EP4226789A1

EP4226789A1 - Inhalation device, program, and system

Info

Publication number: EP4226789A1
Application number: EP21931522.3A
Authority: EP
Inventors: Reijiro KAWASAKI; Kazutoshi SERITA
Original assignee: Japan Tobacco Inc
Current assignee: Japan Tobacco Inc
Priority date: 2021-03-17
Filing date: 2021-03-17
Publication date: 2023-08-16
Also published as: WO2022195770A1; JPWO2022195770A1

Abstract

[Problem] To provide a mechanism capable of preventing the occurrence of defects due to heat in an induction heating-type inhalation device. [Solution] This inhalation device is provided with: a power supply unit that supplies DC power; an inverter circuit that drives at least one switching element to convert the DC power supplied from the power supply unit to AC power; an electromagnetic induction source that uses the AC power supplied from the inverter circuit to generate a variable magnetic field; a holding unit that holds a substrate including an aerosol source; a temperature sensor that detects the temperature of the switching element; and a control unit that controls induction heating by the electromagnetic induction source on the basis of the temperature of the switching element detected by the temperature sensor.

Description

Technical Field

The present invention relates to an inhaler device, a program, and a system.

Background Art

Inhaler devices, such as e-cigarettes and nebulizers, for generating a substance to be inhaled by users are widespread. For example, the inhaler devices generate an aerosol having a flavor component imparted thereto, by using a substrate including an aerosol source for generating the aerosol, a flavor source for imparting the flavor component to the generated aerosol, and the like. Users can enjoy the flavor by inhaling the aerosol having the flavor component imparted thereto, which is generated by the inhaler devices. An action of a user inhaling an aerosol is hereinafter referred to as a puff or a puff action.
Inhaler devices using an external heat source such as a heating blade had been dominant until recently. In recent years, however, inhaler devices of induction heating type have been attracting attention. For example, Patent Literature 1 below discloses a technique of generating an alternating magnetic field by applying, to an induction coil, AC electric power generated using a switching transistor, to heat a susceptor included in a substrate by induction heating.

Citation List

Patent Literature

Patent Literature 1: JP 6623175 B2

Summary of Invention

Technical Problem

It is known that the inhaler devices of induction heating type are harder to be heated than those using an external power supply. However, it is considered that a heat-induced issue may also occur in the inhaler devices of induction heating type.
Accordingly, the present invention has been made in view of the issue described above, and it is an object of the present invention to provide a mechanism that can suppress the occurrence of the heat-induced issue in an inhaler device of induction heating type.

Solution to Problem

To overcome the issue described above, an aspect of the present invention provides an inhaler device including: a power supply configured to supply DC electric power; an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power; an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit; a holder configured to hold a substrate including an aerosol source; a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements; and a controller configured to control induction heating performed by the electromagnetic induction source, in which the electromagnetic induction source is disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, and the controller is configured to control the induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor.
The controller may be configured to prohibit start of the induction heating in a case where the temperature of the switching element is higher than or equal to a first threshold before the induction heating is started.
The inhaler device may further include a first notifier configured to provide information indicating that the start of the induction heating is prohibited.
The first notifier may be configured to provide information indicating a period before the start of the induction heating is permitted.
The first notifier may be configured to provide information based on a difference between the temperature of the switching element and the first threshold, as the information indicating the period before the start of the induction heating is permitted.
The controller may be configured to permit switching of a heating profile to be used between a plurality of heating profiles, the heating profile may be information that defines a time-series change in a target temperature that is a target value of the temperature of the susceptor, and the first threshold may be set in accordance with the heating profile to be used.
The controller may be configured to control, based on the temperature of the switching element, whether to permit switching to a second heating profile after induction heating based on a first heating profile is started.
The controller may be configured to: prohibit the switching to the second heating profile in a case where the temperature of the switching element is higher than or equal to a second threshold set in the second heating profile; and permit the switching to the second heating profile in a case where the temperature of the switching element is lower than the second threshold.
The controller may be configured to set the second threshold in accordance with an elapsed time from the start of induction heating at a timing of switching the heating profile.
The controller may be configured to stop the induction heating in a case where the temperature of the switching element becomes higher than or equal to a third threshold while the induction heating is performed.
The inhaler device may further include a second notifier configured to provide information indicating that the induction heating is stopped.
The controller may be configured to determine that the switching element has failed in a case where a number of times the temperature of the switching element becomes higher than or equal to the third threshold while the induction heating is performed is greater than or equal to a fourth threshold.
The inhaler device may further include a third notifier configured to provide information indicating that the switching element has failed.
The controller may be configured to adjust the first threshold in a case where the temperature of the switching element becomes higher than or equal to the third threshold while the induction heating is performed.
The inverter circuit may include a plurality of the switching elements, the temperature sensor may be configured to detect a temperature of each of the plurality of switching elements, and the controller may be configured to control the induction heating, based on the temperature of at least one of the plurality of switching elements.
The controller may be configured to prohibit or stop electric power supply from the power supply to the inverter circuit to prohibit or stop the induction heating.
The controller may be configured to prohibit or stop driving of all the switching elements included in the inverter circuit to prohibit or stop the induction heating.
To overcome the issue described above, another aspect of the present invention provides a program to be executed by a computer that controls an inhaler device, the inhaler device including: a power supply configured to supply DC electric power; an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power; an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit; a holder configured to hold a substrate including an aerosol source; and a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements, the electromagnetic induction source being disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, the program causing controlling induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor to be performed.
To overcome the issue described above, another aspect of the present invention provides a system including: an inhaler device; and a substrate, the substrate including an aerosol source, the inhaler device including: a power supply configured to supply DC electric power; an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power; an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit; a holder configured to hold the substrate; a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements; and a controller configured to control induction heating performed by the electromagnetic induction source, in which the electromagnetic induction source is disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, and the controller is configured to control the induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor.
The susceptor may be included in the substrate.

Advantageous Effects of Invention

As described above, the present invention provides a mechanism that can suppress the occurrence of a heat-induced issue in an inhaler device of induction heating type.

Brief Description of Drawings

[Fig. 1] Fig. 1 is a schematic diagram of an inhaler device according to a configuration example.
[Fig. 2] Fig. 2 is a block diagram illustrating structural elements related to induction heating performed by the inhaler device according to the present embodiment.
[Fig. 3] Fig. 3 is a diagram illustrating an equivalent circuit of a circuit related to induction heating performed by the inhaler device according to the present embodiment.
[Fig. 4] Fig. 4 is a graph illustrating an example of a time-series change in an actual temperature of a susceptor heated by induction heating based on a heating profile presented by Table 1.
[Fig. 5] Fig. 5 is a flowchart illustrating an example of a procedure of a process of determining whether to start induction heating, performed by the inhaler device according to the present embodiment.
[Fig. 6] Fig. 6 is a flowchart illustrating an example of a procedure of a process of determining whether to switch the heating profile during induction heating, performed by the inhaler device according to the present embodiment.
[Fig. 7] Fig. 7 is a flowchart illustrating an example of a procedure of a process of determining a failure, performed by the inhaler device according to the present embodiment.

Description of Embodiments

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the specification and the drawings, structural elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description thereof will be omitted.

