AEROSOL GENERATING DEVICE WITH FULL BRIDGE DRIVING CIRCUIT

A driving circuit according to an example has a form of a full bridge including four switches, and the driving circuit includes a first alternating current power supply that provides a voltage to a gate terminal of a first switch and a gate terminal of a fourth switch, a second alternating current power supply that provides a voltage to a gate terminal of a second switch and a gate terminal of a third switch, and a direct current power supply that provides a direct current voltage to a drain terminal of the first switch and a drain terminal of the third switch.

TECHNICAL FIELD

The following embodiments relate to a device for generating an aerosol, and more particularly, to a full bridge driving circuit of an aerosol generating device.

BACKGROUND ART

These days, there is a gradual rise in the demand for electronic cigarettes. The rising demand for electronic cigarettes has accelerated the continued development of electronic cigarette-related functions. The electronic cigarette-related functions may include, in particular, functions according to types and characteristics of electronic cigarettes.

DISCLOSURE OF THE INVENTION

Technical Goals

An embodiment may provide a driving circuit for driving a vibrator of an aerosol generating device.

An embodiment may provide an aerosol generating device for generating an aerosol.

Technical Solutions

According to an embodiment, a driving circuit may include, for supplying power to a vibrator of a cartridge, a first electrical contact connectable to a first end of the vibrator and a second electrical contact connectable to a second end of the vibrator, an inductor connected to the first electrical contact, wherein a first end of the inductor is connected to the first electrical contact, a first switch having a source terminal connected to a second end of the inductor, a second switch having a drain terminal connected to the second end of the inductor, wherein a source terminal of the second switch is connected to a ground, a third switch having a source terminal connected to the second electrical contact, a fourth switch having a drain terminal connected to the second electrical contact, wherein a source terminal of the fourth switch is connected to a ground, a first power supply configured to provide a voltage to a drain terminal of the first switch and a drain terminal of the third switch, a second power supply configured to provide a voltage to a gate terminal of the first switch and a gate terminal of the fourth switch, and a third power supply configured to provide a gate terminal of the second switch and a gate terminal of the third switch.

The first power supply may be configured to provide a direct current voltage to a drain terminal of the first switch and a drain terminal of the third switch.

A direct current voltage provided by the first power supply may be less than or equal to 15 volts (V).

The second power supply may be configured to provide a first alternating current voltage to the gate terminal of the first switch and the gate terminal of the fourth switch, and the third power supply may be configured to provide a second alternating current voltage to the gate terminal of the second switch and the gate terminal of the third switch.

A peak value of the first alternating current voltage and a peak value of the second alternating current voltage may each be less than or equal to 4 V.

The second power supply and the third power supply may operate alternately.

A voltage between the first end and the second end of the vibrator may be greater than or equal to 100 V.

The driving circuit may further include a fifth switch connected to the second electrical contact and a sixth switch positioned between the drain terminal of the third switch and the first power supply, wherein a source terminal of the sixth switch is connected to the drain terminal of the third switch, and a drain terminal of the sixth switch is connected to the first power supply, and wherein a first control signal provided to a gate terminal of the fifth switch and a second control signal provided to a gate terminal of the sixth switch may be different from each other.

A voltage between the first end and the second end of the vibrator may be greater than or equal to 50 V.

The driving circuit may be included in an electronic cigarette.

According to an embodiment, an electronic device may include a cartridge unit including a vibrator configured to generate an aerosol by vibrating an aerosol generating material and a body connected to the cartridge unit, wherein the body may include, when the cartridge unit is connected to the body, a driving circuit configured to operate the vibrator and a controller configured to control an operation of the driving circuit, and wherein the driving circuit may include, for supplying power to the vibrator of the cartridge unit, a first electrical contact connectable to a first end of the vibrator and a second electrical contact connectable to a second end of the vibrator, an inductor connected to the first electrical contact, wherein a first end of the inductor is connected to the first electrical contact, a first switch having a source terminal connected to a second end of the inductor, a second switch having a drain terminal connected to the second end of the inductor, wherein a source terminal of the second switch is connected to a ground, a third switch having a source terminal connected to the second electrical contact, a fourth switch having a drain terminal connected to the second electrical contact, wherein the source terminal of the second switch is connected to a ground, a first power supply configured to provide a voltage to a drain terminal of the first switch and a drain terminal of the third switch, a second power supply configured to provide a voltage to a gate terminal of the first switch and a gate terminal of the fourth switch, and a third power supply configured to provide a gate terminal of the second switch and a gate terminal of the third switch.

