Patent Description:
Recently, there is a growing demand for alternative methods of resolving problems of common cigarettes. For example, there is a growing demand for a method of generating aerosol by heating an aerosol generating material in a cigarette instead of burning the cigarette to generate aerosol. Therefore, research into heating-type cigarettes or heating-type aerosol generation devices is being actively carried out.

The aerosol generation device may include a heater for generating an aerosol by generally heating an aerosol generating substrate and a separate main controller unit (MCU) to control power supplied to the heater. The heater of the aerosol generation device has a characteristic of being heated by power supplied by a battery and preheated until reaching a target temperature sufficient to heat the aerosol generating substrate. In general, a preheating time changes according to the power supplied to the heater, and when the voltage level of the battery changes, the power that the battery may supply to the heater also changes, and thus the preheating time of the heater is not constant. When the preheating time of the heater is not constant, not only does the waiting time of a user who wants to inhale the aerosol through the aerosol generation device change every time, but also a thermal energy received by the aerosol generating substrate (a cigarette or liquid) is not constant, which causes a problem in that the smoking satisfaction of the user changes every time. The following documents are representative of the prior art:.

Provided are a method of ensuring a uniform preheating time of a heater regardless of a state of a battery and an aerosol generation device for implementing the method.

According to an aspect of the present disclosure, an aerosol generation device according to the appended claim <NUM> is provided.

According to another aspect of the present disclosure, a method of controlling power of a battery supplied to a heater according to the appended independent claim <NUM> is provided.

Further aspects of the aerosol generation device and the method of controlling power of a battery supplied to a heater are defined in the appended dependent claims.

According to an aerosol generation device of the present disclosure, the preheating time of a heater may be ensured to be uniform regardless of a state or a type of a battery.

As the present disclosure allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. The accompanying drawings for illustrating the present disclosure are referred to in order to gain a sufficient understanding, the merits thereof, and the objectives accomplished by the implementation. However, the present disclosure may have different forms and should not be construed as being limited to the descriptions set forth herein.

The embodiments of the present disclosure will be described below in more detail with reference to the accompanying drawings. Those elements that are the same or are in correspondence are rendered the same reference numeral regardless of the figure number, and redundant explanations are omitted.

While such terms as "first," "second," etc., may be used to describe various elements, such elements must not be limited to the above terms. The above terms are used only to distinguish one element from another.

In the present disclosure, it is to be understood that the terms such as "including," "having," and "comprising" are intended to indicate the existence of the features or elements disclosed in the disclosure, and are not intended to preclude the possibility that one or more other features or elements may exist or may be added.

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, a cigarette <NUM> may be inserted into an inner space of the aerosol generating device <NUM>.

Also, <FIG> and <FIG> illustrate that the aerosol generating device <NUM> includes the heater <NUM>. However, according to necessity (although not according to the claimed invention), a heater may be omitted.

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 from the cigarette <NUM> and/or the vaporizer <NUM>. The aerosol generated by the heater <NUM> and/or the vaporizer <NUM> is delivered to a user by passing through the cigarette <NUM>.

According to necessity, even when the cigarette <NUM> is not inserted into the aerosol generating device <NUM>, the aerosol generating device <NUM> may heat the heater <NUM>.

Specifically, the controller <NUM> may control not only operations of the battery <NUM>, the heater <NUM>, and the vaporizer <NUM>, but also operations of other components included in the aerosol generating device <NUM>.

Specifically, the heater <NUM> may include an electrically conductive coil for heating a cigarette in an induction heating method, and the cigarette may include a susceptor which may be heated by the induction heater.

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 <NUM> to be delivered to the user.

The liquid storage may be formed to be attached/detached to/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 (a puff detecting sensor, a temperature detecting sensor, a cigarette insertion detecting sensor, etc.). 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. Alternatively, 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, the opening and closing and/or a size of the air passage formed in the aerosol generating device <NUM> may be adjusted by the user. Accordingly, the amount of smoke and a smoking impression 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>.

