Aerosol generation device and aerosol generation article

Abstract

[Problem] To provide a mechanism enabling further improvement in determination accuracy of a state of an inhalation device. [Solution] Provided is an aerosol generation device comprising a capacitance sensor that measures a change in capacitance caused by an aerosol passing through a flow path through which an aerosol generated from an aerosol generation article passes, in which the capacitance sensor includes a resonance circuit of which a resonance frequency changes in accordance with the change in the capacitance of the flow path, and measures the change in capacitance on the basis of the resonance frequency of the resonance circuit.

Description

Aerosol generating device and aerosol product

[0001] The present disclosure relates to aerosol generating devices and aerosol product articles.

[0002] Inhalation devices that generate substances to be inhaled by users are widely used. For example, inhalation devices generate aerosols imparted with flavor components using a substrate containing an aerosol source for generating aerosols and a flavor source for imparting flavor components to the generated aerosol. Users can enjoy the flavor by inhaling the aerosols imparted with flavor components generated by the inhalation device. The action of a user inhaling the aerosol is hereinafter also referred to as a puff or puffing action. Examples of devices classified as inhalation devices include heated tobacco products and electronic cigarettes, which are used as alternatives to cigarettes, as well as nebulizers used for medical purposes. Heat-not-burn tobacco products are inhalation devices that generate aerosols by heating an aerosol source. Electronic cigarettes are inhalation devices that generate aerosols by atomizing a liquid aerosol source.

[0003] Various technologies have been developed to determine the state of an inhaler using a sensor mounted on the inhaler. For example, Patent Document 1 below discloses a technology for detecting puffs based on electrostatic capacitance.

[0004] Special Publication No. 2020-513241

[0005] However, the technique disclosed in the above-mentioned Patent Document 1 and the like leaves room for improvement in the determination accuracy.

[0006] Therefore, the present disclosure has been made in consideration of the above problems, and an object of the present disclosure is to provide a mechanism that can further improve the accuracy of determining the state of the suction device.

[0007] In order to solve the above problems, according to one aspect of the present disclosure, an aerosol generating device is provided that includes a capacitance sensor that measures a change in capacitance that occurs when an aerosol generated from an aerosol product passes through a flow path through which the aerosol passes, the capacitance sensor having a resonant circuit whose resonant frequency changes in accordance with the change in capacitance of the flow path, and the change in capacitance is measured based on the resonant frequency of the resonant circuit.

[0008] The capacitance sensor may have a drive circuit that outputs a voltage waveform including a resonant frequency at which resonance occurs in the resonant circuit, a clock circuit that outputs a rectangular waveform repeatedly at a predetermined time width, and a frequency measurement unit that measures the resonant frequency based on the number of rectangular waveforms output from the clock circuit within the time width of the response waveform of the resonant circuit.

[0009] The resonant circuit may have a pair of electrodes, an electric field formed by the pair of electrodes overlapping the flow path, and the capacitance sensor may measure a change in capacitance of the pair of electrodes.

[0010] The resonant circuit may be a parallel resonant circuit in which an inductor, a capacitor, and the pair of electrodes are connected in parallel.

[0011] The resonant circuit may be configured to satisfy the relationship of the following mathematical formula (8), where C is the capacitance of the pair of electrodes when the aerosol passes through the flow path, R is the resistance of the pair of electrodes when the aerosol passes through the flow path, C0 is the capacitance of the capacitor, and f is the resonant frequency of the resonant circuit.

[0012] The resonant circuit may include an adjustment resistor connected in parallel to the pair of electrodes.

[0013] The aerosol generating device may include a load that generates energy to vaporize or atomize the aerosol source contained in the aerosol product, and the pair of electrodes may be positioned downstream of the load in the flow direction of the aerosol.

[0014] The aerosol generating device may further include a storage section for storing the aerosol product, the flow path being formed inside the storage section, and the pair of electrodes being arranged near the inner wall surface of the storage section.

[0015] The aerosol product may have an aerosol source segment containing the aerosol source, and a cooling segment arranged downstream from the aerosol source segment for cooling a substance vaporized or atomized from the aerosol source segment to generate an aerosol, and the pair of electrodes may be arranged in a position overlapping the cooling segment in the flow direction of the aerosol when the aerosol product is contained in the container.

[0016] The pair of electrodes may be spaced apart in the direction of aerosol flow.

[0017] The pair of electrodes may be disposed apart from each other with the flow channel therebetween.

[0018] The pair of electrodes may be disposed in the aerosol generating device.

[0019] The pair of electrodes may be disposed on the aerosol product.

[0020] In addition, in order to solve the above-mentioned problems, according to another aspect of the present disclosure, there is provided an aerosol product comprising an aerosol source segment containing an aerosol source, a cooling segment arranged downstream from the aerosol source segment and configured to cool a substance vaporized or atomized from the aerosol source segment to generate an aerosol, and a pair of electrodes, at least a portion of each of the pair of electrodes being exposed from the surface of the aerosol product.

[0021] The pair of electrodes may be positioned so as to overlap the cooling segment in the aerosol flow direction.

[0022] As described above, the present disclosure provides a mechanism that can further improve the accuracy of determining the state of the suction device.

[0023] 1 is a schematic diagram illustrating an example of the configuration of a suction device. FIG. 1 is a diagram for explaining an overview of a capacitance sensor 10 according to the present embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a capacitance sensor 10 according to the present embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a capacitance sensor 90 according to a comparative example. FIG. 4 is a graph showing the results of a first evaluation experiment using a capacitance sensor 90 according to a comparative example. FIG. 5 is a graph showing the time series transition of the resistance R of a pair of electrodes 21 during the experiment shown in FIG. 5. FIG. 6 is a graph showing the results of a first evaluation experiment using a capacitance sensor 10 according to the present embodiment. FIG. 7 is a graph showing the results of a second evaluation experiment using a capacitance sensor 90 according to the comparative example. FIG. 8 is a graph showing the results of a second evaluation experiment using a capacitance sensor 10 according to the present embodiment. FIG. 9 is a diagram for explaining a first design example of a resonant circuit 20 of a capacitance sensor 10 according to the present embodiment. FIG. 10 is a graph showing the results of an experiment confirming a response waveform when one cycle of a rectangular waveform is input from a drive circuit 23 to a resonant section 24 in the resonant circuit 20. FIG. 11 is a diagram for explaining a second design example of a resonant circuit 20 of a capacitance sensor 10 according to the present embodiment. FIG. 12 is a graph showing the numerical change in the combined resistance of the resistance R of a pair of electrodes 21 and an adjustment resistor Ra shown in Equation (11). FIG. 1 is a diagram showing a first configuration example of a pair of electrodes 21 according to the present embodiment; FIG. 2 is a diagram showing a second configuration example of a pair of electrodes 21 according to the present embodiment; FIG. 3 is a diagram showing a third configuration example of a pair of electrodes 21 according to the present embodiment; FIG. 4 is a diagram showing an example of the configuration of a capacitance sensor 10 according to a first modified example; and FIG. 5 is a schematic diagram showing a configuration example of a suction device 100 according to a second modified example.

[0024] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0025] 1. Configuration Example of Inhalation Device The inhalation device is a device that generates a substance to be inhaled by a user. In the following description, the substance generated by the inhalation device is described as an aerosol. Alternatively, the substance generated by the inhalation device may be a gas.

[0026] 1 is a schematic diagram showing an example of the configuration of a suction device. As shown in FIG. 1, a suction device 100 according to this example configuration includes a power supply unit 111, a sensor unit 112, a notification unit 113, a memory unit 114, a communication unit 115, a control unit 116, a heating unit 121, a storage unit 140, and a heat insulating unit 144.

[0027] The power supply unit 111 stores electric power and supplies electric power to each component of the suction device 100 under the control of the control unit 116. The power supply unit 111 may be configured by, for example, a rechargeable battery such as a lithium ion secondary battery.