Effects

A driving circuit for driving a vibrator of an aerosol generating device may be provided.

An aerosol generating device for generating an aerosol may be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

The following structural or functional description of embodiments is provided as an example only and various alterations and modifications may be made to the embodiments. Accordingly, the embodiments are not construed as limited to the disclosure and should be understood to include all changes, equivalents, or replacements within the idea and the technical scope of the disclosure.

Although terms, such as first, second, and the like, are used to describe various components, the components are not limited to the terms. These terms should be used only to distinguish one component from another component. For example, a first component may be referred to as a second component, and similarly the second component may be referred to as the first component.

It should be understood that if it is described that one component is “connected,” “coupled,” or “joined” to another component, a third component may be “connected,” “coupled,” and “joined” between the first and second components, although the first component may be directly connected, coupled, or joined to the second component.

The singular forms “a,” “an,” and “the” include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises/comprising” or “includes/including” when used herein, specify the presence of stated features, integers, steps, operations, elements, components or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components or combinations thereof.

Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as those generally understood by one of ordinary skill in the art to which this disclosure pertains. Terms, such as those defined in commonly used dictionaries, should be interpreted to have meanings matching with contextual meanings in the relevant art, and are not to be interpreted to have an ideal or excessively formal meaning unless otherwise defined herein.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. When describing the embodiments with reference to the accompanying drawings, like reference numerals refer to like elements and a repeated description related thereto will be omitted.

FIG.1is a block diagram of an aerosol generating device according to an embodiment.

According to an embodiment, an aerosol generating device100ofFIG.1may include a controller110, a sensing unit120, an output unit130, a battery140, a heater150, a user input unit160, a memory170, and a communication unit180. However, an internal structure of the aerosol generating device100is not limited to what is shown inFIG.1. It is to be understood by one of ordinary skill in the art to which the disclosure pertains that some of the components shown inFIG.1may be omitted or new components may be added according to the design of the aerosol generating device100.

The sensing unit120may sense a state of the aerosol generating device100or a state of an environment around the aerosol generating device100, and transmit sensing information obtained through the sensing to the controller110. Based on the sensing information, the controller110may control the aerosol generating device100to control operations of the heater150, restrict smoking, determine whether an aerosol generating article (e.g., an aerosol generating article, a cartridge, etc.) is inserted, display a notification, and perform other functions.

The sensing unit120may include at least one of a temperature sensor122, an insertion detection sensor124, or a puff sensor126. However, embodiments are not limited thereto.

The temperature sensor122may sense a temperature at which the heater150(or an aerosol generating material) is heated. The aerosol generating device100may include a separate temperature sensor for sensing a temperature of the heater150, or the heater150itself may perform a function as a temperature sensor. Alternatively, the temperature sensor122may be arranged around the battery140to monitor a temperature of the battery140.

The insertion detection sensor124may sense whether the aerosol generating article is inserted and/or removed. The insertion detection sensor124may include, for example, at least one of a film sensor, a pressure sensor, a light sensor, a resistive sensor, a capacitive sensor, an inductive sensor, or an infrared sensor, which may sense a signal change by the insertion and/or removal of the aerosol generating article.

The puff sensor126may sense a puff from a user based on various physical changes in an airflow path or airflow channel. For example, the puff sensor126may sense the puff from the user based on any one of a temperature change, a flow change, a voltage change, and a pressure change.

The sensing unit120may further include at least one of a temperature/humidity sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a gyroscope sensor, a position sensor (e.g., a global positioning system (GPS)), a proximity sensor, or a red, green, blue (RGB) sensor (e.g., an illuminance sensor), in addition to the sensors122to126described above. A function of each sensor may be intuitively inferable from its name by one of ordinary skill in the art, and thus, a more detailed description thereof will be omitted here.

The output unit130may output information about the state of the aerosol generating device100and provide the information to the user. The output unit130may include at least one of a display132, a haptic portion134, or a sound outputter136. However, embodiments are not limited thereto. When the display132and a touchpad are provided in a layered structure to form a touchscreen, the display132may be used as an input device in addition to an output device.

