TWI772332B - Aerosol generating device - Google Patents

Abstract

A aerosol generating device includes a power source, a load having a resistance value varied with the temperature and atomizing an aerosol source or heating a fragrance source by the power supplied from the power source, a sensor having a resistor serially connected with the load and outputting a measured value that is a current value flowing through the resistor or a voltage value applied to the resistor, and a controller controlling the power supplied from the power supply to the load and receiving the output of the sensor, wherein the resistor has a resistance value such that the responsiveness of the change of the measured value to the change of the resistance value due to temperature falls within a predetermined range.

Description

mist generating device

The present invention relates to a mist generating device.

For example, so-called electronic cigarettes or nebulizers (inhalers), there is known a mist generating device (electronic vaporizer) for users to inhale, which is equipped with a heater, an actuator, and a A load operated by power supply from a power source atomizes a liquid or solid as a source of aerosol (aerosol).

For example, a system for generating inhalable vapor in an electronic vaporizer has been proposed (for example, Patent Document 1). This technology determines whether vaporization occurs by monitoring the power supplied to a coil equivalent to a heater that vaporizes the mist source. The reduction in the electrical power necessary to maintain the coil at the adjusted temperature means that there is not enough liquid in the fluid core for normal gasification.

In addition, there has been proposed a mist generating device which detects the presence or absence of the presence or absence of a mist by comparing the power or energy supplied to the heating element required to maintain the temperature of the heating element at a target temperature with a threshold value. A mist-forming substrate adjacent to a heating element configured to heat a mist-forming substrate containing a mist source or equivalent to a mist source therein (eg, Patent Document 2).

[Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Publication No. 2017-501805

Patent Document 2: Japanese Patent Publication No. 2015-507476

Patent Document 3: Japanese Patent Publication No. 2005-525131

Patent Document 4: Japanese Patent Publication No. 2011-515093

Patent Document 5: Japanese Patent Publication No. 2013-509160

Patent Document 6: Japanese Patent Publication No. 2015-531600

Patent Document 7: Japanese Patent Publication No. 2014-501105

Patent Document 8: Japanese Patent Publication No. 2014-501106

Patent Document 9: Japanese Patent Publication No. 2014-501107

Patent Document 10: WO 2017/021550

Patent Document 11: Japanese Patent Application Laid-Open No. 2000-041654

Patent Document 12: Japanese Patent Laid-Open No. 3-232481

Patent Document 13: WO 2012/027350

Patent Document 14: WO 1996/039879

Patent Document 15: WO 2017/021550

When a general mist generating device generates mist, the power supply of the power source to the heater is controlled so that the temperature of the heater is near the boiling point of the mist source. In the case where the residual amount of the mist source is still sufficient and the amount of mist generation is being controlled, the power system supplied from the power source to the heater exhibits a constant value or exhibits a continuous change. In other words, under the condition that the residual amount of the mist source is still sufficient and the feedback control to maintain the heater temperature at the target temperature or the target temperature range is performed, the power supplied from the power source to the heater is constant or continuous. Variety.

The residual amount of the mist source is an important variable for various controls of the mist generating device. For example, if the residual amount of the mist source is not detected or cannot be accurately detected, if the mist source is exhausted and the heater continues to be supplied from the power supply, the stored power of the power source may be wasted.

Therefore, the mist generator proposed in Patent Document 2 determines whether or not there is a sufficient amount of mist source based on the electric power required to maintain the temperature of the heater. However, the measurement of electric power usually uses a plurality of sensors, and it is difficult to accurately estimate the electric power from the measured electric power unless the error of these sensors is correctly corrected or the control that takes the error into consideration is not constructed. The residual amount of the mist source may be presumed that the mist source has been exhausted.

Other methods of detecting the residual amount of the mist source include a method using the temperature of a heater and a method using the resistance value of the heater disclosed in Patent Documents 3 and 4. These methods are known to use different values to represent the situation in which the residual amount of the mist source is sufficient and the situation in which the mist source is depleted. However, no matter which method is used, a dedicated sensor or a plurality of sensors must be used, so it is also difficult to correctly estimate the residual amount of the mist source or the exhaustion of the mist source.

Furthermore, if the sensor does not have an appropriate resolution, it is difficult, for example, to correctly detect the reduction in the residual amount. Furthermore, there is also a problem that mist is generated when the sensor measures the residual amount of the mist source.

Therefore, an object of the present invention is to reduce the generation of mist during measurement in a mist generating device, or to improve the accuracy of estimation of the residual amount of mist source by the mist generating device.

The mist generating device of the present invention comprises: a power source; a load, whose resistance value varies with temperature, and is used to atomize the mist source or heat the fragrance source by using the power supply from the power source to generate mist; a sensor is provided with a resistor connected in series with the load, and outputs a measured value belonging to the value of the current flowing through the resistor or the value of the voltage applied to the resistor; and the control unit controls the power supply from the power source to the load, and receives sensing wherein the resistor has a resistance value within a predetermined range so that the responsiveness of the change in the measured value to the change in the temperature of the resistance value is within a predetermined range.

The resistor has a resistance value such that the responsiveness of the change in the measured value to the change in the temperature of the resistance value falls within a predetermined range. For example, when the responsiveness is high, the detection performance by the sensor is improved, but there is a concern of fogging during the measurement. Conversely, when the responsiveness is low, the generation of fog in the measurement can be reduced, but the detection performance by the sensor is also reduced. According to the configuration of the above-mentioned aspect, it is possible to set a balanced resistance value.

Furthermore, the resistor may also have a resistance value that satisfies at least one of the following first conditions and second conditions, and the first condition is that during the power supply period from the power supply to the resistor, the amount of mist generated by the load is The second condition is that the control unit can detect a change in the residual amount of the mist source or the fragrance source based on the measured value. According to the first condition as described above, the generation of mist in the measurement can be reduced, and according to the second condition, the accuracy of estimation of the residual amount of the mist source by the mist generating device can be improved.

Furthermore, the resistance value may be a value satisfying the first condition. That is, a suction port disposed at the end of the mist generating device and used for releasing mist may also be included, and the threshold value is a value at which mist will not be released from the suction port during the power supply period. In other words, the threshold value may also be a value at which the heat generation in the load is the heat of vaporization that cannot be used for the mist source or the aforementioned fragrance source. In addition, the resistance value may be a value that does not generate fog due to the heat generation of the load.

Furthermore, the resistance value may be a value satisfying the second condition. That is, the value of the resistance value may be such that the control unit can distinguish the difference between the measured value at the start of energization to the load and the measured value when the residual amount of the mist source or the fragrance source is less than or equal to a predetermined amount. In other words, the value of the resistance value may be such that the absolute value of the difference between the measured value at the start of energization to the load and the measured value when the residual amount of the mist source or the fragrance source is equal to or less than a predetermined amount is larger than the resolution of the control unit value. In addition, the value of the resistance value may be such that the control unit can distinguish the difference between the measured value when the mist is generated and the measured value when the residual amount of the mist source or the fragrance source is less than or equal to a predetermined amount. Furthermore, the value of the resistance value may be a value that makes the absolute value of the difference between the measured value when the mist is generated and the measured value when the residual amount of the mist source or the fragrance source is less than or equal to a predetermined amount larger than the resolution of the control unit. . In addition, the value of the resistance value may be such that the difference between the measured value at the start of energization to the load and the measured value at the time of fog generation is such that the control can be distinguished. Furthermore, the value of the resistance value may be a value larger than the resolution of the control unit by the absolute value of the difference between the measured value at the start of energization to the load and the measured value at the time of fog generation.

In addition, the resistance value is a value satisfying the first condition and the second condition. According to the above-described method, the generation of mist during measurement can be reduced, and the accuracy of the residual amount of mist source estimated by the mist generating device can be improved. That is, the two contradictory problems can be solved at the same time.

Furthermore, the resistance value may be a value relatively close to the maximum value satisfying the second condition among the minimum value satisfying the first condition and the maximum value satisfying the second condition. According to the above-mentioned method, the generation of fog can be reduced during the measurement, and the resolution of the residual amount detection can be improved as much as possible. That is, the conflicting problems of the two can be solved at the same time, and the resolution can be further improved as much as possible, so the accuracy of the residual amount of the mist source estimated by the mist generating device can be improved to the maximum.

Furthermore, the mist generating device may also include a power supply circuit electrically connected to the power source and the load, the power supply circuit is provided with a first power supply circuit and a second power supply circuit, and the first power supply circuit is not connected to the sensor through a sensor. The load is powered, and the second power supply circuit supplies power to the load via the sensor. Specifically, the configuration as described above can be adopted.

Furthermore, the power supply circuit may also include: a first node (node), which is connected to the power supply and branched into a first power supply circuit and a second power supply circuit; and a second node, which is downstream of the first node for the first power supply. The circuit is combined with the second power supply circuit; and a linear regulator is provided between the first node and the sensor in the second power supply circuit. According to the above method, the conversion loss caused by the linear voltage regulator can be eliminated in the first supply circuit, and the accuracy of residual quantity detection can be improved in the second supply circuit.

Furthermore, in another form, the mist generating device includes: a power source; a load, whose resistance value changes with temperature, and is used to atomize the mist source or heat the aroma source by using the power supply from the power source to generate A fogger; a sensor that includes a resistor connected in series with the load, and outputs a measured value belonging to the value of the current flowing through the resistor or the value of the voltage applied to the resistor; and a control unit that controls the flow of the load from the power source to the load. supplying power, and receiving the output of the sensor; wherein the resistor has a resistance value that satisfies at least one of a first condition and a second condition below, the first condition being in the power supply period from the power supply to the resistor , the amount of mist generated by the load is below a threshold value, and the second condition is that the control unit can detect a change in the residual amount of the mist source or the fragrance source based on the measured value.