<1. Configuration example of inhaler device>

An inhaler device according to the present configuration example heats a substrate including an aerosol source by induction heating (IH) to generate an aerosol. The present configuration example will be described below with reference to Fig. 1.
Fig. 1 is a schematic diagram of the inhaler device according to the configuration example. As illustrated in Fig. 1, an inhaler device 100 according to the present configuration example includes a power supply 111, a sensor 112, a notifier 113, a memory 114, a communicator 115, a controller 116, a susceptor 161, an electromagnetic induction source 162, and a holder 140. A user performs inhalation while a stick substrate 150 is held by the holder 140. Each structural element will be sequentially described below.
The power supply 111 stores electric power. The power supply 111 supplies electric power to each structural element of the inhaler device 100. The power supply 111 may be, for example, a rechargeable battery such as a lithium ion secondary battery. The power supply 111 may be charged by being connected to an external power supply through a Universal Serial Bus (USB) cable or the like. In addition, the power supply 111 may be charged, by using a wireless power transmission technology, without being connected to a power-transmitting device. Further, the power supply 111 alone may be removed from the inhaler device 100 and replaced with a new power supply 111.
The sensor 112 detects various items of information regarding the inhaler device 100. The sensor 112 outputs the detected items of information to the controller 116. In an example, the sensor 112 may be a pressure sensor such as a condenser microphone, a flow sensor, or a temperature sensor. In response to detecting a numerical value in accordance with inhalation performed by a user, the sensor 112 outputs information indicating that the user has performed the inhalation to the controller 116. In another example, the sensor 112 may be an input device that accepts information input by the user, such as a button or a switch. In particular, the sensor 112 may include a button for inputting an instruction to start/stop generation of an aerosol. The sensor 112 outputs the information input by the user to the controller 116. In another example, the sensor 112 may be a temperature sensor that detects a temperature of the susceptor 161. The temperature sensor detects the temperature of the susceptor 161 based on, for example, an electrical resistance value of the electromagnetic induction source 162. The sensor 112 may detect the temperature of the stick substrate 150 held by the holder 140, based on the temperature of the susceptor 161.
The notifier 113 provides information to the user. In an example, the notifier 113 may be a light-emitting device such as a light-emitting diode (LED). In this case, the notifier 113 emits different patterns of light when the power supply 111 needs to be charged, when the power supply 111 is being charged, when the inhaler device 100 has an anomaly, and so on. The pattern of light is a concept including a color, turn-on/turn-off timings, and so on. The notifier 113 may be, along with or instead of the light-emitting device, a display device that displays an image, a sound output device that outputs sound, or a vibration device that vibrates. In addition, the notifier 113 may provide information indicating that the user can perform inhalation. The information indicating that the user can perform inhalation is provided in response to the temperature of the stick substrate 150 that produces heat by electromagnetic induction reaching a predetermined temperature.
The memory 114 stores various items of information for operation of the inhaler device 100. The memory 114 may be a non-volatile storage medium such as a flash memory. An example of the items of information stored in the memory 114 is items of information related to an operating system (OS) of the inhaler device 100, such as details of control performed on the various structural elements by the controller 116. Another example of the items of information stored in the memory 114 is items of information related to inhalation performed by the user, such as the number of times of inhalation, an inhalation time, and an accumulated inhalation time period.
The communicator 115 is a communication interface for transmitting and receiving information between the inhaler device 100 and another device. The communicator 115 performs communication in conformity with any wired or wireless communication standard. Such a communication standard may be, for example, a wireless local area network (LAN), a wired LAN, Wi-Fi (registered trademark), or Bluetooth (registered trademark). In an example, the communicator 115 transmits the items of information related to inhalation performed by the user to a smartphone to cause the smartphone to display the items of information related to inhalation performed by the user. In another example, the communicator 115 receives information of a new OS from a server to update the information of the OS stored in the memory 114.
The controller 116 functions as an arithmetic processing unit and a control circuit, and controls the overall operations of the inhaler device 100 in accordance with various programs. The controller 116 is implemented by an electronic circuit such as a central processing unit (CPU) or a microprocessor, for example. In addition, the controller 116 may include a read-only memory (ROM) that stores a program to be used, an arithmetic parameter, and the like, and a random access memory (RAM) that temporarily stores a parameter that changes as appropriate and the like. The inhaler device 100 performs various processes under the control of the controller 116. Electric power supply from the power supply 111 to each of the other structural elements, charging of the power supply 111, detection of information by the sensor 112, notification of information by the notifier 113, storage and reading of information to and from the memory 114, and transmission and reception of information by the communicator 115 are an example of the processes controlled by the controller 116. Other processes performed by the inhaler device 100, such as input of information to each structural element and a process based on information output from each structural element are also controlled by the controller 116.
The holder 140 has an internal space 141, and holds the stick substrate 150 in a manner such that the stick substrate 150 is partially accommodated in the internal space 141. The holder 140 has an opening 142 that allows the internal space 141 to communicate with outside. The holder 140 holds the stick substrate 150 that is inserted into the internal space 141 through the opening 142. For example, the holder 140 may be a tubular body having the opening 142 and a bottom 143 that is a bottom surface, and may define the pillar-shaped internal space 141. The holder 140 has, in at least a portion of the tubular body in the height direction, an inside diameter that is smaller than an outside diameter of the stick substrate 150 to be able to hold the stick substrate 150 by pressing the stick substrate 150 inserted into the internal space 141 from the outer circumference. The holder 140 also has a function of defining a flow path of air that passes through the stick substrate 150. For example, the bottom 143 has an air inlet hole that is an inlet of air into the flow path. On the other hand, the opening 142 serves as an air outlet hole that is an outlet of air from the flow path.
The stick substrate 150 is a stick-shaped member. The stick substrate 150 includes a substrate 151 and an inhalation port 152.
The substrate 151 includes an aerosol source. The aerosol source is heated to be atomized, so that an aerosol is generated. The aerosol source may be a material derived from tobacco, such as shredded tobacco or a processed material obtained by forming a tobacco raw material into a granular, sheet-like, or powdery shape. In addition, the aerosol source may include a material that is not derived from tobacco, such as a material made from a plant other than tobacco (for example, mint or an herb). In an example, the aerosol source may include a flavor component such as menthol. For the inhaler device 100 that is a medical inhaler, the aerosol source may include a medicine to be inhaled by a patient. The aerosol source is not limited to a solid and may be a liquid such as polyhydric alcohol and water. Examples of the polyhydric alcohol include glycerine and propylene glycol. At least a portion of the substrate 151 is accommodated in the internal space 141 of the holder 140 when the stick substrate 150 is held by the holder 140
The inhalation port 152 is to be held in a mouth of the user during inhalation. At least a portion of the inhalation port 152 protrudes from the opening 142 when the stick substrate 150 is held by the holder 140. When a user performs inhalation while holding, in their mouth, the inhalation port 152 protruding from the opening 142, air flows into the holder 140 through the air inlet hole (not illustrated). The air that has flowed in passes through the internal space 141 of the holder 140, that is, the substrate 151, and reaches the inside of the mouth of the user together with the aerosol generated from the substrate 151.
The stick substrate 150 further includes the susceptor 161. The susceptor 161 produces heat by electromagnetic induction. The susceptor 161 may be made of a conductive material such as metal. In an example, the susceptor 161 is a piece of metal. The susceptor 161 is disposed in proximity to the aerosol source. In the example illustrated in Fig. 1, the susceptor 161 is included in the substrate 151 of the stick substrate 150.
The susceptor 161 is disposed in thermal proximity to the aerosol source. The susceptor 161 being in thermal proximity to the aerosol source means that the susceptor 161 is disposed at a position where heat produced by the susceptor 161 is transferred to the aerosol source. For example, the susceptor 161 is included in the substrate 151 along with the aerosol source and is surrounded by the aerosol source. This configuration enables the heat produced by the susceptor 161 to be efficiently used for heating the aerosol source.
Note that the susceptor 161 may be untouchable from outside of the stick substrate 150. For example, the susceptor 161 may be distributed in a central part of the stick substrate 150, but does not have to be distributed near the outer circumference of the stick substrate 150.
The electromagnetic induction source 162 causes the susceptor 161 to produce heat by electromagnetic induction. For example, the electromagnetic induction source 162 is a coiled conductive wire wound around the outer circumference of the holder 140. Upon being supplied with an alternating current from the power supply 111, the electromagnetic induction source 162 generates a magnetic field. The electromagnetic induction source 162 is disposed at a position where the internal space 141 of the holder 140 overlaps with the generated magnetic field. Thus, when a magnetic field is generated while the stick substrate 150 is held by the holder 140, an eddy current is generated in the susceptor 161 to generate Joule heat. The aerosol source included in the stick substrate 150 is heated by the Joule heat to be atomized, so that an aerosol is generated. In an example, when the sensor 112 detects a predetermined user input, electric power may be supplied and an aerosol may be generated. When the temperature of the stick substrate 150 that is heated by induction heating using the susceptor 161 and the electromagnetic induction source 162 reaches a predetermined temperature, the user can perform inhalation. When the sensor 112 detects a predetermined user input thereafter, electric power supply may be stopped. In another example, electric power may be supplied and an aerosol may be generated, while the sensor 112 detects inhalation performed by the user
Fig. 1 illustrates an example of the susceptor 161 included in the substrate 151 of the stick substrate 150. However, the present configuration example is not limited to such an example. For example, the holder 140 may function as the susceptor 161. In this case, the magnetic field generated by the electromagnetic induction source 162 generates an eddy current in the holder 140, so that Joule heat is generated. The aerosol source included in the stick substrate 150 is heated by the Joule heat to be atomized, so that an aerosol is generated.
The combination of the inhaler device 100 and the stick substrate 150 may be regarded as a single system because an aerosol can be generated by combining the inhaler device 100 and the stick substrate 150.