The display132may visually provide the information about the aerosol generating device100to the user. The information about the aerosol generating device100may include, for example, a charging/discharging state of the battery140of the aerosol generating device100, a preheating state of the heater150, an insertion/removal state of the aerosol generating article, a limited usage state (e.g., an abnormal article detected) of the aerosol generating device100, or the like, and the display132may externally output the information. The display132may be, for example, a liquid-crystal display panel (LCD), an organic light-emitting display panel (OLED), or the like. The display132may also be in the form of a light-emitting diode (LED) device.

The haptic portion134may provide the information about the aerosol generating device100to the user in a haptic way by converting an electrical signal into a mechanical stimulus or an electrical stimulus. The haptic portion134may include, for example, a motor, a piezoelectric element, or an electrical stimulation device.

The sound outputter136may provide the information about the aerosol generating device100to the user in an auditory way. For example, the sound outputter136may convert an electrical signal into a sound signal and externally output the sound signal.

The battery140may supply power to be used to operate the aerosol generating device100. The battery140may supply power to heat the heater150. In addition, the battery140may supply power required for operations of the other components (e.g., the sensing unit120, the output unit130, the user input unit160, the memory170, and the communication unit180) included in the aerosol generating device100. The battery140may be a rechargeable battery or a disposable battery. The battery140may be, for example, a lithium polymer (LiPoly) battery. However, embodiments are not limited thereto.

The heater150may receive power from the battery140to heat the aerosol generating material. Although not shown inFIG.1, the aerosol generating device100may further include a power conversion circuit (e.g., a direct current (DC)-to-DC (DC/DC) converter) that converts power of the battery140and supplies the power to the heater150. In addition, when the aerosol generating device100generates an aerosol in an induction heating manner, the aerosol generating device100may further include a DC-to-alternating current (AC) (DC/AC) converter that converts DC power of the battery140into AC power.

The controller110, the sensing unit120, the output unit130, the user input unit160, the memory170, and the communication unit180may receive power from the battery140to perform functions. Although not shown inFIG.1, the aerosol generating device100may further include a power conversion circuit, for example, a low dropout (LDO) circuit or a voltage regulator circuit, which converts power of the battery140and supplies the power to respective components.

In an embodiment, the heater150may be formed of a predetermined electrically resistive material that is suitable. For example, the electrically resistive material may be a metal or a metal alloy including, for example, titanium, zirconium, tantalum, platinum, nickel, cobalt, chromium, hafnium, niobium, molybdenum, tungsten, tin, gallium, manganese, iron, copper, stainless steel, nichrome, or the like. However, embodiments are not limited thereto. In addition, the heater150may be implemented as a metal heating wire, a metal heating plate on which an electrically conductive track is arranged, a ceramic heating element, or the like, but is not limited thereto.

According to an embodiment, the heater150may be an induction heater. For example, the heater150may include a susceptor that heats the aerosol generating material by generating heat through a magnetic field applied by a coil.

In an embodiment, the heater150may be a vibrator that provides an ultrasonic vibration to the aerosol generating material. For example, when the vibrator vibrates the aerosol generating material with ultrasonic waves, the aerosol generating material may be aerosolized.

In an embodiment, the heater150may include a plurality of heaters. For example, the heater150may include a first heater for heating the aerosol generating article and a second heater for heating a liquid.

The user input unit160may receive information input from the user or may output information to the user. For example, the user input unit160may include a keypad, a dome switch, a touchpad (e.g., a contact capacitive type, a pressure resistive film type, an infrared sensing type, a surface ultrasonic conduction type, an integral tension measurement type, a piezo effect method, etc.), a jog wheel, a jog switch, or the like. However, embodiments are not limited thereto. In addition, although not shown inFIG.1, the aerosol generating device100may further include a connection interface such as a universal serial bus (USB) interface, and may be connected to another external device through the connection interface such as a USB interface to transmit and receive information or to charge the battery140.

The memory170, which is hardware for storing various pieces of data processed in the aerosol generating device100, may store data processed by the controller110and data to be processed by the controller110. The memory170may include at least one type of storage medium of a flash memory type memory, a hard disk type memory, a multimedia card micro type memory, a card type memory (e.g., an SD or XD memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, or an optical disk. The memory170may store an operating time of the aerosol generating device100, a maximum number of puffs, a current number of puffs, at least one temperature profile, data associated with a smoking pattern of the user, or the like.

The communication unit180may include at least one component for communicating with another electronic device. For example, the communication unit180may include a short-range wireless communication unit182and a wireless communication unit184.

