Aerosol generating device

Abstract

There is provided an aerosol generating device for heating an aerosol generating article. The aerosol generating device comprises a heating chamber configured to receive at least part of an aerosol generating article, a light source assembly configured to emit light for heating an aerosol generating article received in the heating chamber, and an elongated light guide arranged at least partially within the heating chamber. The light guide is configured to receive light emitted from the light source assembly at a first end of the light guide, and direct the light, such that the light is emitted from a lateral surface along a length of at least part of the light guide. Also provided is an aerosol generating system and a method of aerosol generation.

Description

[0001] Aerosol Generating Device

[0002] Technical field

[0003] The present invention relates to an aerosol generating device for heating an aerosol generating article to generate aerosol to be inhaled. In particular, the invention relates to an aerosol generating device for heating an aerosol generating article based on light heating. The invention also relates to an aerosol generating system comprising the aerosol generating device and the method of aerosol generation by means of the aerosol generating device.

[0004] Alternatively or additionally, the present invention relates to an aerosol generating device for heating an aerosol generating article to generate aerosol to be inhaled. In particular, the invention relates to an aerosol generating device for heating an aerosol generating article using a heat transfer element in thermal contact with a heating assembly. The invention also relates to an aerosol generating system comprising the aerosol generating device and the method of aerosol generation by means of the aerosol generating device.

[0005] Technical background

[0006] Aerosol generating devices which heat, rather than burn, an aerosol generating material to produce an aerosol for inhalation have become popular with consumers in recent years. Devices of this type generate an aerosol or vapour by heating an aerosol generating material to a temperature typically in the range 150°C to 300°C, and in some cases as high as 350°C. This temperature range is quite low compared to a conventional cigarette where the aerosol generating material is heated to a combustion temperature.

[0007] The aerosol generating material may be a solid, semi-solid (e.g. gel) or liquid. For example, the aerosol generating article may include a solid or semi-solid aerosol generating substrate comprising plant derived material, such as tobacco. The aerosol generating articles can take various forms, for example an elongate cylindrical stick or a flat-shaped cuboid. Alternatively, the aerosol generating article may include the liquid aerosol generating substrate. In such a case, the aerosol generating device or a cartridge for storing the aerosol generating material may include a heater configured to produce vapour from aerosol generating liquid transferred from a cartridge or tank to a wick arranged adjacent to the heater.The aerosol generating article including the aerosol generating substrate may be in the form of a rod, for example, a cylindrical rod, or tubular in shape and designed for insertion of the aerosol generating article into a heating chamber of the aerosol generating device.

[0008] In a typical aerosol generating device, a heating element may be arranged in or around the heating chamber for heating the aerosol-forming substrate when the aerosol generating article is received in the heating chamber. In some aerosol generating devices, the heating element may be arranged to surround a portion of the aerosol generating article (e.g., the aerosol generating substrate) such that the heating element externally heat the aerosol generating article. In some other examples, the heating element may be a central heater arranged to be inserted into the portion of the aerosol generating article, such that the aerosol generating article internally heat the aerosol generating article.

[0009] Alternatively, the heating element may be configured to heat both from an interior and exterior of the aerosol generating article. The combination of the internal heating and the external heating allows for a more uniform heating of the aerosol generating substrate.

[0010] The heating element may be a resistive heater or an induction heater. Another technique for heating the aerosol generating article may be light radiation, or light-based heating. The light heating essentially does not require any contact of the heating element to the aerosol generating article which is preferred for the heating by other methods that require thermal transfer from the heat source. Therefore, the aerosol generating device based on the light heating may require a cleaning less frequently, which advantageously improves user experience. The light heating may also allow for an instant heating of the aerosol generating substrate, which allows for rapid generation of the aerosol vapor, especially in the beginning of a vaping session. The light heating also may achieve more precise and instant control of heating due to the absence of heat transfer which may cause a delay in controlling heating power received by the aerosol generating article. An aerosol generating device may comprise a light source for light heating provided within the housing of the aerosol generating device. The aerosol generating device may further comprises a light guide to manipulate the light from the light source such that the light irradiates a desired portion of a heating chamber of the aerosol generating device wherein the heating chamber is configured to receive at least a part of the aerosol generating article to be heated to generate aerosol vapor.

