amplifier 32 while reducing the power consumption of the operational amplifier 32.

[0149] More specifically, by setting the supply voltage of the operational amplifier 32 to the system voltage Vcc, the supply voltage can be supplied to the operational amplifier 32 before the heating voltage Vheat is applied. This allows the operational amplifier 32 to immediately operate when the MCU 50 supplies a high-level voltage to the EN terminal of the operational amplifier 32, thereby further stabilizing the operation of the operational amplifier 32.

[0150] [4. Another example of the circuit configuration of the inhalation device]

[0151] Next, another example of the circuit configuration of the inhalation device 100 of the present embodiment will be described. Note that hereinafter, the focus is on the area different from that shown in Figure 2 the first example, and the areas common to those described in the first example will be omitted or appropriately simplified.

[0152] <4-1. Second example of the circuit configuration of the inhalation device>

[0153] First, a second example of the circuit configuration of the inhalation device 100 will be described. The second example is a case where an LDO regulator (LDO: low dropout) for generating a step-down voltage by stepping down the system voltage Vcc is further provided to the inhalation device 100, and when the temperature of the heating unit 121 is acquired, a first voltage based on the step-down voltage generated by the LDO regulator is supplied to the heating unit 121.

[0154] Figure 5 is a view showing a second example of the circuit configuration of the inhalation device 100. As Figure 5 shown, the first voltage system 10 in this example further includes an LDO regulator 15 that steps down the system voltage Vcc generated by the first DC / DC converter 11 to generate a step-down voltage Vccl.

[0155] The LDO regulator 15 is provided, for example, in the MCU 50, which is an IC constituting the control unit 116 of the inhalation device 100. The LDO regulator 15 steps down the system voltage Vcc input via the VBAT terminal of the MCU 50 to generate a step-down voltage Vccl, and outputs the generated step-down voltage Vccl to the outside of the MCU 50.

[0156] For example, the step-down voltage Vccl is lower than the system voltage Vcc and can be set to 1.8 V. Hereinafter, the step-down voltage is described as 1.8 V, but the step-down voltage is not limited to this.

[0157] For example, the step-down voltage Vccl generated by the LDO regulator 15 is supplied to the step-down voltage line Lsys2 via an output terminal (not shown) of the MCU 50. In the case of this example, the connection point Cp1 to which the drain of the FET 12b is connected is provided on the step-down voltage line Lsys2.

[0158] Therefore, in the case of this example, in the temperature detection control, when the MCU 50 sets the first switch circuit 12 to the on state, the step-down voltage Vccl is supplied to the series circuit of the resistor Rref and the resistor Rheat. In other words, the reference voltage Vtemp in this example is the step-down voltage Vccl. The measured voltage Vheat_temp, which is a voltage obtained by dividing the reference voltage Vtemp (i.e., the step-down voltage Vccl) by the resistors Rref and Rheat, is input to the IN+ terminal of the operational amplifier 32.

[0159] In this example, by connecting the VS terminal of the operational amplifier 32 to the step-down voltage line Lsys2, preferably, a step-down voltage Vccl is supplied to the operational amplifier 32 as a supply voltage. This makes it possible to reduce the power consumption of the operational amplifier 32 compared with a case where the supply voltage of the operational amplifier 32 (for example, the heating voltage Vheat) is higher than the step-down voltage Vccl. In addition, the supply voltage can be supplied to the operational amplifier 32 before the heating voltage Vheat is applied, which allows the operational amplifier 32 to immediately operate when the MCU 50 supplies a high-level voltage to the EN terminal of the operational amplifier 32 and allows the operation of the operational amplifier 32 to be further stabilized.

[0160] As described above, the first voltage system 10 further includes an LDO regulator 15 that steps down the system voltage Vcc to generate a step-down voltage Vccl. The first voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 can be generated based on the step-down voltage Vccl. This allows the voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 to be further reduced, and the power consumption when obtaining the temperature of the heating unit 121 based on the resistance of the heating unit 121 can be further reduced.

[0161] In addition, the first voltage supplied to the heating unit 121 when obtaining the temperature of the heating unit 121 is based on the step-down voltage Vccl generated by the LDO regulator 15, which makes it possible to more accurately obtain the temperature of the heating unit 121.

[0162] More specifically, the system voltage Vcc generated by the first DC / DC converter 11 is strictly in a sawtooth wave shape. If such a system voltage Vcc is used as the reference voltage Vtemp, the quality of the input of the operational amplifier 32 may be degraded, resulting in a low signal-to-noise ratio (SNR) of the output from the operational amplifier 32.

