Induction heating device, control unit therefor, and operation method therefor

Abstract

To provide an induction heating device that is able to automatically start heating an aerosol-forming base material.SOLUTION: A control unit 118 is for an induction heating device configured to inductively heat a susceptor 110 of an aerosol-forming base material 108, which contains the susceptor 110 and an aerosol source 112, and is configured to stop the inductive heating or report an error when the susceptor 110 cannot be detected during execution of the inductive heating.SELECTED DRAWING: Figure 13A

Description

Technical Field

[0001] The present disclosure relates to an induction heating device capable of dealing with the removal of an aerosol-forming substrate.

Background Art

[0002] Conventionally, there is known a device for generating an aerosol from an aerosol-forming substrate by heating a susceptor by induction heating using an inductor disposed in proximity to the aerosol-forming substrate having the susceptor (Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The first problem to be solved by the present disclosure is to provide an improved induction heating device for heating an aerosol-forming substrate to generate an aerosol.

[0005] The second problem to be solved by the present disclosure is to provide an induction heating device capable of automatically starting the heating of an aerosol-forming substrate.

[0006] The third problem to be solved by the present disclosure is to provide an induction heating device capable of dealing with the removal of an aerosol-forming substrate.

[0007] The fourth problem to be solved by the present disclosure is to provide an induction heating device capable of more appropriately heating an aerosol-forming substrate.

Means for Solving the Problem

[0008] According to an embodiment of the present disclosure, to solve the above-described first problem, there is provided an induction heating device for heating an aerosol forming substrate including a susceptor and an aerosol source, the induction heating device including a power supply, a coil for heating the susceptor by induction heating, and a parallel circuit including a first circuit and a second circuit arranged in parallel between the power supply and the coil, wherein the first circuit is used for heating the susceptor, and the second circuit is used for obtaining a value related to the electrical resistance or temperature of the susceptor, and an alternating current generation circuit arranged between the parallel circuit and the coil or between the parallel circuit and the power supply.

[0009] In one embodiment, the alternating current generation circuit is arranged between the parallel circuit and the coil, and the alternating current generation circuit includes a third switch.

[0010] In one embodiment, the third switch includes a MOSFET.

[0011] In one embodiment, the first circuit includes a first switch, the alternating current generation circuit includes a third switch, and when the third switch is switched at a predetermined period, the first switch remains in the on state.

[0012] In one embodiment, the first switch and the third switch include MOSFETs.

[0013] In one embodiment, the second circuit includes a second switch, the alternating current generation circuit includes a third switch, and when the third switch is switched at a predetermined period, the second switch remains in the on state.

[0014] In one embodiment, the second switch includes a bipolar transistor and the third switch includes a MOSFET.

[0015] In one embodiment, the first circuit includes a first switch including a MOSFET, and the second circuit includes a second switch including a bipolar transistor.

[0016] In one embodiment, the first circuit includes a first switch, the second circuit includes a second switch, the AC generation circuit includes a third switch, and when switching is performed between the first switch and the second switch, switching at a predetermined period of the third switch is continued.

[0017] In one embodiment, the induction heating device further includes a current detection circuit and a voltage detection circuit that are used to measure the impedance of the circuit including the susceptor.

[0018] In one embodiment, the induction heating device further includes a remaining amount measurement IC configured to measure the remaining amount of the power supply. The remaining amount measurement IC is not used as the current detection circuit and / or the voltage detection circuit.

[0019] In one embodiment, the induction heating device further includes a voltage adjustment circuit configured to adjust the voltage of the power supply to generate a voltage supplied to components in the induction heating device. The current detection circuit is disposed at a position closer to the coil than a branch point from the path to the voltage adjustment circuit in a path between the power supply and the coil.

[0020] In one embodiment, the current detection circuit is not disposed in a path between a charging circuit for charging the power supply and the power supply.

[0021] In order to solve the above-described second problem, according to an embodiment of the present disclosure, there is provided an induction heating device for induction heating the susceptor of an aerosol forming substrate including a susceptor and an aerosol source, the induction heating device including a power supply, an alternating current generation circuit that generates alternating current from the power supplied from the power supply, an induction heating circuit for induction heating the susceptor, and a control unit that detects the susceptor based on the impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied, and the control unit configured to start the induction heating in response to the detection of the susceptor.

[0022] In one embodiment, the control unit may be further configured to obtain the temperature of the susceptor based on the impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied, and control the induction heating based on the obtained temperature.

[0023] In one embodiment, the control unit can have at least a first mode in which the impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied is measured, and a second mode in which the impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied is not measured.

[0024] In one embodiment, the induction heating device further includes a connection part configured to be connectable to a charging power supply, and the control unit may be further configured to execute the processing in the first mode until a predetermined time elapses after detecting the removal of the charging power supply from the connection part.

[0025] In one embodiment, the induction heating device further includes a button, and the control unit may be further configured to shift to the first mode in response to a predetermined operation being performed on the button.

[0026] In one embodiment, the induction heating device further includes a button, and the control unit activates a timer in response to the transition to the first mode so that the value increases or decreases with the passage of time from an initial value. In response to the value of the timer reaching a predetermined value, the control unit transitions to the second mode, and in response to a predetermined operation being performed on the button, the control unit may be further configured to return the value of the timer to the initial value, move the value of the timer closer to the initial value, or move the predetermined value away from the value of the timer.

[0027] In one embodiment, the induction heating device further includes a connection portion configured to be connectable to a charging power source, and the control unit may be further configured such that while detecting the connection of the charging power source to the connection portion, the impedance of the circuit to which the alternating current generated by the alternating current generation circuit is supplied is not measured.

[0028] In one embodiment, the control unit may be further configured to measure the impedance of the circuit to which the alternating current generated by the alternating current generation circuit is supplied at the resonance frequency of the circuit to which the alternating current generated by the alternating current generation circuit is supplied.

[0029] In one embodiment, the induction heating device may further include a first circuit and a second circuit configured to be selectively activated to supply energy to the susceptor, and the second circuit having a higher resistance than the first circuit.

[0030] In one embodiment, the control unit may be configured to use the first circuit to perform the induction heating and measure the impedance of the circuit while the induction heating is being performed.

[0031] Also, in order to solve the above-described second problem, according to an embodiment of the present disclosure, there is provided a method of operating an induction heating device for induction heating a susceptor of an aerosol forming substrate including a susceptor and an aerosol source, the induction heating device including a power supply, an alternating current generation circuit that generates an alternating current from the power supplied from the power supply, and an induction heating circuit for induction heating the susceptor, the method including: detecting the susceptor based on an impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied; and starting the induction heating in response to the detection of the susceptor.

[0032] Furthermore, in order to solve the above-described second problem, according to an embodiment of the present disclosure, there is provided an induction heating device for induction heating a susceptor of an aerosol forming substrate including a susceptor and an aerosol source, the induction heating device including: the aerosol forming substrate; a power supply; an alternating current generation circuit that generates an alternating current from the power supplied from the power supply; an induction heating circuit for induction heating the susceptor; and a control unit configured to detect the susceptor based on an impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied and start the induction heating in response to the detection of the susceptor.

[0033] In order to solve the above-described third problem, according to an embodiment of the present disclosure, there is provided a control unit for an induction heating device configured to induction heat a susceptor of an aerosol forming substrate including a susceptor and an aerosol source, the control unit being configured to stop the induction heating or notify an error when the susceptor cannot be detected during the execution of the induction heating.

[0034] In one embodiment, the control unit may be configured to stop the induction heating when the susceptor cannot be detected during the execution of the induction heating.

[0035] In one embodiment, the control unit may be further configured to notify an error simultaneously with or after the stop of the induction heating.

[0036] In one embodiment, the control unit may be further configured to resume the induction heating when the susceptor is detected again before a predetermined time has elapsed since the induction heating was stopped.

[0037] In one embodiment, the induction heating follows at least a heating profile in which a heating target temperature according to the passage of time is determined, while the control unit may be configured to control the induction heating as if time has elapsed also during the period from the stop of the induction heating to the restart thereof.

[0038] In one embodiment, the induction heating follows at least a heating profile in which a heating target temperature according to the passage of time is determined, while the control unit may be configured to control the induction heating as if no time has elapsed during the period from the stop of the induction heating to the restart thereof.

[0039] In one embodiment, the control unit may be configured to notify an error when the susceptor cannot be detected while the induction heating is being executed.

[0040] In one embodiment, the control unit may be further configured to stop the induction heating after notifying the error.

[0041] In one embodiment, the control unit may be configured not to stop the induction heating when the susceptor is detected again after notifying the error and before stopping the induction heating.

[0042] In one embodiment, the induction heating follows a heating profile in which a heating target temperature according to the passage of time is at least determined, and the control unit may be configured such that the period from when the susceptor cannot be detected to when the susceptor is detected again does not affect the overall length of the heating profile.

[0043] In one embodiment, the induction heating follows a heating profile in which at least a heating target temperature according to the passage of time is determined, and the control unit may be configured to extend the length of the heating profile based on the period from when the susceptor cannot be detected until when the susceptor is detected again.

[0044] Also, to solve the above-described third problem, according to an embodiment of the present disclosure, there is provided an induction heating device including a power supply, an alternating current generation circuit that generates alternating current from the power supplied from the power supply, an induction heating circuit for induction heating a susceptor included in an aerosol forming substrate, and the control unit, wherein the control unit is further configured to detect the susceptor based on the impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied.

[0045] In one embodiment, the control unit may be further configured to acquire the temperature of the susceptor based on the impedance of a circuit to which the alternating current generated by the alternating current generation circuit is supplied, and control the induction heating based on the acquired temperature.

[0046] Also, to solve the above-described third problem, according to an embodiment of the present disclosure, there is provided an induction heating device including a power supply that supplies power for induction heating a susceptor included in an aerosol forming substrate, and the control unit, wherein the control unit sets the number of usable aerosol forming substrates that can be induction heated until the power supply is charged based on the remaining amount of the power supply, and when at least a part of the aerosol forming substrate cannot be detected during the execution of the induction heating, the induction heating is stopped and the number of usable substrates is decreased.

[0047] Also, in order to solve the above-described third problem, according to an embodiment of the present disclosure, there is provided an induction heating device including a power source that supplies power for inductively heating at least a part of an aerosol-forming substrate, and the control unit, wherein the control unit sets the number of available uses, which is the number of aerosol-forming substrates that can be inductively heated until the power source is charged, based on the remaining amount of the power source, and when the susceptor is detected again after the susceptor cannot be detected during the execution of the inductive heating, the inductive heating is continued and the number of available uses is not decreased.

[0048] Also, in order to solve the above-described third problem, according to an embodiment of the present disclosure, there is provided a method of operating an induction heating device configured to inductively heat the susceptor of an aerosol-forming substrate including a susceptor and an aerosol source, the method including the step of stopping the inductive heating or notifying an error when the susceptor cannot be detected during the execution of the inductive heating.

[0049] Furthermore, in order to solve the above-described third problem, according to an embodiment of the present disclosure, there is provided an induction heating device for inductively heating the susceptor of an aerosol-forming substrate including a susceptor and an aerosol source, the induction heating device including the aerosol-forming substrate, a power source, an alternating current generation circuit that generates alternating current from the power supplied from the power source, an induction heating circuit for inductively heating the susceptor, and a control unit configured to stop the inductive heating or notify an error when the susceptor cannot be detected during the execution of the inductive heating.