[0028] The sensor unit 112 acquires various types of information related to the suction device 100. As one example, the sensor unit 112 is configured with a pressure sensor such as a condenser microphone, a flow rate sensor, a temperature sensor, or the like, and acquires values ​​associated with suction by the user. As another example, the sensor unit 112 is configured with an input device such as a button or a switch that accepts information input from the user.

[0029] The notification unit 113 notifies the user of information. The notification unit 113 is configured by, for example, a light emitting device that emits light, a display device that displays an image, a sound output device that outputs sound, or a vibration device that vibrates.

[0030] The storage unit 114 stores various types of information for the operation of the suction device 100. The storage unit 114 is configured by a non-volatile storage medium such as a flash memory, for example.

[0031] The communication unit 115 is a communication interface capable of performing communication conforming to any wired or wireless communication standard, such as Wi-Fi (registered trademark), Bluetooth (registered trademark), BLE (Bluetooth Low Energy (registered trademark)), NFC (Near Field Communication), or LPWA (Low Power Wide Area).

[0032] The control unit 116 functions as an arithmetic processing unit and a control unit, and controls the overall operation of the suction device 100 in accordance with various programs. The control unit 116 is realized by an electronic circuit such as a CPU (Central Processing Unit) or a microprocessor.

[0033] The storage unit 140 has an internal space 141 and holds the stick-shaped substrate 150 while accommodating a portion of the stick-shaped substrate 150 in the internal space 141. The storage unit 140 has an opening 142 that connects the internal space 141 to the outside and accommodates the stick-shaped substrate 150 inserted into the internal space 141 through the opening 142. For example, the storage unit 140 is a cylindrical body with the opening 142 and a bottom 143 as its bottom surface, and defines a columnar internal space 141. An air flow path that supplies air to the internal space 141 is connected to the storage unit 140. An air inlet, which is an air inlet to the air flow path, is arranged, for example, on a side surface of the suction device 100. An air outlet, which is an air outlet from the air flow path to the internal space 141, is arranged, for example, on the bottom 143.

[0034] The stick-shaped substrate 150 includes a substrate portion 151 and a mouthpiece portion 152. The substrate portion 151 includes an aerosol source. The aerosol source includes a tobacco-derived or non-tobacco-derived flavor component. When the inhalation device 100 is a medical inhaler such as a nebulizer, the aerosol source may include a medicament. The aerosol source may be, for example, a liquid such as a polyhydric alcohol, such as glycerin or propylene glycol, or water, containing a tobacco-derived or non-tobacco-derived flavor component, or a solid containing a tobacco-derived or non-tobacco-derived flavor component. When the stick-shaped substrate 150 is held in the storage portion 140, at least a portion of the substrate portion 151 is housed in the internal space 141, and at least a portion of the mouthpiece portion 152 protrudes from the opening 142. When a user holds the mouthpiece portion 152 protruding from the opening 142 in their mouth and inhales, air flows into the internal space 141 via an air flow path (not shown) and reaches the user's mouth along with the aerosol generated from the substrate portion 151.

[0035] The heating unit 121 generates aerosol by heating the aerosol source and atomizing the aerosol source. In the example shown in FIG. 1 , the heating unit 121 is configured in a film shape and is arranged to cover the outer periphery of the storage unit 140. When the heating unit 121 generates heat, the substrate unit 151 of the stick-shaped substrate 150 is heated from the outer periphery, generating aerosol. The heating unit 121 generates heat when power is supplied from the power supply unit 111. As an example, power may be supplied when the sensor unit 112 detects that the user has started inhaling and / or that predetermined information has been input. Power supply may be stopped when the sensor unit 112 detects that the user has stopped inhaling and / or that predetermined information has been input.

[0036] The heat insulating section 144 prevents heat transfer from the heating section 121 to other components. For example, the heat insulating section 144 is made of a vacuum heat insulating material, an aerogel heat insulating material, or the like.

[0037] The above describes an example of the configuration of the suction device 100. Of course, the configuration of the suction device 100 is not limited to the above, and various configurations such as those exemplified below may be used.

[0038] As one example, the heating unit 121 may be configured in a blade shape and disposed so as to protrude from the bottom 143 of the storage unit 140 into the internal space 141. In this case, the blade-shaped heating unit 121 is inserted into the substrate 151 of the stick-shaped substrate 150 and heats the substrate 151 of the stick-shaped substrate 150 from the inside. As another example, the heating unit 121 may be disposed so as to cover the bottom 143 of the storage unit 140. Furthermore, the heating unit 121 may be configured as a combination of two or more of a first heating unit covering the outer periphery of the storage unit 140, a blade-shaped second heating unit, and a third heating unit covering the bottom 143 of the storage unit 140.

[0039] As another example, the storage unit 140 may include an opening / closing mechanism such as a hinge that opens and closes a portion of the outer shell that forms the internal space 141. The storage unit 140 may then open and close the outer shell to hold and store the stick-shaped substrate 150 inserted into the internal space 141. In this case, the heating unit 121 may be provided at the holding location in the storage unit 140, and may heat the stick-shaped substrate 150 while pressing it.

[0040] Furthermore, the means for atomizing the aerosol source is not limited to heating by the heating unit 121. For example, the means for atomizing the aerosol source may be induction heating. In that case, the suction device 100 has at least an electromagnetic induction source such as a coil that generates a magnetic field, instead of the heating unit 121. A susceptor that generates heat by induction heating may be provided in the suction device 100 or may be included in the stick-shaped substrate 150.

[0041] The inhalation device 100 is an example of an aerosol generating device in the present disclosure. The stick-shaped substrate 150 is an example of an aerosol product in the present disclosure. The combination of the inhalation device 100 and the stick-shaped substrate 150 may be considered as an aerosol generating system.

[0042] <2. Technical Features> <2.1. Overview> Fig. 2 is a diagram for explaining an overview of the capacitance sensor 10 according to this embodiment. Fig. 2 schematically illustrates a cross section of the suction device 100, in which the stick-shaped substrate 150 is housed in the housing portion 140, cut along the vertical direction. The vertical direction corresponds to the axial direction of the housing portion 140 and the insertion / removal direction of the stick-shaped substrate 150.

[0043] 2, the aerosol V generated by heating the stick-shaped substrate 150 by the heating unit 121 flows along a flow direction F with the puff and reaches the user's mouth. The flow direction F of the aerosol V corresponds to the upward direction.

[0044] As shown in FIG. 2, the substrate portion 151 of the stick-shaped substrate 150 includes an aerosol source segment 151A and a cooling segment 151B.

[0045] The aerosol source segment 151A is a section containing an aerosol source. The aerosol source contained in the aerosol source segment 151A is vaporized or atomized by heating.

[0046] The cooling segment 151B is disposed downstream of the aerosol source segment 151A and cools the substance vaporized or atomized from the aerosol source segment 151A to generate the aerosol V. The cooling segment 151B may be, for example, a paper tube having through holes in the vertical direction. In this case, the substance vaporized or atomized from the aerosol source segment 151A is cooled as it passes through the paper tube, and the aerosol V is generated.

[0047] As shown in FIG. 2 , the suction device 100 according to this embodiment includes a pair of electrodes 21 (21A and 21B). The pair of electrodes 21 are disposed on a side wall 145 of the housing 140. The pair of electrodes 21 may be exposed to the internal space 141 of the housing 140. The portions of the pair of electrodes 21 exposed to the internal space 141 may be coated or may be bare. The coating may be, for example, a coating made of an insulating material.

[0048] 2, the pair of electrodes 21 may be disposed spaced apart from each other in the vertical direction. In this case, the electric field E formed by the pair of electrodes 21 is formed in the vertical direction.

