Patent Description:
In recent years, the demand for alternative methods of overcoming shortcomings of general cigarettes has increased. For example, there is growing demand for a method of generating aerosol by heating a tobacco material in a cigarette, rather than by combusting a cigarette. Accordingly, research into a heating-type cigarette and a heating-type aerosol generating device is actively being conducted.

An alternative heating method has been proposed to replace a method of heating a cigarette by disposing a heater formed of an electric resistor inside or outside a cigarette accommodated in an aerosol generating device and by supplying power to the heater. In particular, research is being conducted into an induction heating method of generating aerosol by including a magnetic substance that generates heat by an external magnetic field and supplying a current to a coil included in the aerosol generating device to apply a magnetic field to the cigarette.

If a magnetic substance for generating heat by receiving a magnetic field is included in the cigarette, it may be difficult to directly measure a temperature of the magnetic substance that heats a cigarette, and thus, it may be difficult to control the temperature of the magnetic substance. In addition, if a magnetic substance is not uniformly distributed in the cigarette in a process of making the cigarette, the aerosol may be generated non-uniformly from the cigarette.

In order to resolve concerns that aerosol is generated non-uniformly and to improve quality of the aerosol generated from a cigarette by controlling a temperature of a magnetic substance more precisely, it may be required to improve a structure of a magnetic substance for heating a cigarette using an induction heating method. <CIT> relates to an internal induction heating smoking apparatus comprising a shell, a power supply arranged in the shell, an electronic control system and a heating cavity; the heating cavity is formed in one end of the shell and used for allowing a to-be-heated cigarette to be inserted; the internal induction heating smoking apparatus also comprises an induction heating element; the induction heating element comprises an induction coil and a heating element arranged in the heating cavity; and the electronic control system is used for converting electric energy provided by the power supply into a high-frequency induced current to be provided to the induction coil, and the high-frequency induced current in the induction coil generates an alternating magnetic field with constantly changed directions, so that the heating element in the alternating magnetic field forms a vortex current to be heated. <CIT> relates to an atomizer including a heating element, being configured for heating and atomizing tobacco liquid to generate an aerosol; a tobacco liquid reservoir, being configured for storing the tobacco liquid; and a liquid drive component, being connected with the tobacco liquid reservoir directly or indirectly, and being configured for controlling a volume of tobacco liquid conveyed to the heating element, with the tobacco liquid reservoir set on the atomizer, to control the volume of tobacco liquid in the tobacco liquid reservoir conveyed to the heating element so as to convey measurable tobacco liquid as well as generate measurable aerosol. <CIT> relates to a smoking set for a cigarette. <CIT> relates to a heating and atomizing device. The device comprises a shell; the shell comprises an air inlet and an air outlet, wherein a heating chamber is arranged in the shell, and an air flue is formed by the connection of the air inlet, the heating chamber and the air outlet; the heating chamber is filled with an atomizing material, a heat conductor of which one surface is closely propped against the atomizing material is arranged in the atomizing material, and the heat conductor is heated by an electric heating device. <CIT> relates to a hybrid heating formula electronic smoking set and heating element.

Various embodiments are directed to provide a heater assembly for heating a cigarette and an aerosol generating device including the same. Technical problem to be solved by the present disclosure are not limited to the technical problems described above, and other technical problems may be inferred from the following embodiments.

To solve the technical problems described above, an aerosol generating device including a heater assembly according to appended claim <NUM> is provided.

As a temperature sensor included in a heater assembly according to the present disclosure is included in the heater assembly and is disposed at a position in direct contact with an inner surface of a heating element for generating heat by receiving an external magnetic field, a temperature of the heater assembly heating a cigarette using an induction heating method may be directly measured and provided to an aerosol generating device, and thus, the temperature of the heater assembly for heating the cigarette may be more precisely controlled.

As a heating element including a ferromagnetic substance for generating heat by receiving an external magnetic field is disposed inside an aerosol generating device, not inside the cigarette, a problem that a magnetic substance is non-uniformly distributed when the magnetic substance is included in the cigarette may be solved is included in the cigarette, and aerosol may be generated more uniformly.

According to the claimed invention an aerosol generating device according to claim <NUM> is provided.

Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings. It should be understood that the following description is only for the purpose of embodying the embodiments and does not limit the scope of the disclosure.

Terms "configure", "include", and so on used in the present specification should not be construed as including all the various configuration elements or various steps described in the specification, and some of the configuration elements or steps may not be included, or additional configuration elements or steps may be further included.

Terms including an ordinal number such as "first" or "second" used in the present specification may be used to describe various configuration elements, but the configuration elements should not be limited by the terms. The terms are used only to distinguish one configuration element from other configuration elements.

With respect to the terms used in the present specification, general terms which are currently used as widely as possible are selected in consideration of functions of structural elements in the various embodiments of the present disclosure. However, meanings of the terms may be changed according to intention, a judicial precedence, the appearance of new technology, and the like. In addition, in a certain case, some terms are randomly selected by the applicant, and in this case, meanings thereof will be described in detail in the description of the corresponding disclosure. Accordingly, the terms used in the present disclosure should be defined based on the meanings of the terms and the content of the present disclosure, not simply by the names of the terms.

The present embodiments relate to a heater assembly for heating a cigarette and an aerosol generating device including the same, and detailed descriptions on matters well known to those skilled in the art to which the following embodiments belong will be omitted.