The short-range wireless communication unit182may include a Bluetooth communication unit, a Bluetooth low energy (BLE) communication unit, a near field communication unit, a wireless area network (WLAN) (wireless fidelity (Wi-Fi)) communication unit, a ZigBee communication unit, an infrared data association (IrDA) communication unit, a Wi-Fi direct (WFD) communication unit, an ultra-wideband (UWB) communication unit, and an Ant+ communication unit. However, embodiments are not limited thereto.

The wireless communication unit184may include, for example, a cellular network communication unit, an Internet communication unit, a computer network (e.g., a local area network (LAN) or a wide-area network (WAN)) communication unit, or the like. However, embodiments are not limited thereto. The wireless communication unit184may use subscriber information (e.g., international mobile subscriber identity (IMSI)) to identify and authenticate the aerosol generating device100in a communication network.

The controller110may control the overall operation of the aerosol generating device100. In an embodiment, the controller110may include at least one processor. The processor 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 by the microprocessor is stored. In addition, it is to be understood by one of ordinary skill in the art to which the disclosure pertains that the processor may be implemented in other types of hardware.

The controller110may control the temperature of the heater150by controlling supply of power from the battery140to the heater150. For example, the controller110may control the supply of power by controlling switching of a switching element between the battery140and the heater150. As another example, a direct heating circuit may control the supply of power to the heater150according to a control command from the controller110.

The controller110may analyze a sensing result obtained by the sensing of the sensing unit120and control processes to be performed thereafter. For example, the controller110may control power to be supplied to the heater150to start or end an operation of the heater150based on the sensing result obtained by the sensing unit120. As another example, the controller110may control an amount of power to be supplied to the heater150and a time for which the power is to be supplied, such that the heater150may be heated up to a predetermined temperature or maintained at a desired temperature, based on the sensing result obtained by the sensing unit120.

The controller110may control the output unit130based on the sensing result obtained by the sensing unit120. For example, when a number of puffs counted through the puff sensor126reaches a preset number, the controller110may inform the user that the aerosol generating device100is to be ended soon, through at least one of the display132, the haptic portion134, or the sound outputter136.

In an embodiment, the controller110may control a power supply time and/or a power supply amount for the heater150according to a state of the aerosol generating article sensed by the sensing unit120. For example, when the aerosol generating article is in an over-humidified state, the controller110may control the power supply time for an inductive coil to increase a preheating time, compared to a case where the aerosol generating article is in a general state.

An embodiment may also be implemented in the form of a recording medium including instructions executable by a computer, such as a program module executable by the computer. A computer-readable medium may be any available medium that may be accessed by a computer and includes a volatile medium, a non-volatile medium, a removable medium, and a non-removable medium. In addition, the computer-readable medium may include both a computer storage medium and a communication medium. The computer storage medium includes all of a volatile medium, a non-volatile medium, a removable medium, and a non-removable medium implemented by any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. The communication medium typically includes computer-readable instructions, data structures, other data in modulated data signals such as program modules, or other transmission mechanisms, and includes any information transfer medium.

FIG.2is a cross-sectional view of an aerosol generating device according to an embodiment.

According to an embodiment, an aerosol generating device200(e.g., the aerosol generating device100ofFIG.1) may include a housing210, an aerosol generating module220, a cartridge230, a driving circuit235, a controller240, a mouthpiece250, a battery260, and an auxiliary elements270.

In an embodiment, the housing210may be configured to accommodate various electronic/mechanical components. For example, the aerosol generating module220, the cartridge230, the driving circuit235, the controller240, the battery260, and the auxiliary elements270may all be accommodated in the housing210and safely protected from an external stimulus (e.g., dust, impact, heat, etc.). As another example, the aerosol generating device200may include a cartridge unit including the aerosol generating module220and the cartridge230and a body including the driving circuit235, the controller240, and the battery260. The auxiliary elements270may be included in either the cartridge unit or the body.

In an embodiment, the aerosol generating module220may include an ultrasonic vibrator222, a surface acoustic wave vibrator224, and a transfer element226. The aerosol generating module220according to an embodiment is described in detail below with reference toFIG.3.