According to the above-mentioned first condition, the generation of mist in the measurement can be reduced, and according to the second condition, the accuracy of estimation of the residual amount of the mist source by the mist generating device can be improved.

Furthermore, another form of the mist generating device includes: a power source; a load, whose resistance value changes with temperature, and is used to atomize the mist source or heat the fragrance source by using the power supply from the power source to generate A mister; a sensor, which is provided with a resistor connected in series with a load, and outputs a measured value belonging to the value of the current flowing through the resistor or the value of the voltage applied to the resistor; one or a plurality of adjustment resistors are used for to adjust the magnitude of the current supplied to the load; and the control unit controls the power supply from the power supply to the load and receives the output of the sensor; wherein, the resistance values of the resistor and the adjusting resistor are set so that the power is supplied from the power supply During the power supply period to the load, the first condition is that the amount of mist generated by the load becomes a value below a predetermined threshold value, and the resistor has a responsiveness that allows the change of the measured value to the change of the temperature of the resistance value to fall within a predetermined range. resistance.

According to the above, by using the resistance value of the adjustment resistor different from the resistance value of the sensor, the generation of mist during the measurement can be reduced or the residual amount of the mist source estimated by the mist generating device can be increased. accuracy.

Furthermore, the resistance value of the resistor may also be greater than the resistance value of the load. For example, it is possible to reduce the generation of fog in the measurement.

The contents described in this [Means for Solving the Problems] can be combined in various possible ways within the scope of not departing from the subject or technical idea of the present invention. Furthermore, the content of this [Means for Solving the Problems] can be provided in the form of a device including a computer, a processor, an electrical circuit, etc., or a system including a plurality of devices, a method executed by the device, or a program executed by the device. It is also possible to make the program executable over the network. In addition, a recording medium holding the program can also be provided.

According to the present invention, in the mist generating device, the generation of mist during measurement can be reduced, or the accuracy of estimation of the residual amount of the mist source by the mist generating device can be improved.

1‧‧‧Mist generating device

2‧‧‧Main body

3‧‧‧Mist source holding part

4‧‧‧Adding ingredient holding part

21‧‧‧Power

22‧‧‧Control Department

23‧‧‧Taste Sensor

31‧‧‧Storage

32‧‧‧Supply Department

33‧‧‧Load

34‧‧‧Residual sensor

41‧‧‧ Fragrance ingredients

51‧‧‧First Node

52‧‧‧Second Node

211‧‧‧Voltage conversion section

212‧‧‧Power supply circuit

341‧‧‧Shunt Resistor

342‧‧‧Voltmeter

C1, C2‧‧‧Capacitor

Q1, Q2, Q3‧‧‧Switch

R1, R2‧‧‧resistors

Comp‧‧‧Comparators

Fig. 1 is a perspective view showing an example of the appearance of the mist generator.

Fig. 2 is an exploded view showing an example of a mist generating device.

FIG. 3 is a schematic diagram showing an example of the internal structure of the mist generator.

FIG. 4 is a circuit diagram showing an example of the circuit configuration of the mist generating device.

FIG. 5 is a block diagram for explaining the process of estimating the amount of the mist source stored in the storage unit.

FIG. 6 is a processing flowchart showing an example of the remaining amount estimation processing.

FIG. 7 is a timing chart showing an example of the state in which the user uses the mist generating device.

FIG. 8 is a diagram for explaining an example of a method of determining the length of the determination period.

Fig. 9 is a diagram showing another example of the change in the value of the current flowing through the load.

FIG. 10 is a processing flow chart showing an example of processing for setting the determination period.

FIG. 11 is a schematic diagram showing the energy consumed in the storage part, the supply part and the load.

Fig. 12 is a schematic line graph showing the relationship between the energy consumed at the load and the amount of mist generated.

Fig. 13 is a graph showing the relationship between the residual amount of the mist source and the resistance value of the load.

FIG. 14 is a diagram showing a modified example of the circuit included in the mist generator.

Fig. 15 is a diagram showing another modification of the circuit included in the mist generating device.

Hereinafter, embodiments of the mist generator of the present invention will be described based on the drawings. The dimensions, materials, shapes, relative arrangements, and the like of the constituent elements described in the present embodiment are merely examples. In addition, the order of processing is only an example, and various possible substitutions or parallel executions can be made within the scope of not departing from the subject or technical idea of the present invention. Therefore, the technical scope of the invention is not limited only to the following examples unless otherwise specified.

<Embodiment>

Fig. 1 is a perspective view showing an example of the appearance of the mist generator. Fig. 2 is an exploded view showing an example of a mist generating device. The mist generating device 1 is an electronic cigarette or a nebulizer, etc., which generates mist according to the user's inhalation action, and provides the mist to the user. Hereinafter, one continuous puff performed by the user is referred to as "puff". In the present embodiment, the mist generating device 1 adds components such as fragrance to the generated mist and releases it into the oral cavity of the user.

As shown in FIGS. 1 and 2 , the mist generator 1 includes a main body 2 , a mist source holding portion 3 , and an additive component holding portion 4 . The main body 2 supplies power and controls the entire operation of the device. The mist source holding portion 3 holds the mist source to be atomized to generate mist. The additive component holding unit 4 holds components such as fragrance and nicotine. The user can hold the end part on the side of the additive component holding part 4 belonging to the suction port, and inhale the mist to which the fragrance and the like are added.

The mist generator 1 is formed by combining the main body 2 , the mist source holding part 3 , and the additive component holding part 4 by a user or the like. In this embodiment, the shapes of the main body 2, the mist source holding part 3 and the additive component holding part 4 are respectively a cylindrical shape with a predetermined diameter, a frustoconical shape, etc. The order of the component holding parts 4 is such that they are combined. The main body 2 and the mist source holding part 3 are combined by, for example, the screwing of the male thread part and the female thread part provided at the respective ends. The mist source holding portion 3 and the additive component holding portion 4 are coupled by, for example, fitting the additive component holding portion 4 having a tapered side surface into a cylindrical portion provided at one end of the mist source holding portion 3 . The mist source holding part 3 and the additive component holding part 4 can be used as replacement parts that can be thrown away.

<Internal composition>

FIG. 3 is a schematic view showing an example of the inside of the mist generator 1 . The main body 2 includes a power source 21 , a control unit 22 , and a taste sensor 23 . The control unit 22 is electrically connected to the power source 21 and the inhalation sensor 23 respectively. The power source 21 is a secondary battery or the like, and supplies electric power to an electrical circuit included in the mist generating device 1 . The control unit 22 is a processor such as a microcontroller (MCU: Micro-Control Unit), and controls the operation of an electrical circuit included in the mist generating device 1 . The inhalation sensor 23 is an air pressure sensor, a flow sensor or the like. When the user inhales from the suction port of the mist generating device 1 , the inhalation sensor 23 outputs a value corresponding to the negative pressure or the flow rate of the gas generated inside the mist generating device 1 . That is, the control unit 22 can detect the action of the user's sucking according to the output value of the sucking sensor 23.

The mist source holding unit 3 of the mist generator 1 includes a storage unit 31 , a supply unit 32 , a load 33 , and a residual amount sensor 34 . The storage part 31 is a container which stores the liquid mist source which is atomized by heating. The mist source is a polyol-based material such as glycerin and propylene glycol. The mist source can also be a mixed solution (also referred to as a "scent source") that also contains nicotine liquid, water, fragrance, and the like. Such a mist source is previously stored in the storage unit 31 . In addition, the mist source may also be a solid that does not require the storage portion 31 .

The supply portion 32 includes a wick formed by kneading a fiber material such as glass fiber. The supply unit 32 is connected to the storage unit 31 . Further, the supply unit 32 is connected to the load 33 , or at least a part of the supply unit 32 is arranged in the vicinity of the load 33 . The mist source will infiltrate the wick due to capillary phenomenon and move to the part where the mist source can be atomized due to the heating of the load 33 . In other words, the supply part 32 sucks the mist source from the storage part 31 and sends it to the load 33 or the vicinity of the load 33 . Porous ceramics can also be used as absorbent cores instead of glass fibers.

The load 33 is, for example, a coil-shaped heater, and generates heat by supplying an electric current. For example, the load 33 has a positive temperature coefficient (PTC: Positive Temperature Coefficient) characteristic, and its resistance value is approximately proportional to the heating temperature. The load 33 does not necessarily have to have a positive temperature coefficient characteristic, as long as its resistance value is related to the heating temperature. For example, the load 33 may also have a negative temperature coefficient (NTC: Negative Temperature Coefficient) characteristic. In addition, the load 33 may be wound on the outside of the absorbent core, or the absorbent core may be covered around the load 33 on the contrary. The power supply to the load 33 is controlled by the control unit 22 . The mist source is supplied from the storage portion 31 to the load 33 by the supply portion 32, and the heat of the load 33 evaporates the mist source to generate mist. When the control unit 22 detects that the user has performed a sucking action based on the output value of the sucking sensor 23 , the control unit 22 supplies power to the load 33 to generate mist. When the residual amount of the mist source stored in the storage part 31 is sufficient, the sufficient mist source is supplied to the load 33, and the heat generated by the load 33 will be transferred to the mist source. In other words, the heat generated by the load 33 will be used for the mist source. Therefore, the temperature of the load 33 hardly exceeds the pre-designed predetermined temperature. On the other hand, when the mist source stored in the storage unit 31 is depleted, the amount of mist source supplied to the load 33 per unit time decreases. As a result, the heat generated by the load 33 cannot be transferred to the mist source. In other words, the heat generated by the load 33 is not used to heat up and vaporize the mist source, so the load 33 is overheated, and the resistance value of the load 33 increases accordingly.