[0050] In order to solve the above-described fourth problem, according to an embodiment of the present disclosure, there is provided an induction heating device for heating an aerosol-forming substrate including a susceptor and an aerosol source, the induction heating device including a circuit including a coil for heating the susceptor by induction heating, wherein the susceptor is heated by a heating mode including a plurality of phases, and the frequency of the alternating current supplied to the coil is different in at least a part of the plurality of phases.

[0051] In one embodiment, in the preheating mode for preheating the susceptor, which is executed before the heating mode, the frequency of the alternating current is the resonance frequency of the circuit.

[0052] In one embodiment, in the preheating mode for preheating the susceptor, which is executed before the heating mode, the frequency of the alternating current is configured to be closest to the resonance frequency of the circuit as compared with the plurality of phases of the heating mode.

[0053] In one embodiment, in the heating mode, the frequency of the alternating current is a frequency other than the resonance frequency of the circuit.

[0054] In one embodiment, as the plurality of phases constituting the heating mode progress, the frequency of the alternating current increases, and suction by the user is detected based on the change in the alternating current or the change in the impedance of the circuit.

[0055] In one embodiment, as the plurality of phases constituting the heating mode progress, the frequency of the alternating current increases in a frequency region higher than the resonance frequency.

[0056] In one embodiment, as the plurality of phases constituting the heating mode progress, the frequency of the alternating current increases in a frequency region lower than the resonance frequency.

[0057] In one embodiment, as the plurality of phases constituting the heating mode progress, the frequency of the alternating current decreases.

[0058] In one embodiment, in the interval mode for cooling the susceptor, which is executed between the preheating mode and the heating mode, the frequency of the alternating current is the resonance frequency of the circuit.

[0059] In one embodiment, the induction heating device further includes a power supply, and the circuit is a parallel circuit including a first circuit and a second circuit arranged in parallel between the power supply and the coil. The first circuit is used for heating the susceptor, and the second circuit is used for obtaining a value related to the electrical resistance or temperature of the susceptor. The induction heating device further includes the parallel circuit, and the second circuit is used in the interval mode.

[0060] In order to solve the above-described fourth problem, according to an embodiment of the present disclosure, there is further provided an induction heating device for heating an aerosol forming substrate including a susceptor and an aerosol source, the device including a circuit including a coil for heating the susceptor by induction heating. The susceptor is heated by a heating mode including a plurality of phases, and the frequency of the alternating current supplied to the coil is constant over the plurality of phases.

[0061] In one embodiment, the frequency of the alternating current is the resonance frequency of the circuit.

[0062] In one embodiment, in an interval mode that is executed before the heating mode and cools the susceptor after preheating the susceptor, the frequency of the alternating current is the resonance frequency of the circuit.

[0063] In one embodiment, the induction heating device further includes a power supply, and the circuit is a parallel circuit including a first circuit and a second circuit arranged in parallel between the power supply and the coil. The first circuit is used for heating the susceptor, and the second circuit is used for obtaining a value related to the electrical resistance or temperature of the susceptor. The induction heating device further includes the parallel circuit, and the second circuit is used in the interval mode.

[0064] In one embodiment, when it is determined that the temperature of the susceptor has reached or exceeded a predetermined temperature in the heating mode, the heating of the susceptor is interrupted.

[0065] In one embodiment, the induction heating device further includes a power supply, and the circuit is a parallel circuit including a first circuit and a second circuit arranged in parallel between the power supply and the coil. The first circuit is used for heating the susceptor, and the second circuit is used for obtaining a value related to the electrical resistance or temperature of the susceptor. The parallel circuit is further provided. While the heating of the susceptor is interrupted, the temperature of the susceptor is monitored using the second circuit.

[0066] In one embodiment, when it is determined that the temperature of the susceptor is less than the predetermined temperature in the heating mode, the heating of the susceptor is resumed using the first circuit.

[0067] In one embodiment, when it is determined that the temperature of the susceptor is less than a temperature lower than the predetermined temperature by a predetermined temperature in the heating mode, the heating of the susceptor is resumed using the first circuit.

[0068] In one embodiment, the circuit further includes an AC generation circuit arranged between the parallel circuit and the coil or between the parallel circuit and the power supply. The AC generation circuit includes a third switch, and the third switch is switched at a predetermined period even while the heating of the susceptor is interrupted.

Brief Description of the Drawings

[0069]

Figure 1

Figure 2

Figure 3

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Figure 12

Figure 13A

Figure 13B

Figure 13C

Figure 13D

Figure 13E

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Mode for Carrying Out the Invention

[0070] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that embodiments of the induction heating device according to the present disclosure include, but are not limited to, an induction heating device for electronic cigarettes and an induction heating device for heated tobacco.

[0071] FIG. 1 is a schematic block diagram of the configuration of an induction heating device 100 according to an embodiment of the present disclosure. It should be noted that FIG. 1 does not show the exact arrangement, shape, dimensions, positional relationship, etc. of the components.

[0072] The induction heating device 100 includes a housing 101, a power source 102, a circuit 104, and a coil 106. The power source 102 may be a rechargeable battery such as a lithium-ion secondary battery. The circuit 104 is electrically connected to the power source 102. The circuit 104 is configured to supply power to the components of the induction heating device 100 using the power source 102. The specific configuration of the circuit 104 will be described later. The induction heating device 100 includes a charging power source connection portion 116 for connecting the induction heating device 100 to a charging power source (not shown) for charging the power source 102. The charging power source connection portion 116 may be a receptacle for wired charging, a power receiving coil for wireless charging, or a combination thereof.

[0073] The induction heating device 100 is configured to be able to accommodate at least a part of an aerosol formation substrate 108 including a susceptor 110, an aerosol source 112, and a filter 114. The aerosol formation substrate 108 may be, for example, a smoking article.

[0074] The aerosol source 112 may contain a volatile compound that can generate an aerosol when heated. The aerosol source 112 may be solid, liquid, or may contain both solid and liquid. The aerosol source 112 may contain, for example, polyhydric alcohols such as glycerin and propylene glycol, liquids such as water, or a mixed liquid thereof. The aerosol source 112 may contain nicotine. The aerosol source 112 may also contain a tobacco material formed by aggregating particulate tobacco. Alternatively, the aerosol source 112 may contain a non-tobacco-containing material.

[0075] The coil 106 is embedded in the housing 101 at the proximal end of the housing 101. The coil 106 is configured to surround a portion of the aerosol-forming substrate 108 accommodated in the induction heating device 100 when the aerosol-forming substrate 108 is inserted into the induction heating device 100. The coil 106 may have a helically wound shape. The coil 106 is electrically connected to the circuit 104 and is used to heat the susceptor 110 by induction heating as described later. By heating the susceptor 110, an aerosol is generated from the aerosol source 112. The user can inhale the aerosol through the filter 114.

[0076] FIG. 2 shows the configuration of the circuit 104 in detail. The circuit 104 includes a control unit 118 configured to control components within the induction heating device 100. The control unit 118 may be constituted by a microcontroller unit (MCU). The circuit 104 is also electrically connected to the power supply 102 via a power connection portion and to the coil 106 via a coil connection portion. The circuit 104 includes a parallel circuit 130 including a path (hereinafter also referred to as the "first circuit") including a switch Q1 disposed between the power supply 102 and the coil 106 and a path (hereinafter also referred to as the "second circuit") including a switch Q2 disposed in parallel with the switch Q1.

[0077] The first circuit is used for heating the susceptor 110. As an example, the switch Q1 may be a Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET). The control unit 118 controls the on / off of the switch Q1 by applying a heating switch signal (high or low) to the gate terminal of the switch Q1. For example, when the switch Q1 is a P-channel MOSFET, the switch Q1 is in the on state when the heating switch signal is low.

[0078] The second circuit is used for obtaining a value related to the electrical resistance or temperature of the susceptor 110. The value related to the electrical resistance or temperature may be, for example, impedance, temperature, etc. The current flowing through the switch Q2 when the switch Q2 is in the on state is smaller compared to the current flowing through the switch Q1 when the switch Q1 is in the on state by the resistors R shunt1 and the resistor R shunt2 and so on. Therefore, a bipolar transistor, which is less expensive and smaller than a MOSFET but not suitable for large currents, may be used as the switch Q2. As shown in the figure, the second circuit may include the resistors R shunt1 and the resistor R shunt2 . The control unit 118 controls the on / off of the switch Q2 by applying a monitor switch signal (high or low) to the base terminal of the switch Q2. For example, when the switch Q2 is an npn-type bipolar transistor, the switch Q2 is in the on state when the monitor switch signal is low.

[0079] The control unit 118 can switch between a mode of inductively heating the susceptor 110 to generate an aerosol by switching between the on state of the switch Q1 and the on state of the switch Q2, and a mode of acquiring a value related to the electrical resistance or temperature of the susceptor 110. The switching between the on state of the switch Q1 and the on state of the switch Q2 can be performed at any timing. For example, while a puff is being performed by the user, the control unit 118 may turn on the switch Q1 and turn off the switch Q2. In this case, after the puff is finished, the control unit 118 may turn off the switch Q1 and turn on the switch Q2. Alternatively, while a puff is being performed by the user, the control unit 118 may switch between the on state of the switch Q1 and the on state of the switch Q2 at any timing.

[0080] The circuit 104 includes an AC generation circuit 132 including a switch Q3 and a capacitor C1. As an example, the switch Q3 may be a MOSFET. The control unit 118 controls the on / off of the switch Q3 by applying an alternating current (AC) switch signal (high or low) to the gate terminal of the switch Q3. For example, when the switch Q3 is a P-channel MOSFET, the switch Q3 is in the on state when the AC switch signal is low. In FIG. 2, the AC generation circuit 132 is disposed between the parallel circuit 130 and the coil 106. As another example, the AC generation circuit 132 may be disposed between the parallel circuit 130 and the power supply 102. The alternating current generated by the AC generation circuit 132 is supplied to an inductive heating circuit including a capacitor C2, a coil connection portion, and the coil 106.

[0081] FIG. 3 shows the voltage V1 applied to the gate terminal of the switch Q1 or the base terminal of the switch Q2, the voltage V2 applied to the gate terminal of the switch Q3, the current I generated by the switching of the switch Q3, DC and the current I flowing through the coil 106 when the alternating current supplied to the coil 106 is generated by the AC generation circuit 132. ACIt is a diagram conceptually showing the relationship with the horizontal axis being time t. Note that for simplicity of explanation, the voltages applied to the gate terminal of switch Q1 and the base terminal of switch Q2 are represented as V1 in one graph.

[0082] When V1 goes low at time t1, switch Q1 or Q2 turns on. When V2 is high, switch Q3 turns off, and current I DC flows into capacitor C1, and charge is accumulated in capacitor C1. When V2 is switched to low at time t2, switch Q3 turns on. In this case, the flow of current I DC stops, while the charge accumulated in C1 is discharged. After time t3, the same operation is repeated. As a result of the above operation, as shown in FIG. 3, an alternating current I AC is generated and flows into coil 106.