[0163] In contrast, compared with the system voltage Vcc generated by the first DC / DC converter 11, the step-down voltage Vccl generated by the LDO regulator 15 has a stable value. Therefore, by setting such a step-down voltage Vccl as the reference voltage Vtemp, the SNR of the output from the operational amplifier 32 can be improved and the accuracy of the temperature of the heating unit 121 can be improved, and the temperature is obtained based on the output of the operational amplifier 32.

[0164] In addition, the LDO regulator 15 can be provided, for example, in the MCU 50, which is an IC constituting the control unit 116 of the inhalation device 100. Therefore, the step-down voltage Vccl can be generated using fewer components than a configuration including an LDO regulator separate from the MCU 50. Therefore, the configuration of the inhalation device 100 can be prevented from becoming complicated.

[0165] <4-2. Third Example of Circuit Configuration of Inhalation Device>

[0166] A third example of the circuit configuration of the inhalation device 100 will be described next. The third example described below is an example when the configuration of the first switch circuit 12 is changed with respect to the first example or the second example described above.

[0167] Figure 6 is a view showing a third example of the circuit configuration of the inhalation device 100. As Figure 6 shown, the first switch circuit 12 of this example includes a BJT 12a, FETs 12b, 12c, and two resistors Ra (resistor Ra1 and resistor Ra2).

[0168] In this example, the respective drains of the FETs 12b and 12c are connected to each other. The source of the FET 12b is connected to one end of the resistor Rheat (i.e., the heating unit 121) via the resistor Rref and is also connected to the gate of the FET 12b via the resistor Ra1. The source of the FET 12c is connected to the connection point Cp1 provided on the system voltage line Lsys1 or the step-down voltage line Lsys2 and is also connected to the gate of the FET 12c via the resistor Ra2. It should be noted that although the illustration and detailed explanation are omitted, the connection relationship of the BJT 12a in this example is also the same as that in the first example or the second example described above. In this example, similar to the first example or the second example described above, an N-channel MOSFET can also be provided instead of the BJT 12a (bipolar transistor) in this example.

[0169] Even if the first switch circuit 12 is configured as shown in this example, in temperature detection control, the MCU 50 can turn on the FETs 12b and 12c, or turn on the first switch circuit 12 by turning on the BJT 12a, that is, by setting the output from the F9 terminal to a high level. Therefore, similar to the first example or the second example described above, a reference voltage Vtemp can be supplied to the series circuit of the resistor Rref and the resistor Rheat.

[0170] In addition, even if the first switching circuit 12 is configured as shown in this example, during heating control, the MCU 50 can also turn off the BJT 12a by setting the output from the F9 terminal to a low level, or turn off the first switching circuit 12 by turning off the BJT 12a. This makes it possible to suppress current from flowing into the first voltage system 10 due to the potential difference between the first voltage system 10 and the second voltage system 20 when the second voltage is supplied to the heating unit 121. Therefore, the MCU 50 etc. connected to the first voltage system 10 can be protected from the current caused by the potential difference between the first voltage system 10 and the second voltage system 20. The potential difference between the source and the gate of the FET 12b can be calculated based on the potential difference between the first voltage system 10 and the second voltage system 20, the resistance of the two resistors Ra, etc., but the gate threshold voltage of the FET 12b is set to be higher than the voltage dropped at the resistor Ra1 when the second voltage is supplied to the heating unit 121 during heating control.

[0171] In addition, a connection point Cp3 provided between the source of the FET 12b and the resistor Rref is connected to a connection point Cp1 provided on the system voltage line Lsys1 or the buck voltage line Lsys2, and the resistors Ra1 and Ra2 are interposed between the two connection points. Therefore, when the second voltage is supplied to the heating unit 121, a small current flows into the first voltage system 10. Considering this, when the first switching circuit 12 is configured as in this example, it is preferable to select the first DC / DC converter 11 or the LDO regulator 15 having a configuration that can tolerate such a small current inflow.

[0172] In addition, when the first switching circuit 12 is configured as in this example, after the second voltage is supplied to the heating unit 121 (i.e., after heating control), charge does not accumulate between the FET 12b and the FET 12c. This is because the body diode D1 of the FET 12b and the body diode D2 of the FET 12c operate to release the charge between the FET 12b and the FET 12c to the outside. Therefore, when the first switching circuit 12 is configured as in this example, after the second voltage is supplied to the heating unit 121, it is not necessary to temporarily set the BJT 12a to the on state, and the control of the first switching circuit 12 by the MCU 50 can be simplified.

