Patent Description:
Recently, the demand for alternative methods to overcome the shortcomings of traditional cigarettes has increased. For example, there is growing demand for a method of generating aerosol by heating an aerosol-generating material, rather than by combusting cigarettes. Accordingly, research into heating-type cigarettes and heating-type aerosol-generating devices has been actively conducted.

A heater of the aerosol-generating device heats a cigarette inserted into the aerosol-generating device. The aerosol-generating device may control power supplied to the heater based on a preset temperature profile.

However, even when a failure occurs in a processor or the like that controls the heater, the heater may continue to generate heat. In this case, the heater may generate heat differently from the temperature profile. As a result, the optimum taste may not be provided to a user, and there may be a safety problem. Accordingly, there is a need for a technique for preventing the heater from generating heat due to a malfunction of the aerosol-generating device. <CIT> relates to a method of controlling an electric heater in an electrically heated smoking system, the method comprising: providing electrical power to the heater in pulses such that during an active periods power is supplied to the heater and during inactive periods power is not supplied to the heater; charging a capacitor in an RC circuit during inactive periods and allowing the capacitor to discharge during active periods; and monitoring a discharge voltage of the capacitor and if the discharge voltage of the capacitor drops below a threshold voltage level, then stopping further supply of electrical power to the heater. <CIT> relates to an electronic cigarette including a microcontroller, a light emitting unit and a power supply unit; wherein the microcontroller is electrically connected to the power supply unit, the light emitting unit is electrically connected to the microcontroller and the power supply unit; the power supply unit is configured to supply power to the microcontroller and the light emitting unit; the microcontroller is configured to control the light emitting unit in different light emitting states, so as to indicate the different smoking states of the electronic cigarette; the different light emitting states of the light emitting unit includes: gradually brightening to a preset first brightness, gradually darkening from the preset first brightness to a preset second brightness and maintaining the second brightness within a preset period of time, and stopping emitting light.

Provided are an apparatus and a method for generating an aerosol to block heat generation of a heater due to malfunction.

The technical problems are not limited to the above-described description, and other technical problems may be derived from the embodiments to be described hereinafter.

An aerosol-generating device according to an aspect includes: a heater; a first switch electrically connected to the heater in series; a second switch electrically connected to the heater and the first switch in series; a first processor configured to output a first control signal that controls an open/closed state of the first switch; and a second processor configured to perform communication with the first processor and output a second control signal that controls an open/closed state of the second switch such that the open/closed state of the second switch is changed according to a communication status with the first processor, wherein when the communication status with the first processor is defective, the second processor is configured to output the second control signal such that the second switch is opened.

As the first processor and the second processor control the first switch and the second switch, respectively, the heater may be prevented from operating abnormally if at least one processor of the first processor and the second processor malfunctions.

In addition, in preferred embodiments a rectifying circuit may be connected to an output terminal of the first processor and a capacitor may be connected to on output terminal of the second processor, and the heater may be prevented from operating abnormally if at least one processor of the first processor and the second processor malfunctions.

According to an aspect, an aerosol-generating device includes: a heater; a first switch electrically connected to the heater in series; a second switch electrically connected to the heater and the first switch in series; a first processor configured to output a first control signal that controls an open/closed state of the first switch; and a second processor configured to perform communication with the first processor and output a second control signal that controls an open/closed state of the second switch such that the open/closed state of the second switch is changed according to a communication state with the first processor, and wherein when the communication status with the first processor is defective, the second processor outputs the second control signal such that the second switch is opened.

In the aerosol-generating device, the first processor outputs the first control signal so that the open/closed state of the first switch is changed according to a communication status with the second processor.

In the aerosol-generating device, when the communication status with the second processor is defective, the first processor outputs the first control signal such that the first switch is opened.

In the aerosol-generating device, the first processor and the second processor perform serial communication.