<FIG> is a view illustrating elements constituting an aerosol generating device including a heater assembly according to an embodiment. Referring to <FIG>, an aerosol generating device <NUM> may include a heater assembly <NUM>, an accommodation space <NUM>, a coil <NUM>, a power supply unit <NUM>, and a controller <NUM>. However, the aerosol generating device <NUM> is not limited thereto and may further include other general-purpose elements in addition to the elements illustrated in <FIG>.

The aerosol generating device <NUM> may generate aerosol by heating a cigarette accommodated in the aerosol generating device <NUM> by using an induction heating method. The induction heating method may include a method of generating heat from a magnetic substance by applying an alternating magnetic field of which direction is periodically changed to a magnetic substance that generates heat by receiving an external magnetic field.

When an alternating magnetic field is applied to a magnetic substance, energy loss may occur in the magnetic substance due to eddy current loss and hysteresis loss, and the lost energy may be released from the magnetic substance as thermal energy. As the amplitude or frequency of the alternating magnetic field applied to the magnetic substance increases, the heat energy released from the magnetic substance also increases. The aerosol generating device <NUM> may release heat energy from a magnetic substance by applying an alternating magnetic field to the magnetic substance and may transfer the heat energy emitted from the magnetic substance to a cigarette.

A magnetic substance that generates heat by receiving an external magnetic field may be a susceptor. The susceptor may be disposed in the aerosol generating device <NUM> instead of being included in the cigarette in the form of a chip, a slice, or a strip. For example, the susceptor may be included in the heater assembly <NUM> disposed inside the aerosol generating device <NUM>.

The susceptor may include metal or carbon. The susceptor may include at least one of ferrite, ferromagnetic alloy, stainless steel, and aluminum (Al). In addition, the susceptor may also include at least one of graphite, molybdenum, silicon carbide, niobium, nickel alloy, metal film, ceramic such as zirconia, transition metal such as nickel (Ni) or cobalt (Co), and metalloid such as boron (B) or phosphorus (P).

The aerosol generating device <NUM> may include the accommodation space <NUM> for accommodating a cigarette. The accommodation space <NUM> may include an opening that opens to the outside of the accommodation space <NUM> to accommodate a cigarette in the aerosol generating device <NUM>. A cigarette may be accommodated in the aerosol generating device <NUM> in a direction from the outside of the accommodation space <NUM> to the inside of the accommodation space <NUM> through the opening of the accommodation space <NUM>.

The heater assembly <NUM> may be disposed at an inner end portion of the accommodation space <NUM>. The heater assembly <NUM> may be attached to a bottom surface formed at the inner end portion of the accommodation space <NUM>. An upper end portion of the heater assembly <NUM> may be inserted into a cigarette, and the cigarette may reach a bottom surface of the accommodation space <NUM>.

The aerosol generating device <NUM> may include the coil <NUM> that applies an alternating magnetic field to the heater assembly <NUM>. The coil <NUM> may be wound around a side surface of the accommodation space <NUM> and may be disposed at a position corresponding to the heater assembly <NUM>. The coil <NUM> may receive power from the power supply unit <NUM>.

When power is supplied to the coil <NUM>, a magnetic field may be formed inside the coil <NUM>. When an AC current is applied from the power supply unit <NUM> to the coil <NUM>, the magnetic field formed in the coil <NUM> may periodically change in direction. When the heater assembly <NUM> formed inside the coil <NUM> is exposed to an alternating magnetic field that periodically changes a direction, the heater assembly <NUM> generates heat, thus heating a cigarette accommodated in the aerosol generating device <NUM>.

When an amplitude or frequency of the alternating magnetic field formed by the coil <NUM> changes, a temperature of the heater assembly <NUM> that heats the cigarette may also change. The controller <NUM> may adjust the amplitude or frequency of the alternating magnetic field formed by the coil <NUM> by controlling power supplied to the coil <NUM>, and thus, the temperature of the heater assembly <NUM> may be controlled.

For example, the coil <NUM> may be configured with a solenoid. The coil <NUM> may be a solenoid wound along a side surface of the accommodation space <NUM>, and a cigarette <NUM> may be accommodated in the inner space of the solenoid. A material of a conducting wire constituting the solenoid may be copper (Cu). However, the material of the conducting wire is not limited thereto and may be a material with a low specific resistance value allowing a large current to flow. For example, any one of silver (Ag), gold (Au), aluminum (Al), tungsten (W), zinc (Zn), and nickel (Ni) or an alloy containing at least one thereof may be the material of the conducting wire constituting the solenoid.

According to an embodiment, the susceptor may be included in the heater assembly <NUM> provided in the aerosol generating device <NUM> instead of being included in a cigarette. In this case, there may be various advantages as compared with a case in which the susceptor is included in the cigarette. For example, a problem that aerosol and flavor are generated non-uniformly when a material of the susceptor is not uniformly distributed inside the cigarette may be solved. In addition, since the heater assembly <NUM> including the susceptor is provided in the aerosol generating device <NUM>, a temperature of the heater assembly <NUM> that generates heat by induction heating may be directly measured and provided to the aerosol generating device <NUM>. Accordingly, the temperature of the heater assembly <NUM> may be controlled precisely.

<FIG> is a view illustrating a cigarette that is heated by a heater assembly and generates aerosol, according to an embodiment.