[0173] <4-3. Fourth Example of the Circuit Configuration of the Inhaler Device>

[0174] Next, a fourth example of the circuit configuration of the inhaler device 100 will be described. The fourth example described below is an example in which the first switching circuit 12 in the above first example, second example, or third example is configured by an IC serving as a load switch.

[0175] Figure 7 is a view showing a fourth example of the circuit configuration of the inhalation device 100. The first switch circuit 12 of this example includes a load switch 12A, as Figure 7 shown. The load switch 12A is an IC that operates under the control of the MCU 50 and serves as a switch for connecting or disconnecting the connection between the first voltage system 10 and the resistor Rheat (i.e., the heating unit 121).

[0176] For example, the load switch 12A includes a VIN terminal, a GND terminal, a VOUT terminal, and an ON terminal as terminals for electrically connecting the inside and outside of the load switch 12A.

[0177] The VIN terminal of the load switch 12A is the input terminal of the load switch 12A and is connected to the connection point Cp1 provided on the system voltage line Lsys1 or the buck voltage line Lsys2. The GND terminal is the ground terminal of the load switch 12A and is connected to the ground wire Ln. The VOUT terminal is the output terminal of the load switch 12A and is connected to one end of the resistor Rheat via the resistor Rref. The ON terminal is connected to, for example, the F9 terminal of the MCU 50.

[0178] For example, the load switch 12A outputs the voltage supplied from the VOUT terminal to the VIN terminal only when a high-level voltage is input to the ON terminal.

[0179] Even when the first switch circuit 12 is configured with the load switch 12A as in this example, in the temperature detection control, the MCU 50 outputs the system voltage Vcc or the buck voltage Vccl from the load switch 12A by setting the output from the F9 terminal to high level, and similar to the first example, the second example, or the third example above, the reference voltage Vtemp can be supplied to the series circuit of the resistor Rref and the resistor Rheat.

[0180] For example, by providing the above first switch circuit 12 inside the load switch 12A between the VIN terminal and the VOUT terminal, when a low-level voltage is input to the ON terminal, the current anti-backflow function between the VIN terminal and the VOUT terminal operates, and when the heating voltage Vheat is supplied to the heating unit 121, the current flowing into the first voltage system 10 due to the potential difference between the first voltage system 10 and the second voltage system can be suppressed.

[0181] In addition, when the first switch circuit 12 is configured with the load switch 12A as in this example, compared with, for example, when the first switch circuit 12 is configured with separate electronic components, the number of required electronic components can be reduced, and the configuration of the inhalation device 100 can be prevented from becoming complicated. In addition, the installation work of the first switch circuit 12 can also be simplified.

[0182] In addition, the load switch 12A preferably does not have an output discharge function. If the load switch 12A is configured to have a discharge resistor for the output discharge function, when the second voltage system 20 supplies the heating voltage Vheat to the heating unit 121, the voltage applied to the VOUT terminal side is applied to the discharge resistor, and the power consumption increases. Therefore, by configuring the load switch 12A to have no output discharge function, an increase in power consumption when the second voltage system 20 supplies the heating voltage Vheat to the heating unit 121 can be suppressed.

[0183] As described above, according to the present embodiment, the inhalation device 100 can be provided, which can reduce the power consumption when obtaining the temperature of the heating unit 121 based on the resistance of the heating unit 121.

[0184] The MCU 50 only needs the output of the operational amplifier 32 during the temperature detection control. However, in the present embodiment, the MCU 50 supplies a high-level voltage to the EN terminal of the operational amplifier 32, so that the operational amplifier 32 operates not only during the temperature detection control but also during the heating control. This is because it may take a certain amount of time for the operation of the operational amplifier 32 to start until the operation of the operational amplifier 32 (in other words, the output of the operational amplifier 32) stabilizes.

[0185] If the operational amplifier 32 only operates during the temperature detection control, the MCU 50 will obtain the temperature of the heating unit 121 based on the output of the operational amplifier 32 before it stabilizes, which risks reducing the accuracy of the obtained temperature. From the perspective of suppressing the occurrence of this situation, in the present embodiment, the operational amplifier 32 operates not only during the temperature detection control but also during the heating control. Therefore, the accuracy of the temperature of the heating unit 121 obtained based on the output of the operational amplifier 32 can be improved.

[0186] In other words, the MCU 50 can operate the operational amplifier 32 only during the temperature detection control, provided that the operational amplifier 32 has fast stabilization characteristics. As an example, if the EN terminal of the operational amplifier 32 is connected to the F9 terminal of the MCU 50, the MCU 50 can operate the operational amplifier 32 only during the temperature detection control. Therefore, by operating the operational amplifier 32 only during the temperature detection control, the operational amplifier 32 can operate only when the MCU 50 needs the output of the operational amplifier 32, which makes it possible to reduce the power consumption caused by excessive operation of the operational amplifier 32.