In the aerosol-generating device, the first control signal is a signal that closes the first switch during a period in which the heater is heated, and the second control signal is a signal that repeatedly opens and closes the second switch according to a power duty cycle of the heater during the period in which the heater is heated.

In the aerosol-generating device, the first switch and the second switch are field effect transistors.

The aerosol-generating device further includes a rectifying circuit electrically connected to an output terminal of the first processor and an input terminal of the first switch.

In the aerosol-generating device, the first control signal and the second control signal are pulse width modulation signals.

The aerosol-generating device further includes a capacitor electrically connected to an output terminal of the second processor and an input terminal of the second switch.

In the aerosol-generating device, at least one processor of the first processor and the second processor receives a temperature sensing value of the heater, and the at least one processor outputs a control signal so that at least one of the first and second switches corresponding to the at least one processor is opened when the received temperature sensing value is abnormal.

According to another aspect, a method of blocking power for a heater of an aerosol-generating device includes: outputting, from a first processor, a signal that controls an open/closed state of a first switch electrically connected to the heater in series; outputting, from a second processor, a signal that controls an open/closed state of a second switch electrically connected to the heater and the first switch in series; performing communication between the first processor and the second processor; and outputting, from at least one processor of the first and second processors, a signal that controls at least one of the first and second switches corresponding to the at least one processor to be opened according to a communication status between the first processor and the second processor, wherein when the communication status with the first processor is defective, the second processor is configured to output the second control signal such that the second switch is opened.

In addition, in certain cases, terms which are not commonly used may be selected. In such a case, the meanings of the terms will be described in detail at the corresponding portions in the following description of the embodiments. Therefore, the terms used in the various embodiments should be defined based on the meanings of the terms and the descriptions provided herein.

Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

Referring to <FIG>, the aerosol generating device <NUM> may include a battery <NUM>, a controller <NUM>, and a heater <NUM>. Referring to <FIG> and <FIG>, the aerosol generating device <NUM> may further include a vaporizer <NUM>. Also, the cigarette <NUM> may be inserted into an inner space of the aerosol generating device <NUM>.

When the cigarette <NUM> is inserted into the aerosol generating device <NUM>, the aerosol generating device <NUM> may operate the heater <NUM> and/or the vaporizer <NUM> to generate an aerosol. The aerosol generated by the heater <NUM> and/or the vaporizer <NUM> is delivered to a user by passing through the cigarette <NUM>.

As necessary, even when the cigarette <NUM> is not inserted into the aerosol generating device <NUM>, the aerosol generating device <NUM> may heat the heater <NUM>.

The controller <NUM> may control overall operations of the aerosol generating device <NUM>.

For example, when the cigarette is inserted into the aerosol generating device <NUM>, the heater <NUM> may be located outside the cigarette. Thus, the heated heater <NUM> may increase a temperature of an aerosol generating material in the cigarette.

The vaporizer <NUM> may generate an aerosol by heating a liquid composition and the generated aerosol may pass through the cigarette <NUM> to be delivered to a user. In other words, the aerosol generated via the vaporizer <NUM> may move along an air flow passage of the aerosol generating device <NUM> and the air flow passage may be configured such that the aerosol generated via the vaporizer <NUM> passes through the cigarette to be delivered to the user.

The liquid storage may be formed to be detachable from the vaporizer <NUM>, or may be formed integrally with the vaporizer <NUM>.

The aerosol generating device <NUM> may further include general-purpose components in addition to the battery <NUM>, the controller <NUM>, the heater <NUM>, and the vaporizer <NUM>. For example, the aerosol generating device <NUM> may include a display capable of outputting visual information and/or a motor for outputting haptic information. Also, the aerosol generating device <NUM> may include at least one sensor. Also, the aerosol generating device <NUM> may be formed as a structure where, even when the cigarette <NUM> is inserted into the aerosol generating device <NUM>, external air may be introduced or internal air may be discharged.