[0011] However, the light heating by a parallel beam or focused beam tends to heat a very localized portion of the article.The light intensity of diffused light may vary dependent on a distance between the heating portion and the light source when the light from the light source is diverged or converged. Typically, the heating chamber of the aerosol generating device for receiving an aerosol generating article (an aerosol generating stick) is an elongated cavity having one open end to insert the aerosol generating article and one closed end (the bottom end of the heating chamber).

[0012] When the light source is arranged to emit the diverged light from the bottom end of the heating chamber, the intensity of light received at each portion of the heating chamber along a longitudinal direction (or axis) of the heating chamber may be vary significantly dependent on a distance from the light source. Because the light intensity determined the heating power, the aerosol generating article may not be heated homogeneously across the longitudinal axis of the heating chamber. It is also known that the light heating tends to be less power efficient compared to other heating methods due to heat loss associated with heating of the light source when the light source emits light for irradiation.

[0013] It is therefore desirable to provide an aerosol generating device which achieves an improved heating of the aerosol generating substrate. In particular, it is also desirable to provide an aerosol generating device that allow more uniform heating of an aerosol generating article by light irradiation. It is also desirable to provide an aerosol generating device based on the light heating that achieves an improved power efficiency.

[0014] Summary of the Disclosure

[0015] According to a first aspect of the present invention, there is provided an aerosol generating device for heating an aerosol generating article comprising: a heating chamber configured to receive at least part of the aerosol generating article; a light source assembly configured to emit light for heating the aerosol generating article when received in the heating chamber; and an elongated light guide arranged at least partially within the heating chamber, the light guide configured to: receive light emitted from the light source assembly at a first end of the light guide, and direct the light, such that the light is emitted from a lateral surface along a length of at least part of the light guide.

[0016] The lateral surface refers to a surface that extends along the length of the elongated light guide. In other words, the lateral surface refers to a sidewall extending between the first end of the light guide to a second end of the light guide, wherein the second end of the light guide is the end that is opposite to the first end of the light guide. When the light guide is a circular cylinder, a circular frustoconical shape, or a circular conical shape, the lateral surface is a curved sidewall surfacethat extend along the length of the cylinder. When the light guide is a cylinder, or frustoconical / conical shapes with a polygonal base, the lateral surface may comprise different flat segments.

[0017] The light guide allows to heat the area surrounding the lateral surface of the light guide. The light emitted from the lateral surface of the light guide forms distributed light rays rather than a concentrated light spot. In examples, the light guide forms diverged light rays. This way, when the aerosol generating article is inserted in the heating chamber to surround the light guide, the aerosol generating article is heated uniformly across the area of heating, and local overheating of the aerosol generating article due to a concentrated light spot may be prevented.

[0018] According to some examples, the elongated light guide may be a pillar comprising one or more optical components. The pillar may be centrally located within the heating chamber and aligned along the longitudinal direction of the heating chamber.

[0019] When the aerosol generating article is inserted in the heating chamber, the light guide protrudes through a centre or middle (e.g. inside of) of the aerosol generating article. This way, the aerosol generating article may be heated from its interior which may achieve a better heating efficiency than heating from its exterior surface. In examples, the aerosol generating article is simultaneously heated from its exterior. That is, one or both of interior and / or exterior heating may be used to heat the aerosol generating article.

[0020] According to some examples, the heating chamber is a cylindrical cavity with a circular crosssection, and the pillar (the light guide) is positioned at the center of the heating chamber when viewed in cross-section, with a circular cross-section of the cavity. In examples, the cross-section of the heating chamber may be a different shape, for example an alternative rounded or polygonal shape.

[0021] The heating chamber is useful for inserting an article, for example a heat-not-burn (HNB) stick. By configuring the heating chamber to have a cross-sectional diameter similar to that of the stick, the stick is guided by the heating chamber such that the light guide is inserted in the center of the stick when the stick is received in the heating chamber.

[0022] According to examples, the light guide may comprise a plurality of lenses. Especially when the light from the light source assembly is diverged, the plurality of lenses may be an array of convex lenses arranged along the length of the elongated light guide. As discussed further in details, the array of the plurality of convex lenses are formed such that the light received from the first end isemitted from the lateral surface of the light guide in a direction perpendicular to the longitudinal direction of the heating chamber.