[0187] In the present embodiment, the power consumption in obtaining the temperature of the heating unit 121 is reduced by reducing the voltage supplied to the heating unit 121. On the other hand, a method can also be conceived, in which the voltage during obtaining the temperature of the heating unit 121 is set to the heating voltage Vheat, and its current value is reduced to, for example, reduce the power consumption.

[0188] However, the second DC / DC converter 21 that generates the heating voltage Vheat generally has characteristics dedicated to outputting a large current, such that the heating unit 121 (resistor Rheat) can be heated efficiently and quickly, and operations such as outputting a small current cannot be performed efficiently. Therefore, if the voltage during obtaining the temperature of the heating unit 121 is set to the heating voltage Vheat, the effect of reducing the power consumption is limited even if the current value is reduced.

[0189] The switching frequency of the first DC / DC converter 11 is preferably set to be higher than the switching frequency of the second DC / DC converter 21. In other words, as described above, the voltages output from the first DC / DC converter 11 and the second DC / DC converter 21 can fluctuate in the form of a sawtooth wave. The smaller the switching frequency, the greater its fluctuation.

[0190] Therefore, if the switching frequency of the first DC / DC converter 11 that generates the system voltage Vcc serving as the voltage input source of the operational amplifier 32 is reduced, the input quality of the operational amplifier 32 will be reduced, thereby also resulting in a low SNR of the output from the operational amplifier 32. Therefore, there is a risk that the accuracy of the temperature of the heating unit 121 obtained based on the output of the operational amplifier 32 may be reduced.

[0191] Therefore, preferably, the switching frequency of the first DC / DC converter 11 is a frequency that is high to a certain extent. On the other hand, the switching frequency of the second DC / DC converter 21 that generates only the heating voltage Vheat for heating the heating unit 121 can sufficiently heat the heating unit 121 even if it is a bit low, and thus is less likely to cause problems.

[0192] Although an embodiment of the aerosol generating device of the present disclosure has been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to this embodiment. Obviously, those skilled in the art will be able to conceive of a plurality of variant examples or modification examples within the scope disclosed in the claims, and any such variant examples or modification examples are naturally understood to fall within the technical scope of the present disclosure. In addition, the components in the above-described embodiments can be arbitrarily combined without departing from the spirit of the present invention.

[0193] As an example of a modification example, a diode that allows current to flow only from the first voltage system 10 side to the second voltage system 20 side can be provided instead of the FET 12b described above. Even if such a diode is provided instead of the FET 12b, current flowing into the first voltage system 10 due to the potential difference between the first voltage system 10 and the second voltage system 20 can be suppressed. When a diode is provided instead of the FET 12b, preferably, as described above, the MCU 50 obtains the amount of voltage drop caused by the resistor Rheat (i.e., the heating unit 121) based on the respective voltage values of the reference voltage Vtemp and the measured voltage Vheat_temp, obtains the resistance of the resistor Rheat based on this voltage drop amount, and obtains the temperature of the resistor Rheat (in other words, the actual temperature of the heating unit 121) based on this resistance. During temperature detection control, the voltage obtained by subtracting the forward voltage of the diode from the first voltage is applied as the reference voltage Vtemp to the series circuit of the resistor Rref and the resistor Rheat. When obtaining the temperature of the resistor Rheat (in other words, the actual temperature of the heating unit), the MCU 50 obtains the voltage value of the reference voltage Vtemp based on the voltage input to the F1 terminal, and thus, even if a diode is provided instead of the FET 12b, temperature detection control can be performed in the same manner as when the FET 12b is provided.

[0194] Furthermore, the power supply voltage Vbat can be directly supplied to the LDO regulator 15, and the LDO regulator 15 can be configured to generate a step-down voltage Vccl based on the power supply voltage Vbat.

[0195] This specification and the like at least illustrate the following features. The corresponding components and the like in the above-described embodiments are shown in parentheses by way of example, but are not limited thereto.

[0196] (1) An aerosol generating device, comprising: a power source (power supply units 111, 111A, 111B);

[0197] a heating unit (heating units 121, 121A, 121B), the heating unit including a heating resistor (resistor Rheat) having an association between resistance and temperature, and being configured to be able to heat an aerosol source by being supplied with power;

[0198] a first voltage system (first voltage system 10), the first voltage system being provided between the power source and the heating unit, and being configured to supply a first voltage generated based on the output voltage of the power source to the heating unit;

[0199] A second voltage system (second voltage system 20) is provided between the power supply and the heating unit and is configured to supply a second voltage generated based on the output voltage of the power supply to the heating unit; and

[0200] A control unit (control units 116, 116A, 116B, MCU 50) is configured to control the supply of the first voltage from the first voltage system to the heating unit and the supply of the second voltage from the second voltage system to the heating unit, wherein

[0201] the first voltage is lower than the second voltage, and

[0202] the control unit obtains the temperature of the heating unit based on the resistance of the heating unit and controls the supply of the second voltage to the heating unit based on the temperature, and obtains the resistance by supplying the first voltage to the heating unit.