<FIG> illustrates an example of a cigarette.

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, and the second portion <NUM> 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, according to necessity, the filter rod <NUM> may further include at least one segment configured to perform other functions.

The cigarette <NUM> may be packaged via at least one wrapper <NUM>. The wrapper <NUM> may have at least one hole through which external air may be introduced or internal air may be discharged. For example, the cigarette <NUM> may be packaged via one wrapper <NUM>. As another example, the cigarette <NUM> may be double-packaged via at least two wrappers <NUM>. For example, the tobacco rod <NUM> may be packaged via a first wrapper, and the filter rod <NUM> may be packaged via a second wrapper. Also, the tobacco rod <NUM> and the filter rod <NUM>, which are respectively packaged via separate wrappers, may be coupled to each other, and the entire cigarette <NUM> may be packaged via a third wrapper. When each of the tobacco rod <NUM> and the filter rod <NUM> includes a plurality of segments, each segment may be packaged via a separate wrapper. Also, the entire cigarette <NUM> including the plurality of segments, which are respectively packaged via the separate wrappers and which are coupled to each other, may be re-packaged via another wrapper.

Also, shapes of the filter rod <NUM> are not limited.

When the filter rod <NUM> includes a segment configured to cool the aerosol, the cooling segment may include a polymer material or a biodegradable polymer material. For example, the cooling segment may include pure polylactic acid alone, but the material for forming the cooling segment is not limited thereto. In some embodiments, the cooling segment may include a cellulose acetate filter having a plurality of holes. However, the cooling segment is not limited to the above-described example and is not limited as long as the cooling segment cools the aerosol.

Although not illustrated in <FIG>, the cigarette <NUM> according to an embodiment may further include a front-end filter. The front-end filter may be located on a side of the tobacco rod <NUM>, the side facing the filter rod <NUM>. The front-end filter may prevent the tobacco rod <NUM> from being detached outwards and prevent a liquefied aerosol from flowing into the aerosol generating device <NUM> (<FIG>) from the tobacco rod <NUM>, during smoking.

<FIG> is a diagram illustrating a temperature curve of a heater for each voltage of a battery when the heater is preheated at a fixed pulse width modulation (PWM) duty.

Referring to <FIG>, the heater exhibits different preheating patterns for each of the voltage levels of the battery at <NUM>. 5V and <NUM>. 0V First, referring to a preheating curve <NUM>, when the initial voltage of the battery is <NUM>. 2V, according to the fixed PWM duty, power supplied to the heater is determined to be relatively high such that, after about <NUM> seconds have elapsed since the start of preheating, the temperature of the heater reaches a target temperature of <NUM> degrees. Subsequently, referring to a preheating curve <NUM>, when the initial voltage of the battery is <NUM>. 5V, after about <NUM> seconds have elapsed since the start of preheating, the temperature of the heater reaches the target temperature of <NUM> degrees, and referring to a preheating curve <NUM>, when the initial voltage of the battery is <NUM>. 0V, after about <NUM> seconds have elapsed since the start of preheating, the temperature of the heater reaches the target temperature of <NUM> degrees.

When the power is supplied to the heater through a control signal using the fixed PWM duty regardless of the voltage level of the battery as shown in <FIG>, a difference occurs in the preheating time and the temperature rising inclination according to the voltage level of the battery. Because the difference in the preheating time causes a difference in a thermal energy received by an aerosol generating substrate, it is impossible to provide a consistent smoking experience to the user, and thus the present disclosure intends to solve the above problem by controlling the power based on the state information of the battery.

<FIG> is a diagram schematically showing a block diagram of an example of an aerosol generation device <NUM>.

Referring to <FIG>, the aerosol generation device <NUM> according to the present disclosure may include the controller <NUM>, the battery <NUM>, the heater <NUM>, a PWM processor <NUM>, a display <NUM>, a motor <NUM>, a storage device <NUM> and a field effect transistor (FET) <NUM>.