[0083] As shown in FIG. 3, when switch Q3 is switched at a predetermined period T, switch Q1 may remain in the on state. Also, when switch Q3 is switched at a predetermined period T, switch Q2 may remain in the on state. Further, when switching is performed between switch Q1 and switch Q2, the switching of switch Q3 at the predetermined period T may continue.

[0084] The above configuration of the alternating current generation circuit 132 is only an example. It should be understood that various elements for generating the alternating current I AC , such as integrated circuits like DC / AC inverters, can be used as the alternating current generation circuit 132.

[0085] As understood from FIG. 3, the alternating current I ACThe frequency f is controlled by the switching period of switch Q3 (i.e., the switching period of the AC switch signal) T. When switch Q1 is in the on state, the closer the frequency f approaches the resonance frequency f0 of the RLC series circuit including the susceptor 110 (or the circuit including the susceptor 110), the coil 106, and the capacitor C2, the higher the efficiency of energy supply to the susceptor 110 becomes. Although details will be described later, it should be noted that when the aerosol-forming substrate 108 is inserted into the housing 101, the susceptor 110 is included in this RLC series circuit, and when the aerosol-forming substrate 108 is not inserted into the housing 101, the susceptor 110 is not included in this RLC series circuit.

[0086] When the alternating current generated as described above flows through the coil 106, an alternating magnetic field is generated around the coil 106. The generated alternating magnetic field induces eddy currents in the susceptor 110. Joule heat is generated by the eddy currents and the electrical resistance of the susceptor 110, and the susceptor 110 is heated. As a result, the aerosol source around the susceptor 110 is heated to generate an aerosol.

[0087] Returning to FIG. 2, the circuit 104 includes a voltage detection circuit 134 including a voltage dividing circuit having R div1 and R div2 The voltage value of the power supply 102 can be measured by the voltage detection circuit 134. The circuit 104 also includes R sense2It includes a current detection circuit 136. As shown in the figure, the current detection circuit 136 may include an operational amplifier. Alternatively, the operational amplifier may be included within the control unit 118. The current detection circuit 136 can measure the value of the current flowing in the direction of the coil 106. The voltage detection circuit 134 and the current detection circuit 136 are used to measure the impedance of the circuit. This circuit includes the susceptor 110 when the aerosol forming substrate 108 is inserted into the housing 101, and does not include the susceptor 110 when the aerosol forming substrate 108 is not inserted into the housing 101. In other words, when the aerosol forming substrate 108 is inserted into the housing 101, the measured impedance includes the resistance component of the susceptor 110, and when the aerosol forming substrate 108 is not inserted into the housing 101, the measured impedance does not include the resistance component of the susceptor 110. For example, as shown in the figure, the control unit 118 acquires the voltage value from the voltage detection circuit 134 and acquires the current value from the current detection circuit 136. The control unit 118 calculates the above impedance based on these voltage values and current values. More specifically, the control unit 118 divides the average value or the effective value of the voltage value by the average value or the effective value of the current value to calculate the above impedance.

[0088] When the switch Q1 is turned off and the switch Q2 is turned on, the resistor R shunt1 and the resistor R shunt2 A RLC series circuit is formed by the circuit including and the susceptor 110, the coil 106, and the capacitor C2. The impedance of the RLC series circuit can be obtained as described above. By subtracting the resistance value of the circuit including the resistance values of the resistor R shunt1 and the resistor R shunt2 from the obtained impedance, the impedance of the susceptor 110 can be calculated. When the impedance of the susceptor 110 has temperature dependence, the temperature of the susceptor 110 can be estimated based on the calculated impedance.

[0089] Circuit 104 may include a remaining amount measurement integrated circuit (IC) 124. Circuit 104 uses resistor R for the remaining amount measurement IC 124 to measure the value of the current that charges and discharges power supply 102. sense1 It may include. Resistor R sense1 may be connected between the SRN terminal and the SRP terminal of the remaining amount measurement IC 124. The remaining amount measurement IC 124 may obtain a value regarding the voltage of the power supply 102 via the BAT terminal. The remaining amount measurement IC 124 is an IC configured to be able to measure the remaining amount of the power supply 102. In addition, the remaining amount measurement IC 124 may be configured to record information such as information regarding the deterioration state of the power supply 102. For example, the control unit 118 transmits an I 2 C data signal from the SDA terminal of the control unit 118 to the SDA terminal of the remaining amount measurement IC 124, and in accordance with the timing of transmitting an I 2 C clock signal from the SCL terminal of the control unit 118 to the SCL terminal of the remaining amount measurement IC 124, values regarding the remaining amount of the power supply 102, values regarding the deterioration state of the power supply 102, etc. stored in the remaining amount measurement IC 124 can be obtained.

[0090] Normally, the remaining amount measurement IC 124 is configured to update data at a 1-second cycle. Therefore, if an attempt is made to calculate the impedance of the above RLC series circuit using the voltage value and current value measured by the remaining amount measurement IC 124, the impedance is calculated at a 1-second cycle at the fastest. Therefore, the temperature of the susceptor 110 is estimated at a 1-second cycle at the fastest. Such a cycle cannot be said to be short enough to appropriately control the heating of the susceptor 110. Therefore, in the present embodiment, it is desirable not to use the voltage value and current value measured by the remaining amount measurement IC 124 for measuring the impedance of the RLC series circuit. That is, preferably, the remaining amount measurement IC 124 is not used as the voltage detection circuit 134 and the current detection circuit 136 as described above. Thus, in the induction heating device 100 according to the present embodiment, the remaining amount measurement IC 124 is not essential. However, by using the remaining amount measurement IC 124, the state of the power supply 102 can be accurately grasped.

[0091] The induction heating device 100 may include a light-emitting element 138 such as an LED. The circuit 104 may include a light-emitting element drive circuit 126 for driving the light-emitting element 138. The light-emitting element 138 can be used to provide various information such as the state of the induction heating device 100 to the user. The light-emitting element drive circuit 126 may store information regarding various light-emitting modes of the light-emitting element 138. The control unit 118 can control the light-emitting element drive circuit 126 to cause the light-emitting element 138 to emit light in a desired manner by transmitting an I2C data signal from the SDA terminal of the control unit 118 to the SDA terminal of the light-emitting element drive circuit 126 to specify a desired light-emitting mode.

[0092] The circuit 104 may include a charging circuit 122. The charging circuit 122 may be an IC configured to adjust the voltage (the potential difference between the VBUS terminal and the GND terminal) supplied from a charging power source (not shown) connected via the charging power connection portion 116 to a voltage suitable for charging the power supply 102 in response to a charging enable signal from the control unit 118 received at the CE terminal. The adjusted voltage is supplied from the BAT terminal of the charging circuit 122. Note that an adjusted current may be supplied from the BAT terminal of the charging circuit 122. The circuit 104 may also include a voltage dividing circuit 140. When the charging power source is connected, a VBUS detection signal is transmitted from the VBUS terminal of the charging circuit 122 to the control unit 118 via the voltage dividing circuit 140. When the charging power source is connected, the VBUS detection signal becomes a value obtained by dividing the voltage supplied from the charging power source by the voltage dividing circuit 140, so the VBUS detection signal becomes high level. When the charging power source is not connected, since it is connected to ground via the voltage dividing circuit 140, the VBUS detection signal becomes low level. Therefore, the control unit 118 can determine that charging has started. Note that the CE terminal may be positive logic or negative logic.

[0093] Circuit 104 may include button 128. When the user presses button 128, by being connected to ground via button 128, a low-level button detection signal is sent to control unit 118. Thereby, control unit 118 can determine that the button has been pressed and can control circuit 104 to start aerosol generation.

[0094] Circuit 104 may include voltage adjustment circuit 120. Voltage adjustment circuit 120 adjusts the voltage V of power supply 102 BAT (for example, 3.2 to 4.2 volts) and is configured to generate a voltage V sys (for example, 3 volts) to be supplied to components within circuit 104 or induction heating device 100. As an example, voltage adjustment circuit 120 may be a linear regulator such as an LDO (low dropout regulator). As shown, the voltage V generated by voltage adjustment circuit 120 sys may be supplied to the VDD terminal of control unit 118, the VDD terminal of remaining amount measurement IC 124, the VDD terminal of light emitting element drive circuit 126, circuits including button 128, etc.

[0095] As shown, current detection circuit 136 may be arranged at a position closer to coil 106 than the branch point (point A in FIG. 2) from this path to voltage adjustment circuit 120 in the path between power supply 102 and coil 106. According to this configuration, current detection circuit 136 can accurately measure the value of the current supplied to coil 106 without including the current supplied to voltage adjustment circuit 120. Therefore, the impedance and temperature of susceptor 110 can be accurately measured or estimated.

[0096] Circuit 104 may be configured such that the current detection circuit 136 is not arranged in the path between the charging circuit 122 and the power supply 102. Specifically, as shown in the figure, the current detection circuit 136 may be arranged at a position closer to the coil 106 than the branch point (point B in FIG. 2) from the path to the charging circuit 122 in the path between the power supply 102 and the coil 106. With this configuration, during charging of the power supply 102 (switches Q1 and Q2 are in the off state), the current supplied from the charging circuit 122 can be prevented from flowing through the resistor R sense2 in the current detection circuit 136. Therefore, the possibility of the resistor R sense2 failing can be reduced. Also, since current can be prevented from flowing through the operational amplifier of the current detection circuit 136 during charging of the power supply 102, power consumption can be suppressed.

[0097] Circuit 104 may also include a switch Q4 that is switched between an on state and an off state by a ground switch signal transmitted from the control unit 118.

[0098] Next, an exemplary process executed by the control unit 118 of the induction heating device 100 will be described. Hereinafter, it is assumed that the control unit 118 has at least seven modes, namely, SLEEP, CHARGE, ACTIVE, PRE-HEAT, INTERVAL, HEAT, and ERROR modes, and the processes executed by the control unit 118 for each mode are described. The induction heating of the susceptor 100 by the induction heating device 100 is configured by the PRE-HEAT mode, the INTERVAL mode, and the HEAT mode.

[0099] FIG. 4 is a flowchart of an exemplary process 400 executed by the control unit 118 when in the SLEEP mode. The SLEEP mode may be a mode that reduces power consumption when the induction heating device 100 is not in use.

[0100] S410 indicates a step of determining whether the charging power source is detected as connected to the charging power source connection portion 116. Based on the above-described VBUS detection signal, the control unit 118 can determine that the connection of the charging power source is detected. If it is determined that the connection of the charging power source is detected ( "Yes" in S410), the control unit 118 shifts to the CHARGE mode. Otherwise ( "No" in S410), the process proceeds to step S420. As a specific example, in S410, when the VBUS detection signal is at a high level, it is determined as "Yes", and when the VBUS detection signal is at a low level, it is determined as "No".

[0101] S420 indicates a step of determining whether a predetermined operation on the button 128 of the induction heating device 100 is detected. Based on the above-described button detection signal, the control unit 118 can determine that a predetermined operation on the button 128 is detected. An example of the predetermined operation in step S420 is a long press or continuous tapping of the button 128. If it is determined that a predetermined operation on the button 128 is detected ( "Yes" in S420), the control unit 118 shifts to the ACTIVE mode. Otherwise ( "No" in S420), the process returns to step S410.