Referring to <FIG>, the cigarette <NUM> may include a tobacco rod <NUM> and a filter rod <NUM>. The filter rod <NUM> is illustrated as being composed of a single segment in <FIG>, but is not limited thereto and may be composed of a plurality of segments. For example, the filter rod <NUM> may include a first segment for cooling aerosol and a second segment for filtering a specific component included in the aerosol. In addition, the filter rod <NUM> may further include at least one segment that performs other functions.

The cigarette <NUM> may be wrapped by at least one wrapper <NUM>. The wrapper <NUM> may include at least one hole through which external air flows in or internal air flows out. The cigarette <NUM> may be wrapped by one wrapper <NUM>. As another example, the cigarette <NUM> may be wrapped by two or more wrappers <NUM> in an overlapping manner. Specifically, the tobacco rod <NUM> may be wrapped by a first wrapper, and the filter rod <NUM> may be wrapped by a second wrapper. The tobacco rod <NUM> and the filter rod <NUM> respectively wrapped by the wrappers are coupled to each other, and then the entire cigarette <NUM> may be rewrapped by a third wrapper.

For example, the aerosol generating material may contain at least one of glycerin, propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and oleyl alcohol, but is not limited thereto. The tobacco rod <NUM> may contain other additives such as a savoring agent, a wetting agent and/or organic acid. A flavored liquid such as menthol or moisturizer may be sprayed to the tobacco rod <NUM> to be added thereto.

The tobacco rod <NUM> may be made in various ways. For example, the tobacco rod <NUM> may be made of sheets or strands. Alternatively, the tobacco rod <NUM> may also be made of cut tobacco obtained by finely cutting a tobacco sheet.

The tobacco rod <NUM> may be surrounded by a heat-conducting material. For example, the heat-conducting material may be metal foil such as aluminum foil, but is not limited thereto. The heat-conducting material surrounding the tobacco rod <NUM> may evenly dissipate the heat transferred to the tobacco rod <NUM> to increase thermal conductivity of the tobacco rod <NUM>, thereby improving the savor of aerosol generated from the tobacco rod <NUM>.

The filter rod <NUM> may be a cellulose acetate filter. The filter rod <NUM> may have various forms. For example, the filter rod <NUM> may be a cylindrical rod, or a tubular rod including a hollow therein. Alternatively, the filter rod <NUM> may also be a recessed rod including a cavity therein. When the filter rod <NUM> is composed of a plurality of segments, the plurality of segments may have different shapes.

The filter rod <NUM> may be made to generate flavor. For example, a flavored liquid may be sprayed onto the filter rod <NUM>, or fibers coated with a flavored liquid may be inserted into the filter rod <NUM>.

The filter rod <NUM> may include at least one capsule <NUM>. The capsule <NUM> may generate flavor or aerosol. For example, the capsule <NUM> may be formed in a structure that includes a flavor-containing liquid wrapped with a film. The capsule <NUM> may have a spherical or cylindrical shape, but is not limited thereto.

When a cooling segment for cooling aerosol is included in the filter rod <NUM>, the cooling segment may be made of a polymer material or a biodegradable polymer material. For example, the cooling segment may be made of pure polylactic acid only. Alternatively, the cooling segment may be made of a cellulose acetate filter including a plurality of perforations. However, the cooling segment is not limited thereto, and may be composed of other structures and materials capable of cooling aerosol.

<FIG> is a view illustrating a heater assembly that heats a cigarette accommodated in an aerosol generating device according to an embodiment.

<FIG> illustrates the heater assembly <NUM> that heats the cigarette <NUM> accommodated in the aerosol generating device <NUM>. However, the aerosol generating device <NUM>, the cigarette <NUM>, and the heater assembly <NUM> illustrated in <FIG> are merely examples, and the aerosol generating device <NUM> and the heater assembly <NUM> may be arranged to form other structures capable of heating the cigarette <NUM>.

The cigarette <NUM> may be accommodated in the aerosol generating device <NUM> in a longitudinal direction of the cigarette <NUM>. The heater assembly <NUM> may be inserted into the cigarette <NUM> accommodated in the aerosol generating device <NUM>. The heater assembly <NUM> may have a structure extending in the longitudinal direction to be inserted into the cigarette <NUM>.

The heater assembly <NUM> may be located at a central portion of the accommodation space <NUM> to be inserted into a central portion of the cigarette <NUM>. In <FIG>, the heater assembly <NUM> is illustrated as being a single number but is not limited thereto, and the heater assembly <NUM> may be composed of a plurality of heater assemblies that extend in the longitudinal direction to be inserted into the cigarette <NUM> and are disposed in parallel to each other.

<FIG> is a view illustrating elements constituting a heater assembly according to an embodiment.

Referring to <FIG>, the heater assembly <NUM> may include a heating element <NUM> and a temperature sensor <NUM>. However, the heater assembly <NUM> is not limited thereto, and may also further include other general-purpose elements in addition to the elements illustrated in <FIG>. For example, the heater assembly <NUM> may further include a conducting wire connecting the temperature sensor <NUM> to the aerosol generating device <NUM>.

The heating element <NUM> may extend in the longitudinal direction of the cigarette <NUM>. The heating element <NUM> may be formed in an elongated structure extending in the longitudinal direction. A length of the heating element <NUM> extending in the longitudinal direction may be less than the total length of the cigarette <NUM> and may be less than a distance from a bottom surface of the accommodation space <NUM> to an opening of the accommodation space <NUM>. Alternatively, the length of the heating element <NUM> may be greater than a length of the tobacco rod <NUM> included in the cigarette <NUM> but is not limited thereto.