<2. Induction heating>

Induction heating will be described in detail below.
Induction heating is a process of heating a conductive object by causing a varying magnetic field to penetrate the object. Induction heating involves a magnetic field generator that generates a varying magnetic field, and a to-be-heated object that is conductive and is to be heated when exposed to the varying magnetic field. An example of the varying magnetic field is an alternating magnetic field. The electromagnetic induction source 162 illustrated in Fig. 1 is an example of the magnetic field generator. The susceptor 161 illustrated in Fig. 1 is an example of the to-be-heated object.
The magnetic field generator and the to-be-heated object are disposed at relative positions such that a varying magnetic field generated from the magnetic field generator penetrates the to-be-heated object. When a varying magnetic field is generated from the magnetic field generator in this state, an eddy current is induced in the to-be-heated object. The eddy current flows through the to-be-heated object, which produces Joule heat according to the electrical resistance of the to-be-heated object, so that the to-be-heated object is heated. Such heating is also referred to as Joule heating, ohmic heating, or resistive heating.
The to-be-heated object may be magnetic. In this case, the to-be-heated object is further heated by magnetic hysteresis heating. Magnetic hysteresis heating is a process of heating a magnetic object by causing a varying magnetic field to penetrate the object. When a magnetic field penetrates a magnetic body, magnetic dipoles included in the magnetic body are aligned along the magnetic field. Thus, when a varying magnetic field penetrates a magnetic body, the orientation of the magnetic dipoles changes in accordance with the applied varying magnetic field. Such reorientation of the magnetic dipoles produces heat in the magnetic body, so that the to-be-heated object is heated.
Magnetic hysteresis heating typically occurs at a temperature of the Curie point or lower and does not occur at a temperature exceeding the Curie point. The Curie point is the temperature at which a magnetic body loses magnetic properties thereof. For example, when the temperature of a to-be-heated object that is ferromagnetic at a temperature of the Curie point or lower exceeds the Curie point, a reversible phase transition from ferromagnetism to paramagnetism occurs in the magnetism of the to-be-heated object. When the temperature of the to-be-heated object exceeds the Curie point, magnetic hysteresis heating no longer occurs. Thus, the temperature increase rate slows down.
The to-be-heated object is desirably made of a conductive material. Further, the to-be-heated object is desirably made of a ferromagnetic material. This is because the combination of resistive heating and magnetic hysteresis heating can increase the heating efficiency in the latter case. For example, the to-be-heated object may be made of one or more materials selected from a material group including aluminum, iron, nickel, cobalt, conductive carbon, copper, and stainless steel.
In both resistive heating and magnetic hysteresis heating, heat is produced inside the to-be-heated object rather than by thermal conduction from an external heat source. This thus can implement a rapid temperature increase and a uniform heat distribution in the to-be-heated object. This can be implemented by appropriately designing the material and shape of the to-be-heated object and the magnitude and direction of the varying magnetic field. That is, a rapid temperature increase and a uniform heat distribution can be implemented in the stick substrate 150 by appropriately designing the distribution of the susceptor 161 included in the stick substrate 150. This thus can reduce the time for preheating and improve the quality of a flavor tasted by the user
Since induction heating directly heats the susceptor 161 included in the stick substrate 150, the substrate can be heated more efficiently than when the stick substrate 150 is heated from the outer circumference or the like by an external heat source. When heating is performed using an external heat source, the temperature of the external heat source inevitably becomes higher than that of the stick substrate 150. In contrast, when induction heating is performed, the temperature of the electromagnetic induction source 162 does not become higher than that of the stick substrate 150. Thus, the temperature of the inhaler device 100 can be maintained to be lower than that in the case of using an external heat source. This is a great advantage in terms of user safety.
The electromagnetic induction source 162 generates a varying magnetic field by using electric power supplied from the power supply 111. In an example, the power supply 111 may be a direct current (DC) power supply. In this case, the power supply 111 supplies, via a DC/alternate current (AC) inverter, AC electric power to the electromagnetic induction source 162. In this case, the electromagnetic induction source 162 can generate an alternating magnetic field.
The electromagnetic induction source 162 is disposed at a position where the varying magnetic field generated from the electromagnetic induction source 162 penetrates the susceptor 161 disposed in thermal proximity to the aerosol source included in the stick substrate 150 held by the holder 140. The susceptor 161 produces heat upon being penetrated by the varying magnetic field. The electromagnetic induction source 162 illustrated in Fig. 1 is a solenoid coil. The solenoid coil is disposed such that the conductive wire is wound around the outer circumference of the holder 140. When a current is applied to the solenoid coil, a magnetic field is generated in a central space surrounded by the coil, that is, the internal space 141 of the holder 140. As illustrated in Fig. 1, the susceptor 161 is surrounded by the coil when the stick substrate 150 is held by the holder 140. Thus, the varying magnetic field generated from the electromagnetic induction source 162 penetrates the susceptor 161 and heats the susceptor 161 by induction heating.