[0203] According to (1), the control unit obtains the temperature of the heating unit based on the resistance of the heating unit and controls the supply of the second voltage to the heating unit based on the temperature, and obtains the resistance by supplying the first voltage to the heating unit; thus, the power supply to the heating unit can be controlled while considering the actual temperature of the heating unit, and the heating of the aerosol source by the heating unit can be appropriately performed. In addition, the first voltage supplied to the heating unit when obtaining the temperature of the heating unit is lower than the second voltage, and thus the power consumption when obtaining the temperature of the heating unit can be reduced compared with the case where the second voltage is supplied when obtaining the temperature of the heating unit.

[0204] (2) The aerosol generating device according to (1), wherein

[0205] the first voltage system includes a first DC / DC converter (first DC / DC converter 11) that generates a specified system voltage according to the output voltage of the power supply,

[0206] the control unit operates by being supplied with the system voltage, and

[0207] the first voltage is generated based on the system voltage.

[0208] According to (2), the first voltage can be used to obtain the temperature of the heating unit by obtaining the first voltage by using the system voltage required to operate the control unit. Compared with the case where the voltage supplied to the heating unit when obtaining the temperature of the heating unit is a dedicated voltage independent of the system voltage, this makes it possible to suppress the complication of the configuration of the aerosol generating device without using a DC / DC converter or the like to generate a dedicated voltage.

[0209] (3) The aerosol generating device according to (2), wherein,

[0210] The second voltage system includes a second DC / DC converter (second DC / DC converter 21), which boosts the output voltage of the power supply to generate a heating voltage, and

[0211] The second voltage is generated based on the heating voltage.

[0212] According to (3), a voltage higher than the output voltage of the power supply can be supplied to the heating unit as the second voltage. This enables the aerosol source to be efficiently heated by the heating unit.

[0213] (4) The aerosol generating device according to (2) or (3), wherein,

[0214] The first voltage system further includes a switch circuit (first switch circuit 12), which connects or disconnects the connection between the first voltage system and the heating unit,

[0215] The switch circuit operates according to the control of the control unit, and

[0216] When supplying the first voltage to the heating unit, the control unit sets the switch circuit to the on state, and when supplying the second voltage to the heating unit, the control unit sets the switch circuit to the off state.

[0217] According to (4), it is possible to suppress the current flowing into the first voltage system caused by the potential difference between the first voltage system and the second voltage system when supplying the second voltage to the heating unit. This enables protection of electronic components connected to the first voltage system and the like from the influence of the current caused by the potential difference between the first voltage system and the second voltage system.

[0218] (5) The aerosol generating device according to (4), wherein,

[0219] The switch circuit includes a first switch (BJT 12a), a first FET (FET 12b), and a second FET (FET 12c). Each of the first FET and the second FET is a P-channel MOSFET,

[0220] The first switch is connected to the respective gates of the first FET and the second FET, and the opening / closing of the first switch is adjusted by the potential of these gates,

[0221] The respective sources of the first FET and the second FET are connected to each other, and are also connected to the respective gates of the first FET and the second FET through a resistor (resistor Ra) having a specified resistance,

[0222] The drain of the first FET is connected to a power line (system voltage line Lsys1) that supplies the system voltage from the first DC / DC converter, and

[0223] the drain of the second FET is connected to the heating unit.

[0224] According to (5), the number of resistors required for the switching circuit can be reduced, and the configuration of the aerosol generating device can be prevented from becoming complicated.

[0225] (6) An aerosol generating device according to any one of (2) to (5), wherein,

[0226] the aerosol generating device further includes an operational amplifier (operational amplifier 32),

[0227] in the operational amplifier, the non-inverting input terminal is connected to one end of the heating unit, the inverting input terminal is connected to the other end of the heating unit, the output terminal is connected to the control unit, and the operational amplifier operates with the system voltage as the supply voltage, and

[0228] the control unit obtains the resistance based on the output of the operational amplifier.