The heating element <NUM> may include a hollow therein. Therefore, the heating element <NUM> may have an outer surface and an inner surface. In order to have a large hollow formed inside the heating element <NUM>, a side surface of the heating element <NUM> formed between the outer surface and the inner surface of the heating element <NUM> may have a small thickness.

A cross-section of the heating element <NUM> cut along a plane orthogonal to a longitudinal direction may have various shapes. For example, a shape of the cross-section of the heating element <NUM> may be circular. When the cross-section of the heating element <NUM> and a cross-section of the cigarette <NUM> are circular, a diameter of the cross-section of the heating element <NUM> may be less than a diameter of the cross-section of the cigarette <NUM>. However, a cross-section of the heating element <NUM> may have other shape than the circular cross-section, which is suitable for being inserted into the cigarette <NUM> and transferring heat to the tobacco rod <NUM>.

The heating element <NUM> may include a ferromagnetic substance for generating heat by receiving an external magnetic field. The ferromagnetic substance may be a material that is magnetized in a direction of an external magnetic field and maintains a magnetic moment even after the external magnetic field disappears. As the ferromagnetic substance is included in the heating element <NUM>, when the external magnetic field is applied to the heater assembly <NUM>, the heater assembly <NUM> may heat the cigarette <NUM>. For example, the ferromagnetic substance may include one of iron (Fe), nickel (Ni), and cobalt (Co), or an alloy including at least one thereof, but is not limited thereto.

The entire heating element <NUM> may be formed of a ferromagnetic substance. Alternatively, only a part of the heating element <NUM> may also be formed of a ferromagnetic substance. A proportion of a ferromagnetic substance contained in the heating element <NUM> may be appropriately selected within a range suitable for heating the cigarette <NUM>.

When only a part of the heating element <NUM> is formed of a ferromagnetic substance, the ferromagnetic substance may be disposed at a position corresponding to the tobacco rod <NUM> of the cigarette <NUM> accommodated in the aerosol generating device <NUM>. At least a part of the ferromagnetic substance may be disposed at a portion where the heating element <NUM> is in contact with the tobacco rod <NUM>. Accordingly, the efficiency of heat transferred to the tobacco rod <NUM> and the efficiency of generating aerosol from the tobacco rod <NUM> may be increased.

The heating element <NUM> may be divided into detailed elements. For example, the heating element <NUM> may include an upper end portion <NUM>, a middle portion <NUM>, and a lower end portion <NUM>. The upper end portion <NUM> may be located near an opening of the accommodation space <NUM> and may indicate a portion from an end of the heating element <NUM> facing the opening of the accommodation space <NUM> to a boundary between the upper end portion <NUM> and the middle portion <NUM>. The lower end portion <NUM> may be located on an inner end portion of the accommodation space <NUM> and may indicate a portion from a bottom of the heating element <NUM> in contact with a bottom of the accommodation space <NUM> to a boundary between the lower end portion <NUM> and the middle portion <NUM>. The middle portion <NUM> may be located between the upper end portion <NUM> and the lower end portion <NUM>.

For example, when the cigarette <NUM> is accommodated in the aerosol generating device <NUM>, the cigarette <NUM> may be accommodated up to the middle portion <NUM> of the heating element <NUM>. Accordingly, a boundary between the lower end portion <NUM> and the middle portion <NUM> may be aligned with an end of the cigarette <NUM> which is accommodated in the aerosol generating device <NUM>. In addition, the heater assembly <NUM> may further include a supporting body located at the lower end portion <NUM> so that the cigarette <NUM> may not be accommodated beyond the boundary between the lower end portion <NUM> and the middle portion <NUM>.

The middle portion <NUM> of the heating element <NUM> may include a ferromagnetic substance. The middle portion <NUM> may be formed of a material corresponding to a ferromagnetic substance. Accordingly, the middle portion <NUM> may generate heat by receiving an external magnetic field. For example, the middle portion <NUM> may be positioned to come into contact with the tobacco rod <NUM> of the cigarette <NUM> accommodated in the aerosol generating device <NUM>.

The upper end portion <NUM> may have a cross-section that becomes smaller toward an end facing an opening of the accommodation space <NUM>. Specifically, the upper end portion <NUM> may have a conical shape or a poly pyramid shape that become narrower toward an end facing the opening. As such, the heater assembly <NUM> may be easily inserted into the cigarette <NUM>.

According to an embodiment, as the heater assembly <NUM> of the aerosol generating device <NUM> includes a ferromagnetic substance for generating heat by receiving an external magnetic field, the cigarette <NUM> may not include a separate susceptor material. Therefore, a separate process for making a cigarette containing a susceptor material may not be required. Also, a cigarette used in an existing heating-type aerosol generating device may also be used in the aerosol generating device <NUM> according to the present disclosure, and thus, the aerosol generating device <NUM> may have high compatibility with existing cigarettes. In addition, since a separate susceptor material may not be included in the cigarette <NUM>, a problem that aerosol is non-uniformly generated when the susceptor material is non-uniformly distributed in the cigarette may be solved.

As described above, since the heating element <NUM> is formed to include a hollow, a temperature of the heating element <NUM> increases may increase more rapidly compared with a case in which a hollow is not formed in the heating element <NUM>. When the inside of the heater body <NUM> is not empty, the inside tends to heat earlier than a surface thereof, which delays heating of the surface. Thus, a temperature of the surface may increase faster when the inside is empty. The cigarette <NUM> is heated in contact with the surface of the heating element <NUM>, and thus, when a hollow is formed inside the heating element <NUM>, a speed at which the cigarette <NUM> is heated may be increased.