The cigarette <NUM> may be similar as a general combustive cigarette. For example, the cigarette <NUM> may be divided into a first portion including an aerosol generating material and a second portion including a filter, etc. The second portion of the cigarette <NUM> may also include an aerosol generating material. For example, an aerosol generating material made in the form of granules or capsules may be inserted into the second portion.

For example, the external air may flow into at least one air passage formed in the aerosol generating device <NUM>. For example, opening and closing of the air passage and/or a size of the air passage may be adjusted by the user. Accordingly, the amount and quality of the aerosol may be adjusted by the user. As another example, the external air may flow into the cigarette <NUM> through at least one hole formed in a surface of the cigarette <NUM>.

Hereinafter, examples of the cigarette <NUM> will be described with reference to <FIG> and <FIG>.

<FIG> and <FIG> are diagrams showing examples of cigarettes.

Referring to <FIG>, the cigarette <NUM> may include a tobacco rod <NUM> and a filter rod <NUM>. The first portion <NUM> described above with reference to <FIG> may include the tobacco rod <NUM>, and the second portion may include the filter rod <NUM>.

<FIG> illustrates that the filter rod <NUM> includes a single segment. However, the filter rod <NUM> is not limited thereto. In other words, the filter rod <NUM> may include a plurality of segments. For example, the filter rod <NUM> may include a first segment configured to cool an aerosol and a second segment configured to filter a certain component included in the aerosol. Also, as necessary, the filter rod <NUM> may further include at least one segment configured to perform other functions.

The cigarette <NUM> may be packaged by at least one wrapper <NUM>. The wrapper <NUM> may have at least one hole through which external air or internal gas flows. As an example, the cigarette <NUM> may be packaged by one wrapper <NUM>. As another example, the cigarette <NUM> may also be packaged by two or more wrappers <NUM>. For example, the tobacco rod <NUM> may be packaged by a first wrapper <NUM>, and the filter rod <NUM> may be packaged by wrappers <NUM>, <NUM>, and <NUM>. And, the cigarette <NUM> may be entirely repackaged by a single wrapper <NUM>. When the filter rod <NUM> is composed of a plurality of segments, each segment may be packaged by the wrappers <NUM>, <NUM> and <NUM>.

Referring to <FIG>, the cigarette <NUM> may further include a front end plug <NUM>. The front end plug <NUM> may be located on a side of the tobacco rod <NUM> opposite the filter rod <NUM>. The front end plug <NUM> may prevent the tobacco rod <NUM> from falling off and prevent a liquefied aerosol from flowing into the aerosol-generating device <NUM> (see <FIG>) from the tobacco rod <NUM>, during smoking.

The filter rod <NUM> may include a first segment <NUM> and a second segment <NUM>. Here, the first segment <NUM> may correspond to the first segment of the filter rod <NUM> of <FIG>, and the second segment <NUM> may correspond to the third segment of the filter rod <NUM> of <FIG>.

The cigarette <NUM> may be packaged by at least one wrapper <NUM>. The wrapper <NUM> may have at least one hole through which external air or internal gas flows. For example, the front end plug <NUM> may be packaged by a first wrapper <NUM>, the tobacco rod <NUM> may be packaged by a second wrapper <NUM>, the first segment <NUM> may be packaged by a third wrapper (<NUM>), and the second segment <NUM> may be packaged by a fourth wrapper <NUM>. Then, the cigarette <NUM> may be entirely repackaged by a fifth wrapper <NUM>.

Also, the second segment <NUM> may include at least one capsule <NUM>. Here, the capsule <NUM> may generate flavor or an aerosol.

The heater may generate heat even when a failure occurs in the aerosol-generating device. For example, due to a malfunction of a processor, the heater may generate heat when it is not supposed to do so, or may generate excessive heat against a temperature profile. Here, the temperature profile of the heater may be preset for heating the heater. In addition, the heater may generate heat due to various malfunctions. In this case, the optimum taste may not be provided to a user, and there may be a safety problem in using an aerosol-generating device.