[0229] According to (6), compared with the case where the supply voltage of the operational amplifier is set higher than the system voltage (for example, the heating voltage), the power consumption of the operational amplifier can be reduced while avoiding a decrease in the accuracy of the temperature of the heating unit obtained based on the output of the operational amplifier.

[0230] (7) An aerosol generating device according to (2) or (3), wherein,

[0231] the first voltage system further includes an LDO regulator (LDO regulator 15), the LDO regulator steps down the system voltage to generate a stepped-down voltage, and

[0232] the first voltage is generated based on the stepped-down voltage.

[0233] According to (7), the voltage supplied to the heating unit when obtaining the temperature of the heating unit can be further reduced, and the power consumption when obtaining the temperature of the heating unit can be further reduced. In addition, the first voltage supplied to the heating unit when obtaining the temperature of the heating unit is based on the stepped-down voltage generated by the LDO regulator, which enables the temperature of the heating unit to be obtained more accurately.

[0234] (8) An aerosol generating device according to (7), wherein,

[0235] the LDO regulator is provided in an IC (MCU 50) that constitutes the control unit.

[0236] According to (8), a step-down voltage can be generated without adding an electronic component separate from the IC constituting the control unit. Therefore, it is possible to suppress the configuration of the aerosol generating device from becoming complicated.

[0237] (9) The aerosol generating device according to (7) or (8), wherein

[0238] The first voltage system further includes a switching circuit (first switching circuit 12) that connects or disconnects the connection between the first voltage system and the heating unit,

[0239] The switching circuit operates according to the control of the control unit, and

[0240] When supplying the first voltage to the heating unit, the control unit sets the switching circuit to the on state, and when supplying the second voltage to the heating unit, the control unit sets the switching circuit to the off state.

[0241] According to (9), it is possible to suppress current from flowing into the first voltage system due to the potential difference between the first voltage system and the second voltage system when the second voltage is supplied to the heating unit. This makes it possible to protect electronic components and the like connected to the first voltage system from the influence of the current caused by the potential difference between the first voltage system and the second voltage system.

[0242] (10) The aerosol generating device according to (9), wherein

[0243] The switching circuit includes a first switch (BJT 12a), a first FET (FET 12b), and a second FET (FET 12c), and each of the first FET and the second FET is a P-channel MOSFET,

[0244] The first switch is connected to the respective gates of the first FET and the second FET, and the opening / closing of the first switch is adjusted by the potential of these gates,

[0245] The respective sources of the first FET and the second FET are connected to each other and are also connected to the respective gates of the first FET and the second FET through a resistor having a predetermined resistance,

[0246] The drain of the first FET is connected to a power line (step-down voltage line Lsys2) to which the step-down voltage is supplied from the LDOL voltage regulator, and

[0247] The drain of the second FET is connected to the heating unit.

[0248] According to (10), the number of resistors required for the switching circuit can be reduced, and the configuration of the inhalation device can be suppressed from becoming complicated.

[0249] (11)The aerosol generating device according to any one of (7) to (10), wherein,

[0250] The aerosol generating device further includes an operational amplifier (operational amplifier 32),

[0251] In the operational amplifier, the non-inverting input terminal is connected to one end of the heating unit, the inverting input terminal is connected to the other end of the heating unit, the output terminal is connected to the control unit, and the operational amplifier operates with the buck voltage as the supply voltage, and

[0252] The control unit obtains the resistance based on the output of the operational amplifier.

[0253] According to (11), compared with the case where the supply voltage of the operational amplifier is set higher than the buck voltage (for example, the heating voltage), the power consumption of the operational amplifier can be reduced while avoiding a decrease in the accuracy of the temperature of the heating unit obtained based on the output of the operational amplifier.

[0254] (12)The aerosol generating device according to (5) or (10), wherein,

[0255] The first switch is a bipolar transistor, and

[0256] In the bipolar transistor, the base is connected to the control unit, the emitter is connected to the ground, and the collector is connected to the respective gates of the first FET and the second FET.

[0257] According to (12), the potentials of the respective gates of the first FET and the second FET can be adjusted by turning on and off (i.e., disconnecting / closing) the bipolar transistor serving as the first switch.

[0258] (13)The aerosol generating device according to (5) or (10), wherein,

[0259] The first switch is an N-channel MOSFET, and

[0260] In the N-channel MOSFET, the gate is connected to the control unit, the source is connected to the ground, and the drain is connected to the respective gates of the first FET and the second FET.

[0261] According to (13), the potentials of the respective gates of the first FET and the second FET can be adjusted by turning on and off (i.e., disconnecting / closing) the MOSFET serving as the first switch.

[0262] (14)The aerosol generating device according to (5) or (11), wherein,

[0263] After supplying the second voltage to the heating unit, the control unit further sets the first switch to the ON state at a prescribed timing.