<3. Technical features>

(1) Detailed internal configuration

Structural elements related to induction heating according to the present embodiment will be described in detail with reference to Fig. 2. Fig. 2 is a block diagram illustrating structural elements related to induction heating performed by the inhaler device 100 according to the present embodiment.
As illustrated in Fig. 2, the inhaler device 100 includes a drive circuit 169 including the electromagnetic induction source 162 and an inverter circuit 163. The drive circuit 169 is a circuit for generating a varying magnetic field. The drive circuit 169 may further include another circuit such as a matching circuit. The drive circuit 169 operates by using electric power supplied from the power supply 111.
The power supply 111 is a DC power supply and supplies DC electric power. The inverter circuit 163 includes one or more switching elements 164. The inverter circuit 163 drives the one or more switching elements 164 to convert DC electric power into AC electric power. In an example, the switching element 164 may be a metal-oxide-semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The inverter circuit 163 may be a half-bridge inverter or a full-bridge inverter. The electromagnetic induction source 162 generates a varying magnetic field by using the AC electric power supplied from the inverter circuit 163. When the varying magnetic field generated from the electromagnetic induction source 162 penetrates the susceptor 161, the susceptor 161 produces heat.
As illustrated in Fig. 2, the sensor 112 includes a temperature sensor 171. The temperature sensor 171 detects a temperature of the switching element 164. When the inverter circuit 163 includes the plurality of switching elements 164, the temperature sensor 171 detects the temperature of each of the plurality of switching elements 164 included in the inverter circuit 163. The temperature sensor 171 detects the temperature of the switching element 164 at least before induction heating is started. The temperature sensor 171 may also detect the temperature of the switching element 164 at predetermined time intervals while induction heating is performed.
The controller 116 controls induction heating performed by the electromagnetic induction source 162. Specifically, the controller 116 controls electric power supply to the electromagnetic induction source 162. For example, the controller 116 estimates the temperature of the susceptor 161, based on information of DC electric power supplied from the power supply 111 to the drive circuit 169. The controller 116 then controls electric power supply to the electromagnetic induction source 162, based on the estimated temperature of the susceptor 161. For example, the controller 116 controls electric power supply to the electromagnetic induction source 162 such that the temperature of the susceptor 161 changes in accordance with a heating profile described later.
An example of a target to be controlled is a voltage of the DC electric power supplied from the power supply 111 to the drive circuit 169. Another example of the target to be controlled is a switching period in the inverter circuit 163.
Patent Literature 1 above discloses details of the method of estimating the temperature of the susceptor 161. The method of estimating the temperature of the susceptor 161 will be briefly described with reference to Fig. 3.
Fig. 3 is a diagram illustrating an equivalent circuit of a circuit related to induction heating performed by the inhaler device 100 according to the present embodiment. An apparent electrical resistance value R_A illustrated in Fig. 3 is an electrical resistance value of a closed circuit including the drive circuit 169, calculated from a current value I_DC and a voltage value V_DC of the DC electric power supplied from the power supply 111 to the drive circuit 169. As illustrated in Fig. 3, the apparent electrical resistance value R_A corresponds to a series connection formed by an electrical resistance value R_C of the drive circuit 169 and an electrical resistance value Rs of the susceptor 161. The apparent electrical resistance value R_A and the temperature of the susceptor 161 have a very monotonic relationship therebetween. For example, the apparent electrical resistance value R_A and the temperature of the susceptor 161 have a substantially linear relationship therebetween within a range (for example, from 0°C to 400°C) in which the temperature of the susceptor 161 may change due to induction heating performed by the inhaler device 100. Thus, the controller 116 can calculate the apparent electrical resistance value R_A, based on the current value I_DC and the voltage value V_DC, and estimate the temperature of the susceptor 161, based on the apparent electrical resistance value R_A
The switching element 164 repeats switching at a high speed when converting DC electric power into AC electric power. At this time, the switching element 164 produces heat. When heating based on the heating profile is repeated at short intervals, the switching element 164 reaches a high temperature. This may cause a heat-induced issue such as thermal runaway. Accordingly, the controller 116 controls induction heating performed by the electromagnetic induction source 162, based on the temperature of the switching element 164 detected by the temperature sensor 171. As will be described in detail later, the controller 116 prohibits or stops induction heating when the temperature of the switching element 164 is excessively high. When the inverter circuit 163 includes the plurality of switching elements 164, the controller 116 controls induction heating, based on the temperature of at least one of the plurality of switching elements 164. In an example, when the temperature of even one of the switching elements 164 is excessively high, the controller 116 prohibits or stops induction heating. Such a configuration can suppress the occurrence of a heat-induced issue in the switching element 164.
When the inverter circuit 163 includes the plurality of switching elements 164, thermal influences of a heat source on the respective switching elements 164 may be substantially equal. Likewise, when the inhaler device 100 includes a plurality of temperature sensors 171 for detecting the temperatures of the plurality of switching elements 164, thermal influences of a heat source on the respective temperature sensors 171 may be substantially equal. In an example, the distances between the holder 140 and the respective switching elements 164/the respective temperature sensors 171 may be substantially equal. In another example, the switching elements 164/the temperature sensors 171 may be disposed on the same circuit board.
In addition, the circuit board may be conceivably disposed to have a proximal end and a distal end relative to the holder 140. In this case, the switching element 164 and the temperature sensor 171 may be disposed on the distal end side of the circuit board (that is, the side closer to the distal end than to the center in the longitudinal direction).
The notifier 113 provides information indicating content of control based on the temperature of the switching element 164. The provided content will be described in detail later.

(2) Heating profile

The inhaler device 100 controls electric power supply to the electromagnetic induction source 162 based on a heating profile. The heating profile is information that defines a time-series change in a target temperature that is a target value of the temperature of the susceptor 161. The inhaler device 100 controls electric power supply to the electromagnetic induction source 162 such that a real temperature (hereinafter, also referred to as an actual temperature) of the susceptor 161 changes in the same manner as the time-series change in the target temperature defined in the heating profile. Consequently, an aerosol is generated as planned in the heating profile. The heating profile is typically designed to optimize a flavor tasted by a user when the user inhales the aerosol generated from the stick substrate 150. Thus, by controlling the operation of the electromagnetic induction source 162 based on the heating profile, the flavor tasted by the user can be optimized.
The heating profile includes one or more combinations of an elapsed time from the start of heating and a target temperature to be reached at the elapsed time. The controller 116 controls the temperature of the susceptor 161, based on a deviation of the current actual temperature from the target temperature corresponding to the current elapsed time from the start of heating in the heating profile. Control of the temperature of the susceptor 161 can be implemented by known feedback control, for example. In the feedback control, the controller 116 may control electric power to be supplied to the electromagnetic induction source 162, based on a difference between the actual temperature and the target temperature or the like. The feedback control may be, for example, a proportional-integral-differential controller (PID controller). Alternatively, the controller 116 may simply perform ON-OFF control. For example, the controller 116 may supply electric power to the electromagnetic induction source 162 until the actual temperature reaches the target temperature, and may interrupt electric power supply to the electromagnetic induction source 162 upon the actual temperature reaching the target temperature.
A time section from the start to the end of a process of generating an aerosol by using the stick substrate 150, more specifically, a time section in which the electromagnetic induction source 162 operates based on the heating profile, is also referred to as a heating session hereinafter. The start of the heating session is a timing at which heating based on the heating profile is started. The end of the heating session is a timing at which a sufficient amount of aerosol is no longer generated. The heating session is constituted by a preheating period which is a first part and a puffable period which is a latter part. The puffable period is a period in which a sufficient amount of aerosol is expected to be generated. The preheating period is a period from the start of heating to the start of the puffable period. Heating performed in the preheating period is also referred to as preheating.
Table 1 below presents an example of the heating profile.