The residual amount sensor 34 outputs sensing data required to push the residual amount of the mist source stored in the side storage unit 31 according to the temperature of the load 33 . For example, the residual amount sensor 34 includes: a resistor for current measurement (shunt resistance) connected in series with the load 33; and a measuring device connected in parallel with the resistor to measure the voltage value of the resistor . The resistance value of the resistor is a predetermined constant value that hardly changes with temperature. Therefore, according to the known resistance value and the measured voltage value, the current value flowing to the resistor can be obtained.

Instead of the above-mentioned measuring device using shunt resistance, a measuring device using a Hall element can also be used. The Hall element is placed in series with the load 33 . That is, a gap core provided with a Hall element is arranged around the lead wire connected in series with the load 33 . The Hall element detects the magnetic field generated by the current running through itself. In the case of using the Hall element, the so-called "current flowing through itself" refers to the current flowing through the wire that is arranged in the center of the gap core and is not connected to the Hall element, and its current value is the same as the current flowing through the load 33 . same. In this embodiment, the residual sensor 34 outputs the current value flowing through the resistor. Alternatively, instead of using the voltage value applied across the resistor, the current value, or the original value of the voltage value, a value obtained by applying a predetermined calculation to it may be used. These measured values, which can be used in place of the value of the current flowing through the resistor, are values whose value varies with the value of the current flowing through the resistor. That is, the residual amount sensor 34 only needs to be capable of outputting a measurement value corresponding to the value of the current flowing through the resistor. Of course, the technical means of using these measured values in place of the value of the current flowing to the resistor is also included in the technical idea of the present invention.

The additive component holding part 4 of the mist generator 1 holds the flavor components 41 such as shredded tobacco leaves and menthol in the inside thereof. In addition, the additive component holding part 4 is provided with a ventilation hole in the part where it is combined with the suction port side and the mist source holding part 3. When the user inhales from the suction port, a negative pressure is generated inside the additive component holding part 4, and the mist is sucked in. In the mist generated in the source holding part 3 , ingredients such as nicotine and fragrance are added to the mist inside the additive component holding part 4 , and then released into the user's oral cavity.

The internal configuration shown in FIG. 3 is an example. The mist source holding part 3 may be provided along the side surface of the cylinder and may be an annular shape having a hollow in the center of the circular cross section. In this case, the supply part 32 and the load 33 can be arranged in the central cavity. In order to output the state of the device to the user, an output unit such as an LED (Light Emitting Diode) or a vibrator may be further provided.

<Circuit configuration>

FIG. 4 is a circuit diagram showing an example of a portion related to detection of the residual amount of the mist source and control of power supply to a load, among the circuit configurations in the mist generating device. The mist generator 1 includes a power source 21 , a control unit 22 , a voltage conversion unit 211 , switches (switching elements) Q1 and Q2 , a load 33 , and a residual sensor 34 . Hereinafter, the part including the switches Q1 and Q2 and the voltage conversion part 211 connected between the power source 21 and the load 33 is also referred to as a "power supply circuit" in the present invention. For example, the power supply 21 and the control unit 22 are provided in the main body 2 in Figs. 1 to 3, and the voltage conversion portion 211, the switches Q1 and Q2, the load 33 and the residual sensor 34 are provided in the mist in Figs. 1 to 3 Source holding unit 3 . By combining the main body 2 and the mist source holding part 3, the internal constituent elements are electrically connected to form a circuit as shown in FIG. 4 . For example, the voltage conversion part 211 , the switches Q1 and Q2 , and at least a part of the residual sensor 34 can also be provided in the main body 2 . When the mist source holding part 3 and the additive component holding part 4 are configured as disposable replacement parts, the cost of replacement parts can be reduced as the number of components included in both of them is reduced.

The power source 21 is directly or indirectly electrically connected to each constituent element, and supplies electric power to the circuit. The control unit 22 is connected to the switches Q1 and Q2 and the residual sensor 34 . Furthermore, the control unit 22 obtains the output value of the remaining amount sensor 34, calculates the estimated value of the mist source remaining in the storage unit 31, and controls the switch Q1 based on the calculated estimated value and the output value of the inhalation sensor 23, etc. and the switch of Q2.

The switches Q1 and Q2 are semiconductor switches such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor). One end of the switch Q1 is connected to the power source 21 , and the other end is connected to the load 33 . By turning on the switch Q1, power can be supplied to the load 33 to generate mist. For example, when the control unit 22 detects that the user has performed a sucking action, the switch Q1 is turned on. Hereinafter, the path passing through the switch Q1 and the load 33 is also referred to as a "mist generation path" and a "first supply circuit".

One end of the switch Q2 is connected to the power source 21 via the voltage conversion unit 211 , and the other end is connected to the load 33 via the residual amount sensor 34 . By turning on the switch Q2, the output value of the residual sensor 34 can be obtained. Hereinafter, the path for outputting a predetermined measured value from the residual amount sensor 34 through the switch Q2, the residual amount sensor 34 and the load 33 is also referred to as the "residual amount detection path" and the "second supply circuit" in the present invention. When the residual amount sensor 34 adopts a Hall element, the residual amount sensor 34 need not be connected to the switch Q2 and the load 33 , and only needs to be configured to output a predetermined measured value between the switch Q2 and the load 33 . In other words, it is only necessary to configure the wire connecting the switch Q2 and the load 33 to pass through the Hall element.

As described above, the circuit shown in FIG. 4 includes: the first node 51 branched from the power source 21 into the mist generation path and the residual amount detection path; and the mist generation path and the residual amount detection path are combined and connected to the load The second node 52 of 33.

The voltage conversion part 211 can convert the voltage output by the power source 21 and output it to the load 33 . Specifically, it is a voltage regulator such as an LDO (Low Drop-Out, low dropout) voltage regulator as shown in FIG. 4, which outputs a certain voltage. One end of the voltage conversion unit 211 is connected to the power source 21, and the other end is connected to the switch Q2. The voltage conversion unit 211 includes a switch Q3, resistors R1 and R2, capacitors C1 and C2, a comparator Comp, and a constant voltage source that outputs the reference voltage V _REF . In the case of using the LDO voltage regulator as shown in Fig. 4, the output voltage V _out can be obtained by the following equation (1).

V _out =R ₂ /(R ₁ +R ₂ )×V _REF . . . (1)

The switch Q3 is a semiconductor switch or the like, and is opened and closed in accordance with the output of the comparator Comp. One end of the switch Q3 is connected to the power supply 21 so that the output voltage is changed according to the duty ratio of the switch Q3 on and off. The output voltage of switch Q3 is divided by resistors R1 and R2 connected in series and then applied to one input terminal of the comparator Comp. The reference voltage V _REF is applied to the other input terminal of the comparator Comp. Then, a signal indicating the comparison result of the reference voltage V _REF and the output voltage of the switch Q3 is output. In this way, even if the voltage value applied to the switch Q3 varies, as long as it is above the predetermined value, the feedback from the comparator Comp will be received, so that the output voltage of the switch Q3 can be kept constant. Hereinafter, the comparator Comp and the switch Q3 are also referred to as a "voltage conversion unit" in the present invention.

One end of the capacitor C1 is connected to the end on the power supply 21 side in the voltage converter 211 , and the other end is grounded. Capacitor C1 stores power and protects the circuit from surge voltages. One end of the capacitor C2 is connected to the output terminal of the switch Q3 to smooth the output voltage.

In the case of using a power source such as a secondary battery, the power source voltage decreases as the charging rate decreases. According to the voltage conversion part 211 of this embodiment, a constant voltage can be supplied even when the power supply voltage fluctuates to some extent.

The residual sensor 34 includes a shunt resistor 341 and a voltmeter 342 . One end of the shunt resistor 341 is connected to the voltage conversion unit 211 via the switch Q2. The other end of the shunt resistor 341 is connected to the load 33 . That is, the shunt resistance 341 is connected in series with the load 33 . The voltmeter 342 is connected in parallel with the shunt resistor 341 , and can measure the voltage drop in the shunt resistor 341 . The voltmeter 342 is also connected to the control unit 22 , and outputs the measured voltage drop amount at the shunt resistor 341 to the control unit 22 .

<Remaining Amount Estimation Processing>

FIG. 5 is a block diagram for explaining the process of estimating the amount of the mist source stored in the storage unit 31 . Here, it is assumed that the voltage V _out output by the voltage conversion unit 211 is constant. Also, the resistance value R _shunt of the shunt resistor 341 is a known constant. Therefore, using the voltage V _shunt across the shunt resistor 341 , the following equation (2) can be used to obtain the current value I _shunt flowing to the shunt resistor 341 .

I _shunt =V _shunt /R _shunt . . . (2)

The current value I _HTR flowing to the load 33 connected in series with the shunt resistor 341 is the same as I _shunt . The shunt resistor 341 is connected in series with the load 33, and the value corresponding to the value of the current flowing through the load is measured.

Here, using the resistance value R _HTR of the load 33 , the output voltage V _out of the voltage converter 211 can be expressed by the following equation (3).