Hereinafter, a heater control circuit and a heater control method for preventing heater from generating heat due to a malfunction of the aerosol-generating device will be described.

<FIG> is a diagram schematically showing an example of a heater control circuit of an aerosol-generating device.

Referring to <FIG>, the heater control circuit includes a heater <NUM>, a first switch <NUM>, a second switch <NUM>, a first processor <NUM>, and a second processor <NUM>.

The first processor <NUM> and the second processor <NUM> may be included in the controller <NUM> illustrated in <FIG>. The first switch <NUM> and the second switch <NUM> may be included in the controller <NUM> illustrated in <FIG> or may be included in a heater that is controlled by the controller <NUM>.

The heater control circuit is applicable to all heating elements included in the aerosol-generating device. For example, the heater <NUM> may be a heater <NUM> for heating the cigarette shown in <FIG>. As another example, the heater <NUM> may be a heating element included in the vaporizer <NUM> shown in <FIG> and <FIG>. As another example, when the aerosol-generating device further includes heating elements other than those shown in <FIG>, the heater <NUM> may be the heating elements further included in the aerosol-generating device.

The first switch <NUM> may be electrically connected to the heater <NUM> in series. For example, the first switch <NUM> may be arranged between the heater <NUM> and the battery (<NUM> in <FIG>) such that it is electrically connected to the heater <NUM> in series. Unlike <FIG>, the first switch <NUM> may be arranged between the heater <NUM> and the second switch <NUM>, and the position of the first switch <NUM> is not limited to the position shown in <FIG>.

The state of the first switch <NUM> may be switched between an open state and a closed state according to an external input signal. The heater <NUM> may not receive power from the battery as the first switch <NUM> is in an open state, and may receive power from the battery as the first switch <NUM> is in a closed state.

The first switch <NUM> may be a field effect transistor (FET). The first switch <NUM> may be arranged such that a source is connected to the battery side, a drain is connected to the heater <NUM> side, and a gate is connected to the first processor <NUM> side.

The state of the first switch <NUM> may be determined according to the level of a signal transmitted to the gate of the first switch <NUM>. When a signal equal to or greater than a reference value is applied to the gate, current flows from the source to the drain, and the first switch <NUM> may be closed. Conversely, when a signal less than the reference value is applied to the gate, the first switch <NUM> may be opened.

The first switch <NUM> may be a P-channel FET, but is not limited thereto. That is, the first switch <NUM> may be an N-channel FET.

In addition, the first switch <NUM> may be another electrical element other than the FET, which is capable of switching between the open state and the closed state according to an external input signal. For example, the first switch <NUM> may be a bipolar junction transistor (BJT), an insulated gate bipolar transistor (IGBT), or a thyristor, but is not limited to the listed types.

The first switch <NUM>, the heater <NUM>, and second switch <NUM> may be electrically connected in series. For example, the second switch <NUM> may be arranged between the heater <NUM> and ground such that the first switch <NUM>, the heater <NUM>, and the second switch <NUM> are electrically connected in series. Unlike <FIG>, the second switch <NUM> may be arranged between the heater <NUM> and the first switch <NUM>, and the position of the second switch <NUM> is not limited to the position shown in <FIG>.

The state of the second switch <NUM> may be switched between an open state and a closed state according to an external input signal. The state of the second switch <NUM> may be repeatedly switched between the open state and the closed state in a short time. The second switch <NUM> may be repeatedly switched between open state and closed state based on a duty cycle of power required by the heater <NUM>.

The second switch <NUM>, like the first switch <NUM>, may be a field effect transistor (FET). The second switch <NUM> may be arranged such that a source is connected to the heater <NUM>, a drain is connected to the ground, and a gate is connected to the second processor <NUM>.

The second switch <NUM> may be an N-channel FET, but is not limited thereto. That is, the second switch <NUM> may be a P-channel FET.