The controller <NUM> may collectively control the battery <NUM>, the heater <NUM>, the PWM processor <NUM>, the display <NUM>, the motor <NUM>, the storage device <NUM>, and the FET <NUM> included in the aerosol generation device <NUM>. Although not shown in <FIG>, according to an embodiment, the controller <NUM> may further include an input receiver (not shown) that receives a button input or a touch input of a user and a communicator (not shown) that communicates with an external communication device such as a user terminal.

The battery <NUM> may supply power to the heater <NUM>, and the magnitude of the power supplied to the heater <NUM> may be adjusted by a control signal output from the controller <NUM>.

The heater <NUM> may generate heat by an intrinsic resistance when a current is applied. When an aerosol generating substrate contacts (couples) the heated heater <NUM>, an aerosol that may be inhaled by the user may be generated.

The PWM processor <NUM> may allow the controller <NUM> to control the power supplied to the heater <NUM> through a method of transmitting a PWM signal to the heater <NUM>. According to an embodiment, the PWM processor <NUM> may be implemented in a manner in which the PWM processor <NUM> is included in the controller <NUM>.

The display <NUM> may visually output various alarm messages generated by the aerosol generation device <NUM> such that a user who uses the aerosol generation device <NUM> may confirm the alarm messages. The user may confirm a battery power shortage message or an overheat warning message of the heater <NUM> output on the display <NUM> and take appropriate measures before an operation of the aerosol generation device <NUM> stops or the aerosol generation device <NUM> is damaged.

The motor <NUM> may be driven by the controller <NUM> to allow the user to perceive through the tactile sense that the aerosol generation device <NUM> is ready for use.

The storage device <NUM> may store various information for the controller <NUM> to appropriately control the power supplied to the heater <NUM> and to provide various flavors to the user who uses the aerosol generation device <NUM>. The storage device <NUM> may not only be configured as a nonvolatile memory like a flash memory, but also as a volatile memory that temporarily stores data only when electrically connected in order to secure a faster data input/output (I/O) speed.

The FET <NUM> receives the control signal from the controller <NUM> and repeats an on-off operation to adjust the power provided to the heater <NUM>. According to an embodiment, the FET <NUM> may be omitted from the aerosol generation device <NUM>. When the FET <NUM> is omitted, a signal output from the controller <NUM> or the PWM processor <NUM> is directly transmitted to the heater <NUM>. A detailed operation of the FET <NUM> will be described later with reference to <FIG>.

<FIG> is a diagram for explaining a control signal output from the controller <NUM>.

Referring to <FIG>, a PWM signal for driving power applied to a battery by the controller <NUM> has a constant duty ratio D. Hereinafter, referring to <FIG> and <FIG>, an operation process of an aerosol generation device that controls power supplied to a heater based on the voltage level of the battery <NUM> according to the present disclosure will be described in detail.

Equation <NUM> defines an effective voltage Veff of the battery <NUM>. In Equation <NUM>, VB denotes a battery voltage, and T<NUM> and T<NUM> denote specific time points which are different from each other on the time axis. As shown in Equation <NUM>, the effective voltage Veff between T1 and T2 may be maintained constantly by adjusting the duty ratio D even when the battery voltage VB drops.

Equation <NUM> defines the duty ratio D. The duty ratio D refers to a ratio of the time that a current flows in a specific device or module with respect to a sum of the time that the current flows and the time that no current flows when the current is supplied to the device or the module in the form of a periodic pulse. According to an embodiment, the duty ratio D may be defined for the voltage as well as the current. In Equation <NUM>, T<NUM> <NUM> denotes a time point when a control signal for controlling the heater <NUM> is transmitted to the heater <NUM>, T<NUM> <NUM> denotes a time point when one cycle of the control signal ends, and T<NUM> <NUM> denotes a time point when the current (voltage) in the control signal of the form of pulse is supplied to the heater <NUM> and then cut off. The control signal is generated to keep the battery voltage VB constant for a predetermined period T2-T1.