[0023] Alternatively, or additionally, the light guide may comprise one or more beam splitters. The one or more beam splitters are arranged such that at least a part of the light (beam) entering from the first end of the light guide is reflected towards the lateral surface of the light guide.

[0024] The light guide may be configured such that the light emitted from the light is distributed across the lateral surface. For instance, the lateral surface of the light guide may comprise diffraction gratings or a textured surface to dispersing the light emitted from the light guide.

[0025] According to some examples, the aerosol generating device further comprises a heat transfer element (or a heat sink structure) in thermal contact with the light source assembly and arranged to at least partially surround the heating chamber. This way, the heat loss associated with the heating of the light source assembly may be transferred to the heat transfer element. The heat is then transferred to the heating chamber, i.e. , the aerosol generating article received therein, so that at least a part of the heat generated by the light source assembly can be used for heating an external side of the aerosol generating article. In this way, the aerosol generating article may be heated both internally and from an external side. In examples, the aerosol generating article is simultaneously heated from its exterior as well as interior. Moreover, the heat transfer element acts as a heat sink for preventing heating up the light source assembly, which may lead to increased energy consumption, loss of efficiency of light emission and degradation of beam quality. Thus, the configuration to allow to use the wasted heat while preventing excessive temperature increase of the light source assembly, thereby improving heating efficiency.

[0026] According to some examples, at least a part of the heat transfer element may define the heating chamber. The heat transfer element may be an integrated part into a wall defining the heating chamber.

[0027] This configuration is advantageous in terms of simplicity and compactness of the device. Moreover, the configuration may allow to efficiently re-use heat, because the heat collected in the heat transfer element would be directly conducted to the aerosol generating article if the article is configured to have a thermal contact (conduction) or proximity (convection or radiation) to the sidewall of the heating chamber.

[0028] According to some examples, the heat transfer element comprises a cup shaped structure for surrounding at least a part of the heating chamber. The cup shaped structure may comprise a thermally conductive material, such as metal and alloy, e.g., copper or aluminium.According to some examples, the heat transfer element is configured to collect the wasted heat of the light source assembly and to provide the heat to a peripheral surface of the heat chamber such that the heat transfer element may act as an external heater.

[0029] For example, when the heat transfer element comprises the cup shaped structure, a bottom part of the cup shaped structure may be arranged in thermal contact or adjacent to the light source assembly such that the heat generated at the light source assembly is transferred to the heat transfer element. In some examples, the light source assembly is integrated in the bottom part of the cup shaped structure. The heat collected at the bottom part of the cup shaped structure is then transferred to a sidewall part of the cup shaped structure which is arranged to surround the periphery of the heating chamber.

[0030] According to some examples, the aerosol generating device may comprise a heater. The heater may be arranged adjacent to the heat transfer element for further improving uniformity of heating along the longitudinal direction of the heating chamber. The temperature of the heat transfer element may be higher at a portion closer to the light source assembly due to the delay in heat transfer through the heat transfer element. The additional heater may allow for compensating the temperature gradient within the heat transfer element, thereby improving the uniformity of heating of the heating chamber by the heat transfer element.

[0031] In use, the heater may also be controlled to generate a temperature gradient across the heating chamber. For instance, aerosol tends to be generated more significantly from a portion of the aerosol generating article close to a proximal side (a mouthpiece side). Therefore, aerosol precursor of the aerosol generating article may be consumed faster at that portion when the aerosol generating article is heated uniformly. Therefore, once the aerosol precursor is depleted at the proximal side, the heater may be controlled to reduce the temperature at that part. For example, the aerosol generating device is configured to stop power supply to the heater. Alternatively, the aerosol generating device is configured to reduce power supply to the heater. In some examples, power supply to the heater is controlled to be decreased or stopped based on a progress of a vaping session (a predetermined time and / or number of puffs).