V _out =I _shunt ×(R _shunt +R _HTR ). . . (3)

By modifying the formula (3), the resistance value R _HTR of the load 33 can be expressed by the following formula (4).

R _HTR =V _out /I _shunt -R _shunt . . . (4)

The load 33 has the aforementioned positive temperature coefficient (PTC) characteristic. As shown in FIG. 5 , the resistance value R _HTR of the load 33 is approximately proportional to the temperature T _HTR of the load 33 . Therefore, the temperature T _HTR of the load 33 can be calculated from the resistance value R _HTR of the load 33 . In the present embodiment, information indicating the relationship between the resistance value R _HTR of the load 33 and the temperature T _HTR is stored in advance, for example, in a table. Therefore, the temperature T _HTR of the load 33 can be estimated without using a dedicated temperature sensor. The same is true for the case where the load 33 has a negative temperature coefficient characteristic (NTC), and the temperature T _HTR of the load 33 can be estimated from the information representing the relationship between the resistance value R _HTR and the temperature T _HTR .

In the present embodiment, when the load 33 evaporates the surrounding mist source, when a sufficient amount of mist source is stored in the storage part 31 , the mist source is continuously supplied to the load 33 via the supply part 32 . Therefore, as long as the residual amount of the mist source in the storage unit 31 is greater than or equal to the predetermined amount, the temperature of the load 33 generally does not rise significantly beyond the boiling point of the mist source. However, when the residual amount of the mist source in the storage part 31 decreases, the amount of the mist source supplied to the load 33 via the supply part 32 also decreases, and the temperature of the load 33 exceeds the boiling point of the mist source and rises. The information showing the relationship between the residual amount of the mist source and the temperature of the load 33 is previously known through experiments or the like. Based on this information and the calculated temperature T _HTR of the load 33 , the residual quantity Quantity of the mist source held in the storage unit 31 can be estimated. In addition, the remaining amount obtained may be a ratio of the remaining amount with respect to the capacity of the storage unit 31 .

Since there is a correlation between the residual amount of the mist source and the temperature of the load 33, a threshold value of the temperature of the load 33 corresponding to the threshold value of the predetermined residual amount can be used. When the temperature of the load 33 exceeds the temperature threshold, the It is judged that the mist source of the storage part 31 is exhausted. In addition, since there is a correspondence relationship between the resistance value of the load 33 and the temperature, when the resistance value of the load 33 exceeds the threshold value of the resistance value corresponding to the above-mentioned temperature threshold value, it can be determined that the storage unit 31 has The source of fog has been exhausted. In addition, the variable of the above-mentioned formula (4) is only the current value I _shunt flowing through the shunt resistance 341 , so the threshold value of the current value corresponding to the above-mentioned threshold value of the resistance value is also unique. Here, the so-called current value I _shunt flowing through the shunt resistor 341 is the same as the current value I _HTR flowing through the load 33 . Therefore, when the current value I _HTR flowing through the load 33 is expressed as a value smaller than a predetermined current value threshold, it can be determined that the mist source of the storage unit 31 is exhausted. That is, for the measured value such as the current value flowing to the load 33, a target value or a target range can be set, for example, in a state where the residual amount of the mist source is sufficient, and then, according to whether the measured value falls within a predetermined value including the target value or the target range. within the range to judge whether the residual amount of the mist source is sufficient. The predetermined range can be determined by, for example, the above-mentioned threshold.

As described above, according to the present embodiment, the resistance value R _shunt of the load 33 can be calculated using one measured value of the value I _shunt of the current flowing through the shunt resistor 341 . In addition, the current value I _shunt of the shunt resistor 341 can be obtained by measuring the voltage V _shunt across the shunt resistor 341 as shown in equation (2). Here, generally, various errors such as offset error, gain error, hysteresis error, and linearity error are included in the measured value output by the sensor. In the present embodiment, by using the voltage conversion unit 211 that outputs a constant voltage, when estimating the residual quantity Quantity of the mist source held in the storage unit 31 or whether the mist source in the storage unit 31 is exhausted, a variable of the measured value is substituted. for one. Therefore, compared with the method of calculating the resistance value of the load by substituting the output values of different sensors into, for example, a plurality of variables, the accuracy of the calculated resistance value R _shunt of the load 33 can be improved. As a result, the accuracy of the residual amount of the mist source estimated from the resistance value R _shunt of the load 33 is also improved.

FIG. 6 is a processing flowchart showing an example of the remaining amount estimation processing. FIG. 7 is a timing chart showing an example of the state in which the user uses the mist generating device. In Fig. 7, the direction of the arrow indicates the elapse of time t(s), and the respective graphs indicate the opening and closing of switches Q1 and Q2, the value I _HTR of the current flowing through the load 33 , the calculated temperature T _HTR of the load 33 , Changes in the residual quantity Quantity of the mist source. The thresholds Thre1 and Thre2 are predetermined thresholds used to detect whether the mist source is exhausted. The mist generating device 1 performs estimation of the remaining amount when the user uses the mist generating device 1, and performs predetermined processing when it is detected that the mist source has decreased.

The control unit 22 of the mist generating device 1 determines whether or not the user has performed the inhalation operation based on the output of the inhalation sensor 23 ( S1 in FIG. 6 ). In this step, the control unit 22 determines that the user's ingestion has been detected when the generation of negative pressure, the change in the flow rate, etc. are detected based on the output of the snorting sensor 23 . If no ingestion is detected ("No" in S1), the process of S1 is repeated. The user's ingestion can be detected by comparing the change in negative pressure or flow to a threshold value other than zero.

On the other hand, if it is detected (S1 result is YES), the control part 22 performs Pulse Width Modulation (PWM: Pulse Width Modulation) control to the switch Q1 (S2 in FIG. 6). For example, it is assumed that ingestion is detected at time t1 in FIG. 7 . After time t1, the control unit 22 opens and closes the switch Q1 at a predetermined cycle. With the opening and closing of the switch Q1, current flows to the load 33, and the temperature T _HTR of the load 33 rises to the boiling point of the mist source. Furthermore, the mist source is heated and evaporated by the temperature of the load 33, and the residual quantity Quantity of the mist source is reduced. In addition, when the switch Q1 is controlled in step S2, Pulse Frequency Modulation (PFM: Pulse Frequency Modulation) control can also be used instead of PWM.

Next, the control unit 22 judges whether the user's inhalation action has ended according to the output of the inhalation sensor 23 (S3 in FIG. 6). In this step, the control unit 22 determines that the user's inhalation has ended when the generation of negative pressure or the change in the flow rate is not detected based on the output of the inhalation sensor 23 . If the puffing has not ended (the result of S3 is "NO"), the control unit 22 repeats the process of S2. The end of the user's puff can be detected by comparing the change in negative pressure or flow to a threshold value other than zero. Alternatively, it is possible to automatically proceed to step S4 after a predetermined time has elapsed after detecting that the user has inhaled in step S1 without performing the determination of step S3.

On the other hand, if the sucking has ended (YES in S3 ), the control unit 22 stops the PWM control of the switch Q1 ( S4 in FIG. 6 ). For example, it is assumed that it is determined that the smoking has ended at time t2 in FIG. 7 . After time t2, the switch Q1 is turned off (OFF), and the power supply to the load 33 is stopped. Since the mist source is supplied from the storage part 31 to the load 33 via the supply part 32 , the temperature T _HTR of the load 33 is gradually lowered due to heat dissipation. Then, the evaporation of the mist source is stopped because the temperature T _HTR of the load 33 is lowered, and the reduction of the residual quantity Quantity is also stopped.

As described above, by turning on the switch Q1, in steps S2 to S4 enclosed by a dotted-line rounded square in FIG. 6, the current flows to the mist generating path in FIG. 4 .

Then, the control unit 22 keeps the switch Q2 closed for a predetermined period (S5 in FIG. 6). By turning on the switch Q2 (conducting), in steps S5 to S10 enclosed by a dotted-line rounded box in FIG. 6 , the current flows to the residual amount detection path in FIG. 4 . At time t3 in FIG. 7, the switch Q2 is in a closed state (ON). A shunt resistor 341 connected in series with the load 33 is connected to the residual amount detection path. Therefore, the resistance value on the path of the residual amount detection path is larger than that of the mist generation path by the shunt resistor 341 , and the current value I _HTR flowing through the load 33 becomes lower.

Then, when the switch Q2 is closed, the control unit 22 obtains the measured value from the residual amount sensor 34, and detects the current value flowing through the shunt resistor 341 (S6 in FIG. 6). In this step, the current value I _shunt of the shunt resistor 341 is calculated by the above-mentioned formula (2) using the voltage across the shunt resistor 341 measured by, for example, the voltmeter 342 . The current value I _shunt of the shunt resistor 341 is the same as the current value I _HTR flowing through the load 33 .

Then, when the switch Q2 is closed, the control unit 22 determines whether or not the value of the current flowing through the load 33 becomes a value smaller than a predetermined current threshold (S7 in FIG. 6). That is, the control unit 22 determines whether or not the measurement value falls within the range including the target value or the target range. Here, the threshold value of the current (Thre1 in Fig. 7) is a value corresponding to a predetermined threshold value (Thre2 in Fig. 7) of the residual amount of the mist source for judging whether the mist source in the storage unit 31 is exhausted or not . That is, when the current value I _HTR flowing through the load 33 becomes a value smaller than the threshold value Thre1, it can be determined that the residual amount of the mist source has become a value smaller than the threshold value Thre2.