[0049] The electric field E formed between the pair of electrodes 21 overlaps with the flow path through which the aerosol V generated from the stick-shaped substrate 150 passes. The flow path of the aerosol V is a space formed inside the storage unit 140. The internal space 141 of the storage unit 140 corresponds to the flow path. More specifically, the cooling segment 151B corresponds to the flow path. With this configuration, when the aerosol V passes through the flow path, the aerosol V passes through the electric field E formed by the pair of electrodes 21, and as a result, the capacitance C of the pair of electrodes 21 changes.

[0050] Here, the pair of electrodes 21 is disposed above the heating unit 121, i.e., downstream of the heating unit 121 in the flow direction F of the aerosol V. With this configuration, the aerosol V passes through the electric field E formed by the pair of electrodes 21 as the aerosol V is puffed, and the capacitance C of the pair of electrodes 21 changes.

[0051] In particular, the pair of electrodes 21 are arranged in a position overlapping with the cooling segment 151B in the flow direction F of the aerosol V when the stick-shaped substrate 150 is housed in the housing 140. In this case, as shown in FIG. 2 , the electric field E formed by the pair of electrodes 21 can be formed along the outer edge of the cooling segment 151B. As a result of the puff, a large amount of aerosol V is generated in the cooling segment 151B and passes through it, and therefore a large amount of aerosol also passes through the portion overlapping with the electric field E formed by the pair of electrodes 21. Therefore, with this configuration, the change in capacitance C caused by the puff can be increased.

[0052] The capacitance sensor 10 measures the capacitance C of the pair of electrodes 21. That is, the capacitance sensor 10 measures a change in capacitance C that occurs when the aerosol V passes through the flow path of the aerosol V. The capacitance sensor 10 then detects a puff based on the change in capacitance C. According to the arrangement of the pair of electrodes 21 described above, the capacitance C of the pair of electrodes 21 changes significantly in response to a puff, making it possible to accurately detect a puff.

[0053] The main component of the aerosol V generated from the stick-shaped substrate 150 is an insulating liquid with a high relative dielectric constant, such as water, glycerin, or propylene glycol. Therefore, the capacitance C of the pair of electrodes 21 changes depending on the amount of aerosol V present in the electric field E formed by the pair of electrodes 21.

[0054] However, the aerosol V actually generated from the stick-shaped substrate 150 contains a substance that imparts conductivity to the aerosol V, such as a fragrance or its ions, or carbon. Therefore, as shown in FIG. 2 , the circuit model of the capacitance sensor 10 includes not only capacitance C but also resistance R as components related to the pair of electrodes 21.

[0055] A switched capacitor capacitance sensor is one method for measuring the capacitance C of the pair of electrodes 21. However, the measurement accuracy of the switched capacitor capacitance sensor decreases in an environment where a resistance R exists between the pair of electrodes 21. This is because, when a resistance R exists between the pair of electrodes 21, the charge stored in the pair of electrodes 21 is consumed by the resistance R (i.e., converted into heat).

[0056] Taking the above circumstances into consideration, a capacitance sensor 10 according to an embodiment of the present disclosure has been created. The capacitance sensor 10 according to this embodiment measures the capacitance C of a pair of electrodes 21 based on the resonant frequency of a resonant circuit including the pair of electrodes 21. With this configuration, the measurement accuracy of the capacitance C of the pair of electrodes 21 can be improved.

[0057] 3 is a diagram showing an example of the configuration of the capacitance sensor 10 according to this embodiment. As shown in Fig. 3, the capacitance sensor 10 is a capacitance sensor of a resonant circuit type that includes a resonant circuit 20 and a sensor control unit 30.

[0058] (Resonant Circuit 20) The resonant circuit 20 is a resonant circuit whose resonant frequency changes in response to a change in the capacitance of the flow path through which the aerosol passes, i.e., a change in the capacitance C of the pair of electrodes 21. As shown in Fig. 3 , the resonant circuit 20 includes the pair of electrodes 21, a substrate circuit 22, and a drive circuit 23.

[0059] The drive circuit 23 outputs a predetermined voltage waveform. The drive circuit 23 includes an AC power supply that outputs an AC current of a predetermined frequency. The drive circuit 23 outputs a voltage waveform including a resonant frequency at which resonance occurs in the resonant circuit 20. For example, the drive circuit 23 may output a composite wave of multiple frequency components that may correspond to the resonant frequency. An example of such a composite wave is a voltage waveform that uniformly includes all frequency components within a predetermined range that includes frequencies that may become the resonant frequency. Because the resonant circuit 20 removes components other than the resonant frequency and / or amplifies the resonant frequency component, it is possible to estimate the resonant frequency of the resonant circuit 20 based on the response waveform to the input waveform from the drive circuit 23.

[0060] The substrate circuit 22 is the configuration of the resonant circuit 20 other than the pair of electrodes 21 and the drive circuit 23. The substrate circuit 22 is configured by, for example, a substrate or wiring. The substrate circuit 22 is configured by the inductor L ０ and capacitor C ０ Includes.

[0061] In the following description, the symbol indicating the inductor and the value of the inductor (i.e., inductance) may be expressed by the same symbol. The same applies to capacitance and resistance. For example, an inductor L ０ The inductance of ０ Also referred to as capacitor C ０ The capacitance of ０ It is also called.

[0062] The pair of electrodes 21 is as described above with reference to Fig. 2. The pair of electrodes 21 has a capacitance C and a resistance R as a resistance component caused by the aerosol.

[0063] (Sensor Control Unit 30) The sensor control unit 30 controls the operation of the capacitance sensor 10. As shown in FIG.

[0064] The clock circuit 31 outputs a rectangular waveform repeatedly at a predetermined time interval.

[0065] The frequency measurement unit 32 measures the resonant frequency of the resonant circuit 20 .

[0066] The control circuit 33 measures the change in capacitance C of the pair of electrodes 21 based on the resonant frequency of the resonant circuit 20 measured by the frequency measurement unit 32. Then, the control circuit 33 detects a puff based on the change in capacitance C of the pair of electrodes 21.

[0067] (Frequency Sweep Method) The frequency measurement unit 32 may control the drive circuit 23 to output a sine wave of each frequency while sweeping it, and identify the frequency at which a peak occurs as the resonant frequency.

[0068] Here, the resonant circuit 20 shown in FIG. ０ and capacitor C ０ and a pair of electrodes 21 connected in parallel. Therefore, the resonant frequency f of the resonant circuit 20 is expressed by the following equation.

[0069]

[0070] The control circuit 33 receives the resonance frequency f measured by the frequency measurement unit 32 and the known inductance L ０ , and a known capacitance C ０ The capacitance C of the pair of electrodes 21 may be calculated from the above formula (1) based on the above formula (1). As shown in the above formula (1), the resonant frequency f is not affected by the resistance R of the pair of electrodes 21. In this way, when the frequency sweep method is adopted, it is possible to avoid the effect of the resistance R of the pair of electrodes 21 and measure the capacitance C with high accuracy.

[0071] (Method Using Response Waveform in Transient State) Alternatively, the frequency measurement unit 32 may measure the resonant frequency f of the resonant circuit 20 using the response waveform in the transient state. Specifically, the frequency measurement unit 32 measures the resonant frequency f of the resonant circuit 20 based on the number of rectangular waveforms output from the clock circuit 31 within the time width of the response waveform of the resonant circuit 20. Here, the resonant circuit 20 removes components other than the resonant frequency f and / or amplifies the component of the resonant frequency f, so that the main component of the response waveform is the resonant frequency f, and the period of the response waveform corresponds to the resonant frequency f. Therefore, for example, the frequency measurement unit 32 counts how many peaks or valleys of the rectangular waveform output from the clock circuit 31 are included within any peak included in the response waveform of the resonant circuit 20, and measures the resonant frequency f of the resonant circuit 20 based on this count value. In this case, the frequency measurement unit 32 can calculate the resonant frequency f by multiplying the count value by a value corresponding to the time width of the rectangular waveform.