Equation <NUM> defines power supplied by the battery <NUM>. In Equation <NUM>, RH denotes a resistance value of the heater <NUM>. As shown in Equation <NUM>, the power supplied to the heater <NUM> depends on the duty ratio D of the voltage VB of the battery <NUM>, the resistance of the battery <NUM>, and the power transfer signal (the control signal) applied to the heater <NUM>, and thus, even if the voltage VB of the battery <NUM> decreases, the power may be maintained at a constant value by increasing the duty ratio D.

Equation <NUM> summarizes Equation <NUM> with respect to the duty ratio D. As shown in Equation <NUM>, the duty ratio D of the power transfer signal applied to the heater <NUM> is proportional to the power applied to the heater <NUM> and the resistance value of the heater <NUM>, and is inversely proportional to the square of the voltage VB of the battery <NUM>.

Equation <NUM> is another example of the duty ratio D described in Equation <NUM>. In Equation <NUM>, KP denotes a proportional constant, Vmin denotes a minimum value of the voltage used by the battery <NUM>, PWMmax denotes a maximum value of the PWM duty, and Vc denotes a voltage level of the battery <NUM> at the present time point.

First, the proportional constant KP is an experimentally determined constant value, and is defined as a number that adjusts the duty ratio D to have a value in a predetermined range. Vmin denotes the minimum value of the voltage used by the battery <NUM> and denotes a preset voltage value according to a unique design characteristic of each battery <NUM> or the equivalent impedance of the entire module receiving power from the battery <NUM> in the aerosol generation device <NUM>. The battery <NUM> may output at least one voltage as much as Vmin as an output voltage. PWMmax denotes the maximum value of the PWM duty, and may be arbitrarily selected from values between <NUM> and <NUM>. Vc denotes the voltage level of the battery <NUM> at the present time point. In this regard, the present time point may be various time points other than the time point when the heater <NUM> starts to be heated.

Equation <NUM> is a formula that further generalizes Equation <NUM> to highlight the effect of the present disclosure, and the controller <NUM> included in the aerosol generation device <NUM> according to the present disclosure calculates the duty ratio D of the control signal through Equation <NUM> and transfers the control signal according to the calculated duty ratio D to the heater <NUM>, and thus according to the present disclosure, a constant preheating time may be ensured at all times regardless of a state of the battery <NUM>. As shown in Equation <NUM>, even when the resistance value RH of the heater <NUM> or the battery voltage VB changes, the power supplied to the heater <NUM> may be maintained constant by adjusting the duty ratio D.

The controller <NUM> may identify the state information of the battery <NUM> at the time point when the heater <NUM> starts to be heated, and calculate the duty ratio D of the control signal based on the identified state information. Here, the duty ratio D of the control signal calculated by the controller <NUM> refers to the duty ratio D calculated by Equation <NUM>, and the state information of the battery <NUM> is a concept encompassing information used to identify the state of the battery <NUM> output from the battery <NUM> when the time point is fixed, and may include all of the voltage values of the battery <NUM>, the maximum storage capacity when the battery <NUM> was produced, the remaining capacity of the battery <NUM>, the intrinsic identification information of the battery <NUM> itself or information directly related to battery life.

As an example, the controller <NUM> may calculate the duty ratio D of the control signal based on the voltage value of the battery <NUM> extracted from the state information of the battery <NUM>. The voltage value of the battery <NUM> at this time means a voltage value at the time point when the heater <NUM> starts to be heated by the power supplied by the battery <NUM>.