[0032] In examples, the heater may be arranged such that the distance between the heater and a second end of the light guide, opposite to the first end of the light guide, is closer than the distance between the heater and the first end of the light guide. In other words, the heater may be arranged adjacent to a portion of the heat transfer element that is away from the light source assembly. When the heat transfer element comprises the cup shaped structure, the heater may be arranged around at a top part (an opening) of the cup shaped structure. The heater may compensate thetemperature gradient across the heat transfer element, by heating the heating chamber at the opposite end to the light source assembly. In examples, the heater may be arranged in any location relative to the light guide in order to suitably compensate the temperature gradient within the heating chamber.

[0033] The heater may be any electrical heater, such as a resistive heater, inductive heater, radiation heater.

[0034] According to some examples, the heater forms a part of the heat transfer element. This configuration ensures a good thermal contact of the heater to the heat transfer element which may allow for more precise adjustment of the temperature gradient within the heat transfer element.

[0035] Additionally or alternatively, the heat transfer element may further comprise phase change materials (PCM). The PCM may be arranged on a surface of the heat transfer element and / or it may be embedded in the heat transfer element. The PCM maintain a predetermined temperature by absorbing and releasing large amounts of latent heat during their phase transitions (e.g., from solid to liquid and vice versa). When the temperature rises, the PCM absorbs heat and melts, storing energy. When the temperature decreases, the PCM solidifies and releases the stored energy, thereby stabilizing the temperature around its melting point. In this way, the heat transfer element comprising the PCM may contribute to maintain the heat transfer element at the predetermined temperature.

[0036] Additionally, or alternatively, the heat transfer element may comprise an array of fins. At least a part of the heat from the light source assembly may be dissipated to the array of fins and may be released into surroundings, e.g. surrounding air. In some examples, the array of fins is arranged at an outer surface of the sidewall of the heat transfer element that surrounds the periphery of the heating chamber. The array of fins may be arranged such that the density of the fins or the size of the fins varies across a length of the heat transfer element. The array of fins may be configured to have a greater surface area at a portion closer to the light source assembly so as to achieve a superior heat release capability at the portion closer to the light source assembly. For example, when the heat transfer element comprises the cup shaped structure, larger fins may be arranged at a lower position of the sidewall of the heat transfer element than a higher position of the sidewall of the heat transfer element. Alternatively or additionally, the density of the fins may be varied to adjust the surface area to release the heat. This configuration may allow to at least partially compensate the temperature gradient generated within the heat transfer element by the delay in heat transfer from the light source assembly.In examples, the aerosol generating device comprises two or more temperature sensors. The two or more temperature sensors are configured to measure temperatures of at least two locations of the heating chamber.

[0037] Preferably, the two or more temperature sensors may be arranged to measure temperatures at different longitudinal positions of the heating chamber or the heat transfer element. This allows to precisely detect the temperature gradients within the heating chamber or the heating transfer element.

[0038] Preferably, the two or more temperature sensors are in thermal contact with the wall defining the heat chamber.

[0039] Alternatively, or additionally, the two or more temperature sensors may be in thermal contact with the heat transfer element.

[0040] In some examples, each of the two or more temperature sensors are configured to provide a signal indicative of the temperature of each corresponding location of the heating chamber. The power supply to the heater may be controlled based on the signals obtained from the two or more temperature sensors. Preferably the heater is integrated within or arranged on the heat transfer element. This way the temperature gradient of the heating chamber or the heat transfer element may be directly modulated.

[0041] In some examples, the aerosol generating device comprises control circuitry configured to control operation of the light source assembly, the heater, and / or the one or more temperature sensors. According to some examples, wherein the light source of the light source assembly comprises a laser. In examples, the light source of the light source assembly may comprise an LED, or noncoherent light source. In examples, the light source may be any light source configured to emit visible light.

[0042] According to some examples, the light source assembly comprise an optical component to diverge the light from the light source assembly.

[0043] In one exemplary example, the optical component to diverge the light form the light source assembly may comprise a concave lens.

[0044] According to some examples, the light guide comprises a plurality of lenses arranged along the lateral surfaces of the light guide.

[0045] In examples, the plurality of lenses is an array of convex lenses having different optical properties.According to some examples, each of the plurality of lenses has optical properties that vary based on its distance from the first end of the light guide.

[0046] When the array of the plurality of lenses is the array of convex lenses, the convex lenses may have different curvatures. These lenses may be arranged such that the curvature of the array of the plurality of concave lenses vary across the length of the light guide.