[0072] When the method using the transient response waveform is adopted, it is possible to shorten the measurement time of the resonance frequency f compared to when the frequency sweep method is adopted. As a result of shortening the measurement time of the resonance frequency f, it is possible to suppress changes in the capacitance C or resistance R of the pair of electrodes 21 during the measurement time, and it is possible to further improve the measurement accuracy of the resonance frequency f. In this way, when the method using the transient response waveform is adopted, it is possible to detect puffs with high accuracy and in high real-time performance.

[0073] When the method using the response waveform in the transient state is adopted, the resonant frequency f is expressed by Equation (4) or Equation (9) described below. The method for measuring the capacitance C of the pair of electrodes 21 is expressed by Equation (10) described below. As will be explained in detail later, even when the method using the response waveform in the transient state is adopted, it is possible to avoid the influence of the resistance R of the pair of electrodes 21 and measure the capacitance C with high accuracy.

[0074] 2.3. Evaluation The capacitance sensor 10 according to this embodiment will be evaluated below in comparison with a capacitance sensor 90 according to a comparative example.

[0075] 4 is a diagram showing an example of the configuration of a capacitance sensor 90 according to a comparative example. As shown in FIG. 4, the capacitance sensor 90 includes, in addition to a pair of electrodes 21, a charging circuit 91, a charge amount measuring unit 92, a control circuit 93, and a switch S １ ~S ３ The present invention relates to a switched capacitor type capacitance sensor including:

[0076] The charging circuit 91 is a constant current source that outputs a constant current I.

[0077] The charge amount measuring unit 92 measures the input charge amount.

[0078] The control circuit 93 controls the operation of the capacitance sensor 90. In detail, the control circuit 93 first turns on the switch S １ and S ２ Open the switch S ３ By closing the switch S, the electric charge accumulated in the pair of electrodes 21 is discharged. １ Close switch S ２ and S ３ By opening the switch S, the pair of electrodes 21 are charged with electric charge. １ and S ３ Open the switch S ２ By closing the pair of electrodes 21 , the electric charge accumulated in the pair of electrodes 21 is discharged toward the electric charge measuring unit 92 .

[0079] As a result, as shown by charge flow 99A, charge accumulates in the pair of electrodes 21, and the accumulated charge is output to charge amount measurement unit 92, which can measure the charge amount Q of the pair of electrodes 21. Here, capacitance C = charge amount Q / voltage V, and charge amount Q = current I × charging time t. Therefore, if the voltage V of the pair of electrodes 21 is measured after the charging circuit 91 outputs current I at charging time t, the capacitance C of the pair of electrodes 21 can be calculated.

[0080] However, as shown by charge flow 99B, if a resistor R is present between the pair of electrodes 21, the resistor R will consume charge (i.e., convert it into heat). Furthermore, because the resistor R is not constant, it is difficult to calculate the amount of charge consumed by the resistor R. Therefore, it is difficult to eliminate the influence of the resistor R from the amount of charge Q measured by the charge amount measurement unit 92. For these reasons, the measurement accuracy of the capacitance C by the capacitance sensor 90 according to the comparative example is reduced due to the influence of the resistor R.

[0081] (First Evaluation Experiment) The inventors conducted a first evaluation experiment to evaluate the capacitance sensor 10 according to this embodiment and the capacitance sensor 90 according to the comparative example. In the first evaluation experiment, after heating of the stick-shaped substrate 150 began, puffing was performed periodically, and various values ​​were measured. The results of the first evaluation experiment will be described below with reference to FIGS. 5 to 7.

[0082] FIG. 5 is a graph showing the results of a first evaluation experiment using a capacitance sensor 90 according to a comparative example. The horizontal axis of graph G1 in FIG. 5 represents the elapsed time from the start of heating. The vertical axis on the left side of graph G1 represents the capacitance C value of the pair of electrodes 21 measured by the capacitance sensor 90 according to the comparative example. The vertical axis on the right side of graph G1 represents a value indicating the presence or absence of a puff, with 1 indicating that a puff was performed and 0 indicating that a puff was not performed. Line G11 represents the time series of the capacitance C of the pair of electrodes 21 measured by the capacitance sensor 90 according to the comparative example. Line G12 represents a puff signal indicating the presence or absence of a puff. As shown in graph G1, the capacitance C value fluctuates significantly approximately 30 seconds after the start of heating. Furthermore, while it can be said that the capacitance C value decreased due to the puff performed approximately 20 seconds after the start of heating, it is difficult to uniquely identify the effect of the subsequent puff on the capacitance C. Therefore, it can be said that it is difficult to accurately detect puffs based on the capacitance C measured by the capacitance sensor 90 according to the comparative example.

[0083] FIG. 6 is a graph showing the time series of the resistance R of the pair of electrodes 21 during the experiment shown in FIG. 5 . The horizontal axis of graph G2 shown in FIG. 6 represents the elapsed time from the start of heating. The vertical axis of graph G2 represents the value of the resistance R of the pair of electrodes 21. As shown in graph G2, the value of the resistance R of the pair of electrodes 21 fluctuates around approximately 60 MΩ immediately after the start of heating, gradually decreases from approximately 30 seconds after the start of heating, and decreases to approximately 120 kΩ after 100 seconds. The drastic fluctuation in the capacitance C measured by the capacitance sensor 90 according to the comparative example shown in FIG. 5 from 30 seconds after the start of heating is thought to be due to this decrease in the resistance R of the pair of electrodes 21.

[0084] FIG. 7 is a graph showing the results of a first evaluation experiment using the capacitance sensor 10 according to this embodiment. The horizontal axis of graph G3 in FIG. 7 represents the elapsed time from the start of heating. The vertical axis of graph G3 represents the capacitance C of the pair of electrodes 21 measured by the capacitance sensor 10 according to this embodiment. Circles G31 to G36 in FIG. 7 enclose the changes in capacitance C when a puff is performed. As shown in graph G3, the capacitance C measured by the capacitance sensor 10 according to this embodiment changes gradually as heating progresses, but then changes significantly instantaneously when a puff is performed. Therefore, the control circuit 33 can accurately detect puffs based on this large, instantaneous change in capacitance C.

[0085] In particular, the control circuit 33 may determine that a puff has occurred when the absolute value of the difference between the long-term moving average of the capacitance C of the pair of electrodes 21 and the short-term moving average of the capacitance C of the pair of electrodes 21 is equal to or greater than a threshold value, and may determine that a puff has not occurred otherwise. The long-term moving average is an index representing long-term data fluctuations, and the short-term moving average is an index representing short-term data fluctuations. Therefore, the difference between these represents short-term data fluctuations that deviate from long-term data fluctuations. Therefore, with this configuration, even if the capacitance C changes over the long term as heating progresses, it is possible to accurately detect a puff based on the short-term change in capacitance C associated with puffing.

[0086] According to the first evaluation experiment described above, it was confirmed that the capacitance sensor 10 according to this embodiment is capable of measuring the capacitance C of a pair of electrodes 21 with high accuracy compared to the capacitance sensor 90 according to the comparative example.

[0087] (Second Evaluation Experiment) The inventors conducted a second evaluation experiment to evaluate the capacitance sensor 10 according to this embodiment and the capacitance sensor 90 according to the comparative example. In the second evaluation experiment, the pair of electrodes 21 were replaced with chip components having capacitance C' and resistance R', and the capacitance C' of the chip components was measured while varying the capacitance C' and resistance R' of the chip components. The capacitance C' of the chip components was 1 to 9 pF. The resistance R' of the chip components was 10 kΩ to 1 MΩ. The results of the second evaluation experiment will be described below with reference to FIGS. 8 and 9.

[0088] FIG. 8 is a graph showing the results of a second evaluation experiment using the capacitance sensor 90 according to the comparative example. The horizontal axis of graph G4 shown in FIG. 8 represents the resistance R' of the chip component. The vertical axis of graph G4 represents the capacitance C' of the chip component measured by the capacitance sensor 90 according to the comparative example. Graph G4 shows the change in the capacitance C' of the chip component measured by the capacitance sensor 90 according to the comparative example relative to the change in the resistance R' of the chip component when chip components having capacitances C' of 1, 3, 5, 7, and 9 pF are used. As shown in graph G4, the capacitance sensor 90 according to the comparative example accurately measures the capacitance C' of the chip component when the resistance R' of the chip component is 820 kΩ or higher.