The temperature sensor <NUM> may measure a temperature of the heating element <NUM>. The heater assembly <NUM> may include the heating element <NUM> and the temperature sensor <NUM>, and the temperature of the heating element <NUM> may be measured by the temperature sensor <NUM>, and thus, the temperature sensor <NUM> may directly measure the temperature of the heating element <NUM>. Accordingly, the temperature at which the heating element <NUM> heats the cigarette <NUM> may be accurately reflected in the temperature measured by the temperature sensor <NUM>.

When the heating element <NUM> further includes a hollow therein, the temperature sensor <NUM> may abuts an inner surface of the heating element <NUM>. The temperature sensor <NUM> in contact with the inner surface of the heating element <NUM> may be in direct contact with the heater assembly <NUM>. Since the heating element <NUM> may have a hollow therein, a sufficient space for the temperature sensor <NUM> may be formed inside the heating element <NUM> and the temperature sensor <NUM> may be disposed on a hollow surface formed inside the heating element <NUM>. As the temperature sensor <NUM> is disposed at a position in direct contact with the inner surface of the heating element <NUM>, the temperature sensor <NUM> may not be contaminated by the tobacco rod <NUM> heated by being in contact with an outer surface of the heating element <NUM>.

The temperature of the heating element <NUM> measured by the temperature sensor <NUM> may be provided to the controller <NUM> in the aerosol generating device <NUM>. For example, the heater assembly <NUM> may further include a wire for connecting the temperature sensor <NUM> to the controller <NUM> and delivering the temperature measured by the temperature sensor <NUM>.

The temperature sensor <NUM> may abut an inner surface of a ferromagnetic substance included in the heating element <NUM> although this mode is not covered by the claimed invention. The ferromagnetic substance may be disposed at a position corresponding to the tobacco rod <NUM>, and may heat the tobacco rod <NUM> by receiving an external magnetic field. Thus, if the temperature sensor <NUM> is disposed at a position corresponding to the ferromagnetic substance, the temperature at which the tobacco rod <NUM> is heated may be measured more accurately. However, as illustrated in <FIG> below, the temperature sensor <NUM> according to the claimed invention abuts an inner surface of the heating element <NUM> other than the ferromagnetic substance portion.

The temperature of the heating element <NUM> is directly measured by the temperature sensor <NUM>, and thus, the temperature of the heating element <NUM> may be precisely controlled. If the temperature sensor is not disposed at a position in direct contact with the susceptor material that heats by an external magnetic field, such as in a case where the susceptor material is included in a cigarette, it is difficult to accurately measure or control a temperature at which a cigarette is heated by a susceptor material. The heating element <NUM> according to the present disclosure is included in the heater assembly <NUM> of the aerosol generating device <NUM>, not in the cigarette <NUM>. Thus, a temperature of the heating element <NUM> may be accurately provided to the aerosol generating device <NUM> through the temperature sensor <NUM>, and the temperature of the heating element <NUM> may be precisely controlled.

As described above, the temperature sensor <NUM> may be disposed at a position corresponding to a ferromagnetic substance, but is not limited thereto. The temperature sensor <NUM> may be disposed at various positions on the heating element <NUM>. For example, the temperature sensor <NUM> may be disposed in the accommodation space <NUM> near the lower end portion <NUM> of the heating element <NUM>. When the temperature sensor <NUM> is disposed in the accommodation space <NUM>, the temperature sensor <NUM> may be configured with an infrared sensor that measures a temperature of the heating element <NUM> without coming into contact with the heating element <NUM>, but is not limited thereto.

<FIG> shows views illustrating a heating element further including at least one of a weak magnetic substance and a non-magnetic substance, according to an embodiment.

<FIG> illustrates various heating elements <NUM>, each including the upper end portion <NUM>, the middle portion <NUM>, and the lower end portion <NUM>. As described above, the heating element <NUM> may include a ferromagnetic substance.

The heating element <NUM> may further include at least one of a weak magnetic substance and a non-magnetic substance. The weak magnetic substance may refer to a material that generates heat by receiving an external magnetic field, which is weaker than heat generated by the ferromagnetic substance. The non-magnetic substance may refer to a material that does not generate heat by receiving an external magnetic field.

The weak magnetic substance may further include at least one of a paramagnetic substance and a diamagnetic substance. The paramagnetic substance may indicate a material that is partially magnetized in a direction of an external magnetic field. However, a magnetic moment may disappear when the external magnetic field disappears. The diamagnetic substance may indicate a material that is magnetized in a direction opposite to the external magnetic field. When the external magnetic field is applied to the heating element <NUM>, heating of the paramagnetic substance and the antimagnetic substance may be weaker than heating of the ferromagnetic substance.

For example, the paramagnetic substance may indicate at least one of aluminum (Al), tin (Sn), platinum (Pt), and iridium (Ir), and the diamagnetic substance may indicate metal other than a transition metal, such as bismuth (Bi), lead (Pb), mercury (Hg), copper (Cu), graphite (C), gold (Au), and silver (Ag).

The middle portion <NUM> of the heating element <NUM> may be formed of a ferromagnetic substance. The lower end portion <NUM> of the heating element <NUM> may be formed of a weak magnetic substance or a non-magnetic substance. The upper end portion <NUM> of the heating element <NUM> may be formed of a ferromagnetic substance, a weak magnetic substance, or a non-magnetic substance.