In an embodiment, the cartridge230may be disposed in the housing210and may store an aerosol forming substrate (i.e., aerosol generating material). The aerosol forming substrate may be stored in the cartridge230in at least one of a gaseous phase, a liquid phase, or a solid phase. Desirably, the aerosol forming substrate may be stored in the cartridge230in the liquid phase. The aerosol forming substrate in the liquid phase may be, for example, a liquid including a tobacco-containing material that includes a volatile tobacco flavor component, or may be a liquid including a non-tobacco material. The aerosol forming substrate in the liquid phase may include, for example, water, a solvent, ethanol, a plant extract, a fragrance, a flavoring agent, or a vitamin mixture. The fragrance may include, for example, menthol, peppermint, spearmint oil, various fruit-flavored ingredients, and the like, but is not limited thereto. The flavoring agent may include ingredients that provide a user with a variety of flavors or scents. The vitamin mixture may be a mixture of at least one of vitamin A, vitamin B, vitamin C, or vitamin E, but is not limited thereto. The aerosol forming substrate in the liquid phase may also include an aerosol former such as glycerin and propylene glycol.

The cartridge230according to an embodiment is described in detail below with reference toFIG.4.

In an embodiment, when the ultrasonic vibrator222is electrically connected to the driving circuit235, the driving circuit235may supply power to the ultrasonic vibrator222. For example, a magnitude of the power supplied to the ultrasonic vibrator222may be controlled by the controller240. A vibration frequency, or the like, of the ultrasonic vibrator222may be controlled depending on the magnitude of the power. The driving circuit235according to an embodiment is described in detail below with reference toFIG.5.

In an embodiment, the controller240may include at least one processor. The processor 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. The controller240, included in the aerosol generating device200according to an embodiment, may control whether the ultrasonic vibrator222and the surface acoustic wave vibrator224of the aerosol generating module220vibrate and the vibration frequencies of the ultrasonic vibrator222and the surface acoustic wave vibrator224. The controller240according to an embodiment is described in more detail below.

In an embodiment, the mouthpiece250is a portion that touches a mouth of the user, and an aerosol may be transferred to the user through an aerosol flow path included in the mouthpiece250. In an embodiment, the mouthpiece250may be disposed at an end of the housing210, and desirably, the mouthpiece250may be disposed to touch an end surface of the housing210.

In an embodiment, the battery260(e.g., the battery140ofFIG.1) may supply power used to operate the aerosol generating device200. For example, the battery260may supply power such that the ultrasonic vibrator222and the surface acoustic wave vibrator224of the aerosol generating module220may vibrate, and the battery260may supply power required for the controller240to operate. In addition, the battery260may supply power required to operate a display, a sensor, a motor, or the like installed in the aerosol generating device200.

In an embodiment, the auxiliary elements270may include an elastic body272, an electrode pin274, and a wire276. The auxiliary elements270according to an embodiment may include other additional units for smoothly operating the aerosol generating device200in addition to the above-described module and/or units. The elastic body272according to an embodiment may be disposed adjacent to the aerosol generating module220and compressed to apply pressure to the aerosol generating module220such that the aerosol forming substrate is smoothly transferred to the aerosol generating module220from the cartridge230. As a distance between the transfer element226and the cartridge230of the aerosol generating module220is shortened by the compression of the elastic body272, the aerosol forming substrate stored in the cartridge230in at least one of the gaseous phase, the liquid phase, or the solid phase may be efficiently transferred to the aerosol generating module220. The electrode pin274and the wire276according to an embodiment may connect the controller240and the battery260to the aerosol generating module220such that the battery260transfers power to the aerosol generating module220and the controller240controls the aerosol generating module220.

The aerosol generating module220controlled by the controller240is described below. In an embodiment, the controller240may control the aerosol generating device200such that the aerosol generating device200operates in one of at least two modes.

A first mode according to an embodiment may correspond to a mode in which the ultrasonic vibrator222and the surface acoustic wave vibrator224simultaneously vibrate. In the first mode, the ultrasonic vibrator222and the surface acoustic wave vibrator224may vibrate at different vibration frequencies and with different vibration periods, thereby acting as a main-vibration member and a sub-vibration member. When the ultrasonic vibrator222is the main-vibration member, the surface acoustic wave vibrator224is the sub-vibration member. When the surface acoustic wave vibrator224is the main-vibration member, the ultrasonic vibrator222is the sub-vibration member. When an aerosol is generated by the main-vibration member, the sub-vibration member may further increase an amount of the generated aerosol.