[0089] 6, the value of the resistance R of the pair of electrodes 21 decreases to approximately 120 kΩ during heating of the stick-shaped substrate 150. Therefore, it can be said that it is difficult for the capacitance sensor 90 according to the comparative example to maintain the measurement accuracy of the capacitance C of the pair of electrodes 21 from the start to the end of heating.

[0090] FIG. 9 is a graph showing the results of a second evaluation experiment using the capacitance sensor 10 according to this embodiment. The horizontal axis of graph G5 shown in FIG. 9 represents the resistance R' of the chip component. The vertical axis of graph G5 represents the capacitance C' of the chip component measured by the capacitance sensor 10 according to this embodiment. Graph G5 shows the change in the capacitance C' measured by the capacitance sensor 10 according to this embodiment relative to the change in the resistance R' of the chip component when chip components having capacitances C' of 1, 3, 5, 7, and 9 pF are used. As shown in graph G5, the capacitance sensor 10 according to this embodiment accurately measures the capacitance C' of the chip component when the resistance R' of the chip component is 100 kΩ or greater.

[0091] 6, the value of the resistance R of the pair of electrodes 21 decreases to approximately 120 kΩ during heating of the stick-shaped substrate 150. Therefore, it can be said that the capacitance sensor 10 according to this embodiment can maintain high measurement accuracy of the capacitance C of the pair of electrodes 21 from the start to the end of heating.

[0092] According to the second evaluation experiment described above, it was confirmed that the capacitance sensor 10 according to this embodiment is capable of measuring the capacitance C of a pair of electrodes 21 with high accuracy compared to the capacitance sensor 90 according to the comparative example.

[0093] <2.4. Circuit Design> Hereinafter, a design example of the resonant circuit 20 and a method of calculating the capacitance C of the pair of electrodes 21 will be described when a method of determining the resonant frequency f using a response waveform in a transient state is employed.

[0094] (1) First Design Example Hereinafter, a first design example of the resonant circuit 20 of the capacitance sensor 10 will be described with reference to FIGS. 10 and 11. FIG.

[0095] Fig. 10 is a diagram for explaining a first design example of the resonant circuit 20 of the capacitance sensor 10 according to this embodiment. As described above with reference to Fig. 3, the resonant circuit 20 shown in Fig. 10 includes a pair of electrodes 21, a substrate circuit 22, and a drive circuit 23. Hereinafter, the substrate circuit 22 and the drive circuit 23 will also be referred to as a resonant unit 24.

[0096] 10, the drive circuit 23 includes a power supply 231, a voltage monitoring unit 232, and an inverter circuit 233. The voltage waveform output from the power supply 231 is converted into a rectangular waveform by the inverter circuit 233 and output to the resonator 24. The voltage monitoring unit 232 monitors the response waveform from the resonator 24. The drive circuit 23 has an internal resistance ro.

[0097] 11 is a graph showing the experimental results of confirming the response waveform when a step input waveform is input from the drive circuit 23 to the resonance section 24 in the resonance circuit 20. The horizontal axis of the graph G6 shown in FIG. 11 represents time. The vertical axis of the graph G6 represents voltage. The graph G6 shows the experimental results of confirming the step response while changing the resistance R of the pair of electrodes 21. In this experiment, the current I output from the power supply 231 is set to 1 mA, and the inductance L ０ = 30 [μH], capacitance C ０ =33 [pF], resonance frequency f ０ A substrate circuit 22 with a frequency of 5 MHz was used.

[0098] As shown in graph G6, the smaller the resistance R of the pair of electrodes 21, the more the response waveform attenuates. The resistance R of the pair of electrodes 21 has a lower limit of 0.5 kΩ, and if the resistance R is less than this lower limit, no resonance occurs in the resonant circuit 20. On the other hand, even if the value of the resistance R of the pair of electrodes 21 is equal to or greater than the lower limit, resonance energy is consumed by the resistance R of the pair of electrodes 21, and the response waveform attenuates. As a result, the measurement accuracy of the capacitance C of the pair of electrodes 21 may decrease.

[0099] From this perspective, the following describes the design of the resonant circuit 20 (particularly the resonant portion 24) that can suppress a decrease in the measurement accuracy of the capacitance C of the pair of electrodes 21.

[0100] In the resonant circuit 20, when a rectangular waveform for one period is input from the drive circuit 23 to the resonant section 24, the response waveform is expressed by the following equation.

[0101]

[0102] Here, the angular velocity ω is expressed by the following equation.

[0103]

[0104] The resonance frequency f is expressed by the following equation:

[0105]

[0106] Note that formula (4) expressing the resonant frequency f differs from formula (1) which also expresses the resonant frequency f. This is because the methods for calculating the resonant frequency f are different. In a method for calculating the resonant frequency f using a response waveform in a transient state, the resonant frequency f is expressed by formula (4). In a method for calculating the resonant frequency f by sweeping a sine wave of each frequency, the resonant frequency f is expressed by formula (1).

[0107] Here, the condition for resonance to occur is that the angular velocity ω is a real number (that is, the content of the root of equation (4) is a real number), and is expressed by the following equation.

[0108]

[0109] Inductance L of the substrate circuit 22 ０ , the capacitance C of the substrate circuit 22 ０ , and the resistance R of the pair of electrodes 21 are all real numbers. Therefore, the condition for resonance shown in equation (5) to occur is expressed by the following equation.

[0110]

[0111] The inductance L of the substrate circuit 22 is set so as to satisfy the above formula (6). ０ , the capacitance C of the substrate circuit 22 ０ , and the capacitance C of the pair of electrodes 21. It is desirable that the resistance R of the pair of electrodes 21 be measured in advance using a tester or the like using the stick-shaped substrate 150.

[0112] The decay of the response waveform is defined by the logarithmic part of equation (2) as follows:

[0113]

[0114] Then, 2(C+C ０ ) R is the response waveform is 36.8% (i.e., e －１ ) is the time constant until the capacitance C of the pair of electrodes 21 decays to 10%. For example, to keep the decay at the first peak at 10% or less, the time constant should be set to approximately four times the period. That is, by designing the resonant circuit 20 so that the condition shown in the following equation is satisfied, the decay of the response waveform can be reduced and the measurement accuracy of the measured resonant frequency f can be improved. As a result, the measurement accuracy of the capacitance C of the pair of electrodes 21 can be improved.

[0115]

[0116] If the resistance R of the pair of electrodes 21 is small, the peak of the response waveform will be small, which may make it difficult to measure the resonant frequency with the frequency measurement unit 32. On the other hand, if the resistance R of the pair of electrodes 21 is large, the peak of the response waveform will be large, which may cause an excessive voltage to be applied to the frequency measurement unit 32, which may cause the frequency measurement unit 32 to break down or make it difficult to measure the resonant frequency. Therefore, it is desirable to set the Q value of the resonant circuit 20 based on the resistance R of the pair of electrodes 21 that has been measured in advance.

[0117] (2) Second Design Example Hereinafter, a second design example of the resonant circuit 20 of the capacitance sensor 10 will be described with reference to FIGS. 12 and 13. FIG.

[0118] Fig. 12 is a diagram for explaining a second design example of the resonant circuit 20 of the capacitance sensor 10 according to this embodiment. As described above with reference to Fig. 10, the resonant circuit 20 shown in Fig. 12 includes a pair of electrodes 21 and a resonant unit 24 including a substrate circuit 22 and a drive circuit 23. However, the substrate circuit 22 shown in Fig. 12 further includes an adjustment resistor Ra connected in parallel to the pair of electrodes 21.

[0119] The resonant frequency f of the resonant circuit 20 shown in FIG.