[0102] According to the exemplary process 400, the control unit 118 shifts to the CHARGE mode in response to detecting the connection of the charging power source, and shifts to the ACTIVE mode in response to detecting the operation of the button. In other words, if the control unit 118 does not detect either the connection of the charging power source or the operation of the button, it continues to stay in the SLEEP mode.

[0103] FIG. 5 is a flowchart of an exemplary process 500 executed by the control unit 118 when in the CHARGE mode. The exemplary process 500 can be started in response to the control unit 118 shifting to the CHAEGE mode.

[0104] S510 indicates a step of executing a process for starting the charging of power supply 102. The process for starting the charging of power supply 102 may include the process of turning on the above-described charge enable signal or starting the transmission of the signal. Turning on the charge enable signal means setting the level of the charge enable signal according to the logic of the CE terminal. That is, when the CE terminal is positive logic, the charge enable signal is set to a high level, and when the CE terminal is negative logic, the charge enable signal is set to a low level.

[0105] S520 indicates a step of determining whether the removal of the charging power supply from the charging power supply connection part 116 is detected. The control unit 118 can detect the removal of the charging power supply from the charging power supply connection part 116 based on the above-described VBUS detection signal. If it is determined that the removal of the charging power supply is detected (''Yes'' in S520), the process proceeds to step S530; otherwise (''No'' in S520), the process returns to step S520.

[0106] S530 indicates a step of executing a process for ending the charging of power supply 102. The process for ending the charging of power supply 102 may include the process of turning off the above-described charge enable signal or stopping the transmission of the signal. Turning off the charge enable signal means setting the level of the charge enable signal not according to the logic of the CE terminal. That is, when the CE terminal is positive logic, the charge enable signal is set to a low level, and when the CE terminal is negative logic, the charge enable signal is set to a high level.

[0107] Based on the charging level of the power source 102 (the amount of power remaining in the power source 102), S540 shows the step of setting the available number of aerosol-forming substrates 108 (assuming the aerosol-forming substrate 108 is in a stick shape, but the shape of the aerosol-forming substrate 108 is not limited to this. Therefore, it should be noted that the 'available number' can be generalized to the 'available quantity'). Hereinafter, with reference to FIG. 6, the available number will be described. FIG. 6 is a pseudo-graph for explaining the available number.

[0108] 610 corresponds to the power source 102 when it has not been used yet (hereinafter referred to as 'when not in use'), and its area indicates the full charge capacity when not in use. Note that the power source 102 has not been used yet may mean that the number of discharge times since the power source 102 was manufactured is zero or less than a first predetermined number of discharge times. An example of the full charge capacity of the power source 102 when not in use is about 220 mAh. 620 corresponds to the power source 102 when it has been used in the induction heating device 100, precisely when discharge and charge have been repeated and a certain degree of deterioration has occurred (hereinafter referred to as 'when deteriorated'), and its area indicates the full charge capacity when deteriorated. As is clear from FIG. 6, the full charge capacity of the power source 102 when not in use is larger than the full charge capacity of the power source 102 when deteriorated.

[0109] 630 corresponds to the amount of power (energy) required to consume one aerosol-forming substrate 108, and its area indicates the corresponding amount of power. The four 630s in FIG. 6 all have the same area, and the corresponding amounts of power are also approximately the same. An example of the amount of power 630 required to consume one aerosol-forming substrate 108 is about 70 mAh. Note that when suction for a predetermined number of suction times or heating for a predetermined time is performed, it may be regarded that one aerosol-forming substrate 108 has been consumed.

[0110] 640 and 650 correspond to the charge level of the power supply 102 (hereinafter referred to as "surplus power amount") after consuming two aerosol-forming substrates 108, and the area thereof indicates the corresponding power amount. As is clear from FIG. 6, the surplus power amount 640 when unused is larger than the surplus power amount 650 when deteriorated.

[0111] 660 indicates the output voltage of the power supply 102 when fully charged, and an example thereof is about 3.64V. So that 660 is the same for the power supply 102 (610) when unused and the power supply 102 (620) when deteriorated, the voltage of the power supply 102 when fully charged is basically constant regardless of the deterioration of the power supply 102, that is, regardless of the SOH (State Of Health).

[0112] 670 indicates the discharge cut-off voltage of the power supply 102, and an example thereof is about 2.40V. So that 670 is the same for the power supply 102 (610) when unused and the power supply 102 (620) when deteriorated, the discharge cut-off voltage of the power supply 102 is basically constant regardless of the deterioration of the power supply 102, that is, regardless of the SOH.

[0113] It is preferable that the power supply 102 is not used until the voltage reaches the discharge cut-off voltage 670, in other words, until the charge level of the power supply 102 becomes zero. This is because when the voltage of the power supply 102 becomes equal to or lower than the discharge cut-off voltage 670 or when the charge level of the power supply 102 becomes zero, the deterioration of the power supply 102 progresses rapidly. Also, the closer the voltage of the power supply 102 approaches the discharge cut-off voltage 670, the more the deterioration of the power supply 102 progresses.

[0114] Also, as described above, when the power supply 102 is used, more precisely when discharging and charging are repeated, its full charge capacity decreases, and the surplus power amount after consuming a predetermined number (2 in FIG. 6) of aerosol-forming substrates 108 is smaller when deteriorated (650) than when unused (640).

[0115] Therefore, it is preferable that the control unit 118 sets the number of available units so that, assuming the degradation of the power supply 102, it is not used until the voltage reaches the discharge termination voltage 670 or near it, in other words, until the charge level of the power supply 102 becomes zero or near it. That is, the number of available units can be set as follows, for example. n=int((e - S) / C) Here, n is the number of available units, e is the charge level of the power supply 102 (unit: mAh for example), S is a parameter (unit: mAh for example) with a margin for the surplus power amount 650 at the time of degradation of the power supply 102, C is the power amount (unit: mAh for example) required to consume one aerosol formation substrate 108, and int() is a function that truncates the decimal part within (). Note that e is a variable and can be obtained by the control unit 118 communicating with the remaining amount measurement IC 124. Also, S and C are constants and can be experimentally determined in advance and stored in advance in the memory (not shown) of the control unit 118. In particular, S may be the surplus power amount 650 obtained when discharging the power supply 102 for a second predetermined number of discharges (>> the first predetermined number of discharges), that is, when the assumed degradation occurs, or a value obtained by adding +α to the surplus power amount. Note that when the SOH obtained by the control unit 118 communicating with the remaining amount measurement IC 124 reaches a predetermined value, the control unit 118 may determine that the degradation of the power supply 102 has progressed sufficiently and prohibit the charge and discharge of the power supply 102. That is, the state of degradation when calculating S refers to a state where the SOH has not reached a predetermined value but the degradation has progressed more than when not in use.

[0116] Returning to FIG. 5, after step S540, the control unit 118 shifts to the ACTIVE mode. In the above-described embodiment, in step S520, the control unit 118 determines whether or not it has detected the removal from the charging power supply connection part 116 of the charging power supply. Instead of this, the charging circuit 122 may determine the completion of charging of the power supply 102, and the control unit 118 may determine whether or not it has received the determination by I2C communication or the like.

[0117] FIG. 7 is a flowchart of an exemplary process (hereinafter referred to as the "main process") 700 mainly executed by the control unit 118 when in the ACTIVE mode. The main process 700 can be started in response to the control unit 118 transitioning to the ACTIVE mode.

[0118] S705 indicates a step of starting a first timer. By starting the first timer, the value of the first timer will increase or decrease over time from the initial value. Hereinafter, it is assumed that the value of the first timer increases over time. Also, the first timer may be stopped when the control unit 118 transitions to another mode. The same applies to the second timer and the third timer described later.

[0119] S710 indicates a step of notifying the user of the charge level of the power supply 102. The notification of the charge level can be realized by the control unit 118 communicating with the light-emitting element drive circuit 126 based on the information of the power supply 102 obtained through communication with the remaining amount measurement IC 124 and causing the light-emitting element 138 to emit light in a predetermined manner. The same applies to other notifications described later. The notification of the charge level is preferably performed temporarily.

[0120] S715 indicates a step of starting another process (hereinafter referred to as the "sub-process") to be executed in parallel with the main process 700. The sub-process started in this step will be described later. Also, the execution of the sub-process may be stopped when the control unit 118 transitions to another mode. The same applies to other sub-processes described later.

[0121] S720 indicates a step of determining whether a predetermined time has elapsed based on the value of the first timer. If it is determined that the predetermined time has elapsed ( "Yes" in S720), the control unit 118 transitions to the SLEEP mode; otherwise ( "No" in S720), the process proceeds to step S725.

[0122] S725 controls to supply non-heating AC power to a circuit for inductively heating the above-described RLC series circuit, i.e., the susceptor 110 which is at least a part of the aerosol-forming substrate 108, and shows a step of measuring the impedance of the RLC series circuit. The non-heating AC power may be generated by switching the switch Q3 after turning off the switch Q1 and turning on the switch Q2. The average value or effective value of the energy applied to the RLC series circuit by the supply of the non-heating AC power is smaller than the average value or effective value of the energy applied to the RLC series circuit by the supply of the heating AC power described later. Note that the non-heating AC power preferably has the resonance frequency f0 of the RLC series circuit.

[0123] Note that the supply of the non-heating AC power is only for measuring the impedance of the RLC series circuit. Therefore, after data for measuring the impedance of the RLC series circuit (for example, the effective value V of the voltage measured by the voltage detection circuit 134 and the current detection circuit 136 described later RMS and the effective value I of the current RMS ) is acquired, the supply of this non-heating AC power may be promptly stopped. On the other hand, the supply of this non-heating AC power may be continued until a predetermined time point, for example, until the control unit 118 shifts to another mode. The stop of the supply of the non-heating AC power can be realized by one or both of turning off the switch Q2 and stopping the switching of the switch Q3 and turning it off. Note that it should be noted that the switch Q1 may originally be in the off state at the time of step S725.

[0124] S730 shows the step of determining whether the measured impedance is abnormal. When the impedance measured in step 725 is not included in the impedance range determined based on the impedance measured when the normal aerosol generation substrate 108 is properly inserted into the induction heating device 100, including the measurement error, the control unit 118 can determine that the measured impedance is abnormal. If it is determined that the impedance is abnormal (\"Yes\" in S730), the process proceeds to step S735; otherwise (\"No\" in S730), the process proceeds to step S745.

[0125] S735 shows the step of executing a predetermined fail - safe action. The predetermined fail - safe action may include turning all of the switches Q1, Q2, and Q3 off.

[0126] S740 shows the step of giving a predetermined error notification to the user. After step S740, the control unit 118 shifts to the ERROR mode for performing predetermined error processing. Note that the specific processing in the ERROR mode is omitted.

[0127] S745 shows the step of determining whether the susceptor 110 has been detected based on the impedance measured in step S725. Note that the detection of the susceptor 110 can be regarded as the detection of the aerosol - forming substrate 108 including the susceptor 110. The detection of the susceptor 110 based on the impedance will be described later.

[0128] S750 shows the step of determining whether the number of available units is 1 or more. If the number of available units is 1 or more (\"Yes\" in S750), the control unit 118 shifts to the PRE - HEAT mode; otherwise (\"No\" in S750), the process proceeds to step S755.