The ferromagnetic substance may serve as a main heating portion for heating the cigarette <NUM>. The paramagnetic substance may serve as an auxiliary heating portion for performing auxiliary heating of the cigarette <NUM>. A diamagnetic substance does not heat the cigarette <NUM>, but may support the heating element <NUM> or secure a length of the heating element <NUM>.

In the case of a heating element <NUM> and a heating element <NUM>, an upper end portion <NUM>, a middle portion <NUM>, and a middle portion <NUM> may be formed of a ferromagnetic substance to become a main heating portion, and a lower end portion <NUM>, an upper end portion <NUM>, and a lower end portion <NUM> may be formed of a paramagnetic substance to become an auxiliary heating portion. When the cigarette <NUM> is accommodated in the aerosol generating device <NUM>, the heating element <NUM> and the heating element <NUM> may have a size suitable for contacting the tobacco rod <NUM>.

In the case of a heating element <NUM>, the middle portion <NUM> may be formed of a ferromagnetic substance to become a main heating portion, a lower end portion <NUM> may be formed of a paramagnetic substance to become an auxiliary heating portion, and an upper end portion <NUM> may be formed of a diamagnetic substance. When the cigarette <NUM> is accommodated in the aerosol generating device <NUM>, the middle portion <NUM> and the lower end portion <NUM> come into contact with the tobacco rod <NUM>, and a size of the heating element <NUM> may be set so that the lower end portion <NUM> is located at the filter rod <NUM>.

In the case of a heating element <NUM>, a heating element <NUM>, and a heating element <NUM>, lower end portions <NUM>, <NUM>, and <NUM> may be formed of a non-magnetic substance, and middle portions <NUM>, <NUM>, and <NUM> may be formed of a ferromagnetic substance. Upper end portions <NUM>, <NUM>, and <NUM> may be formed of a ferromagnetic substance, a paramagnetic substance, and a non-magnetic substance, respectively. Portions formed of the ferromagnetic substance and the paramagnetic substance may generate heat by coming into contact with the tobacco rod <NUM>.

The lower end portions <NUM>, <NUM>, and <NUM> may not come into contact with the tobacco rod <NUM>. For example, supporting bodies may be disposed on side surfaces of the lower end portions <NUM>, <NUM>, and <NUM>, and thus, the middle portions <NUM>, <NUM>, and <NUM> and the upper end portions <NUM> and <NUM> may come into contact with the tobacco rod <NUM>. Alternatively, if the cigarette <NUM> further includes a front-end plug, the lower end portions <NUM>, <NUM>, and <NUM> may come into contact with the front-end plug, and the middle portions <NUM>, <NUM>, and <NUM> and the upper end portions <NUM> and <NUM> may come into contact with the tobacco rod <NUM>.

<FIG> shows views illustrating a temperature sensor disposed at a position in direct contact with an inner surface of a heating element according to embodiments.

<FIG> illustrates a heater assembly <NUM> including the temperature sensor <NUM> disposed at a position in direct contact with an inner surface of the middle portion <NUM>, and a heater assembly <NUM> including the temperature sensor <NUM> disposed at a position in direct contact with an inner surface of the lower end portion <NUM>. The heating element <NUM> includes a hollow therein.

In the case of the heater assembly <NUM>, which is not covered by the claimed invention, the middle portion <NUM> may be formed of a ferromagnetic substance, and the temperature sensor <NUM> may be disposed at a position abutting the inner surface of the middle portion <NUM>. Thus, a temperature at which the cigarette <NUM> is heated may be accurately reflected in a temperature measured by the temperature sensor <NUM>.

In the case of the heater assembly <NUM>, the middle portion <NUM> may be formed of a ferromagnetic substance, and the lower end portion <NUM> may be formed of a weak magnetic substance or a non-magnetic substance. The temperature sensor <NUM> may be disposed at a position abutting an inner surface of the lower end portion <NUM>. When the lower end portion <NUM> is formed of a weak magnetic substance or a non-magnetic substance, a temperature of the lower end portion <NUM> may be lower than a temperature of the middle portion <NUM> formed of a ferromagnetic substance. However, the temperature of the lower end portion <NUM> may maintain a constant relationship with the temperature of the middle portion <NUM>. Accordingly, the temperature at which the cigarette <NUM> is heated may be derived based on a relationship between the temperature of the lower end portion <NUM> and the temperature of the middle portion <NUM>, which are measured by the temperature sensor <NUM>.

<FIG> is a view illustrating a heater assembly further including a supporting body and a coil disposed at a position corresponding to a ferromagnetic substance, according to an embodiment.

<FIG> illustrates a structure in which a heater assembly <NUM> further including a supporting body <NUM> and a coil <NUM> are disposed in the aerosol generating device <NUM> and the cigarette <NUM> is accommodated in the aerosol generating device <NUM>. The heater assembly <NUM> may further include the supporting body <NUM> that is fixed to an outer surface of the heating element <NUM> and extends from the outer surface of the heating element <NUM> toward a side surface of the accommodation space <NUM>.

The supporting body <NUM> may be fixed to the outer surface of the heating element <NUM>. The supporting body <NUM> may surround the outer surface of the heating element <NUM>. For example, the supporting body <NUM> may surround an outer surface of the lower end portion <NUM> of the heating element <NUM>. However, the supporting body <NUM> is not limited thereto, and may also be disposed at the middle portion <NUM>.