[0120]

[0121] When the above equation (9) is solved for the capacitance C of the pair of electrodes 21, the following equation is derived:

[0122]

[0123] Here, in equation (9), the resistance R of the pair of electrodes 21 in equation (4) is replaced by the combined resistance of the resistance R of the pair of electrodes 21 and the adjustment resistance Ra, as shown in the following equation.

[0124]

[0125] As shown in Equation (10), the value of the combined resistance shown in Equation (11) is used to calculate the capacitance C of the pair of electrodes 21. The value of the combined resistance will be described with reference to FIG.

[0126] 13 is a graph showing the change in the numerical value of the combined resistance of the resistance R of the pair of electrodes 21 and the adjustment resistance Ra shown in Equation (11). The horizontal axis of graph G7 represents the value of the resistance R of the pair of electrodes 21. The vertical axis of graph G7 represents the value of the combined resistance. Graph G7 shows the value of the combined resistance when the resistance R of the pair of electrodes 21 is changed when the adjustment resistance Ra is 10 kΩ, 50 kΩ, or 100 kΩ.

[0127] Referring to graph G7, the larger the value of the adjusting resistor Ra, the larger the change in the value of the combined resistance when the value of the resistance R of the pair of electrodes 21 changes. On the other hand, the smaller the value of the adjusting resistor, the smaller the change in the value of the combined resistance when the value of the resistance R of the pair of electrodes 21 changes. When the value of the adjusting resistor Ra is sufficiently small, it can be said that the combined resistance is approximately equal to the adjusting resistor Ra.

[0128] From the above, it is desirable to set the value of the adjusting resistor Ra to, for example, 1 / 10 or less of the previously measured lower limit value of the resistance R of the pair of electrodes 21. For example, if the lower limit value of the resistance R of the pair of electrodes 21 is 100 kΩ, as shown in graph G7, by setting the value of the adjusting resistor Ra to 10 kΩ, which is 1 / 10 of the lower limit value, it is possible to set the value of the combined resistance to 10 kΩ, which is approximately equal to the value of the adjusting resistor Ra.

[0129] In this way, the combined resistance shown in Equation (11) can be regarded as the adjustable resistance Ra by setting the value of the adjustable resistance Ra to a sufficiently small value, eliminating the influence of the resistance R of the pair of electrodes 21. The resonant frequency f can be measured by the frequency measuring unit 32, and the inductance L of the substrate circuit 22 can be calculated. ０ and capacitance C ０ is known. That is, all variables in Equation (10) are known except for the capacitance C of the pair of electrodes 21. Therefore, the control circuit 33 can accurately calculate the capacitance C of the pair of electrodes 21 using Equation (10).

[0130] 2.5. Configuration Examples of the Pair of Electrodes 21 Configuration examples of the pair of electrodes 21 are not limited to the example shown in Fig. 2. The pair of electrodes 21 may be disposed near the inner wall surface (i.e., the inner surface of the side wall portion 145 or the bottom portion 143) of the storage portion 140 that forms an aerosol flow path therein. "Nearby" here refers to within a range in which the capacitance C of the pair of electrodes 21 changes due to the influence of the aerosol generated from the stick-shaped substrate 150. Configuration examples of the pair of electrodes 21 will be described below.

[0131] (1) First Configuration Example Figure 14 is a diagram showing a first configuration example of a pair of electrodes 21 according to this embodiment. The upper part of Figure 14 schematically illustrates a cross section taken along the vertical direction of suction device 100 in which stick-shaped substrate 150 is housed in housing portion 140. The lower part of Figure 14 schematically illustrates a cross section taken along line A-A in the diagram shown in the upper part of Figure 14.

[0132] 14, each of the pair of electrodes 21 may be disposed at a distance from each other across the flow path (i.e., the internal space 141 or the cooling segment 151B) of the aerosol V. In this case, the electric field E formed by the pair of electrodes 21 may be formed in the circumferential direction along the outer edge of the cooling segment 151B.

[0133] (2) Second Configuration Example Figure 15 is a diagram showing a second configuration example of a pair of electrodes 21 according to this embodiment. The upper part of Figure 15 schematically shows a cross section taken along the vertical direction of suction device 100 in which stick-shaped substrate 150 is housed in housing section 140. The lower part of Figure 15 schematically shows a cross section taken along line B-B in the diagram shown in the upper part of Figure 15.

[0134] 15, each of the pair of electrodes 21 may be configured in an annular shape. The pair of electrodes 21 may be disposed spaced apart from each other in the flow direction F of the aerosol V. In this case, the electric field E formed by the pair of electrodes 21 may be formed in the vertical direction along the outer edge of the cooling segment 151B.

[0135] (3) Third Configuration Example Fig. 16 is a diagram showing a third configuration example of a pair of electrodes 21 according to this embodiment. Fig. 16 schematically shows a cross section of suction device 100, in which stick-shaped substrate 150 is housed in housing portion 140, cut along the vertical direction.

[0136] 16 , the pair of electrodes 21 may be disposed on a stick-shaped substrate 150. With this configuration, the pair of electrodes 21 can be brought closer to the aerosol V than when the pair of electrodes 21 are disposed on the inhalation device 100. This increases the change in capacitance C of the pair of electrodes 21 caused by puffing, thereby improving the accuracy of puff detection.

[0137] 16, each of the pair of electrodes 21 may be disposed spaced apart in the flow direction F of the aerosol V. In this case, the electric field E formed by the pair of electrodes 21 may be formed in the vertical direction along the outer edge of the cooling segment 151B.

[0138] As shown in FIG. 16 , at least a portion of each of the pair of electrodes 21 may be exposed from the surface of the stick-shaped substrate 150. The portion of the pair of electrodes 21 exposed from the surface of the stick-shaped substrate 150 may be coated or may be bare. Each of the pair of electrodes 21 may be connected to the resonant circuit 20 (particularly, the substrate circuit 22) via electrical contacts 29 (29A and 29B) arranged so as to be exposed on the inner surface of the side wall portion 145 of the housing portion 140. The pair of electrodes 21 and the electrical contacts 29 may be in contact or not in contact. With this configuration, the resonant frequency f of the resonant circuit 20 changes in response to a change in the capacitance C of the pair of electrodes 21, making it possible to measure the capacitance C of the pair of electrodes 21 based on the resonant frequency f.

[0139] 16 , the pair of electrodes 21 are preferably disposed at positions overlapping the cooling segment 151B in the flow direction F of the aerosol V. With this configuration, as the aerosol V puffs, it passes through the electric field E formed by the pair of electrodes 21, causing a change in the capacitance C of the pair of electrodes 21. As a result, it becomes possible to accurately detect the puff based on the change in capacitance C measured by the capacitance sensor 10.

[0140] The pair of electrodes 21 may have various configurations and arrangements, similar to the arrangement in the suction device 100. As an example, similar to the example shown in Fig. 14, each of the pair of electrodes 21 may be arranged to be spaced apart in the radial direction of the stick-shaped substrate 150. As another example, similar to the example shown in Fig. 15, each of the pair of electrodes 21 may be configured in an annular shape.

[0141] 16 is difficult to adopt in a switched capacitor type capacitance sensor, because a short circuit occurs between the electrical contacts 29.

[0142] 17 is a diagram showing an example of the configuration of a capacitance sensor 10 according to a first modification. As shown in Fig. 17, the capacitance sensor 10 according to this modification is a capacitance sensor of a resonant circuit type that includes a resonant circuit 20 and a sensor control unit 30.

[0143] However, the resonant circuit 20 according to this modification does not include an inductor L ０ and capacitor C ０ and a pair of electrodes 21 connected in series. Therefore, the resonant frequency f of the resonant circuit 20 is expressed by the following equation.

[0144]

[0145] Here, the coefficients a and b shown in the equation (12) are expressed by the following equations.