In addition, the second switch <NUM>, like the first switch <NUM>, may be an electrical element other than the FET, which is capable of switching between the open state and the closed state according to an external input signal. For example, the second switch <NUM> may be a bipolar junction transistor (BJT), an insulated gate bipolar transistor (IGBT), or a thyristor, but is not limited to the listed types.

The first processor <NUM> may be implemented as an array of a plurality of logic gates or may be implemented as a combination of a general-purpose microprocessor and a memory in which a program executable in the microprocessor is stored. For example, the first processor <NUM> may be a micro controller unit including a microprocessor and an input/output module.

The first processor <NUM> may output a first control signal that controls the open/closed state of the first switch <NUM>. The first processor <NUM> may output a first control signal that controls the first switch <NUM> to be closed during a heating period of the heater <NUM> and to be opened during other periods.

The first control signal may be a direct current (DC) signal. For example, the waveform of the first control signal output from the first processor <NUM> during the heating period of the heater <NUM> may be the same as the graph shown on the left side of <FIG>. In addition, the first processor <NUM> may output a first control signal having a value higher than a gate reference value of the first switch <NUM> during the heating period of the heater <NUM>, and may output a first control signal having a value lower than the gate reference value in other periods.

The first processor <NUM> may receive a temperature value of the heater <NUM>. For example, the first processor <NUM> may receive the temperature value of the heater <NUM> measured by a temperature sensor.

The first processor <NUM> may output the first control signal based on the received temperature value. For example, when the received temperature value is out of a safe heating temperature range or not consistent with the temperature profile, the first processor <NUM> may output the first control signal to open the first switch <NUM>. That is, when the received temperature value is abnormal, the first processor <NUM> may determine that the aerosol-generating device is malfunctioning due to a failure of the heater <NUM>, the second processor <NUM>, etc., and output the first control signal to open the first switch <NUM> so that the heater <NUM> does not generate heat.

The second processor <NUM> may be a processor that operates independently of the first processor <NUM>. The second processor <NUM> may be implemented as an array of a plurality of logic gates or may be implemented as a combination of a general-purpose microprocessor and a memory in which a program executable in the microprocessor is stored. For example, the second processor <NUM> may be a micro controller unit including a microprocessor and an input/output module.

The second processor <NUM> may output the second control signal that controls the open/closed state of the second switch <NUM>. The second processor <NUM> may output the second control signal that causes the state of the second switch <NUM> to switch between the open state and the closed state so that the heater <NUM> generates heat according to the temperature profile.

The second control signal may be an alternate current (AC) signal. For example, the second control signal output from the second processor <NUM> may be a pulse width modulation (PWM) signal such as the graph shown on the right side of <FIG>. Also, according to the duty cycle of the power required by the heater <NUM>, the second processor <NUM> may output a second control signal having a value higher than the gate reference value of the second switch <NUM> so that the second switch <NUM> is in the closed state, or may output a second control signal having a value lower than the gate reference value of the second switch <NUM> so that the second switch <NUM> is in the open state.

In <FIG>, it is shown that the first processor <NUM> receives the temperature value of the heater <NUM>, but unlike this, the second processor <NUM> may receive the temperature value of the heater <NUM>. The second processor <NUM> may directly receive a sensing value obtained by measuring the temperature of the heater <NUM> from the temperature sensor or indirectly receive the sensing value through the first processor <NUM>. Alternatively, both the first processor <NUM> and the second processor <NUM> may receive the temperature value of the heater <NUM>.

The second processor <NUM> may output the second control signal based on the received temperature value. For example, when the received temperature value is out of a safe heating temperature range, the second processor <NUM> may output the second control signal so that the second switch <NUM> is opened. For another example, when the received temperature value is out of an allowable error range based on the temperature profile of the heater <NUM>, the second processor <NUM> may output the second control signal so that the second switch <NUM> is opened. That is, when the received temperature value is abnormal, the second processor <NUM> may determine that the aerosol-generating device is malfunctioning due to a failure of the heater <NUM>, the first processor <NUM>, etc., and output the second control signal to open the second switch <NUM> so that the heater <NUM> does not generate heat.