If the current value I _HTR becomes smaller than the threshold value Thre1 during the predetermined period in which the switch Q2 is closed (the result of S7 is YES), the control unit 22 detects that the mist source is exhausted, and performs predetermined processing ( S8 in Figure 6). When the voltage value measured in S6 and the current value obtained therefrom are smaller than the predetermined threshold value, since the residual amount of the mist source is decreasing, this step S8 is to control the voltage value measured in S6 And the current value obtained therefrom is further reduced. For example, the control unit 22 may stop the operation of the switch Q1 or the switch Q2, or cut off the power supply to the load 33 by a power fuse (not shown) to stop the operation of the mist generating device 1 .

As shown at times t3 to t4 in FIG. 7, when the residual amount of the mist source is sufficient, the current value I _HTR is larger than the threshold value Thre1.

After S8, or when the current value I _HTR is equal to or greater than the threshold value Thre1 during a predetermined period during which the switch Q2 is closed (the result of S7 is NO), the control unit 22 opens the switch Q2 (in FIG. 6 ). S9). At time t4 in FIG. 7, since the current value I _HTR is equal to or greater than the threshold value Thre1 for a predetermined period, the switch Q2 is turned off (OFF). The predetermined period for closing the switch Q2 (corresponding to time t3 to t4 in Fig. 7) is longer than the predetermined period for closing the switch Q1 in S2 to S4 (corresponding to the time t1 to t2 in Fig. 7) short. In addition, when it is determined in S7 that the measured value falls within the predetermined range, and then the presence of ingestion is detected (the result of S1 is "Yes"), the switch Q1 is opened and closed (S2) by adjusting, for example, The duty ratio of the switch is used to control the current value (measured value) calculated in S6 to converge to the target value or the target range. Here, compared with the control of the power supply circuit (also referred to as the "first control mode" in the present invention) for converging the measured value to the target value or target range when the measured value falls within a predetermined range, The control of the power supply circuit for reducing the amount of current flowing to the load 33 when the measured value does not fall within the predetermined range (also referred to as the "second control mode" in the present invention) is such that the measured value is Control in such a way that the amount of change becomes larger.

After the above steps, the residual amount estimation process is completed. Then, it returns to the process of S1, and if it is detected that the user has performed a sucking action, the process of FIG. 6 is performed again.

At time t5 in Fig. 7, the user's inhalation action is detected (the result of S1 in Fig. 6 is "Yes"), and the PWM control of the switch Q1 is started. At time t6 in FIG. 7 , it is determined that the user's inhalation operation has ended (the result of S3 in FIG. 6 is YES), and the PWM control of the switch Q1 is stopped. Then, at time t7 in FIG. 7, the switch Q2 is turned on (S5 in FIG. 6), and the current value of the shunt resistance is calculated (S6 in FIG. 6). Then, as shown at time t7 in FIG. 7, the residual amount Quantity of the mist source is smaller than the threshold value Thre2, and the temperature T _HTR of the load 33 rises. Then, the current value I _HTR flowing through the load 33 decreases, and at time t8 , the control unit 22 detects that the current value I _HTR becomes smaller than the threshold value Thre1 (YES in S7 in FIG. 6 ). In this case, since it is known that the mist cannot be generated due to the exhaustion of the mist source, the control unit 22 does not open and close the switch Q1 even if it detects that the user has inhaled after the time t8, for example. In the example of FIG. 7, when a predetermined period elapses at time t9, the switch Q2 is turned off (S9 in FIG. 6). At time t8 when the current value I _HTR becomes a value smaller than the threshold value Thre1, the control unit 22 may turn off the switch Q2.

As described above, by providing the voltage conversion unit 211 that converts the voltage in the present embodiment, when estimating the remaining amount of the mist source or whether it is depleted, the error mixed in the variables used for control can be reduced, and the error can be reduced according to, for example, the mist source. The accuracy of the residual amount control is improved.

<Judgment Period>

In the above-described embodiment, in the remaining amount determination process, the control unit 22 keeps the switch Q2 on for a predetermined period to obtain the measurement value of the remaining amount sensor 34 . The period during which the switch Q2 is closed is also referred to as a "powering procedure" for powering the residual sensor 34 and the load 33 . Here, in order to judge the residual amount of the mist source, a "judgment period" for judging the residual amount can be used. The determination period is included in, for example, the power supply program on the time axis, and its length is variable.

FIG. 8 is a diagram for explaining an example of a method of determining the length of the determination period. In the line graph of FIG. 8 , the horizontal axis represents the elapse of time t, and the vertical axis represents the current value I _HTR flowing through the load 33 . In the example of FIG. 8 , the current value I _HTR that changes with the opening and closing of the switch Q1 is omitted for convenience, and only the current value I _HTR flowing through the load 33 in the power supply process of closing the switch Q2 is shown.

The period p1 in Fig. 8 is the normal power supply procedure, and the current value I _HTR shown on the left is a schematic line when the residual amount of the mist source is sufficient. In the initial stage, the determination period is the same as the power supply procedure (p1). In the example shown on the left, the temperature T _HTR of the load 33 increases as the power is turned on, and the current value I _HTR gradually decreases due to the increase of the resistance value R _HTR of the load 33 , but does not become a value smaller than the threshold Thre1 . In such a case, the determination period is not changed.

The current value I _HTR displayed in the center is an example of the case where the current value I _HTR becomes a value smaller than the threshold value Thre1 in the determination period (p1). Here, the period p2 from the start of the power supply process until the current value I _HTR becomes a value smaller than the threshold value Thre1 is set as the length of the determination period included in the subsequent power supply process. That is, the determination period in the following power supply process is adjusted according to the time when the current value I _HTR becomes smaller than the threshold value Thre1 in the previous power supply process. In other words, the higher the possibility that the mist source is depleted, the shorter the determination period is set. In addition, based on the length of the power supply program, when the current value I _HTR becomes smaller than the threshold value Thre1 during the power supply program (determination period), it can be determined that the possibility of depletion of the mist source is equal to or higher than the threshold value (also referred to as the present invention). "Second Threshold"). In other words, the determination period is made shorter than the power supply procedure only when the possibility of depletion of the mist source is equal to or higher than the threshold value.

The current value I _HTR shown on the right shows an example of the case where the current value I _HTR becomes a value smaller than the threshold value Thre1 in the determination period (p2). During use of the mist generating device 1, the amount of mist source held by the storage unit 31 is constantly decreasing. Therefore, when the mist source is exhausted, it can be said that the period from the start of power supply until the current value I _HTR becomes smaller than the threshold value Thre1 is only shortened. In the example of FIG. 8 , if the current value I _HTR becomes smaller than the threshold value Thre1 during the determination period changed as described above, and it occurs continuously more than a predetermined number of times in the repeated determination period, it is determined that the mist source is exhausted (ie exception). When the mist source is exhausted, the power supply to the residual amount detection circuit can be stopped as shown in Fig. 8.

FIG. 9 is a diagram showing another example of the change in the value of the current flowing through the load. The changes of the current value I _HTR shown on the left and the center of Fig. 9 are the same as those shown in Fig. 8 . The current value I _HTR shown on the right in Fig. 9 is the same as the line when the residual amount of the mist source is sufficient, and the current value I _HTR does not become a value smaller than the threshold Thre1 during the determination period (p2). Here, in the mist generating device 1 shown in FIG. 3, in terms of its structure, the supply of the mist source from the storage part 31 to the supply part 32 is carried out by the capillary phenomenon, and this part is caused by the user's inhalation. It is difficult to control by the control unit 22 or the like, depending on the method. When the user puffs at a time longer than expected, or when the user puffs at a shorter interval than the expected normal interval, the amount of the mist source from around the load 33 is temporarily reduced more than the normal interval. less possibility. In such a case, there is a possibility that the current value I _HTR becomes a value smaller than the threshold value Thre1 during the determination period as shown in the center of FIG. 9 . Then, if the user's drinking pattern is changed, as shown on the right side of FIG. 9, the current value I _HTR does not become a value smaller than the threshold value Thre1 during the determination period. Therefore, in the example of FIG. 9 , when the current value I _HTR becomes smaller than the threshold value Thre1 during the determination period, it does not continuously exceed the predetermined number of times during the repeated determination period, so it is determined that the value stored in the storage unit 31 is The source of fog has not been exhausted.

By using the determination period as described above, the accuracy of determination as to whether or not the mist source has been exhausted can be further improved. That is, by changing the determination period, the criterion in the determination operation can be adjusted, and the accuracy of determination can be improved.

<Variation of Judgment Processing>

FIG. 10 is a processing flow chart showing an example of processing for setting the determination period. In the present modification, the control unit 22 performs the determination process of FIG. 10 in place of the processes of S5 to S9 in the remaining amount estimation process shown in FIG. 6 .

First, the control unit 22 of the mist generator 1 turns on the switch Q2 (S5 in FIG. 10). This step is the same as S5 in FIG. 6 .

Then, the control unit 22 activates the timer and starts counting the elapsed time t (S11 in FIG. 10).

Then, the control unit 22 determines whether or not the elapsed time t is equal to or longer than the determination period (S12 in FIG. 10). If the elapsed time t is not equal to or longer than the determination period (the result of S12 is NO), the control unit 22 counts the elapsed time (S21 in FIG. 10). In this step, the difference Δt of the elapsed time from the start of the timer or from the start of the previous S21 process is added to t.