[0047] According to some examples, the plurality of lenses comprises convex lenses, and each of the convex lenses has a curvature that increases with an increase of the distance from the first end of the light guide. This way, the light emitted from the light source assembly and received by the convex lenses of the light guide may be directed to a direction substantially perpendicular to the longitudinal direction of the heating chamber, i.e., the light incident in the aerosol generating substrate with an angle of incidence of substantially zero. This allows for a more precise control of heating across different portions of the aerosol generating article.

[0048] In an examples, the light source assembly is arranged at the second end, or bottom, of the heating chamber and the light source assembly emits the light in the direction parallel to the longitudinal axis of the heating chamber. The optical component to diverge the light, for example, the concave lens, above the light source, such that the light emitted from the light source assembly is diverged. In such a case, the light beam received by the bottom part of the heating chamber has an angle of deviation (an angle between the direction of the original light path from the light path, i.e., the longitudinal direction of the heating chamber and the direction after the light is diverged by the optical component) is greater than the light ray received by the top part of the heating chamber. In some examples, the heating chamber has a sidewall that is parallel to the longitudinal axis of the heating chamber. This means that the light may be incident in the light guide at a greater angle of incidence at a top part of the heating chamber (a part closer to the opening of the heating chamber) than the bottom part of the heating chamber. In order to direct the light in the direction perpendicular to the longitudinal direction of the heating chamber, the convex lens at each longitudinal position in the heating chamber may be adjusted. When the light incidents at a greater angle of incidence, a greater curvature of the lens would be required.

[0049] According to examples, the heating chamber comprises a cylindrical cavity having an open end and a closed end, and the light guide extends from the closed end along a longitudinal direction of the chamber such that a second end of the light guide, opposite to the first end, is arranged within the heating chamber. The heating chamber is convenient for use with a typical aerosol generating stick (a heat-not-burn stick).Preferably, the light guide is arranged in the center of the heating chamber from the view of a horizontal cross section. In this way, the light guide may be inserted in the middle of the aerosol generating substrate of the aerosol generating stick. In some examples, the aerosol generating article is provided in the form of a hollow tube, and the light guide may be configured to be inserted in the hollow tube when the aerosol generating article is received in the heating chamber.

[0050] Preferably, the light source assembly is arranged adjacent to the first end of the light guide. According to a second aspect of the invention, there is provided an aerosol generating system comprises: the aerosol generating device according to any one of the preceding examples; and an aerosol generating article configured to be at least partially received in the heating chamber such that at least a part of an aerosol generating substrate of the aerosol generating article is inserted in a gap between an inner wall of the heating chamber and the light guide.

[0051] In some examples, the aerosol generating article is an aerosol generating stick (a heat-not -burn stick) comprising an aerosol generating substrate arranged at a distal end of the aerosol generating stick. The aerosol generating substrate may be in the form of a hollow tubular structure. The aerosol generating stick may further comprises a mouthpiece at a proximal end, the mouthpiece may comprise a filter, and a cooling section arranged between the mouthpiece ant the aerosol generating substrate. All components of the aerosol generating stick may be held by a wrapper to form a stick.

[0052] The hollow tubular structure of the aerosol generating substrate may have an inner diameter which is sufficiently large such that the light guide may be inserted in the hollow tubular structure. The aerosol generating stick may have an outer diameter which is smaller than the diameter of the heating chamber for inserting the aerosol generating. This way, when the aerosol generating stick is received in the heating chamber, at least a portion of the aerosol generating substrate is sandwiched between the wall of the heating chamber and the light guide.

[0053] Preferably, the aerosol generating article is configured such that an entire portion of the aerosol generating substrate is sandwiched between the wall of the heating chamber and the light guide, so that the aerosol generating substrate is uniformly heated.

[0054] Preferably, the aerosol generating article is configured such that the aerosol generating article may have a diameter substantially same or a slightly smaller than the diameter of the heating chamber. This way, the aerosol generating article may receive heat from the heat transfer element most efficiently.According to a third aspect of the invention, there is provided a method of aerosol generation comprising steps of: providing the aerosol generating system according to the previous examples; and operating the light source assembly to emit light.