A second mode according to an embodiment may be a mode in which one of the ultrasonic vibrator222and the surface acoustic wave vibrator224vibrates first to preheat the aerosol forming substrate of the transfer element226, and the other one of the ultrasonic vibrator222and the surface acoustic wave vibrator224vibrates to generate an aerosol. When the aerosol forming substrate is in the liquid phase, viscosity of the aerosol forming substrate may generally be high. It is desirable that a predetermined level of heat is applied to preheat the aerosol forming substrate such that the aerosol forming substrate is more smoothly aerosolized. Accordingly, one of the ultrasonic vibrator222and the surface acoustic wave vibrator224may vibrate to preheat the aerosol forming substrate included in the transfer element226, and then the other one may vibrate to generate a larger amount of aerosol. In particular, when the aerosol forming substrate is to be preheated above a predetermined temperature (e.g., the Curie temperature) by vibration of the ultrasonic vibrator222, components included in the ultrasonic vibrator222may be damaged, resulting in damage to the device. In this regard, the device may have better durability when the preheating is performed by the surface acoustic wave vibrator224and an aerosol is generated by the ultrasonic vibrator222.

The controller240according to an embodiment may enable the aerosol generating device200to operate in various modes in addition to the above-described first and second modes.

FIG.3is a cross-sectional view of an aerosol generating module according to an example.

Referring toFIG.3, the transfer element226included in the aerosol generating module220according to an embodiment may include a first surface226afacing or disposed adjacent to the ultrasonic vibrator222and/or the surface acoustic wave vibrator224, and a second surface226bdisposed opposite to the first surface226a. The first surface226aof the transfer element226according to an embodiment may be disposed to the ultrasonic vibrator222and/or the surface acoustic wave vibrator224. Desirably, a partial region of the first surface226amay be adjacent to the ultrasonic vibrator222, and another partial region of the first surface226amay be adjacent to the surface acoustic wave vibrator224. As such, efficiency in aerosol generation may be improved by an interaction between the ultrasonic vibrator222and the surface acoustic wave vibrator224. In the aerosol generating module220according to an embodiment, frictional heat may be generated by a vibration of at least one of the ultrasonic vibrator222and the surface acoustic wave vibrator224, and some electrical energy may be converted into thermal energy in a process of converting electrical energy into mechanical energy through a piezoelectric body and/or a piezoelectric substrate224-1. The heat and thermal energy may heat the aerosol forming substrate. As the temperature of the aerosol forming substrate increases, the viscosity of the aerosol forming substrate decreases, and accordingly, an aerosol may be more smoothly generated by the ultrasonic vibrator222and the surface acoustic vibrator224.

The ultrasonic vibrator222according to an embodiment may include a piezoelectric body. The piezoelectric body according to an embodiment may be a conversion element that may convert electrical energy into mechanical energy and may generate an ultrasonic wave under the control of a controller (e.g., the controller110ofFIG.1). In an embodiment, when alternating current power is applied to a piezoelectric body that has undergone polarization processing, the piezoelectric body may repeatedly expand and contract. Accordingly, the ultrasonic vibrator222may vibrate at a characteristic frequency. In an embodiment, the ultrasonic vibrator222may further include a diaphragm (not shown) in contact with the piezoelectric body. The diaphragm in contact with the piezoelectric body may vibrate at the characteristic frequency together with the piezoelectric body due to the expansion and contraction of the piezoelectric body. One of ordinary skill in the art may obviously understand the principle of a piezoelectric vibration element, so any detailed description related thereto is omitted.

The ultrasonic vibrator according to an embodiment may include a piezoelectric transducer and a mesh plate. The piezoelectric transducer may be a conversion element that may convert electrical energy into mechanical energy and may generate an ultrasonic wave under the control of the controller (e.g., the controller110ofFIG.1). The mesh plate according to an embodiment may touch the aerosol forming substrate and atomize (aerosolize) the aerosol forming substrate. A vibration generated by the piezoelectric transducer may produce a pressure wave on the aerosol forming substrate, and the pressure wave may atomize the aerosol forming substrate by pushing the substrate into the gaps of the mesh plate.