[Table 1]

Table 1. Example of heating profile

Time section	Elapsed time from start of heating	Target temperature
Initial temperature rise section	25 s	295°C
Initial temperature rise section	35 s	295°C
Intermediate temperature drop section	45 s	230°C
Temperature re-rise section	180 s	230°C
	260 s	260°C
	355 s	260°C
Heating termination section	Thereafter	-

A time-series change in the actual temperature of the susceptor 161 when the controller 116 controls electric power supply to the electromagnetic induction source 162 in accordance with the heating profile presented by Table 1 will be described with reference to Fig. 4. Fig. 4 is a graph illustrating an example of a time-series change in the actual temperature of the susceptor 161 heated by induction heating based on the heating profile presented by Table 1. The horizontal axis of this graph represents time (seconds). The vertical axis of the graph represents the temperature of the susceptor 161. A line 21 in this graph represents a time-series change in the actual temperature of the susceptor 161. Points 22 (22A to 22F) in this graph each correspond to a target temperature defined in the heating profile. As illustrated in Fig. 4, the actual temperature of the susceptor 161 changes in the same manner as the time-series change in the target temperature defined in the heating profile.
As presented by Table 1, the heating profile first includes an initial temperature rise section. The initial temperature rise section is a time section included at the beginning of the heating profile, and is a section in which the target temperature set at the end of the section is higher than an initial temperature. The initial temperature is a temperature expected as the temperature of the susceptor 161 before heating is started. An example of the initial temperature is any temperature such as 0°C. Another example of the initial temperature is a temperature corresponding to an ambient temperature. As illustrated in Fig. 4, according to the target temperature set in the initial temperature rise section, the actual temperature of the susceptor 161 reaches 295°C after 25 seconds from the start of heating, and is maintained at 295°C until after 35 seconds from the start of heating. Accordingly, the temperature of the stick substrate 150 is expected to reach a temperature at which a sufficient amount of aerosol is to be generated. Since the actual temperature quickly rises to 295°C immediately after the start of heating, preheating can be finished early and the puffable period can be started early. Fig. 4 illustrates an example in which the initial temperature rise section coincides with the preheating period. However, the initial temperature rise section and the preheating period may differ from each other.
As presented by Table 1, the heating profile next includes an intermediate temperature drop section. The intermediate temperature drop section is a time section after the initial temperature rise section, and is a time section in which the target temperature set at the end of the time section is lower than the target temperature set at the end of the initial temperature rise section. As illustrated in Fig. 4, according to the target temperature set in the intermediate temperature drop section, the actual temperature of the susceptor 161 drops from 295°C to 230°C from 35 seconds to 45 seconds after the start of heating. In this section, electric power supply to the electromagnetic induction source 162 may be stopped. Even in such a case, a sufficient amount of aerosol is generated by residual heat of the susceptor 161 and the stick substrate 150. If the susceptor 161 is maintained at a high temperature, the aerosol source included in the stick substrate 150 is rapidly consumed. This may cause inconvenience that a flavor tasted by the user becomes too strong. However, by providing the intermediate temperature drop section in midstream, such inconvenience can be avoided and the quality of the user's puff experience can be improved.
As presented by Table 1, the heating profile next includes a temperature re-rise section. The temperature re-rise section is a time section after the intermediate temperature drop section, and is a time section in which the target temperature set at the end of the time section is higher than the target temperature set at the end of the intermediate temperature drop section. As illustrated in Fig. 4, according to the target temperature set in the temperature re-rise section, the actual temperature of the susceptor 161 increases stepwise from 230°C to 260°C from 45 seconds to 355 seconds after the start of heating. If the temperature of the susceptor 161 is continuously decreased, the temperature of the stick substrate 150 also decreases. Thus, the amount of generated aerosol decreases, and the flavor tasted by the user may deteriorate. However, by causing the actual temperature to re-rise after dropping, deterioration of the flavor tasted by the user can be prevented even in the latter part of the heating session.
As presented by Table 1, the heating profile lastly includes a heating termination section. The heating termination section is a time section after the temperature re-rise section, and is a time section in which heating is not performed. No target temperature may be set. As illustrated in Fig. 4, the actual temperature of the susceptor 161 drops after 355 seconds from the start of heating. Electric power supply to the electromagnetic induction source 162 may be terminated after 355 seconds from the start of heating. Even in such a case, a sufficient amount of aerosol is generated for a while by residual heat of the susceptor 161 and the stick substrate 150. In the example illustrated in Fig. 4, the puffable period, that is, the heating session ends after 365 seconds from the start of heating.
The user may be notified of the start timing and the end timing of the puffable period. The user may also be notified of a timing that is before the end of the puffable period by a predetermined time (for example, the end timing of the temperature re-rise section). In this case, the user can perform a puff in the puffable period with reference to the notification.

(3) Determination of start of induction heating

The controller 116 prohibits the start of induction heating if the temperature of the switching element 164 is higher than or equal to a first threshold before induction heating is started. For example, when a user operation for an instruction to start induction heating is detected, the controller 116 determines whether the temperature of the switching element 164 is higher than or equal to the first threshold. Note that the user operation for an instruction to start induction heating may be, for example, an operation of pressing a button of the inhaler device 100. Another example of the user operation for an instruction to start induction heating is insertion of the stick substrate 150 into the inhaler device 100. That is, when the stick substrate 150 is inserted into the inhaler device 100, induction heating may be automatically started. The controller 116 does not start the heating session if the temperature of the switching element 164 is higher than or equal to the first threshold. On the other hand, the controller 116 starts the heating session if the temperature of the switching element 164 is lower than the first threshold. The first threshold is set as a temperature at which it is estimated that the temperature of the switching element 164 does not reach a temperature at which a heat-induced issue may occur, over the entire period of the heating session if the temperature of the switching element 164 is lower than the first threshold at the start of induction heating. Such a configuration can suppress the occurrence of a heat-induced issue in the switching element 164.
The notifier 113 may function as a first notifier that provides information indicating that the start of induction heating is prohibited. In an example, the notifier 113 may provide information indicating that the switching element 164 has a high temperature. Such a configuration allows the user to know the reason why induction heating is not started. This thus can reduce the stress felt by the user because the inhaler device 100 does not operate in accordance with the user operation.
The notifier 113 may provide information indicating a period before the start of induction heating is permitted. Such a configuration allows the user to wait until the switching element 164 is sufficiently lowered while grasping the remaining time to the start of induction heating. This thus can further reduce the stress felt by the user
The notifier 113 may provide information based on a difference between the temperature of the switching element 164 and the first threshold, as the information indicating the period before the start of induction heating is permitted. For example, the notifier 113 may display a bar having a length corresponding to the difference between the temperature of the switching element 164 and the first threshold. In this case, the notifier 113 displays a longer bar as the difference between the temperature of the switching element 164 and the first threshold is larger, and reduces the length of the bar as the temperature of the switching element 164 decreases. Such a configuration allows the user to easily grasp the remaining time to the start of induction heating.
The first threshold may be set in accordance with the heating profile to be used. Such a configuration can suppress the occurrence of a heat-induced issue in the switching element 164 even when a heating profile having a high target temperature is used.
A procedure of a process will be described below with reference to Fig. 5. Fig. 5 is a flowchart illustrating an example of a procedure of a process of determining whether to start induction heating, performed by the inhaler device 100 according to the present embodiment.
First, the sensor 112 accepts a user operation for an instruction to start induction heating (S102).
Subsequently, the controller 116 determines whether the temperature of the switching element 164 is higher than or equal to the first threshold (step S104).
If determining that the temperature of the switching element 164 is higher than or equal to the first threshold (step S104: YES), the controller 116 prohibits the start of induction heating (step S106).
Subsequently, the notifier 113 provides information indicating that the start of induction heating is prohibited (step S108). The notifier 113 may also provide information indicating a period before the start of induction heating is permitted. The process then ends.
On the other hand, if determining that the temperature of the switching element 164 is lower than the first threshold (step S104: NO), the controller 116 permits the start of induction heating (step S110).
Then, the controller 116 performs induction heating (step S112). For example, the controller 116 performs electric power supply from the power supply 111 to the drive circuit 169, based on the heating profile. The process then ends.