The first processor <NUM> and the second processor <NUM> may communicate with each other. The communication between the first processor <NUM> and the second processor <NUM> may be done via serial communication. For example, a universal asynchronous receiver transmitter (UART), serial peripheral interface (SPI), inter integrated circuit (I2C), etc. may be used for the first processor <NUM> and the second processor <NUM> to perform serial communication, but is not limited to the listed types.

The second processor <NUM> may output the second control signal to change the open/closed state of the second switch <NUM> according to a communication status with the first processor <NUM>. When the first processor <NUM> malfunctions due to a failure or the like, the communication status between the first processor <NUM> and the second processor <NUM> may be defective. For example, the first processor <NUM>, due to a malfunction, may output white noise or a signal that does not conform to a communication protocol or may be in a non-responsive state, so that the communication status between the first processor <NUM> and the second processor <NUM> may become defective.

When the communication status with the first processor <NUM> becomes defective, the second processor <NUM> may output the second control signal to open the second switch <NUM> so that the heater <NUM> does not generate heat. That is, when the communication status with the first processor <NUM> becomes defective, the second processor <NUM> may determine that the first processor <NUM> is malfunctioning and output the second control signal to open the second switch <NUM> to prevent the heater <NUM> from generating heat while the first processor <NUM> malfunctions.

Also, the first processor <NUM> may output the first control signal so that the open/closed state of the first switch <NUM> is changed according to a communication status with the second processor <NUM>. When the communication status with the second processor <NUM> becomes defective, the first processor <NUM> may determine that the second processor <NUM> is malfunctioning and may output the first control signal to open the first switch <NUM> so that the heater <NUM> is prevented from generating heat.

As described above, the aerosol-generating device may include a plurality of processors, and the first processor <NUM> and the second processor <NUM> may control the first switch <NUM> and the second switch <NUM>, respectively. In particular, the first processor <NUM> and the second processor <NUM> may determine the failure of each other through the communication status. As such, when any one of the first processor <NUM> and the second processor <NUM> fails, the heater <NUM> may be prevented from malfunctioning.

The heater control circuit illustrated in <FIG> further includes a capacitor C1 between an output terminal of the second processor <NUM> and an input terminal of the second switch <NUM>, compared to the heater control circuit illustrated in <FIG>.

The second processor <NUM> may output the second control signal so that the open/closed state of the second switch <NUM> is changed according to the duty cycle of the power required by the heater <NUM>, and the second control signal may be an AC signal. For example, the second control signal may be a PWM signal.

The capacitor C1 has a characteristic of blocking an input signal when the input signal is a DC signal, and passing the input signal when the input signal is an AC signal.

The second processor <NUM> may output a second control signal of PWM in the normal state, and then output a second control signal that is a DC signal due to a malfunction. In this case, the heater <NUM> may generate heat or be overheated to a temperature out of the temperature profile. Since the capacitor C1 is mounted at the output terminal of the second processor <NUM>, even if the second processor <NUM> outputs a DC signal due to the malfunction, the second signal <NUM> may be prevented from being transmitted to the second switch <NUM> by the capacitor C1.

Therefore, even if both the first processor <NUM> and the second processor <NUM> output a DC signal (for example, a control signal of a waveform such as a graph shown on the left side of <FIG>) due to a malfunction, the heater <NUM> may be prevented from generating heat since the second control signal is blocked by the capacitor C1 and the second switch <NUM> is opened.

<FIG> is a diagram schematically showing an example of a heater control circuit of an aerosol-generating device. device which does not form part of the present invention.

The heater control circuit of the aerosol-generating device includes a first switch <NUM>, a second switch <NUM>, a first processor <NUM>, a heater <NUM>, and a rectifying circuit <NUM>. When compared to the heater control circuit shown in <FIG>, the heater control circuit shown in <FIG> does not include the second processor <NUM> and further includes a rectifying circuit <NUM>. The rest of configuration is the same.