The surface acoustic wave vibrator224according to an embodiment may include the piezoelectric substrate224-1and a transducer224-2. The transducer224-2may include a first electrode and a second electrode. Each of the first electrode and the second electrode according to an embodiment may include two or more fingers. A piezoelectric substrate generated between the fingers may be deformed by being stretched and compressed due to a voltage applied to the individual fingers of the electrodes of the transducer224-2. Accordingly, the piezoelectric substrate224-1may vibrate. A distance between the fingers of the electrodes according to an embodiment may correspond to a wavelength of a mechanical wave. The mechanical wave may generally have a nanometer-scale amplitude and may be propagated along a surface of the piezoelectric substrate224-1. An aerosol may be generated by a surface acoustic wave generated by the surface acoustic wave vibrator224according to an embodiment.

In an embodiment, a commonly known surface acoustic wave (SAW) sensor chip may be used as the surface acoustic wave vibrator224. The SAW sensor chip according to an embodiment may include at least one interdigital transducer including an electrode typically disposed on the piezoelectric substrate224-1.

The transfer element226according to an embodiment may include the first surface226aand the second surface226b. A partial region of the first surface226aof the transfer element226may be adjacent to the ultrasonic vibrator222, and another partial region of the first surface226amay be adjacent to the surface acoustic wave vibrator224. For example, the first surface226aof the transfer element226may include a first region Z1and a second region Z2. In an embodiment, the first region Z1of the first surface226aof the transfer element226may be a region overlapping the ultrasonic vibrator222. The second region Z2of the first surface226aof the transfer element226may be a region overlapping the surface acoustic wave vibrator224. According to embodiments, areas of the first region Z1and the second region Z2may vary depending on the sizes of the ultrasonic vibrator222and the surface acoustic wave vibrator224.

The transfer element226according to an embodiment may be a capillary tube element (e.g., a paper strip or a wick) for delivering the aerosol forming substrate from the cartridge, but embodiments are not limited thereto.

FIG.4is a schematic view of a cartridge according to an example.

The cartridge230according to an embodiment may include a first end wall230a, a second end wall230bdisposed opposite to the first end wall230a, and an outer wall230cand an inner wall230dconnecting the first end wall230aand the second end wall230b. The first end wall230a, the second end wall230b, the outer wall230c, and the inner wall230dmay form a storage space232for storing an aerosol forming substrate.

In this case, the cartridge230may include a through-hole that penetrates the first end wall230aand the second end wall230b. As such, an aerosol formed from an upper portion (e.g., the second surface226bof the transfer element226ofFIG.3) of the transfer element226may travel through the through-hole. That is, the cartridge230according to an embodiment may include an airflow path (e.g., the airflow path P ofFIG.2) penetrating the first end wall230aand the second end wall230band enclosed by the inner wall230d, and the aerosol may be transferred to the mouthpiece250through the airflow path P and reach a mouth of a user.

FIG.5illustrates a driving circuit according to an embodiment.

A driving circuit500according to an embodiment may be included in a body of the aerosol generating device and may supply power to a vibrator510(e.g., the ultrasonic vibrator222ofFIG.3) included in a cartridge unit. The driving circuit500may include a first electrical contact511connectable to a first end of the vibrator510, a second electrical contact513connectable to a second end of the vibrator510, an inductor520(e.g., a coil) of which a first end is connected to the first electrical contact511, a first switch SW1531having a source terminal connected to a second end of the inductor520, a second switch SW2533having a drain terminal connected to the second end of the inductor520and having a source terminal connected to a ground, a third switch SW3535having a source terminal connected to the second electrical contact513, a fourth switch537having a drain terminal connected to the second electrical contact513and having a source terminal connected to a ground, a first power supply501that provides a voltage to a drain terminal of the first switch531and a drain terminal of the third switch535, a second power supply V2503that provides a voltage to a gate terminal of the first switch531and a gate terminal of the fourth switch537, and a third power supply V3505that provides a voltage to a gate terminal of the second switch533and a gate terminal of the third switch535. For example, each of the first switch531, the second switch533, the third switch535, and the fourth switch537may be a switch based on a field effect transistor (FET). Here, when two elements are “connectable,” it refers to a configuration where the elements get connected to each other when a detachable part (e.g., a cartridge unit) of the aerosol generating device including one element is coupled to another detachable part (i.e., a body) of the aerosol generating device including the other element.

According to an embodiment, the vibrator510may be included in a cartridge unit. When the cartridge unit is mechanically coupled to a body, the vibrator510may be electrically connected to the first electrical contact511and the second electrical contact513of the driving circuit500by the coupling. When the first electrical contact511and the second electrical contact513are connected through the vibrator510, the controller240may recognize that the vibrator510is coupled and may supply power to the vibrator510through the driving circuit500.