Then, the control unit 22 detects the current value I _HTR flowing through the load 33 ( S6 in FIG. 10 ). The processing of this step is the same as that of S6 in FIG. 6 .

Then, the control unit 22 determines whether or not the calculated current value I _HTR is smaller than a predetermined threshold value Thre1 ( S7 in FIG. 10 ). This step is the same as S7 in Figure 6. If the current value I _HTR is greater than or equal to the threshold Thre1 (the result of S7 is "NO"), the process returns to S12.

On the other hand, if the current value I _HTR is smaller than the threshold value Thre1 (YES in S7 ), the control unit 22 increments a counter that counts the number of determination periods when depletion is detected ( S22 in FIG. 10 ).

Then, the control unit 22 determines whether or not the counter exceeds a predetermined value (threshold value) (S23). When it is determined that the counter exceeds the predetermined value (YES in S23 ), the control unit 22 determines that the depletion of the mist source has been detected, and performs predetermined processing ( S8 in FIG. 10 ). This step is the same as S8 in FIG. 6 .

On the other hand, if it is determined that the counter does not exceed the predetermined value (NO in S23 ), the control unit 22 determines whether the power supply process has ended ( S31 in FIG. 10 ). If the power supply process has not been completed (“No” in S31 ), the control unit 22 updates the elapsed time t and returns to the process of S31 .

On the other hand, if it is determined that the power supply process has ended (YES in S31 ), the control unit 22 updates the determination period ( S32 in FIG. 10 ). In this step, the elapsed time t when it is determined in S7 that the current value I _HTR is smaller than the threshold value Thre1 is set as a new determination period. That is, the determination period in the subsequent power supply process is adjusted according to the time when the measured value in the previous power supply process becomes a value smaller than the threshold value. In other words, the length of the determination period in the following power supply process is adjusted based on the measured value in the previous power supply process. It can also be said that the length of the determination period in the future power supply program is adjusted based on the value measured in the current power supply program.

If it is determined in S12 that the elapsed time t is equal to or greater than the determination period (the result of S12 is YES), the control unit 22 determines whether or not the power supply process has ended (S13 in FIG. 10). If the power supply process has not ended (“No” in S13 ), the control unit 22 continues to supply power until the power supply process ends. The state in which the so-called determination period has elapsed but the power supply process has not been completed is a state before the period p2 has elapsed but the period P1 has not yet ended in the period shown on the right side of FIG. 9 .

On the other hand, when it is determined that the power supply process has ended (YES in S13 ), the control unit 22 sets the length of the determination period to be the same as that of the power supply process ( S14 in FIG. 10 ).

Then, the control unit 22 resets the counter (S15 in FIG. 10). That is, the current value I _HTR does not become a value smaller than the threshold value Thre1 in the determination period defined along with the power supply period, so the counter for counting the number of consecutive determination periods in which depletion is detected is reset. The counter may not be reset, and it may be determined as abnormal when the number of determination periods when the depletion is detected exceeds a predetermined threshold.

After S15, S8, or S32, the control unit 22 turns off the switch Q2 (S9 in FIG. 10). This step is the same as S9 in Figure 6.

The variable determination period shown in Figs. 8 and 9 can be realized by the above-mentioned processing.

<Shunt resistance>

The control unit 22 estimates the remaining amount of the mist source by functioning the remaining amount detection path while the user is not breathing the mist generating device 1 . However, it is not good for the mist to come out of the suction port during the period when the user is not taking a breath. That is, it is desirable that the load 33 evaporates the mist source as little as possible while the switch Q2 is closed.

On the other hand, when the residual amount of the mist source is only a little, it is preferable that the control unit 22 can accurately detect the change of the residual amount. That is, it is preferable that the measured value of the residual amount sensor 34 corresponds to the residual amount of the mist source, and the resolution is improved when there is a large change. From the viewpoints described above, the resistance value of the shunt resistor will be described below.

FIG. 11 is a schematic diagram showing the energy consumed in the storage part, the supply part and the load. Q1 represents the calorific value of the liquid absorbing wick of the supply part 32, _Q2 represents the calorific value of the coil of the load ₃₃ , _Q3 represents the calorific value required to raise the temperature of the liquid mist source, _Q4 represents the mist source from the liquid to the gas The heat required for state change, Q ₅ represents the heating of the air due to radiation, etc. The consumed energy Q is the sum _of Q1 to _Q5 .

In addition, the heat capacity C (J/K) of an object is the product of the mass m (g) of the object and the specific heat c (J/g·K). The heat Q(J/K) required to change the temperature of an object by T(K) can be expressed as m×C×T. Therefore, when the temperature T _HTR of the load 33 is lower than the boiling point T _b of the mist source Q, the consumed energy Q can be schematically represented by the following formula (6). where m ₁ is the mass of the wick of the supply part 32 , C ₁ is the specific heat of the wick of the supply part 32 , m ₂ is the mass of the coil of the load 33 , C ₂ is the specific heat of the coil of the load 33 , m ₃ is the mass of the liquid mist gas source, C ₃ is the specific heat of the liquid mist gas source, and T ₀ is the initial value of the temperature of the load 33 .

Q=(m ₁ C ₁ +m ₂ C ₂ +m ₃ C ₃ )(T _HTR −T ₀ ). . . (6)

The consumed energy Q can be expressed as the following equation (7) when the temperature T _HTR of the load 33 is higher than or equal to the boiling point T _b of the mist source. Among them, m ₄ is the mass of the vaporized part in the liquid mist source, and H ₄ is the evaporation heat of the liquid mist source.

Q=(m ₁ C ₁ +m ₂ C ₂ )(T _HTR -T ₀ )+m ₃ C ₃ (T _b -T ₀ )+m ₄ H ₄ . . . (7)

Therefore, the threshold value E _thre must satisfy the condition shown by the following formula (8) in order to prevent the mist from evaporation from being generated.

E _thre <(m ₁ C ₁ +m ₂ C ₂ +m ₃ C ₃ )(T _b −T ₀ ). . . (8)

FIG. 12 is a schematic line graph showing the relationship between the energy (electricity) consumed by the load 33 and the amount of mist generated. The horizontal axis of FIG. 12 represents energy, and the vertical axis represents TPM (Total Particle Matter: the amount of mist-forming substance). As shown in FIG. 12 , when the energy consumed by the load 33 exceeds a predetermined threshold E _thre , mist starts to be generated, and the amount of generated mist increases in approximately proportional to the consumed energy. The vertical axis of FIG. 12 is not necessarily the amount of mist generated by the load 33 . For example, it may be the amount of mist generated by evaporation from the mist source. Alternatively, it may be the amount of mist released from the mouthpiece.

Here, the energy E _HTR consumed by the load 33 can be expressed by the following equation (9). Wherein, W _HTR is the duty rate of the load 33 , and t _{Q2_ON} is the time (s) for turning on the switch Q2 . In order to measure the resistance value of the shunt resistor, the switch Q2 must be kept on for a certain amount of time.

E _HTR =W _HTR ×t _{Q2_ON} . . . (9)

Equation (9) is modified by using the current value I _Q2 flowing through the residual amount detection path, the resistance value R _HTR (T _HTR ) which changes according to the temperature T _HTR of the load 33 , and the measurement voltage V _meas of the shunt resistance, so that It becomes the following formula (10).

Therefore, as shown in the following formula (11), as long as the energy E _HTR consumed by the load 33 is made smaller than the threshold value E _thre in Fig. 12, fog will not be generated.

By modifying the above formula, the following formula (12) is obtained. That is, as long as the resistance value R _shunt of the shunt resistor is a value satisfying the formula (12), fog will not be generated in the residual amount estimation process, and it is a preferable resistance value.

In general, in order to reduce the influence on the circuit to which the shunt resistor is added, the resistance value of the shunt resistor is preferably as low as several 10 mΩ. However, in the present embodiment, the lower limit of the resistance value of the shunt resistor as described above is determined from the viewpoint of suppressing the generation of mist. The lower limit value is larger than the resistance value of the load 33, and is preferably a value in the order of several Ω, for example. Therefore, it is preferable to set the resistance value of the shunt resistor to satisfy the first condition that the amount of mist generated by the load during the power supply procedure from the power source to the resistor will be below a predetermined threshold value.

Furthermore, in order not to increase the resistance value of the shunt resistor, an adjustment resistor may be added in series with the shunt resistor to increase the overall resistance value. In this case, it is not necessary to measure the voltage across the additional adjustment resistor.

FIG. 13 is an example of a graph showing the relationship between the residual quantity Quantity of the mist source and the resistance value of the load 33 . In the line graph of FIG. 13 , the horizontal axis represents the residual amount of the mist source, and the vertical axis represents the resistance value depending on the temperature of the load 33 . Here, R _HTR (T _Depletion ) is the resistance value when the residual amount of the mist source has been depleted, and R _HTR (T _RT ) is the resistance value at room temperature. Here, the measurement range (range) of the voltage, current, resistance value of the load 33, and temperature is appropriately set with respect to the resolution of the control unit 22 including the number of bits, and the estimation accuracy of the residual amount of the mist source will be obtained. improve. On the other hand, the larger the difference between R _HTR (T _Depletion ) and R _HTR (T _RT ) of the resistance value of the load 33 is, the larger the fluctuation range is in accordance with the residual amount of the mist source. In other words, in addition to the resolution and measurement range of the control unit 22 , by increasing the fluctuation range of the resistance value that changes according to the temperature of the load 33 , the accuracy of the estimated value of the residual amount calculated by the control unit 22 can be improved. .