The heater control circuit may include the rectifying circuit <NUM>. The rectifying circuit <NUM> may be electrically connected to at least one of input terminals L and M of the first switch, and may be electrically connected to an output terminal N of the first processor <NUM>.

When the received signal is an AC signal, the rectifying circuit <NUM> may convert the AC signal to a DC signal and output the DC signal. In addition, when the received signal is a DC signal, the rectifying circuit <NUM> may block the DC signal and may not output the DC signal.

For example, the rectifying circuit <NUM> may include resistors R1 and R2, capacitors C2 and C3, and a transistor TR as shown in <FIG>. The transistor may be an NPN transistor, but is not limited thereto.

The resistor R1 and the capacitor C2 may be electrically connected to the source input terminal L and the gate input terminal M of the first switch <NUM>. In addition, the resistor R2, the transistor TR, and the capacitor C3 may be electrically connected to the gate input terminal M of the first switch <NUM> and the output terminal N of the first processor <NUM>.

The rectifying circuit <NUM> may be a circuit different from that shown in <FIG>, and may include other electrical elements such as a diode in addition to the resistors, capacitors, and transistor.

As the heater control circuit illustrated in <FIG> further includes the rectifying circuit <NUM>, the first control signal output by the first processor <NUM> may be an AC signal. For example, the first control signal may be a PWM signal.

When the first processor <NUM> outputs the PWM signal, the PWM signal is converted into a DC signal by the rectifying circuit <NUM> and then transmitted to the first switch <NUM>, so that the first switch <NUM> may be maintained in the closed state.

In addition, as the rectifying circuit <NUM> includes the capacitor C3, when the first control signal output from the first processor <NUM> is a DC signal, the first switch <NUM> may be maintained in the open state. That is, when the first control signal is a DC signal, the first control signal is blocked by the capacitor C3, so that the first switch <NUM> may be maintained in the open state. Accordingly, even if the first processor <NUM> outputs a DC signal as the first control signal due to a malfunction, the DC signal is blocked by the rectifying circuit <NUM>, and therefore, the first switch <NUM> may be opened.

The first processor <NUM> may output the first control signal that is a PWM signal (for example, a signal having a waveform such as a graph shown on the right side of <FIG>) in the normal state and then output a DC signal (for example, a signal having a waveform such as a graph shown on the left side of <FIG>) due to a malfunction. When the DC signal is transmitted to the heater <NUM>, the heater <NUM> may generate heat or be overheated to a temperature out of the temperature profile. Since the first control signal output from the first processor <NUM> due to a malfunction corresponds to a DC signal, delivery of the first control signal to the first switch <NUM> may be blocked by the rectifying circuit <NUM>, and the heater <NUM> may be prevented from generating heat.

In addition, the first processor <NUM> may output a PWM signal in the normal state to control the second switch <NUM> and then output a DC signal due to a malfunction. Even in this case, the DC signal output due to a malfunction may be blocked by the capacitor C1, so that the second switch <NUM> may be opened, and the heater <NUM> may be prevented from generating heat.

Therefore, even if the first switch <NUM> and the second switch <NUM> are controlled by one processor, since the signal output due to the malfunction of the first processor <NUM> is blocked by the rectifying circuit <NUM> and the capacitor C1, the heater <NUM> may be prevented from generating heat due to a malfunction of the first processor <NUM>.

In addition, even if one of the capacitors C1 and C3 is short-circuited, the DC signal is blocked by the other capacitor, so that the heater <NUM> may be prevented from generating heat.

The heater control circuit shown in <FIG> further includes a rectifying circuit <NUM>, compared to the heater control circuit shown in <FIG>.