The first power supply501according to an embodiment may provide a direct current (DC) voltage to the drain terminal of the first switch531and the drain terminal of the third switch535. For example, the direct current voltage may be less than or equal to 15 volts (V) (e.g., 10 V), but embodiments are not limited thereto.

The second power supply503according to an embodiment may provide a first alternating current (AC) voltage to the gate terminal of the first switch531and the gate terminal of the fourth switch537, and the third power supply505may provide a second alternating current voltage to the gate terminal of the second switch533and the gate terminal of the third switch535. For example, a peak value of the first alternating current voltage and a peak value of the second alternating current voltage may be less than or equal to 4 V, but embodiments are not limited thereto.

The second power supply503and the third power505supply according to an embodiment may operate alternately. That is, the second power supply503and the third power supply505may not operate simultaneously. A voltage between the first end and the second end of the vibrator510provided by the driving circuit500(i.e., the voltage between the first electrical contact511and the second electrical contact513when the vibrator510is electrically connected to the driving circuit) may be greater than or equal to 100 V, but embodiments are not limited thereto.

When the driving circuit500is used, it may be possible to apply a high voltage to generate a vibration of the vibrator510even at a voltage (e.g., 10 V) lower than a voltage (e.g., 17 V) applied to a switch of a driving circuit in a form of a boost converter.

Since a voltage applied to a switch of the driving circuit500is a voltage (e.g., 10 V) directly applied to a drain of the switch, there is no need for a switch capable of handling a high voltage. Accordingly, a switch with a low Rds(on) resistance may be applied to the driving circuit500, and issues such as component overheating may be reduced.

FIG.6illustrates a voltage applied to a vibrator through a driving circuit according to an example.

According to an embodiment, a waveform610of a voltage applied through the driving circuit500to the first end and the second end of the vibrator510is illustrated inFIG.6. For example, the first power supply501of the driving circuit500may provide a direct current voltage of 10 V, and alternating current voltages of the second power supply503and the third power supply505may be provided alternately. For this experiment, the alternating current voltages of the second power supply503and the third power supply505are set to have a peak of 3.3 V, a delay time (TD) of 0, a rise time (TR) of 10 nanoseconds (ns), a fall time (TF) of 10 ns, a pulse width (PW) of 0.16 microsecond (μs), and a period (PER) of 0.32 μs.

Under the above-mentioned conditions, a voltage across the vibrator510may reach 500 V at about 20 μs. A magnitude of the voltage applied to the vibrator510may be controlled by adjusting operating frequencies of the second power supply503and the third power supply505and voltages and currents applied to the switches.

FIG.7illustrates a driving circuit for switching between a full bridge mode and a half bridge mode according to an embodiment.

According to an embodiment, when compared with the driving circuit500described with reference toFIG.5, a driving circuit700may further include a fifth switch738connected to a second electrical contact713and a sixth switch739positioned between a drain terminal of a third switch735and a first power supply701. A source terminal of the sixth switch739is connected to the drain terminal of the third switch735, and a drain terminal of the sixth switch739is connected to the first power supply701. For example, a first control signal provided to a gate terminal of the fifth switch738and a second control signal provided to a gate terminal of the sixth switch739may be different from each other, and the first control signal and the second control signal may be provided by the controller240.

FIG.8illustrates an equivalent circuit of a driving circuit that operates in a half bridge mode according to an embodiment.

According to an embodiment, when a first control signal is LOW and a second control signal is HIGH, the driving circuit700may operate in a full bridge mode. Conversely, when the first control signal is HIGH and the second control signal is LOW, the driving circuit700may operate in a half bridge mode.FIG.8may illustrate an equivalent circuit800of the driving circuit700that operates in the half bridge mode.

According to an embodiment, when the second power supply703and the third power supply705operate alternately, a direction of a current flowing through the vibrator710may also change alternately.

When compared with the full bridge mode, in the half bridge mode, a maximum voltage applied to the vibrator710may be reduced, and the total power consumed by the driving circuit700may also be reduced. In this regard, when the aerosol generating device200operates in a mode in which a relatively smaller amount of aerosol is generated, the half bridge mode may be used. For example, in the half bridge mode, the voltage the first electrical contact711and the second electrical contact713(i.e., the voltage across the vibrator710) may be greater than or equal to 50 V.