[0129] S755 indicates a step of giving a predetermined low remaining amount notification to the user that the remaining amount of the power of the power supply 102 is low. After step S755, the control unit 118 shifts to the SLEEP mode.

[0130] As will be described later, according to the PRE-HEAT process that can be shifted from step S750, the induction heating of the aerosol formation substrate 108 is performed. Therefore, according to the main process 700, the automatic induction heating of the aerosol formation substrate 108 after the aerosol formation substrate 108 is inserted into the housing 101 is realized.

[0131] FIG. 8 is a flowchart of an exemplary first sub-process 800 activated in step S715 in the main process 700 of the ACTIVE mode.

[0132] S810 indicates a step of determining whether a predetermined operation on the button 128 is detected. An example of the predetermined operation in step S810 is a short press of the button 128. When it is determined that a predetermined operation on the button 128 is detected (''Yes'' in S810), the process proceeds to step S820, and otherwise (''No'' in S810), the process returns to step S810.

[0133] S820 indicates a step of resetting the first timer and returning its value to the initial value. Instead of this embodiment, the value of the first timer may be made closer to the initial value, or the predetermined time in step S720 may be made farther from the value of the first timer.

[0134] S830 indicates a step of notifying the user of the charging level of the power supply 102. After step S830, the process returns to step S810.

[0135] According to the main process 700, the control unit 118 may shift to the SLEEP mode when a predetermined time has elapsed since the transition to the ACTIVE mode. According to the sub-process 800, a predetermined operation on the button 128 can notify the user of the charging level of the power supply 102 again and defer the transition to the SLEEP mode.

[0136] FIG. 9 is a flowchart of an exemplary second sub-process 900 activated in step S715 in the main process 700 of the ACTIVE mode.

[0137] S910 indicates a step of determining whether the connection to the charging power supply connection part 116 of the charging power supply is detected. If it is determined that the connection of the charging power supply is detected (''Yes'' in S910), the control unit 118 shifts to the CHARGE mode, and if not (''No'' in S910), the process returns to step S910. Similar to step S410, the control unit 118 can determine that the connection of the charging power supply is detected based on the above-described VBUS detection signal. When shifting to the CHARGE mode, it is preferable that the control unit 118 turns off all of the switches Q1, Q2, and Q3.

[0138] According to the second sub-process 900, in response to the connection of the charging power supply, the control unit 118 automatically shifts to the CHARGE mode.

[0139] FIG. 10 is a flowchart of an exemplary process (main process) 1000 mainly executed by the control unit 118 when in the PRE-HEAT mode. The main process 1000 can start in response to the control unit 118 shifting to the PRE-HEAT mode.

[0140] S1010 indicates a step of controlling to start supplying heating AC power to the RLC series circuit. The heating AC power is generated by turning on switch Q1, turning off switch Q2, and then switching switch Q3. The average value or effective value of the energy applied to the RLC series circuit by the supply of the heating AC power is greater than the average value or effective value of the energy applied to the RLC series circuit by the supply of the above-mentioned non-heating AC power.

[0141] S1020 indicates a step of starting another process (sub-process) so as to be executed in parallel with the main process 1000. The sub-process started in this step will be described later.

[0142] S1030 indicates a step of executing a process according to the detection of the susceptor 110. This step will be described later. The step includes at least a step of measuring the impedance of the RLC series circuit.

[0143] S1040 indicates a step of obtaining at least a part of the temperature of the susceptor 110 or the aerosol-forming substrate 108 (hereinafter, for convenience, referred to as "susceptor temperature") from the impedance measured in step S1030. The acquisition of the susceptor temperature based on the impedance will be described later. In step S1050 described later, step S1040 may be omitted by using a preheating target impedance corresponding to the preheating target temperature instead of the preheating target temperature. In this case, in step S1050, the impedance is compared with the preheating target impedance.

[0144] S1050 indicates a step of determining whether the acquired susceptor temperature has reached a predetermined preheating target temperature. If it is determined that the susceptor temperature has reached the preheating target temperature (\"Yes\" in S1050), the process proceeds to step S1060; otherwise (\"No\" in S1050), the process returns to step S1030. Note that even if a predetermined time has elapsed since the PRE-HEAT mode was started, it may be determined as \"Yes\" in step S1050 assuming that the preheating is completed.

[0145] S1060 indicates a step of notifying the user that the preheating of the aerosol forming substrate 108 is completed. This notification may be performed by the LED138, or may be performed by a vibration motor or a display (not shown). After step S1060, the control unit 118 shifts to the INTERVAL mode.

[0146] According to the main process 1000, preheating of the aerosol forming substrate 108 can be realized.

[0147] FIG. 11 is a flowchart of an exemplary process (main process) 1100 mainly executed by the control unit 118 when in the INTERVAL mode. The main process 1100 can be started in response to the control unit 118 shifting to the INTERVAL mode.

[0148] S1110 indicates a step of controlling to stop the supply of heating alternating current power to the RLC series circuit. The stop of the supply of heating alternating current power can be realized by turning off the switch Q1 and / or stopping the switching of the switch Q3 and turning it off. Note that it should be noted that at the time of step S1110, the switch Q2 may originally be in the off state.

[0149] S1120 indicates a step of starting another process (sub-process) so as to be executed in parallel with the main process 1100. The sub-process started in this step will be described later.

[0150] S1130 shows a step of controlling to supply non-heating AC power to the RLC series circuit and measuring the impedance of the RLC series circuit. This step may be the same as step S725 of the main process 700 in the ACTIVE mode.

[0151] S1140 shows a step of obtaining the susceptor temperature from the measured impedance. In step S1150 described later, step S1140 may be omitted by using the cooling target impedance corresponding to the cooling target temperature instead of the cooling target temperature. In this case, in step S1150, the impedance and the cooling target impedance are compared.

[0152] S1150 shows a step of determining whether the obtained susceptor temperature has reached a predetermined cooling target temperature. When it is determined that the susceptor temperature has reached the cooling target temperature (''Yes'' in S1150), the control unit 118 shifts to the HEAT mode. Otherwise (''No'' in S1150), the process returns to step S1130. Note that even when a predetermined time has elapsed since the INTERVAL mode was started, it may be determined as ''Yes'' in step S1150 assuming that the cooling is completed.

[0153] In the PRE-HEAT mode, the susceptor is rapidly heated so that the aerosol can be supplied rapidly. On the other hand, such rapid heating may cause an excessive amount of the generated aerosol. Therefore, by executing the INTERVAL mode before the HEAT mode, the amount of the generated aerosol can be stabilized from the completion time of the PRE-HEAT mode to the completion time of the HEAT mode. In other words, according to the main process 1100, the preheated aerosol formation substrate 108 can be cooled before the HEAT mode for stabilizing the aerosol generation.

[0154] FIG. 12 is a flowchart of an exemplary process (main process) 1200 mainly executed by the control unit 118 when in the HEAT mode. The main process 1200 can start in response to the control unit 118 transitioning to the HEAT mode.

[0155] S1205 shows a step of starting the second timer.

[0156] S1210 shows a step of starting another process (sub - process) to be executed in parallel with the main process 1200. The sub - process started in this step will be described later.

[0157] S1215 shows a step of controlling to start supplying heating AC power to the RLC series circuit.

[0158] S1220 shows a step of executing a process in response to the detection of the susceptor 110. Although this step will be described later, the step includes at least a step of measuring the impedance of the RLC series circuit.

[0159] S1225 shows a step of obtaining the susceptor temperature from the impedance measured in step S1220. Note that in step S1230 described later, by using the heating target impedance corresponding to the heating target temperature instead of the heating target temperature, step S1225 may be omitted. In this case, in step S1230, the impedance and the heating target impedance are compared.

[0160] S1230 shows a step of determining whether the obtained susceptor temperature is equal to or higher than a predetermined heating target temperature. If the susceptor temperature is equal to or higher than the heating target temperature (''Yes'' in S1230), the process proceeds to step S1235; otherwise (''No'' in S1230), the process proceeds to step S1240.

[0161] S1235 shows a step of waiting for a predetermined time after controlling to stop the supply of heating AC power to the RLC series circuit. This step is intended to temporarily stop the supply of heating AC power to the RLC series circuit and reduce the susceptor temperature that has reached above the heating target temperature.

[0162] S1240 shows a step of determining whether a predetermined heating end condition is satisfied. Examples of the predetermined heating end condition may be a condition that a predetermined time has elapsed based on the value of the second timer, a condition that a predetermined number of inhalations have been performed using the currently used aerosol-forming substrate 108, or an OR condition of these conditions. The method for detecting inhalation will be described later. When it is determined that the heating end condition is satisfied (''Yes'' in S1240), the process proceeds to step S1245, and otherwise (''No'' in S1240), the process returns to step S1220.

[0163] S1245 shows a step of decreasing the available number by one. After step S1245, the control unit 118 shifts to the SLEEP mode.

[0164] According to the main process 1200, the susceptor temperature can be maintained at a predetermined temperature for aerosol generation in a desired manner.

[0165] Hereinafter, the process according to the detection of the susceptor 110 described above in relation to the main process 1000 in the PRE-HEAT mode and the main process 1200 in the HEAT mode will be described.

[0166] FIG. 13A is a flowchart of a process 1300A according to the detection of an exemplary susceptor 110.

[0167] S1305 shows a step of measuring the impedance of the RLC series circuit. Note that before step S1305, the supply of heating AC power to the RLC series circuit has been started.

[0168] S1310 shows a step of determining whether the susceptor 110 has been detected based on the measured impedance. If the susceptor 110 is detected based on the impedance (\"Yes\" in S1310), the exemplary process 1300A ends and returns to the main process 1000 or the main process 1200. Otherwise (\"No\" in S1310), the process proceeds to step S1315.

[0169] S1315 shows a step of stopping the supply of heating AC power to the RLC series circuit.

[0170] S1320 shows a step of decreasing the available number by one. After step S1320, the control unit 118 shifts to the ACTIVE mode.

[0171] According to the exemplary process 1300A, induction heating can be stopped when the aerosol formation substrate 108 is removed during induction heating, etc. Thereby, the safety of the induction heating device 100 can be improved and the waste of the power stored in the power supply 102 can be reduced. Also, according to the exemplary process 1300A, when the aerosol formation substrate 108 is removed, the control unit 118 decreases the available number by one. Thereby, compared with the case where the available number is not decreased, it becomes difficult for the voltage of the power supply 102 after consuming all the available numbers to reach the discharge termination voltage or near the discharge termination voltage. Therefore, it is also possible to suppress the acceleration of the deterioration of the power supply 102.

[0172] FIG. 13B is a flowchart of a process 1300B in response to the detection of another exemplary susceptor 110. Since some steps included in the exemplary process 1300B are common to the exemplary process 1300A, the differences will be described below.

[0173] In the exemplary process 1300B, after step S1315, the process proceeds to step 1325.

[0174] S1325 indicates a step of giving a predetermined error notification to the user. This predetermined error notification corresponds to the failure to detect the susceptor 110 during induction heating due to, for example, the aerosol-forming substrate 108 being accidentally removed. This predetermined error notification may be given by an LED 138 or the like.

[0175] S1330 indicates a step of starting a third timer.

[0176] S1335 indicates a step of controlling to supply non-heating AC power to the RLC series circuit and measuring the impedance of the RLC series circuit. This step may be the same as step S725 of the main process 700 in the ACTIVE mode.