[0146]

[0147]

[0148] By measuring the resonant frequency f, it is possible to estimate the capacitance C of the pair of electrodes 21 using the above formulas (12) to (14). Note that the sensor control unit 30 according to this modification may control the drive circuit 23 to output a sine wave of each frequency while sweeping it, and identify the frequency at which a peak occurs as the resonant frequency f.

[0149] However, as shown in the above formulas (12) to (14), the resonant frequency f is affected by the resistance R of the pair of electrodes 21. Because the resistance R of the pair of electrodes 21 is unknown, it can be said that there is still room for improvement in the estimation accuracy of the capacitance C of the pair of electrodes 21.

[0150] 12 and 13, the substrate circuit 22 of the resonant circuit 20 according to this modification may further include an adjustment resistor Ra connected in parallel to the pair of electrodes 21. In this case, the unknown value of the resistance R of the pair of electrodes 21 is replaced with the known value of the adjustment resistor Ra, and the influence of the resistance R of the pair of electrodes 21 on the resonant frequency f can be eliminated. As a result, the capacitance C of the pair of electrodes 21 can be measured with high accuracy.

[0151] (2) Second Modification Example In the above, an example in which the inhalation device 100 generates an aerosol by heating the stick-shaped substrate 150 has been described, but the present disclosure is not limited to such an example. The inhalation device 100 may be configured as a so-called liquid atomization aerosol generator that generates an aerosol by heating and atomizing an aerosol source in the form of a liquid. The technology disclosed herein can also be applied to a liquid atomization aerosol generator.

[0152] Hereinafter, with reference to FIG. 18, a configuration example of the inhalation device 100 configured as a liquid atomization type aerosol generating device will be described.

[0153] Fig. 18 is a schematic diagram showing an example configuration of an inhalation device 100 according to a second modified example. As shown in Fig. 18, the inhalation device 100 according to this example configuration includes a power supply unit 110 and a cartridge 120. The power supply unit 110 and the cartridge 120 are configured to be detachable from each other. Puffing is performed with the cartridge 120 attached to the power supply unit 110.

[0154] 18 , the power supply unit 110 includes a power supply section 111, a sensor section 112, a notification section 113, a storage section 114, a communication section 115, and a control section 116. The cartridge 120 includes a heating section 121, a liquid guiding section 122, a liquid storage section 123, and a mouthpiece 124. An air flow path 180 is formed in the cartridge 120.

[0155] Each of the power supply unit 111, sensor unit 112, notification unit 113, memory unit 114, communication unit 115, and control unit 116 is substantially identical to the corresponding component included in the suction device 100 described with reference to Figure 1.

[0156] The liquid reservoir 123 stores the aerosol source configured as a liquid.

[0157] The liquid guide portion 122 guides and holds the aerosol source, which is a liquid stored in the liquid storage portion 123, from the liquid storage portion 123. The liquid guide portion 122 is, for example, a wick formed by twisting a fiber material such as glass fiber or a porous material such as porous ceramic. The liquid guide portion 122 is in liquid communication with the liquid storage portion 123. Therefore, the aerosol source stored in the liquid storage portion 123 spreads throughout the liquid guide portion 122 due to the capillary effect.

[0158] The heating unit 121 generates an aerosol by heating the aerosol source and atomizing the aerosol source. In the example shown in Fig. 18, the heating unit 121 is configured with a metal coil and is wound around the liquid guiding unit 122. Therefore, when the heating unit 121 generates heat, the aerosol source held in the liquid guiding unit 122 is heated and atomized, and an aerosol is generated.

[0159] The air flow path 180 is a flow path for air inhaled by the user. The air flow path 180 has a tubular structure with an air inlet hole 181, which is an entrance for air into the air flow path 180, and an air outlet hole 182, which is an exit for air from the air flow path 180, at both ends. As the user inhales, air flows into the air flow path 180 from the air inlet hole 181 and flows out of the air flow path 180 from the air outlet hole 182. As an example, the air inlet hole 181 may be a gap formed between the power supply unit 110 and the cartridge 120 when the cartridge 120 is attached to the power supply unit 110. The air outlet hole 182 is disposed in the mouthpiece 124.

[0160] A liquid guide section 122 is disposed midway along air flow path 180. The aerosol generated by heating section 121 is mixed with air flowing in through air inlet hole 181. Then, as the user inhales, the mixed fluid of the aerosol and air is transported to air outlet hole 182 as shown by arrow 190.

[0161] Mouthpiece 124 is a member that is held in the mouth by the user when inhaling. Air outlet holes 182 of air flow path 180 are arranged in mouthpiece 124. By holding mouthpiece 124 in the mouth and inhaling, the user can take in the mixed fluid of aerosol and air transported by air flow path 180 into the oral cavity.

[0162] The portion of air flow path 180 downstream of heating unit 121 corresponds to the flow path through which the aerosol passes. Therefore, as shown in Fig. 18 , pair of electrodes 21 may be disposed in air flow path 180 downstream of heating unit 121, for example, in mouthpiece 124. With this configuration, even inhalation device 100 configured as a liquid atomization aerosol generator, it is possible to detect puffs based on changes in capacitance C of pair of electrodes 21.

[0163] <4. Supplementary Information> Although preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art to which the present disclosure pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0164] Although the above describes an example in which the drive circuit 23 outputs a rectangular waveform to the resonator 24, the present disclosure is not limited to such an example. As an example, the drive circuit 23 may output an impulse waveform to the resonator 24. As another example, when a frequency sweep method is adopted as a method for measuring the resonant frequency f, the drive circuit 23 may output a sine wave of each frequency to the resonator 24 while sweeping it.

[0165] The control circuit 33 can determine the state of the suction device 100 based on changes in the capacitance C of the pair of electrodes 21. The state of the suction device 100 determined based on changes in the capacitance C of the pair of electrodes 21 is not limited to the presence or absence of a puff as described above. As one example, the control circuit 33 may detect insertion / removal of the stick-shaped substrate 150 into the housing 140 based on changes in the capacitance C of the pair of electrodes 21. As another example, the control circuit 33 may estimate the heating state of the stick-shaped substrate 150 based on changes in the capacitance C of the pair of electrodes 21.

[0166] Furthermore, the change in capacitance C of the pair of electrodes 21 can be used for various purposes. As one example, puffs may be detected and counted based on the change in capacitance C. As another example, the notification unit 113 may issue a notification using light, sound, or vibration based on the change in capacitance C. As another example, the heating temperature of the heating unit 121 may be controlled based on the change in capacitance C. As another example, in the inhalation device 100 according to the above embodiment, the insertion / removal of the stick-shaped substrate 150 may be detected based on the change in capacitance C, and the execution / permission / prohibition of heating may be controlled. As another example, in the inhalation device 100 according to the second modified example, heating may be started based on pressing a button, puffs may be detected based on the change in capacitance C, and the heating temperature may be increased at the timing when the puff is detected.

[0167] The heating unit 121 described above is an example of a load that generates energy for vaporizing or atomizing the aerosol source contained in the stick-shaped substrate 150. Alternatively, the suction device 100 may have a vibration source as the load, and may vaporize or atomize the aerosol source configured as a liquid by vibration. Furthermore, the suction device 100 may have an electromagnetic induction source such as an induction coil and a susceptor heated by electromagnetic induction as the load, and may vaporize or atomize the aerosol source by induction heating.

[0168] The series of processes performed by each device described herein may be implemented using software, hardware, or a combination of software and hardware. The software programs may be stored in advance, for example, on a recording medium (more specifically, a non-transitory computer-readable storage medium) internal or external to each device. Each program is then loaded into a random access memory (RAM) and executed by a processing circuit such as a central processing unit (CPU). The recording medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. The computer program may also be distributed, for example, via a network, without using a recording medium. The computer may be an application-specific integrated circuit (ASIC), a general-purpose processor that executes functions by loading a software program, or a computer on a server used in cloud computing. The series of processes performed by each device described herein may be centrally processed by a single computer or distributed across multiple computers. Furthermore, in each of the above embodiments, two or more communication means present in a single device may be physically implemented on a single medium.