(4) Determination of switching during induction heating

The controller 116 can switch the heating profile to be used between a plurality of heating profiles. In response to switching the heating profile to be used, the controller 116 controls induction heating based on the heating profile after the switching.
After starting induction heating, the controller 116 can switch the heating profile to be used while induction heating is performed. For example, after starting induction heating based on a first heating profile, the controller 116 may start induction heating based on a second heating profile in response to a user operation. Such a configuration enables the heating profile to be switched to a heating profile corresponding to a user's preference, such as switching to the second heating profile having a higher target temperature than the first heating profile, while induction heating is performed.
Note that the elapsed time from the start of heating may be continuously used before and after the switching of the heating profile. For example, when heating using the first heating profile is performed until the initial temperature rise period elapses, the controller 116 may start heating using the second heating profile from the intermediate temperature drop period.
Based on the temperature of the switching element 164, the controller 116 may control whether to permit switching to the second heating profile after induction heating based on the first heating profile is started. For example, when a user operation for an instruction to switch the heating profile to the second heating profile is detected, the controller 116 may determine whether to permit the switching. Such a configuration can suppress the occurrence of a heat-induced issue in the switching element 164 due to switching of the heating profile.
Specifically, the controller 116 determines whether the temperature of the switching element 164 is higher than or equal to a second threshold set in the second heating profile. If the temperature of the switching element 164 is higher than or equal to the second threshold, the controller 116 prohibits switching to the second heating profile. That is, the controller 116 continues induction heating based on the first heating profile. On the other hand, if the temperature of the switching element 164 is higher than or equal to the second threshold, the controller 116 permits switching to the second heating profile. That is, the controller 116 starts induction heating based on the second heating profile. The second threshold is set as a temperature at which it is estimated that the temperature of the switching element 164 does not reach a temperature at which a heat-induced issue may occur, over the entire remaining period of the heating session if the temperature of the switching element 164 is lower than the second threshold at the switching. Such a configuration can suppress the occurrence of a heat-induced issue in the switching element 164 due to the switching of the heating profile.
Note that the controller 116 may set the second threshold in accordance with the elapsed time from the start of induction heating at the timing of switching the heating profile. An example of the timing at which the heating profile is switched is a timing at which a user operation for an instruction to switch the heating profile to the second heating profile is detected. For example, the second threshold in the case of switching the heating profile at the end of the initial temperature rise period may be different from the second threshold in the case of switching the heating profile at the end of the intermediate temperature drop period. Such a configuration can appropriately adjust the second threshold in accordance with the switching timing of the heating profile.
The notifier 113 may provide information indicating that switching of the heating profile is prohibited. In an example, the notifier 113 may provide information indicating that the switching element 164 has a high temperature. Such a configuration allows the user to know the reason why the heating profile is not switched. This thus can reduce the stress felt by the user because the inhaler device 100 does not operate in accordance with the user operation.
A procedure of a process will be described below with reference to Fig. 6. Fig. 6 is a flowchart illustrating an example of a procedure of a process of determining whether to switch the heating profile during induction heating, performed by the inhaler device 100 according to the present embodiment.
As illustrated in Fig. 6, first, the sensor 112 accepts a user operation for an instruction to start induction heating (step S202).
Subsequently, the controller 116 starts induction heating based on the first heating profile (step S204).
Then, the sensor 112 accepts a user operation for an instruction to switch the heating profile to the second heating profile (step S206).
Subsequently, the controller 116 determines whether the temperature of the switching element 164 is higher than or equal to the second threshold (step S208).
If determining that the temperature of the switching element 164 is higher than or equal to the second threshold (step S208: YES), the controller 116 prohibits switching to the second heating profile (step S210).
Subsequently, the controller 116 provides information indicating that switching of the heating profile is prohibited (step S212).
Then, the controller 116 continues induction heating based on the first heating profile (step S214). The process then ends.
On the other hand, if determining that the temperature of the switching element 164 is lower than the second threshold (step S208: NO), the controller 116 permits switching to the second heating profile (step S216).
Subsequently, the controller 116 starts induction heating based on the second heating profile in midstream of the second heating profile (step S218). That is, the controller 116 controls induction heating based on the second heating profile, using the elapsed time from the start of induction heating based on the first heating profile as the elapsed time from the start of induction heating. The process then ends.

(5) Determination of failure

If the temperature of the switching element 164 becomes higher than or equal to a third threshold while induction heating is performed, the controller 116 stops induction heating. The third threshold is set as a high temperature that is not to be reached when the inhaler device 100 performs a normal operation. Alternatively, the third threshold is set as a temperature at which it is estimated that a heat-induced issue may occur in the switching element 164 if the temperature of the switching element 164 exceeds a third temperature. It is considered that such a situation may occur when a temporary failure occurs in the switching element 164. However, the above configuration can suppress the occurrence of a heat-induced issue in the switching element 164 even when a temporary failure occurs.
The notifier 113 may function as a second notifier that provides information indicating that induction heating is stopped. In an example, the notifier 113 may provide information indicating that the switching element 164 has a high temperature. Such a configuration allows the user to know the reason why induction heating is stopped. This thus can reduce the stress felt by the user because of interruption of the heating session.
If the number of times the temperature of the switching element 164 becomes higher than or equal to the third threshold while induction heating is performed is greater than or equal to a fourth threshold, the controller 116 determines that the switching element 164 has failed. That is, when the number of times induction heating is stopped is greater than or equal to the fourth threshold, the controller 116 determines that the switching element 164 has failed. The fourth threshold is set as a value at which it can be reasonably considered that a non-temporary (that is, permanent or irreversible) failure has occurred in the switching element 164 when the number of times the temperature of the switching element 164 becomes higher than or equal to the third threshold reaches the fourth threshold. If determining that the switching element 164 has failed, the controller 116 prohibits subsequent induction heating unless the switching element 164 is repaired. Such a configuration can guarantee the safety even when a non-temporary failure occurs in the switching element 164.
The notifier 113 may function as a third notifier that provides information indicating that the switching element 164 has failed. For example, the notifier 113 provides information for prompting the user to send the inhaler device 100 for repair or replace the inhaler device 100. Such a configuration can continuously provide a safe puff experience to the user
When the temperature of the switching element 164 becomes higher than or equal to the third threshold while induction heating is performed, the controller 116 may adjust the first threshold. Specifically, the controller 116 may decrease the first threshold. Consequently, the start of induction heating is prohibited at a temperature lower than the temperature set before the adjustment. It is considered that if a temporary failure occurs in the switching element 164, a heat-induced issue is more likely to occur in the switching element 164 such as the switching element 164 is likely to have a high temperature, than in a case where a temporary failure has not occurred. However, the above configuration can further suppress the occurrence of a heat-induced issue in the switching element 164.
For the same reason, the controller 116 may adjust the second threshold when the temperature of the switching element 164 becomes higher than or equal to the third threshold while induction heating is performed. Specifically, the controller 116 may decrease the second threshold. Consequently, switching of the heating profile is prohibited at a temperature lower than the temperature set before the adjustment. The above configuration can further suppress the occurrence of a heat-induced issue in the switching element 164.
A procedure of a process will be described below with reference to Fig. 7. Fig. 7 is a flowchart illustrating an example of a procedure of a process of determining a failure, performed by the inhaler device 100 according to the present embodiment.
As illustrated in Fig. 7, first, the sensor 112 accepts a user operation for an instruction to start induction heating (step S302).
Subsequently, the controller 116 starts induction heating based on the heating profile (step S304).
Then, the controller 116 determines whether the temperature of the switching element 164 is higher than or equal to the third threshold (step S306).
If determining that the temperature of the switching element 164 is higher than or equal to the third threshold (step S306: YES), the controller 116 stops induction heating (step S308).
Subsequently, the controller 116 determines whether the number of times the temperature of the switching element 164 becomes higher than or equal to the third threshold is greater than or equal to the fourth threshold (step S310).
If the controller 116 determines that the number of times the temperature of the switching element 164 becomes higher than or equal to the third threshold is greater than or equal to the fourth threshold (step S310: YES), the notifier 113 provides information indicating that the switching element 164 has failed (step S312). The process then ends.
On the other hand, if the controller 116 determines that the number of times the temperature of the switching element 164 becomes higher than or equal to the third threshold is less than the fourth threshold (step S310: NO), the notifier 113 provides information indicating that induction heating is stopped (step S314). The process then ends.
If the controller 116 determines that the temperature of the switching element 164 is lower than the third threshold (step S306: NO), the controller 116 continues induction heating (step S316). The process then ends.