As another example, the controller <NUM> may calculate the duty ratio D of the control signal based on the minimum value Vmin of the voltage used by the battery <NUM> that is preset according to the equivalent impedance of the entire module receiving power from the battery <NUM>. Here, the minimum value Vmin of the voltage used by the battery <NUM> in Equation <NUM> is the intrinsic value determined according to the design of the aerosol generation device <NUM> or the battery <NUM> and may be obtained from the battery <NUM> or the storage device <NUM>.

As another example, the controller <NUM> may analyze the state information of the battery <NUM> to estimate the remaining capacity of the battery <NUM> and calculate the duty ratio D based on the estimated remaining capacity. In this case, the controller <NUM> may estimate the remaining capacity of the battery <NUM> using the voltage value of the battery <NUM> at the present time point. As a method of estimating the remaining capacity of the battery <NUM> using the voltage value of the battery <NUM>, a well-known method as described in <CIT> may be adopted.

As another example, the aerosol generation device <NUM> according to the present disclosure may also include the FET <NUM> that performs an on-off operation according to the duty ratio D when the controller <NUM> calculates the duty ratio D of the control signal and to allow the power of the battery <NUM> to be supplied to the heater <NUM>. More specifically, when the PWM processor <NUM> receives the control signal of the controller <NUM> and inputs the PWM signal that changes the duty value by modulating a pulse width of the control signal to the FET <NUM>, the FET <NUM> supplies the power to the heater <NUM> according to the duty value of the PWM signal through a process of repeatedly performing the on-off operation. At this time, the duty value is a value for supplying a constant power to the heater <NUM> regardless of the state information of the battery <NUM> and may be calculated using Equation <NUM>.

According to the claimed invention, the controller <NUM> is configured to control power to be supplied to the heater <NUM> by using a control signal according to a first duty ratio at the heating start time point, and, when the state information of the battery <NUM> changes exceeding a preset range before the temperature of the heater <NUM> reaches a target temperature, the controller <NUM> calculates a second duty ratio at a time point of the change and controls the power to be supplied to the heater <NUM> by using a control signal according to the second duty ratio. In a further embodiment, the controller <NUM> may monitor not only the temperature of the heater <NUM>, but also the voltage level of the battery <NUM> in real time, and when the voltage level of the battery <NUM> falls exceeding a preset range before the temperature of the heater <NUM> reaches the target temperature, the controller <NUM> may increase the duty ratio by a predetermined value in real time such that the power supplied to the heater <NUM> does not fall.

Here, the first duty ratio is calculated according to the voltage level of the battery <NUM> at the heating start time point when the heater <NUM> starts to be heated, and the second duty ratio is calculated according to the voltage level of the battery <NUM> at the time when the voltage level of the battery <NUM> rapidly falls before the temperature of the heater <NUM> reaches the target temperature.

The battery voltage has a characteristic in which the voltage level gradually decreases according to the discharged capacitance and rapidly falls while the battery <NUM> is rapidly discharged at a specific time point. Accordingly, as described with Equation <NUM>, because the voltage level of the battery <NUM> drops, a voltage applied from the battery <NUM> to the heater <NUM> also tends to gradually decrease, and the controller <NUM> may determine that the state information of the battery <NUM> has changed exceeding the preset range when the voltage level of the battery <NUM> rapidly falls and may increase the duty ratio D of the control signal, thereby controlling the power supplied to the heater <NUM> to be constantly maintained.

<FIG> is a diagram for explaining a relationship between a battery voltage and a duty ratio according to a power value.

Referring to <FIG>, the voltage level of the battery <NUM> and the duty ratio vary according to the power supplied to the heater <NUM>. More specifically, the duty ratio of a control signal increases as the supply power value increases.

<FIG> is a diagram illustrating a relationship between a resistance value of a heater and a duty ratio.

As shown in <FIG>, the duty ratio of a control signal increases as the resistance value of the heater increases.

Referring to <FIG>, the duty ratio of the control signal may be calculated in consideration of at least one of the state information of the battery, such as the voltage level of the battery, the resistance value of the heater, and a supply power supplied to the heater, which are already described in Equations <NUM> to <NUM>.