The supporting body <NUM> may have a ring shape or a donut shape that includes the heating element <NUM> in contact with its inner surface and extends outwards from the outer surface of the heating element <NUM>. The supporting body <NUM> may extend from the outer surface of the heating element <NUM> to a side surface of the accommodation space <NUM> to be fitted in the accommodation space <NUM>. Accordingly, the supporting body <NUM> and the heating element <NUM> may be supported and fixed inside the accommodation space <NUM>. However, the supporting body <NUM> is not limited thereto, and may have another shape as long as the supporting body <NUM> may include the heating element <NUM> therein and may be accommodated in the accommodation space <NUM>.

The supporting body <NUM> may be formed of a material having heat insulation and heat resistance. The supporting body <NUM> holds heating element <NUM>, and thus, it may be heated by heat transferred from the heating element <NUM>. Therefore, it is necessary for the supporting body <NUM> to have heat resistance so as not to be deformed or damaged by heat transferred from the heating element <NUM>, and to have heat insulation so as not to transfer heat to the accommodation space <NUM> and the aerosol generating device <NUM>.

For example, the supporting body <NUM> may be formed of at least one of polypropylene (PP), polyether ether ketone (PEEK), polyethylene (PE), polyimide, sulfone-based resin, fluorine-based resin, and aramid. The sulfone-based resin may include resins such as polyethyl sulfone and polyphenylene sulfide, and the fluorine-based resin may include polytetrafluoroethylene (Teflon).

The supporting body <NUM> may prevent tobacco residues generated from the cigarette <NUM> from flowing into the accommodation space <NUM> and the aerosol generating device <NUM>. In addition, the supporting body <NUM> may prevent aerosol generated from the cigarette <NUM> from being liquefied again and flowing into the accommodation space <NUM> and the aerosol generating device <NUM>.

The supporting body <NUM> may be made in a single body that includes the heating element <NUM> therein and is accommodated in the accommodation space <NUM>. Alternatively, the supporting body <NUM> may be made of a structure that includes a flange in contact with the heating element <NUM> and a mold portion between the flange and a side surface of the accommodation space <NUM>.

The coil <NUM> may be wound around a side surface of the accommodation space <NUM> to extend in a longitudinal direction. The coil <NUM> extending in the longitudinal direction may be disposed on the side surface of the accommodation space <NUM>. The coil <NUM> may be disposed at a position corresponding to the heater assembly <NUM>. The coil <NUM> may extend in a length direction to a length corresponding to the heater assembly <NUM> and may be disposed at a position corresponding to the heater assembly <NUM>.

The coil <NUM> may be disposed at a position corresponding to a ferromagnetic substance included in the heating element <NUM>. For example, when the middle portion <NUM> of the heating element <NUM> is formed of a ferromagnetic substance and the upper end portion <NUM> and the lower end portion <NUM> are formed of a diamagnetic substance, the coil <NUM> may be disposed at a position corresponding to the middle portion <NUM>. Alternatively, when the upper end portion <NUM> and the middle portion <NUM> are formed of a ferromagnetic substance, the coil <NUM> may be disposed at a position corresponding to the upper end portion <NUM> and the middle portion <NUM>.

As illustrated in <FIG>, when the supporting body <NUM> is disposed at the lower end portion <NUM> and the middle portion <NUM> is formed of a ferromagnetic substance, the middle portion <NUM>, the tobacco rod <NUM>, and the coil <NUM> may be disposed at positions corresponding to each other. The middle portion <NUM> may be formed to have a length corresponding to a length of the tobacco rod <NUM>, and the coil <NUM> may be disposed to have a length corresponding to the length of the middle portion <NUM>. When the lengths of the middle portion <NUM>, the tobacco rod <NUM>, and the coil <NUM> correspond to each other, energy loss may be minimized during a process in which heat is generated from the middle portion <NUM> by the coil <NUM> and the tobacco rod is heated by the middle portion <NUM>. Accordingly, power required for the aerosol generating device <NUM> to generate aerosol from the cigarette <NUM> may be reduced.

<FIG> is a diagram illustrating a process of controlling a temperature of a heater assembly according to an embodiment.

Referring to <FIG>, the aerosol generating device <NUM> may include the heater assembly <NUM>, the accommodation space <NUM>, the coil <NUM>, the power supply unit <NUM>, and the controller <NUM>. The heater assembly <NUM> may include the heating element <NUM> and the temperature sensor <NUM>, and the power supply unit <NUM> may include a battery <NUM> and a converter <NUM>. However, other general-purpose elements other than the elements illustrated in <FIG> may be further included in the aerosol generating device <NUM>, the heater assembly <NUM>, or the power supply unit <NUM>.

The power supply unit <NUM> may supply power to the aerosol generating device <NUM>. The power supply unit <NUM> may supply power to the coil <NUM>. The power supply unit <NUM> may include the battery <NUM> for supplying a direct current to the aerosol generating device <NUM> and the converter <NUM> for converting the direct current supplied from the battery into an alternating current supplied to the coil <NUM>.

The converter <NUM> may include a low-pass filter for filtering a direct current supplied from the battery <NUM> to output an alternating current to be supplied to the coil <NUM>. The converter <NUM> may further include an amplifier for amplifying a direct current supplied from the battery <NUM>. For example, the converter <NUM> may be a class-D amplifier that includes a load network constituting a low-pass filter and further includes an amplifier. When the converter <NUM> is a class-D amplifier, the coil <NUM> may be an inductor included in the load network of the class-D amplifier.