In addition, the resistance value R _HTR (T _Depletion ) of the load 33 when the residual amount of the mist source is exhausted can be used, and the current value I _{Q2_ON} (T _Depletion ) detected from the output value of the residual amount sensor 34 at this point in time can be used. ) is represented by the following formula (13).

Similarly, using the resistance value R _HTR (T _RT ) of the load 33 at room temperature, the current value I _{Q2_ON} (T _RT ) detected from the output value of the residual quantity sensor 34 at this point can be expressed as the following Formula (14).

Then, the difference _{ΔI Q2_ON} obtained by subtracting the current value I _{Q2_ON} (T _Depletion ) from the current value I _{Q2_ON} (T _RT ) can be expressed by the following equation (15).

It can be seen from equation (15) that when R _shunt is increased, the difference _ΔI Q2_ON between the current value I _{Q2_ON} (T _RT ) and the current value I _{Q2_ON} (T _Depletion ) will become smaller, and the residual amount of the mist source cannot be accurately estimated. Therefore, as shown in Equation (16), the resistance value R _shunt of the shunt resistor is determined so that the difference _{ΔI Q2_ON} can be larger than the predetermined threshold value ΔI _thre .

To solve the resistance value R _shunt from Equation (16), in order to make the resolution of the estimated value of the residual amount sufficiently large, the condition to be satisfied by the resistance value R _shunt can be expressed as the following using a desired threshold value _{ΔI thre} Formula (17). Therefore, it is only necessary to set the resistance value R _shunt to satisfy the expression (17).

In this embodiment, the resistance value R _shunt is set so that the current value I _{Q2_ON} (T _RT ) flowing to the load 33 at room temperature and the current value I _{Q2_ON} (T _Depletion ) flowing to the load 33 when the mist source is exhausted ) of the difference _{ΔI Q2_ON} has a magnitude that can be detected by the control unit 22 . Instead of this, the resistance value R _shunt may be set so that the difference between the current value flowing to the load 33 in the vicinity of the boiling point of the mist source and the current value flowing to the load 33 when the mist source is exhausted becomes the control unit 22 . The size of the detectable extent. Generally speaking, the smaller the temperature difference corresponding to the current difference detectable by the control unit 22 is, the more accurate the estimation of the residual amount of the mist source will be.

Here, the influence of the setting of the residual amount detection circuit including the resolution of the control unit 22 and the resistance value of the load 33 on the estimation accuracy of the residual amount of the mist source will be described in more detail. When an n-bit microcontroller is used as the control unit 22 and V _REF is applied as the reference voltage, the resolution Resolution of the control unit 22 can be expressed by the following equation (18).

In addition, the difference ΔV _{Q2_ON} between the value detected by the voltmeter 342 when the load 33 is at room temperature and the value detected by the voltmeter 342 when the residual amount of the mist source has been exhausted can be expressed according to equation (15) into the following formula (19).

Therefore, from equations (18) and (19), the control unit 22 can detect a value represented by the following equation (20) and its integer multiples within the range of 0 to ΔV _{Q2_ON} as a voltage difference.

From the equation (20), the control unit 22 can detect the value represented by the following equation (21) and its integer multiples within the range from room temperature to the temperature of the load 33 when the mist source is exhausted as a heater. temperature.

As an example, the resolution of the control unit 22 with respect to the temperature of the load 33 when the variable in the formula (21) is changed is shown in Table 1 below.

As can be seen from Table 1, adjusting the value of each variable tends to greatly change the resolution of the control unit 22 with respect to the temperature of the load 33 . In order to determine whether the residual amount of the mist source has been exhausted, the control unit 22 must at least be able to distinguish between the temperature (ie, room temperature) when the control unit 22 does not control and when the control starts (ie, room temperature) and the temperature when the residual amount of the mist source is exhausted. That is, the measured value of the residual amount sensor 34 at room temperature and the measured value of the residual amount sensor 34 when the residual amount of the mist source has been exhausted must have a significant difference to the extent that the control unit 22 can distinguish it. . In other words, the resolution of the control unit 22 with respect to the temperature of the load 33 must be equal to or less than the difference between the temperature when the residual amount of the mist source is exhausted and the room temperature.

As mentioned above, when the residual amount of the mist source is sufficient, the temperature of the load 33 is maintained near the boiling point of the mist source. In order to more accurately determine whether the residual amount of the mist source is exhausted, the control unit 22 preferably can distinguish the boiling point of the mist source from the temperature at which the residual amount of the mist source is exhausted. That is, the measured value of the residual amount sensor 34 at the boiling point of the mist source and the measured value of the residual amount sensor 34 when the residual amount of the mist source has been depleted must be significant enough to be distinguished by the control unit 22 Difference is better. In other words, the resolution of the control unit 22 with respect to the temperature of the load 33 is preferably equal to or less than the difference between the temperature when the residual amount of the mist source is exhausted and the boiling point of the mist source.

In addition, in the case where the measured value of the residual amount sensor 34 is not only used for judging whether the residual amount of the mist source has been exhausted, but also as a temperature sensor of the load 33, the control unit 22 preferably can distinguish that the control unit 22 does not The room temperature and the boiling point of the mist source at the time of control and the temperature at the time of starting control. That is, the measured value of the residual amount sensor 34 at room temperature and the measured value of the residual amount sensor 34 at the boiling point of the mist source must have a significant difference to the extent that the control unit 22 can distinguish. In other words, the resolution of the control unit 22 with respect to the temperature of the load 33 is preferably equal to or less than the difference between the boiling point of the mist source and the room temperature.

In order to use the temperature sensor as the load 33 with higher accuracy, the resolution of the control unit 22 with respect to the temperature of the load 33 is preferably 10° C. or lower, more preferably 5° C. or lower. More preferably, it is 1°C or lower. In addition, in order to accurately distinguish the situation that the residual amount of the mist source is about to be depleted and the situation that the residual amount of the mist source has actually been exhausted, the resolution of the control unit 22 to the temperature of the load 33 is preferably the residual amount of the mist source. The factor of the difference between the temperature and room temperature when the quantity has been depleted.

Also, as can be seen from Table 1, by increasing the number of bits of the control unit 22, in other words by increasing the performance of the control unit 22, the resolution of the control unit 22 with respect to the temperature of the load 33 can be easily improved. However, increasing the performance of the control unit 22 leads to an increase in cost, weight, size, and the like.

As described above, the resistance value of the shunt resistor can be determined to satisfy the first condition that the amount of mist generated by the load 33 becomes equal to or less than the predetermined threshold value, and the control unit 22 can determine the output value of the residual amount sensor 34 according to the first condition. At least one of the second conditions for detecting the reduction of the residual amount of the mist source can also be determined as a resistance value satisfying both conditions. In addition, among the minimum value satisfying the first condition and the maximum value satisfying the second condition, it may be determined as a value closer to the maximum value satisfying the second condition. In this way, not only the generation of fog in the measurement can be reduced, but also the resolution of residual amount detection can be improved as much as possible. As a result, the residual amount of the mist source can be estimated with high accuracy and in a short time, so that the generation of mist during measurement can be further reduced.

Both the first condition and the second condition can be said to be related to the responsiveness of changes in the value of the current flowing to the load 33 (which is the measured value of the residual sensor 34 ) with respect to changes in the temperature of the load 33 . When the change in the value of the current flowing to the load 33 is highly responsive to changes in the temperature of the load 33 , the load 33 is dominant among the combined resistance of the shunt resistance 341 and the load 33 connected in series. That is, since the resistance value R _shunt of the shunt resistor is a small value, the second condition is easier to satisfy, but the first condition is less difficult to satisfy.

On the other hand, when the responsiveness of the change in the value of the current flowing to the load 33 with respect to the change in the temperature of the load 33 is weak, the shunt resistance 341 has a combined resistance of the shunt resistance 341 and the load 33 connected in series. Dominant situation. That is, since the resistance value R _shunt of the shunt resistor is a relatively large value, the first condition is easier to satisfy, but the second condition is not easily satisfied.

That is, in order to satisfy the first condition, the responsiveness of the change in the value of the current flowing to the load 33 with respect to the change in the temperature of the load 33 must be equal to or less than a predetermined upper limit. On the other hand, in order to satisfy the second condition, the responsiveness of the change in the value of the current flowing to the load 33 with respect to the change in the temperature of the load 33 must be equal to or greater than a predetermined lower limit. In addition, in order to satisfy both the first condition and the second condition, the responsiveness to the change in the temperature of the load 33 and the change in the value of the current flowing to the load 33 must fall within the range defined by the predetermined upper and lower limits.

<Variation 1 of the circuit>

FIG. 14 is a diagram showing a modification of the circuit included in the mist generating device 1 . In the example of FIG. 14, the residual amount detection path also serves as the mist generation path. That is, the voltage conversion part 211, the switch Q2, the residual amount detector 34, and the load 33 are connected in series. Then, the generation of mist and the estimation of the residual amount are performed in one path. Even with such a configuration, estimation of the remaining amount can be performed.

<Variation 2 of the circuit>

FIG. 15 is a diagram showing another modification of the circuit included in the mist generating device 1 . In the example of FIG. 15, the voltage conversion part 212 which is a switching regulator is provided instead of a linear regulator. For example, the voltage conversion unit 212 is a step-up converter, and includes an inductor L1 , a diode D1 , a switch Q4 , and capacitors C1 and C2 that function as smoothing capacitors. The voltage conversion part 212 is provided before branching into the mist generation path and the residual amount detection path after the power source 21 is started. Therefore, the control part 22 can output voltages of different magnitudes to the mist generation path and the residual amount detection path by controlling the opening and closing of the switch Q4 of the voltage conversion part 212 . In the case where a switching regulator is used instead of a linear regulator, the switching regulator can also be located in the same location as the linear regulator in Figure 14.