<FIG> is a diagram schematically illustrating a preheating time of a heater when power is supplied to the heater using a control signal having a flexible duty ratio according to the state information of a battery.

First, in the related art, it is assumed that the power is supplied to the heater by the battery, having the minimum voltage level of 3V and the maximum voltage level of <NUM>. 2V, through the control signal according to the fixed duty ratio without considering the state information of the battery. According to Equation <NUM> described above, because the duty ratio D and the resistance RH of the heater may be regarded as a constant value, the power supplied to the heater further increases when the voltage level of the battery is high, and thus the preheating time is rapidly reduced compared to when the voltage level of the battery is relatively low. For example, according to a preheating time curve <NUM> of the related art, the preheating time of the heater is only about <NUM> seconds when the voltage level of the battery is <NUM>. 2V, whereas the preheating time of the heater is only about <NUM> seconds when the voltage level of the battery is <NUM>.

Meanwhile, when the duty ratio of the control signal is calculated according to the state information (the voltage level) of the battery at the time point when the heater starts to be heated according to the present disclosure, and the power is supplied to the heater according to the control signal having the calculated duty ratio, according to a preheating time curve <NUM> according to the present disclosure, the preheating time of <NUM> seconds is maintained regardless of the voltage level of the battery.

<FIG> is a diagram schematically illustrating a graph of an increase in the temperature of a heater when power is supplied to the heater using a control signal having a flexible duty ratio according to the state information of a battery.

Comparing <FIG> with <FIG>, because the power is supplied to the heater using the control signal of the flexible duty ratio calculated according to the state information of the battery, the time for the heater taken to reach a target temperature is about <NUM> seconds which is the same when the voltage level of the battery is <NUM>. 5V, and <NUM>. 0V at the time point when the heater starts to be heated.

<FIG> is a flowchart illustrating an example of a method of controlling power supplied to a heater according to the present disclosure.

<FIG> may be implemented through the aerosol generation device <NUM> according to <FIG>, and thus the following description will be provided with reference to <FIG>, and redundant descriptions between <FIG> and <FIG> will be omitted.

The controller <NUM> of the aerosol generation device <NUM> detects an operation of the aerosol generation device <NUM> and starts to heat the heater <NUM> (S1210). More specifically, the controller <NUM> may detect the operation of the aerosol generation device <NUM> in various ways. As an example, the controller <NUM> may recognize that a user presses an operation button provided in the aerosol generation device <NUM> as the operation of the aerosol generation device <NUM>.

As another example, the controller <NUM> may recognize that an aerosol generating substrate is mounted on the aerosol generation device <NUM> as the operation of the aerosol generation device <NUM>. In this case, the aerosol generating substrate may be a cigarette or a liquid cartridge according to a type of the aerosol generation device <NUM>.

As an alternative embodiment of operation S1210, in order to detect the operation of the aerosol generation device <NUM>, after the aerosol generating substrate is mounted on the aerosol generation device <NUM>, the controller <NUM> may additionally determine whether aerosol generation device <NUM> satisfies conditions of use. The controller <NUM> may check whether the remaining capacity of the battery <NUM> exceeds a preset value and a connection state or an assembly state is normal between modules constituting the aerosol generation device <NUM> when the aerosol generation device is mounted on the aerosol generation device <NUM> to determine whether the aerosol generation device <NUM> satisfies the conditions of use.

Subsequently, the controller <NUM> determines the state information of the battery <NUM> at a heating start time point when the heater <NUM> starts to be heated (S1230). According to an embodiment, it is already described that the controller <NUM> may further identify the state information of the battery <NUM> at the time point when the voltage level of the battery <NUM> falls exceeding a preset range in addition to the heating start time point.