[0264] According to (14), after supplying the second voltage to the heating unit, the charges accumulated between the first FET and the second FET are allowed to escape to the ground. This makes it possible to suppress the occurrence of failures and the like caused by the charges accumulated between the first FET and the second FET.

[0265] (15)The aerosol generating device according to (4) or (9), wherein,

[0266] The switch circuit is configured by a load switch (load switch 12A).

[0267] According to (15), compared with the case where the switch circuit is configured by individual electronic components, the number of required electronic components can be reduced, and the configuration of the aerosol generating device can be prevented from becoming complicated. In addition, the installation work of the switch circuit can be simplified.

[0268] (16)The aerosol generating device according to (4), wherein,

[0269] The switch circuit includes a bipolar transistor (BJT 12a), a first FET (FET 12b), and a second FET (FET 12c), and each of the first FET and the second FET is a P-channel MOSFET.

[0270] In the bipolar transistor, the base is connected to the control unit, the emitter is connected to the ground, and the collector is connected to the respective gates of the first FET and the second FET.

[0271] The respective drains of the first FET and the second FET are connected to each other.

[0272] The source of the first FET is connected to the heating unit and is also connected to the gate of the first FET via a first resistor (resistor Ra1) having a prescribed resistance, and

[0273] The source of the second FET is connected to a power line (system voltage line Lsys1) supplied with the system voltage from the first DC / DC converter and is also connected to the gate of the second FET via a second resistor (resistor Ra) having a prescribed resistance.

[0274] According to (16), it is possible to prevent charges from accumulating between the first FET and the second FET after supplying the second voltage to the heating unit; therefore, for example, it is not necessary to temporarily turn on the bipolar transistor after supplying the second voltage to the heating unit, thus making it possible to simplify the control of the switch circuit by the control unit.

[0275] (17)The aerosol generating device according to (9), wherein,

[0276] The switching circuit includes a bipolar transistor (BJT 12a), a first FET (FET 12b), and a second FET (FET 12c), and each of the first FET and the second FET is a P-channel MOSFET.

[0277] In the bipolar transistor, the base is connected to the control unit, the emitter is connected to the ground, and the collector is connected to the respective gates of the first FET and the second FET.

[0278] The respective drains of the first FET and the second FET are connected to each other.

[0279] The source of the first FET is connected to the heating unit and is also connected to the gate of the first FET via a first resistor (resistor Ra1) having a predetermined resistance. And

[0280] The source of the second FET is connected to a power line (step-down voltage line Lsys2) that is supplied with the step-down voltage from the LDO regulator and is also connected to the gate of the second FET via a second resistor (resistor Ra) having a predetermined resistance.

[0281] According to (17), charge accumulation between the first FET and the second FET can be prevented after the second voltage is supplied to the heating unit; thus, for example, it is not necessary to temporarily turn on the bipolar transistor after the second voltage is supplied to the heating unit, so that the control of the switching circuit by the control unit can be simplified.

[0282] List of reference numerals

[0283] 100, 100A, 100B Inhalation device (aerosol generating device)

[0284] 111, 111A, 111B Power supply unit (power source)

[0285] 116, 116A, 116B Control unit

[0286] 121, 121A, 121B Heating unit

[0287] 11 First DC / DC converter

[0288] 12 First switching circuit (switching circuit)

[0289] 12a BJT (bipolar transistor)

[0290] 12b FET (first FET)

[0291] 12c FET (second FET)

[0292] 15 LDO Voltage Regulator

[0293] 21 Second DC / DC Converter

[0294] 50 MCU (Control Unit)

[0295] Rheat Resistor (Heating Resistor)

[0296] Lsys1 System Voltage Line (Power Line)

[0297] Lsys2 Step-Down Voltage Line (Power Line)

Claims

1. An aerosol generating device, comprising: Power supply; A heating unit, the heating unit including a heating resistor having an association between resistance and temperature, and configured to be able to heat an aerosol source by being supplied with power; A first voltage system, the first voltage system being disposed between the power supply and the heating unit, and configured to be able to supply a first voltage to the heating unit that is generated based on the output voltage of the power supply; A second voltage system, the second voltage system being disposed between the power supply and the heating unit, and configured to be able to supply a second voltage to the heating unit that is generated based on the output voltage of the power supply; And A control unit, the control unit being configured to be able to control the supply of the first voltage to the heating unit by the first voltage system and the supply of the second voltage to the heating unit by the second voltage system, wherein, The first voltage is a voltage lower than the second voltage, and The control unit obtains the temperature of the heating unit based on the resistance of the heating unit, and controls the supply of the second voltage to the heating unit based on the temperature, and obtains the resistance by supplying the first voltage to the heating unit.