[0055] The aerosol generating device may be configured to detect initiation of use of the aerosol generating device by a user.

[0056] The aerosol generating device may be configured to activate (i.e., supply power to) the light source assembly upon detecting insertion of the aerosol generating article into the heating chamber or user pushing a button arranged on the aerosol generating device. The power supply to the light source assembly may be controlled to heat the aerosol generating substrate at a predetermined target temperature.

[0057] According to some examples, the light source assembly may be controlled based on the signals of the two or more sensors. For controlling the power supply to the heater, at least one of the two or more sensors may be selected to be used for feedback control. Preferably, one of the two or more sensors may be used for feedback control at a time. Additionally, the temperature sensor used for the feedback control may be altered during the progress of the vaping session.

[0058] In examples, the aerosol generating device comprises a first temperature sensor configured to measure a temperature at a top portion of the heating chamber, a second temperature sensor configured to measure a temperature at a middle portion of the heating chamber, and a third temperature sensor configured to measure a temperature at a bottom portion of the heating chamber. In this case, the feedback control for operating the light source assembly may be based on at least one of the first, second and third sensors.

[0059] The aerosol generating device may be configured such that one of the first, second and third sensors for the feedback control of the power supplied to the light source assembly at a time and the temperature sensors to be used is changed sequentially based on the progress of the session. During a vaping session, the aerosol tends to be generated more significantly from a proximal side (a mouthpiece side) portion of the aerosol generating substrate. Therefore, aerosol precursor of the aerosol generating article may be consumed faster at that portion.

[0060] For example, the first sensor is used to control the power to the light source assembly at an initial stage of the session. Then, after a first predetermined time and / or number of puffs of the session is expired, the second temperature sensor is used for feedback control of the power of the light source assembly. Finally, when a second predetermined time and / or number of puffs of thesession is expired, the third temperature sensor may be used to adjust the power to the light source assembly.

[0061] In some examples of the method of aerosol generation, the aerosol generating device may start supplying power to the heater once the initiation of use of the aerosol generating device by a user is detected and / or the light source assembly is activated.

[0062] The power supply to the heater may be adjusted such that the temperature gradient within the heating chamber or the heat transfer element is compensated during operation of the light source assembly.

[0063] For controlling the power of the heater, the method may further comprise a step of measuring the temperature variations in the heating chamber by the two or more temperature sensors. The heater may be activated only when temperature variations in the heating chamber measured by the one or more temperature sensors exceed a predetermined value.

[0064] The method of aerosol generation may further comprise a step of controlling power supply to the heater based on progress of a smoking session (a predetermined time and / or number of puffs). In this step, the power to the heater may be adjusted based on the measurement of the temperature by the two or more temperature sensors. The feedback control of the heater may employ a similar method as that for the light source assembly as described earlier.

[0065] In an example where the aerosol generating device comprises the first, second and third temperature sensors, the feedback control for the power of the heater may be based on one of the first, second and third sensors. Furthermore, the aerosol generating device may be configured to use one of the first, second and third sensors for the feedback control of the heater at a time, and to change the temperature sensors to be used for the feedback control sequentially based on the progress of the session.

[0066] For example, the first sensor is used to control the heater at an initial stage of the session. Then, after a first predetermined time and / or number of puffs of the session is expired, the second temperature sensor is used for controlling the heater. Finally, when a second predetermined time and / or number of puffs of the session is expired, the third temperature sensor may be used. During a vaping session, the aerosol tends to be generated more significantly from a proximal side (a mouthpiece side) portion of the aerosol generating substrate. Therefore, aerosol precursor of the aerosol generating article may be consumed faster at that portion. Therefore, once the aerosol precursor in the proximal side portion is depleted, the heater may be controlled to reduce the temperature at that part. This way, the depleted portion of the aerosol generating substrate isnot heated or heated at lower temperatures, thereby preventing overheating of that portion, leading to an improvement in user experience.

[0067] For example, the aerosol generating device is configured to stop power supply to the heater. Alternatively, the aerosol generating device is configured to reduce power supply to the heater. In some examples, power supply to the heater is controlled to be decreased or stopped based on a progress of a vaping session.