The controller <NUM> calculates a duty ratio of a control signal based on the state information of the battery <NUM> identified in operation S1230 (S1250). The duty ratio calculated in operation S1250 may vary according to a minimum value of the voltage used by the battery <NUM> and the voltage level of the battery <NUM> at the time point when the heater <NUM> starts to be heated according to Equation <NUM>.

The controller <NUM> transmits the control signal according to the duty ratio calculated in operation S1250 to the heater <NUM> and controls the heater <NUM> to be heated (S1270). In operation S1270, the heater <NUM> reaches the target temperature through the same preheating time regardless of the state information (the voltage level) of the battery <NUM> in operation S1230, and uniform heat energy is applied to the aerosol generating substrate through the same preheating time, and thus the user may have a consistent smoking experience through the aerosol generation device <NUM> according to the present disclosure.

Embodiments according to the present disclosure described above may be implemented using a computer program that may be executed through various elements on a computer, and such a computer program may be recorded in a computer-readable medium. In this regard, examples of the medium may include magnetic media such as a hard disk, a floppy disk, and magnetic tape, optical media such as compact disk read only memory (CD-ROM) and digital versatile disk (DVD), magneto-optical media such as a floptical disk, and a hardware device especially configured to store and execute a program command, such as read only memory (ROM), random access memory (RAM) and flash memory, etc.

Meanwhile, the computer program may be a program command specially designed and configured for the present disclosure or a program command known to be used by those of skill in the art of the computer software field. Further, examples of the program commands include machine language code created by a compiler and high-level language code executable by a computer using an interpreter.

The particular implementations shown and described in the present disclosure are illustrative examples and are not intended to otherwise limit the scope of the present invention in any way. For the sake of brevity, conventional electronics, control systems, software development and other functional aspects of the systems may not be described in detail. Furthermore, the connecting lines, or connectors shown in the various figures presented are intended to represent exemplary functional relationships and/or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may be present in a practical device. Moreover, no item or component is essential to the practice of the present disclosure unless the element is specifically described as "essential" or "critical".

Herein (especially, in the claims), the use of "the" and other demonstratives similar thereto may correspond to both a singular form and a plural form. Also, when a range is described in the present disclosure, the range has to be regarded as including disclosure adopting any individual element within the range (unless described otherwise), and it has to be regarded as having written in the detailed description each individual element included in the range. Unless the order of operations of a method according to the present disclosure is explicitly mentioned or described otherwise, the operations may be performed in a proper order. The present disclosure is not limited to the order the operations are mentioned. The use of all examples or exemplary terms (e.g., "etc.,", "and (or) the like", and "and so forth") in the present disclosure is merely intended to describe the embodiment in detail, and the scope of the present disclosure is not necessarily limited by the examples or exemplary terms unless defined by the claims. Also, one of ordinary skill in the art may appreciate that the present disclosure may be configured through various modifications, combinations, and changes according to design conditions and factors.

Claim 1:
An aerosol generation device (<NUM>) comprising:
a heater (<NUM>) configured to generate an aerosol by heating an aerosol generating substrate; and
a controller (<NUM>) configured to control power to be supplied to the heater (<NUM>) for a preheating time by a battery (<NUM>) using a control signal,
wherein the preheating time is a period of time for the heater (<NUM>) to reach a target temperature,
wherein the controller (<NUM>) is further configured to:
identify state information of the battery (<NUM>) at a heating start time point when the heater (<NUM>) starts to be heated,
calculate a duty ratio of the control signal based on the identified state information, and
adjust the duty ratio so that the power supplied to the heater (<NUM>) is maintained at a constant value to provide a constant preheating time, even when the battery voltage drops,
characterised in that the controller (<NUM>) is further configured to: control the power to be supplied to the heater (<NUM>) using a control signal according to a first duty ratio at the heating start time point, and
when a change in the state information of the battery exceeds a preset range before the heater reaches a target temperature, calculate a second duty ratio at a time point of the change to control the power to be supplied to the heater (<NUM>) using a control signal according to the calculated second duty ratio.