When the first processor <NUM> malfunctions, the communication status between the first processor <NUM> and the second processor <NUM> may be defective. When the communication status with the first processor <NUM> is defective, the second processor <NUM> may determine that the first processor <NUM> is malfunctioning and output the second control signal so that the second switch <NUM> is opened. As the second switch <NUM> is opened, the heater <NUM> may be prevented from generating heat while the first processor <NUM> malfunctions.

Likewise, when the second processor <NUM> malfunctions, the communication status between the first processor <NUM> and the second processor <NUM> may be defective. When the communication status with the second processor <NUM> is defective, the first processor <NUM> may determine that the second processor <NUM> is malfunctioning and output the first control signal so that the first switch <NUM> is opened. As the first switch <NUM> is opened, the heater <NUM> may be prevented from generating heat while the second processor <NUM> malfunctions.

Also, the first processor <NUM> and the second processor <NUM> may output a control signal that causes both the first switch <NUM> and the second switch <NUM> to be closed due to a malfunction. For example, the first processor <NUM> and the second processor <NUM> may output a DC signal such as the graph shown on the left side of <FIG> due to a malfunction. In this case, the first control signal is blocked by the rectifying circuit <NUM>, and the second control signal is blocked by the capacitor C1, so that the first switch <NUM> and the second switch <NUM> may be in the open state. As the first switch <NUM> and the second switch <NUM> are in the open state, even if both the first processor <NUM> and the second processor <NUM> malfunction, the heater <NUM> may be prevented from generating heat.

<FIG> is a flowchart illustrating an example of a method of controlling a heater of an aerosol-generating device.

Referring to <FIG>, the method of controlling the heater includes operations that are processed sequentially in the heater control circuits illustrated in <FIG> and <FIG>. Therefore, it may be seen that the contents described above with respect to the heater control circuits shown in <FIG> and <FIG> are applied to the method of controlling the heater of <FIG> even if the contents are not described below.

In operation S110, the first processor <NUM> may output the first control signal that controls the open/closed state of the first switch <NUM>. The first processor <NUM> may output the first control signal that controls the first switch <NUM> to be closed during the period in which the heater <NUM> needs to be heated, and the first switch <NUM> to be opened during other periods.

In operation S120, the second processor <NUM> may output the second control signal that controls the open/closed state of the second switch <NUM>. The second processor <NUM> may output the second control signal that repeatedly switches the state of the second switch <NUM> between the open state and the closed state so that the heater <NUM> generates heat according to the temperature profile.

In operation S130, the first processor <NUM> and the second processor <NUM> may perform communication. The communication method performed between the first processor <NUM> and the second processor <NUM> may be serial communication. For example, a universal asynchronous receiver transmitter (UART), serial peripheral interface (SPI), inter integrated circuit (I2C), etc. may be used for the first processor <NUM> and the second processor <NUM> to perform serial communication, but is limited to the listed types.

In operation S140, the second processor <NUM> may output the second control signal so that the open/closed state of the second switch <NUM> is changed according to a communication status with the first processor <NUM>. Also, the first processor <NUM> may output the first control signal so that the open/closed state of the first switch <NUM> is changed according to a communication status with the second processor <NUM>.

Claim 1:
An aerosol-generating device (<NUM>) comprising:
a heater (<NUM>, <NUM>);
a first switch (<NUM>) electrically connected to the heater (<NUM>, <NUM>) in series;
and a second switch (<NUM>) electrically connected to the heater (<NUM>, <NUM>) and the first switch (<NUM>) in series; characterised in that the aerosol-generating device (<NUM>) further comprises:
a first processor (<NUM>) configured to output a first control signal that controls an open/closed state of the first switch (<NUM>); and
a second processor (<NUM>) configured to perform communication with the first processor (<NUM>), and output a second control signal that controls an open/closed state of the second switch (<NUM>) such that the open/closed state of the second switch (<NUM>) is changed based on a communication status with the first processor (<NUM>),
wherein when the communication status with the first processor (<NUM>) is defective, the second processor (<NUM>) is configured to output the second control signal such that the second switch (<NUM>) is opened.