[0177] S1340 indicates a step of determining whether the susceptor 110 has been detected based on the measured impedance. If it is determined that the susceptor 110 has been detected based on the impedance (''Yes'' in S1340), the process proceeds to step S1350; otherwise (''No'' in S1340), the process proceeds to step S1345.

[0178] S1350 indicates a step of restarting the supply of heating AC power to the RLC series circuit, which was stopped in step S1315.

[0179] S1345 indicates a step of determining whether a predetermined time has elapsed based on the value of the third timer. If it is determined that the predetermined time has elapsed (''Yes'' in S1345), the process proceeds to step S1320; otherwise (''No'' in S1345), the process returns to step S1335.

[0180] Exemplary process 1300B will be further described with reference to FIG. 14. FIG. 14 is a graph showing the change in susceptor temperature. The vertical axis of this graph corresponds to temperature, and the horizontal axis corresponds to time.

[0181] 1410 indicates the predetermined preheating target temperature described above in relation to the main process 700 in the PRE-HEAT mode.

[0182] 1415 indicates the predetermined cooling target temperature described above in relation to the main process 1100 in the INTERVAL mode.

[0183] 1420 indicates the predetermined heating target temperature described above in relation to the main process 1200 in the HEAT mode. As will be described later, the HEAT mode has a heating profile including a plurality of phases to which different heating target temperatures are applied. More specifically, 1420 indicates the heating target temperature of the first phase in the heating profile of the HEAT mode.

[0184] 1430 indicates the period of the PRE-HEAT mode. That is, the period of the PRE-HEAT mode generally ends when the susceptor temperature reaches the predetermined preheating target temperature 1410.

[0185] 1435 indicates the period of the INTERVAL mode. That is, the period of the INTERVAL mode generally starts when the susceptor temperature reaches the preheating target temperature 1410 and ends when the susceptor temperature reaches the cooling target temperature 1415.

[0186] 1440 indicates the period of the HEAT mode. That is, the period of the HEAT mode generally starts when the susceptor temperature reaches the cooling target temperature 1415 and ends at the time point 1445. 1445 indicates the time when the heating end condition is satisfied (step S1240 of the main process 1200).

[0187] 1450 indicates the situation when the susceptor 110 cannot be detected, that is, when it cannot be determined in step S1310 of the exemplary process 1300B that the susceptor 110 is detected based on impedance ( "No" in step S1310). 1455 indicates the situation when the susceptor 110 can be detected again, that is, when it is determined in step S1340 of the exemplary process 1300B that the susceptor 110 is detected based on impedance ( "Yes" in step S1340). S1460 indicates the period during which the susceptor 110 could not be detected.

[0188] According to the exemplary process 1300B, while the heating target temperature according to the passage of time follows at least a defined heating profile, it is assumed that time has passed also between step S1315, which is the stop of the process for induction heating, and step S1350, which is the restart of the process for induction heating, so that induction heating can be controlled. Therefore, substantially, the heating profile corresponding to the period S1460 during which the susceptor 110 could not be detected can be skipped.

[0189] FIG. 13C is a flowchart of a process 1300C according to another exemplary detection of the susceptor 110. Since some steps included in the exemplary process 1300C are common to the exemplary processes 1300A or 1300B, the differences will be described below.

[0190] S1355 indicates the step of detecting the susceptor 110 based on the measured impedance. This step is similar to step S1310, but the difference is that when it cannot be determined that the susceptor 110 is detected ( "No" in S1355), the process proceeds to step S1325.

[0191] In the exemplary process 1300C, after step S1330, the process proceeds to step S1360.

[0192] S1360 shows the step of measuring the impedance of the RLC series circuit. Step S1360 is similar to step S1335, but in step S1360, it is not necessary to control to supply non-heating AC power to the RLC series circuit. This is because the supply of heating AC power to the RLC series circuit has not been stopped at the time of step S1360.

[0193] S1365 shows the step of determining whether the susceptor 110 has been detected based on the measured impedance. This step is similar to step S1340, but the difference is that when it is determined that the susceptor 110 has been detected based on the impedance (\"Yes\" in S1365), the process returns to step S1305, and when not (\"No\" in S1365), the process proceeds to step S1370.

[0194] S1370 shows the step of determining whether a predetermined time has elapsed based on the value of the third timer. This step is similar to step S1345, but the difference is that when it is determined that the predetermined time has elapsed (\"Yes\" in S1370), the process proceeds to step S1315, and when not (\"No\" in S1370), the process returns to step S1360.

[0195] Exemplary process 1300C will be further described with reference to FIG. 14. Hereinafter, the differences from the above description of exemplary process 1300B will be described.

[0196] 1450 indicates when the susceptor 110 cannot be detected, that is, when it cannot be determined in step S1355 of exemplary process 1300C that the susceptor 110 has been detected based on the impedance (\"No\" in step S1355). 1455 indicates when the susceptor 110 can be detected again, that is, when it is determined in step S1365 of exemplary process 1300C that the susceptor 110 has been detected based on the impedance (\"Yes\" in step S1365).

[0197] As described above, the HEAT mode has a heating profile that includes multiple phases to which different heating target temperatures are applied. Further, the process in the HEAT mode can include a process of changing the heating target temperature at one or more timings (for example, step S2115 in FIG. 21 described later). According to the exemplary process 1300C, the period S1460 during which the susceptor 110 could not be detected will not affect the one or more timings. This is because the exemplary process 1300C does not have steps S1315 and S1350 in the exemplary process 1300B. That is, according to the exemplary process 1300C, the period S1460 during which the susceptor 110 could not be detected can be made not to affect the overall length of the heating profile.

[0198] FIG. 13D is a flowchart of a process 1300D in response to the detection of yet another exemplary susceptor 110.

[0199] Since some steps included in the exemplary process 1300D are common to the exemplary processes 1300A, 1300B, or 1300C, the differences will be described below.

[0200] S1375 is a step similar to step S1310, but the difference is that when it is determined that the susceptor 110 has been detected based on impedance, the process proceeds to step S1385.

[0201] In the exemplary process 1300D, after step S1325, the process proceeds to step S1380.

[0202] S1380 indicates a step of stopping the activated second timer and starting the third timer. By stopping the second timer, the value of the second timer will not increase with the passage of time. In other words, the progress of the heating profile is interrupted.

[0203] S1385 indicates a step of determining whether the second timer has been stopped. This step may be a step of determining whether step S1380 has been executed. If it is determined that the second timer has been stopped (\"Yes\" in S1385), the process proceeds to step S1390. Otherwise (\"No\" in S1385), the exemplary process 1300D ends and returns to the main process 1000 or the main process 1200.

[0204] S1390 indicates a step of restarting the stopped second timer. By restarting the second timer, the value of the second timer will increase again due to the passage of time from the value when the second timer was stopped. In other words, the progress of the heating profile is restarted.

[0205] The exemplary process 1300D will be further described with reference to FIG. 14. Hereinafter, the differences between the exemplary process 1300B and the above-described explanation will be described.

[0206] 1450 indicates when the susceptor 110 cannot be detected, that is, when it cannot be determined in step S1375 of the exemplary process 1300D that the susceptor 110 has been detected based on impedance (\"No\" in step S1375).

[0207] That is, according to the exemplary process 1300D, while the heating target temperature according to the passage of time at least follows a determined heating profile, the induction heating can be controlled as if no time has passed between step S1315, which is the stop of the process for induction heating, and step S1350, which is the restart of the process for induction heating. Therefore, the progress of the heating profile can be substantially interrupted.

[0208] FIG. 13E is a flowchart of an exemplary process 1300E for processing according to the detection of yet another exemplary susceptor 110. Since some steps included in the exemplary process 1300E are common to the exemplary processes 1300A, 1300B, 1300C, or 1300D, the differences will be described hereinafter.

[0209] S1392 is the same step as step S1310, but the difference is that when it is determined that the susceptor 110 is detected based on impedance, the process proceeds to step S1394.

[0210] S1394 indicates a step of determining whether the third timer has been started. This step may be a step of determining whether step S1330 has been executed. When it is determined that the third timer has been started (``Yes'' in S1394), the process proceeds to step S1396; otherwise (``No'' in S1394), the exemplary process 1300E ends and returns to the main process 1000 or the main process 1200.

[0211] S1396 indicates a step of executing a predetermined process based on the value of the third timer. This predetermined process may be a process of extending one of the plurality of phases included in the HEAT mode by the value of the third timer, that is, the length of the period during which the susceptor 110 could not be detected. In other words, this predetermined process may be a process of delaying at least one of the one or more timings for changing the heating target temperature by the length of the period during which the susceptor 110 could not be detected. This can be achieved, for example, by delaying the timing determined to be changed in step S2105 of FIG. 21 described later. Note that the extension of the phase and / or the delay of the timing for changing the heating target temperature do not necessarily have to be performed only by the length of the period during which the susceptor 110 could not be detected. The phase may be extended or the timing for changing the heating target temperature may be delayed by a value obtained by performing an operation such as addition or subtraction of a predetermined value to the length of the period during which the susceptor 110 could not be detected, or by a value unrelated to the length of the period during which the susceptor 110 could not be detected.

[0212] The exemplary process 1300E will be further described with reference to FIG. 14. Hereinafter, the differences between the exemplary process 1300C and the above description will be described.

[0213] 1450 indicates the situation when the susceptor 110 cannot be detected, that is, when it cannot be determined based on impedance that the susceptor 110 has been detected in step S1392 of the exemplary process 1300E ( "No" in step S1392).

[0214] According to the exemplary process 1300E, based on the period 1460 from step S1392 when the aerosol forming substrate cannot be detected to step S1365 when the aerosol forming substrate is detected again, the timing for changing the heating target temperature can be delayed, so that the phase of the heating profile can be filled or extended. That is, according to the exemplary process 1300E, based on the period 1460 when the susceptor 110 cannot be detected, the length of the heating profile can be extended.

[0215] FIG. 15 is a flowchart of an exemplary first sub - process 1500 that is activated in step S1020 of the main process 1000 in PRE - HEAT mode, step S1120 of the main process 1100 in INTERVAL mode, or step S1210 of the main process 1200 in HEAT mode.

[0216] S1510 indicates a step for determining whether a predetermined operation on button 128 is detected. This predetermined operation may be the same as or different from the predetermined operation in steps S420 and S810. An example of the predetermined operation in step S1510 is a long press or continuous tapping of button 128. If it is determined that a predetermined operation of the button is detected ( "Yes" in S1510), the process proceeds to step S1520; otherwise ( "No" in S1510), the process returns to step S1510.

[0217] S1520 indicates a step of performing control to stop the supply of alternating current power. When the first sub - process 1500 is activated in step S1020 or step S1210, this alternating current power is heating alternating current power. When the first sub - process 1500 is activated in step S1120, this alternating current power will be non - heating alternating current power.

[0218] S1530 indicates a step of decreasing the available number by one. According to the sub - process 1500, when the supply of alternating current power is stopped by the user's operation, the control unit 118 decreases the available number by one. As a result, compared with the case where the available number is not decreased, the voltage of the power supply 102 after the aerosol - forming substrate 108 of the available number is completely consumed is less likely to reach the discharge termination voltage or near the discharge termination voltage. Therefore, it is also possible to suppress the acceleration of the deterioration of the power supply 102.