(6) Process of prohibiting/stopping induction heating

The controller 116 may prohibit/stop electric power supply from the power supply 111 to the inverter circuit 163 to prohibit or stop induction heating. With such a configuration, since DC electric power is not supplied to the inverter circuit 163, a varying magnetic field is not generated and the susceptor 161 is not heated. Thus, an increase in the temperature in response to switching performed by the switching element 164 can be suppressed.
The controller 116 may prohibit or stop driving of all the switching elements 164 included in the inverter circuit 163 to prohibit or stop induction heating. With such a configuration, an increase in the temperature in response to switching performed by the switching elements 164 can be suppressed. When driving of the switching elements 164 is prohibited or stopped, DC electric power is not converted into AC electric power. Thus, even when DC electric power is supplied to the electromagnetic induction source 162, a varying magnetic field is not generated. Thus, the susceptor 161 is not heated.

<4. Supplementary description>

While the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such examples. Obviously, a person with an ordinary knowledge in the technical field to which the present invention pertains can conceive various modifications and corrections within the scope of the technical spirit described in the claims. It should be understood that these modifications and corrections naturally pertain to the technical scope of the present invention.
For example, in the embodiment described above, an example has been described in which determination based on the first threshold is performed at the start of induction heating. However, the present invention is not limited to such an example. For example, the determination based on the first threshold may be performed at the end of induction heating. In this case, the controller 116 compares the temperature of the switching element 164 with the first threshold when induction heating based on the heating profile ends. Then, the notifier 113 may provide information indicating a period before the start of next induction heating is permitted, based on a difference between the temperature of the switching element 164 and the first threshold. In this case, the user can easily grasp the period before the start of the next induction heating is permitted. Thus, the user can comfortably enjoy a continuous puff experience. The continuous puff experience means that performing puffs by repeating a heating session a plurality of times while replacing a plurality of stick substrates 150.
For example, in the embodiment above, an example has been described in which the susceptor 161 is a piece of metal. However, the present invention is not limited to such an example. For example, the susceptor 161 may have an elongated shape such as a rod shape, a cylindrical shape, or a plate shape. In this case, the susceptor 161 is desirably disposed at the center of the substrate 151 to extend in a longitudinal direction of the substrate 151. With such a configuration, an aerosol can be generated in a short time from the start of heating since the susceptor 161 that produces a large amount of heat by induction heating is disposed at the center of the substrate 151. Obviously, the susceptors 161 having a plurality of shapes may coexist in the substrate 151.
For example, in the embodiment described above, an example has been described in which the substrate 151 includes the susceptor 161. However, the present invention is not limited to such an example. That is, the susceptor 161 may be disposed at any position where the susceptor 161 is in thermal proximity to the aerosol source. In an example, the susceptor 161 may have a blade-like shape, and may be disposed so that the susceptor 161 protrudes from the bottom 143 of the holder 140 toward the internal space 141. When the stick substrate 150 is inserted into the holder 140, the susceptor 161 having the blade-like shape may be inserted so as to pierce the substrate 151 from the end portion of the stick substrate 150 in the insertion direction. In another example, the susceptor 161 may be disposed on an inner wall of the holder 140 that forms the internal space 141.
The series of steps performed by the individual devices described in this specification may be implemented by using any of software, hardware, and a combination of software and hardware. Programs constituting software are, for example, stored in advance in recording media (non-transitory media) provided inside or outside the individual devices. Each program is, for example, at the time of being executed by a computer that controls each of the devices described in this specification, loaded into a RAM and executed by a processor such as a CPU. The recording media are, for example, a magnetic disk, an optical disc, a magneto-optical disk, a flash memory, and the like. The computer programs may be distributed, for example, via a network without using recording media.
The steps described using flowcharts and sequence diagrams in this specification need not necessarily be executed in the order illustrated. Some of the process steps may be executed in parallel. An additional process step may be adopted, or one or some of the process steps may be omitted.
Configurations below also pertain to the technical scope of the present invention.