2. The aerosol generating device according to claim 1, wherein, The first voltage system includes a first DC / DC converter, the first DC / DC converter generating a specified system voltage according to the output voltage of the power supply, The control unit operates by being supplied with the system voltage, and The first voltage is generated based on the system voltage.

3. The aerosol generating device according to claim 2, wherein, The second voltage system includes a second DC / DC converter, the second DC / DC converter boosting the output voltage of the power supply to generate a heating voltage, and The second voltage is generated based on the heating voltage.

4. The aerosol generating device according to claim 2 or 3, wherein, The first voltage system further includes a switching circuit, the switching circuit turning on or off the connection between the first voltage system and the heating unit, The switching circuit operates according to the control of the control unit, and When performing the supply of the first voltage to the heating unit, the control unit sets the switching circuit to an on state, and when performing the supply of the second voltage to the heating unit, the control unit sets the switching circuit to an off state.

5. The aerosol generating device according to claim 4, wherein, The switching circuit includes a first switch and a first FET and a second FET, each of the first FET and the second FET being a P-channel MOSFET, The first switch is connected to the respective gates of the first FET and the second FET, and the opening / closing of the first switch is regulated by the potential of these gates, The respective sources of the first FET and the second FET are connected to each other, and are also connected to the respective gates of the first FET and the second FET through a resistor having a specified resistance, The drain of the first FET is connected to the power line to which the system voltage is supplied from the first DC / DC converter, and The drain of the second FET is connected to the heating unit.

6. The aerosol generating device according to any one of claims 2 to 5, wherein, The aerosol generating device further includes an operational amplifier, in the operational amplifier, the non-inverting input terminal is connected to one end of the heating unit, the inverting input terminal is connected to the other end of the heating unit, the output terminal is connected to the control unit, and the operational amplifier operates with the system voltage as the supply voltage, and the control unit obtains the resistance based on the output of the operational amplifier.

7. The aerosol generating device according to claim 2 or 3, wherein, the first voltage system further includes an LDO voltage regulator, the LDO voltage regulator steps down the system voltage to generate a stepped-down voltage, and the first voltage is generated based on the stepped-down voltage.

8. The aerosol generating device according to claim 7, wherein, the LDO voltage regulator is provided in the IC constituting the control unit.

9. The aerosol generating device according to claim 7 or 8, wherein, the first voltage system further includes a switch circuit, the switch circuit connects or disconnects the connection between the first voltage system and the heating unit, the switch circuit operates according to the control of the control unit, and when supplying the first voltage to the heating unit, the control unit sets the switch circuit to the on state, and when supplying the second voltage to the heating unit, the control unit sets the switch circuit to the off state.

10. The aerosol generating device according to claim 9, wherein, the switch circuit includes a first switch and a first FET and a second FET, each of the first FET and the second FET is a P-channel MOSFET, the first switch is connected to the respective gates of the first FET and the second FET, and the opening / closing of the first switch is adjusted by the potential of these gates, the respective sources of the first FET and the second FET are connected to each other and are also connected to the respective gates of the first FET and the second FET through a resistor having a predetermined resistance, the drain of the first FET is connected to the power line supplied with the stepped-down voltage from the LDOL voltage regulator, and the drain of the second FET is connected to the heating unit.

11. The aerosol generating device according to any one of claims 7 to 10, wherein, the aerosol generating device further includes an operational amplifier, in the operational amplifier, the non-inverting input terminal is connected to one end of the heating unit, the inverting input terminal is connected to the other end of the heating unit, the output terminal is connected to the control unit, and the operational amplifier operates with the stepped-down voltage as the supply voltage, and the control unit obtains the resistance based on the output of the operational amplifier.

12. The aerosol generating device according to claim 5 or 10, wherein, the first switch is a bipolar transistor, and in the bipolar transistor, the base is connected to the control unit, the emitter is connected to the ground, and the collector is connected to the respective gates of the first FET and the second FET.

13. The aerosol generating device according to claim 5 or 10, wherein, the first switch is an N-channel MOSFET, and In the N-channel MOSFET, the gate is connected to the control unit, the source is connected to the ground, and the drain is connected to the respective gates of the first FET and the second FET.

14. The aerosol generating device according to claim 5 or 10, wherein After performing the supply of the second voltage to the heating unit, the control unit further sets the first switch to an on state at a prescribed timing.

15. The aerosol generating device according to claim 4 or 9, wherein The switch circuit is configured by a load switch.

Images