[0219] FIG. 16 is a flowchart of an exemplary second sub - process 1600 that is activated in step S1020 of the main process 1000 in PRE - HEAT mode, step S1120 of the main process 1100 in INTERVAL mode, or step S1210 of the main process 1200 in HEAT mode.

[0220] S1610 indicates a step of measuring the discharge current. The discharge current can be measured by the current detection circuit 136.

[0221] S1620 indicates a step of determining whether the measured discharge current is excessive. If it is determined that the discharge current is excessive (''Yes'' in S1620), the process proceeds to step S1630. Otherwise (''No'' in S1620), the process returns to step S1610.

[0222] S1630 indicates a step of executing a predetermined fail - safe action.

[0223] S1640 indicates a step of giving a predetermined error notification to the user. This predetermined error notification corresponds to the discharge current being excessive. After step S1640, the control unit 118 shifts to the ERROR mode. This error notification may be given by the LED 138.

[0224] FIG. 17 is a diagram for explaining the principle of detecting the susceptor 110 which is at least a part of the aerosol forming substrate 108 based on impedance, and the principle of obtaining the temperature of the susceptor 110 which is at least a part of the aerosol forming substrate 108 based on impedance.

[0225] 1710 shows an equivalent circuit of an RLC series circuit when the aerosol forming substrate 108 is not inserted into the induction heating device 100.

[0226] L indicates the value of the inductance of the RLC series circuit. Although L is strictly the value obtained by synthesizing the inductance components of a plurality of elements included in the RLC series circuit, it may be considered equal to the value of the inductance of the coil 106.

[0227] C2 indicates the value of the capacitance of the RLC series circuit. Although C2 is strictly the value obtained by synthesizing the capacitance components of a plurality of elements included in the RLC series circuit, it may be considered equal to the value of the capacitance of the capacitor C2.

[0228] R Circuit indicates the resistance value of the RLC series circuit. R Circuit is the value obtained by synthesizing the resistance components of a plurality of elements included in the RLC series circuit.

[0229] The values of L, C2 and R Circuit can be obtained in advance from the specification sheet of the electronic element or measured experimentally in advance, and stored in advance in the memory (not shown) of the control unit 118.

[0230] When the aerosol-forming substrate 108 is not inserted into the induction heating device 100, the impedance Z0 of the RLC series circuit can be calculated by the following formula.

[0231]

Equation

[0232] On the other hand, 1720 shows the equivalent circuit of the RLC series circuit when the aerosol-forming substrate 108 is inserted into the induction heating device 100. The difference between 1720 and 1710 lies in the presence of a resistance component (R susceptor ) due to the susceptor 110, which is at least part of the aerosol-forming substrate 108. When the aerosol-forming substrate 108 is inserted into the induction heating device 100, the impedance Z1 of the RLC series circuit can be calculated by the following formula.

[0233]

Equation

[0234] That is, the impedance of the RLC series circuit when the aerosol-forming substrate 108 is inserted into the induction heating device 100 is greater than when it is not inserted. The impedance Z0 when the aerosol-forming substrate 108 is not inserted into the induction heating device 100 and the impedance Z0 when it is inserted are experimentally determined in advance, and the threshold value set between them is stored in advance in the memory (not shown) of the control unit 118. Based on whether the measured impedance Z is greater than the threshold value, it is possible to determine whether the aerosol-forming substrate 108 is inserted into the induction heating device 100, that is, whether the susceptor 110 is detected. As described above, the detection of the susceptor 110 can be regarded as the detection of the aerosol-forming substrate 108.

[0235] Note that the control unit 118 can calculate the impedance Z of the RLC series circuit as follows based on the effective value V of the voltage measured by the voltage detection circuit 134 and the effective value I of the current measured by the current detection circuit 136. RMS and the effective value I of the current RMS Based on this, the impedance Z of the RLC series circuit can be calculated as follows.

Equation

[0236] Also, when solving the above equation for Z1 with respect to R susceptor the following equation is derived.

Equation

[0237] Here, excluding the negative resistance value and replacing Z1 with Z,

Equation

[0238] R suceptor and the susceptor temperature is experimentally determined in advance, and stored in advance in the memory (not shown) of the control unit 118. Based on R suceptor further calculated from the impedance Z of the RLC series circuit, it is possible to obtain the susceptor temperature.

[0239] FIG. 18 shows an equivalent circuit of the RLC series circuit when AC power is supplied at the resonance frequency f0 of the RLC series circuit. 1810 and 1820 respectively show the equivalent circuits of the RLC series circuit when the aerosol forming substrate 108 is not inserted into the induction heating device 100 and when it is inserted. The resonance frequency f0 can be derived as follows.

[0240]

Equation

[0241] Also, since the following relationship is satisfied at the resonance frequency f0, the inductance component and the capacitance component of the RLC series circuit can be ignored with respect to the impedance of the RLC series circuit.

Number

[0242] Therefore, the impedance Z0 of the RLC series circuit when the aerosol-forming substrate 108 is not inserted into the induction heating device 100 and the impedance Z1 of the RLC series circuit when it is inserted at the resonance frequency f0 are as follows.

Number

[0243] Also, the value R of the resistance component by the susceptor 110, which is at least a part of the aerosol-forming substrate 108 when the aerosol-forming substrate 108 is inserted into the induction heating device 100 at the resonance frequency f0 susceptor can be calculated by the following formula

Number

[0244] Thus, using the resonance frequency f0 of the RLC series circuit in one or both of detecting the susceptor 110 and obtaining the susceptor temperature based on the impedance is advantageous in terms of ease of calculation. Of course, using the resonance frequency f0 of the RLC series circuit is also advantageous in terms of supplying the power stored in the power supply 102 to the susceptor 110 with high efficiency and at high speed.

[0245] (Specific Example 1 of Heating Profile) Hereinafter, a specific example of the heating profile will be described.

[0246] In this example, the induction heating device 100 can more appropriately heat the aerosol forming substrate 108 by changing the switching frequency of the alternating current generation circuit 132 in the PRE-HEAT mode, the INTERVAL mode, and the HEAT mode consisting of a plurality of phases.

[0247] FIG. 19 is a diagram showing graphs (a), (b), and (c) respectively representing the temperature of the susceptor 110, the switching frequency of the alternating current generation circuit 132, and the change in the impedance of the circuit 104 in the induction heating device 100 of this example. Similar to FIG. 14, in FIG. 19, the arrow 1430 indicates the period of the PRE-HEAT mode, the arrow 1435 indicates the period of the INTERVAL mode, and the arrow 1440 indicates the period of the HEAT mode. Also, in (a), the solid line graph indicates the temperature of the susceptor 110, and the dashed line graph indicates the target temperature (preheating target temperature, cooling target temperature, heating target temperature) in each period.

[0248] Note that in FIG. 19, it is illustrated such that the temperature of the susceptor 110 (or susceptor temperature) reaches the heating target temperature and the phase is switched, but this is because it illustrates the ideal behavior. That is, the behavior illustrated in FIG. 19 corresponds to the case where, in the exemplary process shown in FIG. 21 described later, the timing of changing the switching frequency of the switch Q3 coincides with the timing when the temperature of the susceptor 110 first reaches the heating target temperature. Generally, the temperature of the susceptor 110 repeats the behavior of decreasing due to a temporary stop of the heating alternating current power after reaching the heating target temperature and then rising again. Therefore, generally, the temperature of the susceptor 110 reaching the heating target temperature does not coincide with the phase switching. The same applies to FIGS. 20 and 22.

[0249] As shown in (b), in this example, the switching frequency of the switch Q3 of the AC generation circuit 132 is the resonance frequency f0 during the period 1430 of the PRE-HEAT mode and the period 1435 of the INTERVAL mode, and is constant within these periods. Then, during the period 1440 of the HEAT mode, the switching frequency of the switch Q3 is controlled to increase step by step as each phase progresses (the timing of increasing the switching frequency of the switch Q3 is scheduled in advance. The same applies to the specific example 2 described later). Also, when the switching frequency of the switch Q3 changes, the impedance of the circuit 104 also changes. By the stepwise increase in the switching frequency of the switch Q3, the impedance of the circuit 104 also continues to increase as shown in (c). In the case of this example, it is possible to detect a temporary temperature drop when the user inhales the aerosol generated from the aerosol source 112 due to the change in the impedance of the circuit 104 (or the change in the alternating current supplied to the coil 106). That is, when it is detected that the temperature has dropped, it may be determined that the user has inhaled the aerosol.

[0250] Also, during the HEAT mode period 1440, the switching frequency of switch Q3 may be controlled to start from the resonance frequency f0 and gradually move away from the resonance frequency f0 as shown by the solid line graph in (b), or may be controlled to once greatly decrease from the resonance frequency f0 and then gradually approach the resonance frequency f0 as shown by the dashed line graph in (b). Further, in the former case, as the plurality of phases constituting the HEAT mode 1440 progress, the switching frequency of switch Q3 increases in a frequency region higher than the resonance frequency, and in the latter case, as the plurality of phases constituting the HEAT mode 1440 progress, the switching frequency of switch Q3 increases in a frequency region lower than the resonance frequency. A rapid temperature rise is only required in the PRE-HEAT mode, and in the stepwise temperature rise in the HEAT mode, highly efficient heating by induction heating may be rather unsuitable. Therefore, in this example, by deviating the switching frequency of switch Q3 from the resonance frequency f0, a gentle temperature rise can be realized. By changing the frequency for each phase in this way, the susceptor 110 can be appropriately heated.

[0251] Further, FIG. 20 is a diagram showing another example of changes in the temperature of the susceptor 110, the switching frequency of the AC generation circuit 132, and the impedance of the circuit 104 in the induction heating device 100. Also in this example, the switching frequency of switch Q3 in the AC generation circuit 132 is the resonance frequency f0 during the PRE-HEAT mode period 1430 and the INTERVAL mode period 1435, and is constant within these periods. However, during the HEAT mode period 1440 in this example, the switching frequency of switch Q3 is controlled to gradually decrease step by step as each phase progresses. Also, by gradually decreasing the switching frequency of switch Q3, the impedance of the circuit 104 also continues to decrease. When the detection of the user's aerosol suction is not performed, it may be controlled to decrease the switching frequency of switch Q3 according to the progress of the phase in the HEAT mode as in this example, and thereby a gentle temperature rise can be realized.

[0252] Also, during the period 1440 in the HEAT mode, the switching frequency of the switch Q3 may be controlled such that, as shown by the solid line graph in (b), it first increases significantly from the resonance frequency f0 and then gradually approaches the resonance frequency f0, or, as shown by the dashed line graph in (b), it starts from the resonance frequency f0 and is controlled to gradually move away from the resonance frequency f0. Also, in the former case, as the plurality of phases constituting the HEAT mode progress, the switching frequency of the switch Q3 decreases in a frequency region higher than the resonance frequency, and in the latter case, as the plurality of phases constituting the HEAT mode progress, the switching frequency of the switch Q3 decreases in a frequency region lower than the resonance frequency.