In addition, in order to detect the residual amount of the mist source, the voltage conversion unit 212 can be controlled to make the mist generation path (compared to the residual amount detection circuit that must apply a certain voltage to the entire path, the limitation of the applied voltage is relatively small). less) The power loss in the case of functioning is smaller than the power loss in the case of functioning the residual amount detection path. In this way, the waste of the stored power of the power source can be suppressed. Moreover, the control part 22 can control so that the electric current flowing in the load 33 may be made smaller in the residual amount detection path than in the mist generation path. In this way, the generation of mist in the load 33 can be suppressed while the residual amount detection path is functioning to estimate the residual amount of the mist source.

In addition, during the period in which the mist generation path is functioning, the switching regulator can stop the opening and closing operation of the low-side switch Q4 and maintain it in the "direct connection mode" (also called the "direct connection mode") in the conducting state. "Direct link state") action. That is, the duty ratio of the switch Q4 can be made 100%. In terms of losses when the switching regulator is made to perform switching operations, in addition to conduction losses, there are also transition losses and switching losses associated with switching. However, by operating the switching regulator in the direct connection mode, the losses in the switching regulator can be reduced to the conduction loss, so that the utilization efficiency of the stored power of the power supply 21 can be improved. In addition, the switching regulator may be operated in the direct connection mode only in a part of the period in which the mist generation path is made to function. For example, when the power storage capacity of the power supply 21 is sufficient and the output voltage thereof is high, the switching regulator operates in the direct connection mode. On the other hand, when the power storage amount of the power supply 21 is reduced and the output voltage thereof is low, the switching regulator is caused to perform a switching operation. With such a configuration, the residual amount can also be estimated, and the loss can be reduced compared to the case of using a linear voltage regulator. Also, a step-down converter or a buck-boost converter may be used instead of the step-up converter.

<Other>

The object heated by the mist generating device can also be the fragrance source of the liquid containing other additive materials such as nicotine. In this case, the generated mist is made to be inhaled by the user without passing through the additive component holding portion. Even in the case of using such a fragrance source, the residual amount can be accurately estimated from the above-mentioned mist generating device.

In addition, the control unit 22 can control the switches Q1 and Q2 so that both of them are not turned on at the same time. That is, it is controlled so that the mist generation path and the residual amount detection path do not function at the same time. In addition, when switching the on-off states of the switches Q1 and Q2, a dead time during which both of the switches are turned off can be set. In this way, current can be suppressed from flowing to both paths. On the other hand, in order not to lower the temperature of the load 33 during the dead time as much as possible, the dead time is preferably as short as possible.

In the processing shown in FIG. 6, an example in which the residual amount estimation processing is performed once in response to the user performing one suction is described. However, the residual amount estimation process may be alternately performed once not for each time but for a plurality of puffs. In addition, since the residual amount of the mist source is sufficient after the mist source holder 3 is replaced, the residual amount estimation process can be started only after a predetermined number of puffs. That is, the energization frequency of the residual amount detection path can be made lower than that of the mist generation path. In this way, since the excessive remaining amount estimation processing is suppressed and performed only at an appropriate timing, the utilization efficiency of the stored power of the power supply 21 can be improved.

21‧‧‧Power

22‧‧‧Control Department

33‧‧‧Load

34‧‧‧Residual sensor

51‧‧‧First Node

52‧‧‧Second Node

211‧‧‧Voltage conversion section

341‧‧‧Shunt Resistor

342‧‧‧Voltmeter

C1, C2‧‧‧Capacitor

Q1, Q2, Q3‧‧‧Switch

R1, R2‧‧‧resistors

Comp‧‧‧Comparators

Claims (20)

A mist generating device, comprising: a power source; a load, whose resistance value changes with temperature, and is used to atomize a mist source or heat a fragrance source by using the power supply from the power source to generate mist; a sensor, It includes a resistor connected in series with the load, and outputs a measured value belonging to a current value flowing through the resistor or a voltage value applied to the resistor; and a control unit controls the power supply from the power source to the load, and receiving the output of the sensor; the resistor has a resistance value that makes the change of the measurement value relative to the change of the temperature of the resistance value within a predetermined range of responsiveness. The mist generating device according to claim 1, wherein the resistor has a resistance value that satisfies at least one of the following first condition and second condition, the first condition being when the power is supplied from the power source to During the power supply period of the resistor, the amount of mist generated by the load is below a threshold value, and the second condition is that the control unit can detect a change in the residual amount of the mist source or the fragrance source based on the measured value. The mist generating device according to claim 2, wherein the resistance value is a value satisfying the first condition. The mist generating device as described in claim 3, wherein, The mist generating device includes a suction port disposed at the end of the mist generating device and used to release the mist, and the threshold value is a value that does not release the mist from the suction port during the power supply period. The mist generating device according to claim 3, wherein the threshold value is a value at which the energy supplied to the load cannot be used for the vaporization heat of the mist source or the aroma source. The mist generating device according to claim 3, wherein the threshold value is a value at which the mist is not generated due to the heat generation of the load. The mist generating device according to claim 2, wherein the resistance value is a value satisfying the second condition. The mist generating device according to claim 7, wherein the resistance value is a value obtained when the measured value at the start of energization to the load and the residual amount of the mist source or the fragrance source are equal to or less than a predetermined amount The difference of the said measurement value is the value of the degree which the said control part can distinguish. The mist generating device according to claim 7, wherein the resistance value is a value obtained when the measured value at the start of energization to the load and the residual amount of the mist source or the fragrance source are equal to or less than a predetermined amount The absolute value of the difference between the measurement values is a value larger than the resolution of the control unit. The mist generating device according to claim 7, wherein the resistance value is a value before the measured value at the time of mist generation and the residual amount of the mist source or the fragrance source is equal to or less than a predetermined amount The difference between the measured values is a value that can be distinguished by the control unit. The mist generating device according to claim 7, wherein the resistance value is the difference between the measurement value when mist is generated and the measurement value when the residual amount of the mist source or the fragrance source is equal to or less than a predetermined amount The absolute value of the difference is a value larger than the resolution of the control unit. The mist generating device according to any one of claims 8 to 11, wherein the resistance value is a difference between the measurement value at the start of energization to the load and the measurement value at the time of generation of the mist The difference is a value of the degree to which the aforementioned control unit can distinguish. The mist generating device according to any one of claims 8 to 11, wherein the resistance value is a difference between the measurement value at the start of energization to the load and the measurement value at the time of generation of the mist The absolute value of the difference is a value larger than the resolution of the control unit. The mist generating device according to claim 2, wherein the resistance value is a value satisfying the first condition and the second condition. The mist generating device according to claim 14, wherein the resistance value is relatively close to a minimum value that satisfies the first condition and a maximum value that satisfies the second condition among the maximum value that satisfies the second condition value. As described in any one of claims 1 to 11, 14 and 15 of the scope of the application The mist generating device includes a power supply circuit electrically connected to the power supply and the load, the power supply circuit is provided with a first power supply circuit and a second power supply circuit, and the first power supply circuit is not connected to the sensor through the sensor. The load is powered, and the second power supply circuit supplies power to the load via the sensor. The mist generating device according to claim 16, wherein the power supply circuit comprises: a first node connected to the power source and branched into the first power supply circuit and the second power supply circuit; a second node , which is downstream of the first node for the merging of the first power supply circuit and the second power supply circuit; and a linear voltage regulator, which is arranged at the first node and the sensor in the second power supply circuit between. A mist generating device, comprising: a power source; a load, whose resistance value changes with temperature, and is used to atomize a mist source or heat a fragrance source by using the power supply from the power source to generate mist; a sensor is provided with a resistor connected in series with the load, and outputs a measured value belonging to the value of the current flowing through the resistor or the value of the voltage applied to the resistor; and a control unit that controls the power supply from the power source to the load , and receive the output of the aforementioned sensor; the aforementioned resistor has the following first condition and second condition At least one of the resistance values, the first condition is that the amount of mist generated by the load is below a threshold value during the power supply period from the power supply to the resistor, and the second condition is that the control unit can measure according to the above-mentioned measurement The value detects a change in the residual amount of the aforementioned mist source or the aforementioned fragrance source. A mist generating device, comprising: a power source; a load, whose resistance value changes with temperature, and utilizes the power supply from the aforementioned power source to atomize a mist source or heat a fragrance source to generate mist; a sensor, which is It has a resistor connected in series with the load, and outputs a measured value belonging to the current value flowing through the resistor or the voltage value applied to the resistor; one or a plurality of adjustment resistors are used to adjust the value supplied to the the magnitude of the current of the load; and a control unit that controls the power supply from the power supply to the load and receives the output of the sensor; the resistance values of the resistor and the adjustment resistor are set so that the power is supplied from the power supply During the power supply period to the load, the first condition is that the amount of mist generated by the load becomes a value equal to or less than a predetermined threshold value, and the resistor has responsiveness to change the measured value with respect to the temperature change of the resistance value. A resistance value that falls within a given range. The mist generating device according to any one of claims 1 to 11, 14, 15, 18 and 19, wherein the resistance value of the resistor is greater than the resistance value of the load.

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