The controller <NUM> may be configured with an array of multiple logic gates or may be configured with a combination of a general-purpose microprocessor and a memory in which a program executable in the microprocessor is stored. In addition, the controller <NUM> may be configured with a plurality of processing elements.

The controller <NUM> may control power supplied from the power supply unit <NUM> to the coil <NUM>. The controller <NUM> may control a direct current supplied from the battery <NUM> to generate a DC pulse. For example, the controller <NUM> may generate the DC pulse by controlling a switch connected to the battery <NUM> to be turned on-off.

The converter <NUM> may convert a DC pulse generated from the battery <NUM> into an alternating current. For example, a low-pass filter included in the converter <NUM> may receive a DC pulse and may output an alternating current by removing frequencies exceeding a cutoff frequency among a plurality of frequencies included in the DC pulse.

An alternating current may be transferred from the power supply unit <NUM> to the coil <NUM>. When an alternating current is applied to the coil <NUM>, the coil <NUM> may generate an alternating magnetic field. When the alternating magnetic field generated from the coil <NUM> is applied to the heater assembly <NUM>, the heating element <NUM> may generate heat, and the temperature sensor <NUM> may measure a temperature of the heating element <NUM>.

The controller <NUM> may control a temperature of the heater assembly <NUM> based on the temperature of the heating element <NUM> which is measured by the temperature sensor <NUM>. For example, the controller <NUM> may modulate a DC pulse generated from the battery <NUM> based on the temperature of the heating element <NUM>. Furthermore, the controller <NUM> may compare the temperature of the heating element <NUM>, which is measured by the temperature sensor <NUM>, with a reference temperature, and may control the temperature of the heater assembly <NUM> based on a difference between the measured temperature of the heating element <NUM> and the reference temperature.

The controller <NUM> may modulate a DC pulse generated from the battery <NUM> based on the temperature of the heating element <NUM>. For example, the controller <NUM> may amplify the DC pulse through an amplifier included in the converter <NUM>. When the DC pulse is amplified, an amplitude of an alternating current output from the converter <NUM> may increase. When the amplitude of the alternating current applied to the coil <NUM> increases, an amplitude of an alternating magnetic field generated from the coil <NUM> may increase, and accordingly, heat energy emitted from the heating element <NUM> may increase. Reversely, the controller <NUM> may reduce the intensity of the DC pulse to reduce the heat energy emitted from the heating element <NUM>.

As another example, the controller <NUM> may perform a pulse width modulation on a DC pulse. When the DC pulse modulated by the pulse width modulation is input to the converter <NUM>, a frequency of an alternating current output from the converter <NUM> may also be changed. Since the frequency of the alternating current applied to the coil <NUM> is changed, the frequency of the alternating magnetic field generated from the coil <NUM> may also be changed, and accordingly, the heat energy emitted from the heating element <NUM> may be changed. As such, a temperature of the heater assembly <NUM> may be controlled.

Specifically, the controller <NUM> may perform the pulse width modulation on a direct current supplied from the battery <NUM> by modulating at least one of a frequency of a DC pulse and a duty cycle of the DC pulse. The controller <NUM> may modulate a frequency or a duty cycle by adjusting a cycle of turning on and off a switch connected to the battery <NUM> or a ratio of turning on and off a switch. However, the frequency and duty cycle of the DC pulse is not limited thereto and may also be modulated by means other than the switch. Also, the controller <NUM> may perform the pulse width modulation by turning on and off the direct current of the battery <NUM>, according to a section in which the pulse width modulation and a section for blocking the direct current supplied from the battery <NUM>.

The controller <NUM> may compare a temperature of the heating element <NUM>, which is measured by the temperature sensor <NUM>, with a reference temperature. Also, the controller <NUM> may control a temperature of the heater assembly <NUM> based on a difference value between the measured temperature of the heating element <NUM> and a reference temperature. For example, when the temperature of the heating element <NUM> is higher than the reference temperature, the controller <NUM> may reduce at least one of a frequency and a duty cycle of a DC pulse supplied from the battery <NUM> or may reduce the intensity of the DC pulse.

In addition, the controller <NUM> may calculate the difference value between the measured temperature of the heating element <NUM> and the reference temperature, and may perform a feedback control by a PID method of adjusting the DC pulse supplied from the battery <NUM>, based on at least one of a component proportional to the difference value, a component proportional to a value obtained by integrating the difference value, and a component proportional to a value obtained by differentiating the difference value.

Claim 1:
An aerosol generating device (<NUM>) comprising a heater assembly (<NUM>, <NUM>, <NUM>) for heating a cigarette (<NUM>) accommodated in the aerosol generating device (<NUM>), comprising:
a heating element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) that extends in a longitudinal direction of the cigarette (<NUM>) and includes a ferromagnetic substance that is configured to generate heat by an external magnetic field; and
a temperature sensor (<NUM>) that is configured to measure a temperature of the heating element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
wherein the heater assembly (<NUM>, <NUM>, <NUM>) is disposed at an inner end portion of an accommodation space (<NUM>) provided in the aerosol generating device (<NUM>) to accommodate the cigarette (<NUM>),
wherein the heating element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) further comprises a hollow, wherein the temperature sensor (<NUM>) abuts an inner surface of the heating element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
the aerosol generating device (<NUM>) being characterised in that
the temperature sensor (<NUM>) abuts an inner surface of a section other than the ferromagnetic substance in the heating element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>).