(1) An inhaler device including:
- a power supply configured to supply DC electric power;
- an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power;
- an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit;
- a holder configured to hold a substrate including an aerosol source;
- a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements; and
- a controller configured to control induction heating performed by the electromagnetic induction source, in which
- the electromagnetic induction source is disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, and
- the controller is configured to control the induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor.
(2) The inhaler device according to (1), in which
the controller is configured to prohibit start of the induction heating in a case where the temperature of the switching element is higher than or equal to a first threshold before the induction heating is started.
(3) The inhaler device according to (2), further including:
a first notifier configured to provide information indicating that the start of the induction heating is prohibited.
(4) The inhaler device according to (3), in which
the first notifier is configured to provide information indicating a period before the start of the induction heating is permitted.
(5) The inhaler device according to (4), in which
the first notifier is configured to provide information based on a difference between the temperature of the switching element and the first threshold, as the information indicating the period before the start of the induction heating is permitted.
(6) The inhaler device according to any one of (2) to (5), in which
- the controller is configured to permit switching of a heating profile to be used between a plurality of heating profiles,
- the heating profile is information that defines a time-series change in a target temperature that is a target value of the temperature of the susceptor, and
- the first threshold is set in accordance with the heating profile to be used.
(7)The inhaler device according to any one of (1) to (6), in which
the controller is configured to control, based on the temperature of the switching element, whether to permit switching to a second heating profile after induction heating based on a first heating profile is started.
(8) The inhaler device according to (7), wherein
the controller is configured to: prohibit the switching to the second heating profile in a case where the temperature of the switching element is higher than or equal to a second threshold set in the second heating profile; and permit the switching to the second heating profile in a case where the temperature of the switching element is lower than the second threshold.
(9) The inhaler device according to (8), in which
the controller is configured to set the second threshold in accordance with an elapsed time from the start of the induction heating at a timing of switching the heating profile.
(10) The inhaler device according to any one of (1) to (9), in which
the controller is configured to stop the induction heating in a case where the temperature of the switching element becomes higher than or equal to a third threshold while the induction heating is performed.
(11) The inhaler device according to (10), further including:
a second notifier configured to provide information indicating that the induction heating is stopped.
(12) The inhaler device according to (10) or (11), in which
the controller is configured to determine that the switching element has failed in a case where a number of times the temperature of the switching element becomes higher than or equal to the third threshold while the induction heating is performed is greater than or equal to a fourth threshold.
(13) The inhaler device according to (12), further including:
a third notifier configured to provide information indicating that the switching element has failed.
(14) The inhaler device according to any one of (10) to (13) directly or indirectly dependent on (2), in which
the controller is configured to adjust the first threshold in a case where the temperature of the switching element becomes higher than or equal to the third threshold while the induction heating is performed.
(15) The inhaler device according to any one of (1) to (14), in which
- the inverter circuit includes a plurality of the switching elements,
- the temperature sensor is configured to detect a temperature of each of the plurality of switching elements, and
- the controller is configured to control the induction heating, based on the temperature of at least one of the plurality of switching elements.
(16) The inhaler device according to any one of (1) to (15), in which
the controller is configured to prohibit or stop electric power supply from the power supply to the inverter circuit to prohibit or stop the induction heating.
(17) The inhaler device according to any one of (1) to (15), in which
the controller is configured to prohibit or stop driving of all the switching elements included in the inverter circuit to prohibit or stop the induction heating.
(18) A program to be executed by a computer that controls an inhaler device,
- the inhaler device including:
  - a power supply configured to supply DC electric power;
  - an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power;
  - an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit;
  - a holder configured to hold a substrate including an aerosol source; and
  - a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements,
  - the electromagnetic induction source being disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field,
- the program causing
  controlling induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor
- to be performed.
(19) A system including: an inhaler device; and a substrate,
- the substrate including an aerosol source,
- the inhaler device including:
  - a power supply configured to supply DC electric power;
  - an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power;
  - an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit;
  - a holder configured to hold the substrate;
  - a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements; and
  - a controller configured to control induction heating performed by the electromagnetic induction source, in which
  - the electromagnetic induction source is disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, and
  - the controller is configured to control the induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor.
(20) The system according to (19), in which
the susceptor is included in the substrate.

Reference Signs List

100: inhaler device
111: power supply
112: sensor
113: notifier
114: memory
115: communicator
116: controller
140: holder
141: internal space
142: opening
143: bottom
150: stick substrate
151: substrate
152: inhalation port
161: susceptor
162: electromagnetic induction source
163: inverter circuit
164: switching element
169: drive circuit
171: temperature sensor

Claims

An inhaler device comprising:
a power supply configured to supply DC electric power;

an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power;

an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit;

a holder configured to hold a substrate including an aerosol source;

a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements; and

a controller configured to control induction heating performed by the electromagnetic induction source, wherein

the electromagnetic induction source is disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, and

the controller is configured to control the induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor.
The inhaler device according to claim 1, wherein
the controller is configured to prohibit start of the induction heating in a case where the temperature of the switching element is higher than or equal to a first threshold before the induction heating is started.
The inhaler device according to claim 2, further comprising:
a first notifier configured to provide information indicating that the start of the induction heating is prohibited.
The inhaler device according to claim 3, wherein
the first notifier is configured to provide information indicating a period before the start of the induction heating is permitted.
The inhaler device according to claim 4, wherein
the first notifier is configured to provide information based on a difference between the temperature of the switching element and the first threshold, as the information indicating the period before the start of the induction heating is permitted.
The inhaler device according to any one of claims 2 to 5, wherein
the controller is configured to permit switching of a heating profile to be used between a plurality of heating profiles,

the heating profile is information that defines a time-series change in a target temperature that is a target value of the temperature of the susceptor, and

the first threshold is set in accordance with the heating profile to be used.
The inhaler device according to any one of claims 1 to 6, wherein
the controller is configured to control, based on the temperature of the switching element, whether to permit switching to a second heating profile after induction heating based on a first heating profile is started.
The inhaler device according to claim 7, wherein
the controller is configured to: prohibit the switching to the second heating profile in a case where the temperature of the switching element is higher than or equal to a second threshold set in the second heating profile; and permit the switching to the second heating profile in a case where the temperature of the switching element is lower than the second threshold.
The inhaler device according to claim 8, wherein
the controller is configured to set the second threshold in accordance with an elapsed time from the start of the induction heating at a timing of switching the heating profile.
The inhaler device according to any one of claims 1 to 9, wherein
the controller is configured to stop the induction heating in a case where the temperature of the switching element becomes higher than or equal to a third threshold while the induction heating is performed.
The inhaler device according to claim 10, further comprising:
a second notifier configured to provide information indicating that the induction heating is stopped.
The inhaler device according to claim 10 or 11, wherein
the controller is configured to determine that the switching element has failed in a case where a number of times the temperature of the switching element becomes higher than or equal to the third threshold while the induction heating is performed is greater than or equal to a fourth threshold.
The inhaler device according to claim 12, further comprising:
a third notifier configured to provide information indicating that the switching element has failed.
The inhaler device according to any one of claims 10 to 13 directly or indirectly dependent on claim 2, wherein
the controller is configured to adjust the first threshold in a case where the temperature of the switching element becomes higher than or equal to the third threshold while the induction heating is performed.
The inhaler device according to any one of claims 1 to 14, wherein
the inverter circuit includes a plurality of the switching elements,

the temperature sensor is configured to detect a temperature of each of the plurality of switching elements, and

the controller is configured to control the induction heating, based on the temperature of at least one of the plurality of switching elements.
The inhaler device according to any one of claims 1 to 15, wherein
the controller is configured to prohibit or stop electric power supply from the power supply to the inverter circuit to prohibit or stop the induction heating.
The inhaler device according to any one of claims 1 to 15, wherein
the controller is configured to prohibit or stop driving of all the switching elements included in the inverter circuit to prohibit or stop the induction heating.
A program to be executed by a computer that controls an inhaler device,
the inhaler device including:
a power supply configured to supply DC electric power;

an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power;

an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit;

a holder configured to hold a substrate including an aerosol source; and

a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements,

the electromagnetic induction source being disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field,

the program causing
controlling induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor

to be performed.
A system comprising: an inhaler device; and a substrate,
the substrate including an aerosol source,

the inhaler device including:
a power supply configured to supply DC electric power;

an inverter circuit configured to drive one or more switching elements to convert the DC electric power supplied from the power supply into AC electric power;

an electromagnetic induction source configured to generate a varying magnetic field by using the AC electric power supplied from the inverter circuit;

a holder configured to hold the substrate;

a temperature sensor configured to detect a temperature of a switching element among the one or more switching elements; and

a controller configured to control induction heating performed by the electromagnetic induction source, wherein

the electromagnetic induction source is disposed at a position where the varying magnetic field generated from the electromagnetic induction source penetrates a susceptor that is disposed in thermal proximity to the aerosol source included in the substrate held by the holder and that is configured to produce heat upon being penetrated by the varying magnetic field, and

the controller is configured to control the induction heating performed by the electromagnetic induction source, based on the temperature of the switching element detected by the temperature sensor.
The system according to claim 19, wherein
the susceptor is included in the substrate.