[0169] The following configurations also fall within the technical scope of the present disclosure. (1) An aerosol generation device comprising a capacitance sensor that measures a change in capacitance caused by the aerosol generated from an aerosol product passing through a flow path through which the aerosol passes, the capacitance sensor having a resonant circuit whose resonant frequency changes in response to a change in capacitance of the flow path, and measuring the change in capacitance based on the resonant frequency of the resonant circuit. (2) The aerosol generation device described in (1), wherein the capacitance sensor has: a drive circuit that outputs a voltage waveform including a resonant frequency at which resonance occurs in the resonant circuit; a clock circuit that repeatedly outputs a rectangular waveform over a predetermined time width; and a frequency measurement unit that measures the resonant frequency based on the number of rectangular waveforms output from the clock circuit within the time width of the response waveform of the resonant circuit. (3) The aerosol generation device described in (1) or (2), wherein the resonant circuit has a pair of electrodes, an electric field formed by the pair of electrodes overlaps the flow path, and the capacitance sensor measures the change in capacitance of the pair of electrodes. (4) The aerosol generating device according to (3), wherein the resonant circuit is a parallel resonant circuit in which an inductor, a capacitor, and the pair of electrodes are connected in parallel. (5) The resonant circuit is configured to satisfy the following relationship, where C is the capacitance of the pair of electrodes when the aerosol passes through the flow path, and R is the resistance of the pair of electrodes when the aerosol passes through the flow path, and C ０ is the capacitance of the capacitor, and f is the resonant frequency of the resonant circuit. The aerosol generating device according to (4), (6) The aerosol generation device according to any one of (3) to (5), wherein the resonant circuit has an adjusting resistor connected in parallel to the pair of electrodes. (7) The aerosol generation device according to any one of (3) to (6), wherein the aerosol generation device includes a load that generates energy for vaporizing or atomizing the aerosol source contained in the aerosol product, and the pair of electrodes are arranged downstream of the load in the direction of aerosol flow. (8) The aerosol generation device according to any one of (3) to (7), wherein the aerosol generation device further includes a storage unit that stores the aerosol product, the flow path is formed inside the storage unit, and the pair of electrodes are arranged near an inner wall surface of the storage unit. (9) The aerosol generation device according to (8), wherein the aerosol product comprises: an aerosol source segment containing the aerosol source; and a cooling segment arranged downstream of the aerosol source segment and configured to generate an aerosol by cooling a substance vaporized or atomized from the aerosol source segment, and wherein the pair of electrodes are arranged at a position overlapping the cooling segment in the direction of aerosol flow when the aerosol product is accommodated in the accommodation section. (10) The aerosol generation device according to any one of (3) to (9), wherein each of the pair of electrodes is arranged spaced apart in the direction of aerosol flow. (11) The aerosol generation device according to any one of (3) to (9), wherein each of the pair of electrodes is arranged spaced apart across the flow path. (12) The aerosol generation device according to any one of (3) to (11), wherein the pair of electrodes is arranged in the aerosol generation device. (13) The aerosol generating device according to any one of (3) to (11), wherein the pair of electrodes is disposed on the aerosol product.(14) An aerosol product comprising: an aerosol source segment containing an aerosol source, a cooling segment arranged downstream from the aerosol source segment and configured to generate an aerosol by cooling a substance vaporized or atomized from the aerosol source segment, and a pair of electrodes, wherein at least a portion of each of the pair of electrodes is exposed from a surface of the aerosol product. (15) The aerosol product according to (14), wherein the pair of electrodes is arranged at a position overlapping the cooling segment in the flow direction of the aerosol.

[0170] DESCRIPTION OF SYMBOLS 100 Suction device 110 Power supply unit 111 Power supply section 112 Sensor section 113 Notification section 114 Memory section 115 Communication section 116 Control section 121 Heating section 140 Storage section 141 Internal space 142 Opening 143 Bottom section 144 Heat insulation section 145 Side wall section 150 Stick-shaped substrate 151 Substrate section 151A Aerosol source segment 151B Cooling segment 152 Suction mouth section 10 Capacitive sensor 20 Resonant circuit 21 Electrode 22 Substrate circuit 23 Drive circuit 231 Power supply 232 Voltage monitoring section 233 Inverter circuit 24 Resonant section 30 Sensor control section 31 Clock circuit 32 Frequency measurement section 33 Control circuit

Claims

1. An aerosol generating device comprising a capacitance sensor that measures a change in capacitance caused by an aerosol generated from an aerosol product passing through a flow path through which the aerosol passes, the capacitance sensor having a resonant circuit whose resonant frequency changes in accordance with the change in capacitance of the flow path, and measuring the change in capacitance based on the resonant frequency of the resonant circuit.

2. The aerosol generating device of claim 1, wherein the capacitance sensor comprises: a drive circuit that outputs a voltage waveform including a resonant frequency at which resonance occurs in the resonant circuit; a clock circuit that outputs a rectangular waveform repeatedly at a predetermined time width; and a frequency measuring unit that measures the resonant frequency based on the number of rectangular waveforms output from the clock circuit within the time width of the response waveform of the resonant circuit.

3. The aerosol generating device according to claim 1 or 2, wherein the resonant circuit has a pair of electrodes, an electric field formed by the pair of electrodes overlaps with the flow path, and the capacitance sensor measures a change in capacitance of the pair of electrodes.

4. The aerosol generating device according to claim 3, wherein the resonant circuit is a parallel resonant circuit in which an inductor, a capacitor, and the pair of electrodes are connected in parallel.

5. The resonant circuit is configured to satisfy the following relationship: C is the capacitance of the pair of electrodes when the aerosol passes through the flow path; R is the resistance of the pair of electrodes when the aerosol passes through the flow path; and C ０ The aerosol generating device according to claim 4 , wherein: π is the capacitance of the capacitor; and f is the resonant frequency of the resonant circuit.

6. The aerosol generating device according to any one of claims 3 to 5, wherein the resonant circuit has an adjusting resistor connected in parallel to the pair of electrodes.

7. The aerosol generating device according to any one of claims 3 to 6, further comprising a load that generates energy for vaporizing or atomizing the aerosol source contained in the aerosol product, and the pair of electrodes are disposed downstream of the load in the direction of aerosol flow.

8. The aerosol generating device according to any one of claims 3 to 7, further comprising a storage section for storing the aerosol product, the flow path being formed inside the storage section, and the pair of electrodes being arranged near the inner wall surface of the storage section.

9. The aerosol generating device according to claim 8, wherein the aerosol product comprises: an aerosol source segment containing the aerosol source; and a cooling segment arranged downstream of the aerosol source segment for cooling a substance vaporized or atomized from the aerosol source segment to generate an aerosol; and wherein the pair of electrodes are arranged at a position overlapping the cooling segment in the direction of aerosol flow when the aerosol product is accommodated in the accommodation section.

10. An aerosol generating device according to any one of claims 3 to 9, wherein each of the pair of electrodes is arranged spaced apart in the direction of aerosol flow.

11. The aerosol generating device according to any one of claims 3 to 9, wherein each of the pair of electrodes is disposed at a distance from each other across the flow path.

12. The aerosol generating device according to any one of claims 3 to 11, wherein the pair of electrodes is disposed in the aerosol generating device.

13. The aerosol generating device according to any one of claims 3 to 11, wherein the pair of electrodes is disposed on the aerosol producing article.

14. An aerosol product comprising: an aerosol source segment containing an aerosol source; a cooling segment arranged downstream from the aerosol source segment and configured to cool a substance vaporized or atomized from the aerosol source segment to generate an aerosol; and a pair of electrodes, wherein at least a portion of each of the pair of electrodes is exposed from a surface of the aerosol product.

15. The aerosol product according to claim 14, wherein the pair of electrodes are positioned so as to overlap the cooling segment in the aerosol flow direction.

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