[0253] FIG. 21 is a diagram showing a flowchart of exemplary processing mainly executed by the control unit 118 when in the HEAT mode. In the flowchart of FIG. 21, the processing of step S2105, step S2110, and step S2115 is further added to the flowchart of FIG. 12. Since the other steps are the same as those in FIG. 12, the description thereof is omitted.

[0254] Step S2105 shows a step of determining whether it is the timing for the second timer to change the switching frequency of the switch Q3. If it is determined that it is the timing to change the switching frequency of the switch Q3 (''Yes'' in step S2105), the switching frequency of the switch Q3 is changed (increased or decreased) in step S2110. Then, in step S2115, the heating target temperature is increased by a predetermined value. If it is determined in step S2105 that it is not the timing to change the switching frequency of the switch Q3 (''No'' in step S2105), the processing of step S2110 and step S2115 is skipped (that is, the switching frequency of the switch Q3 is not changed). Note that the processing of step S2110 and the processing of step S2115 may be executed in the reverse order or may be executed in parallel.

[0255] (Specific Example 2 of Heating Profile) Furthermore, another specific example of the heating profile will be described. In this example, in the PRE-HEAT mode, INTERVAL mode, and HEAT mode consisting of multiple phases, the switching frequency of the alternating current generation circuit 132 is fixed at a specific frequency without change, and in particular, in this example, it is fixed at the resonance frequency.

[0256] FIG. 22 is a diagram showing graphs (a), (b), and (c) respectively representing the temperature of the susceptor 110, the switching frequency of the alternating current generation circuit 132, and the change in the impedance of the circuit 104 in the induction heating apparatus 100 of this example. As shown in (b), in this example, the induction heating apparatus 100 fixes the switching frequency of the alternating current generation circuit 132 at the resonance frequency in the PRE-HEAT mode, INTERVAL mode, and HEAT mode consisting of multiple phases.

[0257] FIGS. 23 and 24 are diagrams showing flowcharts of exemplary processes mainly executed by the control unit 118 when in the HEAT mode. The flowchart of FIG. 23 is different in that the heating control of step S2310 is executed instead of step S1235 in FIG. 12, and steps S2320 and S2325 are added. For the other steps, since they are the same as those in FIG. 12, the description is omitted.

[0258] Step S2320 indicates a step of determining whether it is the timing for the second timer to change the heating target temperature. If it is determined that it is the timing to change the heating target temperature here (''Yes'' in step S2320), in step S2325, the heating target temperature is increased by a predetermined value. If it is determined in step S2320 that it is not the timing to change the heating target temperature (''No'' in step S2320), the process of step S2325 is skipped (that is, the heating target temperature is not changed).

[0259] FIG. 24 is a diagram showing a flowchart illustrating an example of the details of the heating control in step S2310. Step S23101 indicates a step of controlling to stop the supply of heating AC power to the RLC series circuit. Step S23102 indicates a step of controlling to start the supply of non-heating AC power to the RLC series circuit in order to measure the impedance of the RLC series circuit. Step S23103 indicates a step of measuring the impedance of the RLC series circuit. Step S23104 indicates a step of controlling to stop the supply of non-heating AC power to the RLC series circuit. Step S23105 indicates a step of obtaining the susceptor temperature from the impedance measured in step S23103. Note that the processes of steps S23101 to S23105 may be the same as the processes of the flowchart described above. Further, step S23106 indicates a step of determining whether the susceptor temperature obtained in step S23105 is equal to or lower than (predetermined heating target temperature - Δ). When the susceptor temperature is equal to or lower than (predetermined heating target temperature - Δ), the heating control is terminated and the process proceeds to step S1215 in FIG. 23. When the susceptor temperature is higher than (predetermined heating target temperature - Δ), the process returns to step S23102. That is, when the susceptor temperature is higher than (heating target temperature - Δ), the susceptor temperature is continuously monitored in the second circuit with high resistance including switch Q2. At this time, switch Q3 may be switched at a predetermined period even while the heating of susceptor 110 is interrupted. Then, when the susceptor temperature becomes equal to or lower than (heating target temperature - Δ), switch Q1 is turned on again and susceptor 110 is reheated in the first circuit. Also, when Δ is a value greater than "0", hysteresis can be provided in the heating control. More specifically, the value of Δ is about 5°C at maximum.

[0260] As described above, embodiments of the present disclosure have been explained, but it should be understood that these are merely examples and do not limit the scope of the present disclosure. It should be understood that changes, additions, improvements, etc. to the embodiments can be appropriately made without departing from the spirit and scope of the present disclosure. The scope of the present disclosure should not be limited by any of the above-described embodiments, but should be defined only by the claims and their equivalents.

[0261] In the above-described embodiments, control using the resonance frequency f0 of the RLC series circuit has been explained. However, since there are product tolerances in the elements constituting the RLC circuit, it is not necessary to use the resonance frequency f0 precisely. For example, a deviation of about ±5% from the resonance frequency f0 calculated from the actual parameters of the elements constituting the RLC series circuit may be acceptable.

[0262] In the above-described embodiments, the user's inhalation was detected based on the change in impedance. However, instead of this, a suction sensor (not shown in FIG. 2) may be used to detect the user's inhalation.

[0263] In the above-described embodiments, the control unit 118 detected the aerosol generation substrate 108 based on the susceptor 110. However, instead of this, the aerosol generation substrate 108 may be detected from a marker or RFID provided on the aerosol formation substrate 108. It will be apparent that such a marker or RFID also constitutes at least a part of the aerosol formation substrate 108.

Explanation of Reference Numerals

[0264] 100…Induction heating device, 101…Housing, 102…Power supply, 104…Circuit, 106…Coil, 108…Aerosol forming substrate, 110…Susceptor, 112…Aerosol source, 114…Filter, 116…Charging power supply connection part, 118…Control part, 120…Voltage adjustment circuit, 122…Charging circuit, 126…Light emitting element drive circuit, 128…Button, 130…Parallel circuit, 132…AC generation circuit, 134…Voltage detection circuit, 136…Current detection circuit, 138…Light emitting element, 140…Voltage dividing circuit, 610…When not in use, 620…When deteriorated, 630…Electric energy required to consume one aerosol forming substrate, 640…Surplus electric energy (when not in use), 650…Surplus electric energy (when deteriorated), 660…Discharge voltage at full charge, 770…Discharge termination voltage, 1410…Preheat target temperature, 1415…Cooling target temperature, 1420…Heating target temperature, 1430…Period of PRE-HEAT mode, 1435…Period of INTERVAL mode, 1440…Period of HEAT mode, 1445…When the heating end condition is satisfied, 1450…When the susceptor cannot be detected, 1455…When the susceptor can be detected again, 1460…Period during which the susceptor could not be detected, 1710…Equivalent circuit of the RLC series circuit when the aerosol forming substrate is not inserted into the induction heating device, 1720…Equivalent circuit of the RLC series circuit when the aerosol forming substrate is inserted into the induction heating device, 1710…Equivalent circuit of the RLC series circuit when the aerosol forming substrate is not inserted into the induction heating device (resonance frequency), 1720…Equivalent circuit of the RLC series circuit when the aerosol forming substrate is inserted into the induction heating device (resonance frequency)

Claims

1. A control unit for an induction heating device configured to inductively heat a susceptor of an aerosol forming substrate including a susceptor and an aerosol source, wherein when the susceptor cannot be detected during the execution of the induction heating, the induction heating is stopped or an error is notified. A control unit configured as described above.

2. The control unit according to claim 1, wherein when the susceptor cannot be detected during the execution of the induction heating, the induction heating is stopped. A control unit configured as described above.

3. The control unit according to claim 2, wherein an error is notified simultaneously with or after the stop of the induction heating. A control unit further configured as described above.

4. The control unit according to claim 2, wherein when the susceptor is detected again before a predetermined time elapses after the induction heating is stopped, the induction heating is restarted. A control unit further configured as described above.

5. The control unit according to claim 4, wherein the induction heating is controlled in accordance with a heating profile in which at least a heating target temperature according to the passage of time is determined, while assuming that time has elapsed also from the stop of the induction heating to the restart of the induction heating. A control unit.

6. The control unit according to claim 4, wherein the induction heating is controlled in accordance with a heating profile in which at least a heating target temperature according to the passage of time is determined, while assuming that no time has elapsed from the stop of the induction heating to the restart of the induction heating. A control unit.

7. The control unit according to claim 1, wherein when the susceptor cannot be detected during the execution of the induction heating, an error is notified. A control unit configured as described above.

8. The control unit according to claim 7, wherein the induction heating is stopped after the notification of the error. A control unit further configured as described above.

9. The control unit according to claim 8, wherein when the susceptor is detected again after the notification of the error and before the stop of the induction heating, the induction heating is not stopped. A control unit configured as described above.

10. The control unit according to claim 9, wherein the induction heating follows a heating profile in which at least a heating target temperature according to the passage of time is determined, The period from when the susceptor can no longer be detected until when the susceptor is detected again is configured so as not to affect the overall length of the heating profile, Control unit. **Claim 11** The control unit according to claim 9, wherein the induction heating follows a heating profile in which at least a heating target temperature according to the passage of time is determined, and is configured to extend the length of the heating profile based on the period from when the susceptor can no longer be detected until when the susceptor is detected again. Control unit. **Claim 12** A power supply, an AC generation circuit that generates AC from the power supplied from the power supply, an induction heating circuit for induction heating a susceptor included in an aerosol forming substrate, and the control unit according to any one of claims 1 to 11 An induction heating device including: wherein the control unit is further configured to detect the susceptor based on the impedance of a circuit to which the AC generated by the AC generation circuit is supplied. Induction heating device. **Claim 13** The induction heating device according to claim 12, wherein the control unit acquires the temperature of the susceptor based on the impedance of a circuit to which the AC generated by the AC generation circuit is supplied, and is further configured to control the induction heating based on the acquired temperature. Induction heating device. **Claim 14** A power supply that supplies power for induction heating a susceptor included in an aerosol forming substrate, and the control unit according to any one of claims 1 to 11, An induction heating device including: wherein the control unit sets the number of usable aerosol forming substrates that can be induction heated until the power supply is charged based on the remaining amount of the power supply, and when at least a part of the aerosol forming substrate cannot be detected during the execution of the induction heating, stops the induction heating and decreases the number of usable units. Configured as Induction heating device. **Claim 15** A power supply that supplies power for induction heating at least a part of an aerosol forming substrate, and the control unit according to any one of claims 1 to 11, An induction heating device including: wherein the control unit sets the number of usable aerosol forming substrates that can be induction heated until the power supply is charged based on the remaining amount of the power supply, After the susceptor cannot be detected during the execution of the induction heating and then the susceptor is detected again, the induction heating is continued and the available number is not decreased. configured to induction heating device.

16. A method of operating an induction heating device configured to inductively heat the susceptor of an aerosol-forming substrate including a susceptor and an aerosol source, When the susceptor cannot be detected during the execution of the induction heating, stopping the induction heating or notifying an error A method including.

17. An induction heating device for inductively heating the susceptor of an aerosol-forming substrate including a susceptor and an aerosol source, the aerosol-forming substrate, a power source, an alternating current generation circuit that generates alternating current from the power supplied from the power source, an induction heating circuit for inductively heating the susceptor, a control unit, When the susceptor cannot be detected during the execution of the induction heating, stopping the induction heating or notifying an error the control unit configured as The induction heating device provided with.

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