[0068] According to some examples, the aerosol generating device may be configured such that the power supply to the heater is based on the signals of the two or more sensors. For controlling the power supply to the heater, one of the two or more sensors may be selected to be used for feedback control. The temperature sensor that is used for the feedback control may be altered during the process of a session.

[0069] According to a fourth aspect, there is provided: an aerosol generating device for heating an aerosol generating article, comprising: a heating chamber configured to receive at least part of an aerosol generating article; a heating assembly comprising a heating source configured heat an aerosol generating article received in the heating chamber; wherein the heating chamber further comprises a heat transfer element in thermal contact with the heating assembly.

[0070] In use, the heat loss associated with the heating may be transferred to the heat transfer element. The heat is then transferred to the heating chamber, i.e., the aerosol generating article received therein, so that at least a part of the heat generated by the light source assembly can be used for heating the aerosol generating article. The heat transfer element may also be known as a heat sink structure. This may prevent excess, undesired of the heating source assembly, which may advantageously lead to reduced energy consumption and improved efficiency of the heating assembly.

[0071] In examples, the heat transfer element is arranged to at least partially surround the heating chamber.

[0072] As such, excess heat in the heating chamber (heat that is not being used to heat the aerosol generating article in the first instance) may be transferred to the heat transfer element since it surrounds the heating chamber. The heat is then transferred back to the heating chamber, i.e., the aerosol generating article received therein, to assist with heating of the aerosol generating article by acting as an external heater in addition to the heating assembly.

[0073] In examples, the heating chamber may comprise a first end and a second end opposite the first end, wherein the heat transfer element surrounds at least the second end of the heating chamber.As such, the heat transfer element may be provided as a cup shaped structure around the heating chamber. Therefore, a bottom part of the cup shaped structure may be arranged in thermal contact or adjacent to the heating assembly such that excess heat generated at the heating source is transferred to the heat transfer element, for more efficient heat transfer.

[0074] In examples, at least a part of the heat transfer element may define the heating chamber. This may advantageously provide for improved heat transfer between the heating chamber and the heat transfer element.

[0075] In examples, the heat transfer element comprises one or more fins.

[0076] The fins may improve heat transfer via the heat transfer element by providing for improved heat dissipation. At least a part of the heat from the heating source assembly may be dissipated to one or more fins and may be released into surroundings, e.g. surrounding air.

[0077] In examples, the fins may be arranged one or more arrays, wherein the density of the fins, the size of the fins and / or the geometry, thickness and length of the fins in the one or more arrays varies across a length of the heat transfer element.

[0078] The array of fins may be arranged such that the density of the fins or the size of the fins varies across a length of the heat transfer element. The array of fins may be configured to have a greater surface area at a portion closer to the light source assembly so as to achieve a superior heat release capability at the portion closer to the light source assembly. For example, larger fins may be arranged at a lower position of the sidewall of the heat transfer element than a higher position of the sidewall of the heat transfer element. Alternatively or additionally, the density of the fins may be varied to adjust the surface area to release the heat. This configuration may allow to at least partially compensate for a temperature gradient generated within the heat transfer element by the delay in heat transfer from the heating source assembly.

[0079] In examples, the heat transfer element comprises a high thermal conductivity material, for example copper or aluminium. Advantageously, this allows for effective thermal management using the heat transfer element.

[0080] In examples, the heating assembly comprises a light source assembly, wherein the light source assembly is configured to emit light for heating an aerosol generating article received in the heating chamber.

[0081] In examples, the aerosol generating device further comprises an elongated light guide arranged at least partially within the heating chamber, the light guide configured to receive light emittedfrom the light source assembly at a first end of the light guide, and direct the light, such that the light is emitted from a lateral surface along a length of at least part of the light guide.

[0082] Use of the heat transfer element in examples using a light source assembly may reduce undesired heating of the light source assembly and may prevent loss of efficiency of light emission. This may be particularly advantageous in examples where the light source is a laser, to prevent loss of efficiency of the laser and degradation of beam quality. As such, the heat transfer element utilised wasted heat while preventing excessive temperature increase of the light source, thereby improving heating efficiency.

[0083] In examples, the aerosol generating device comprises an additional heater. In examples, the additional heater is arranged adjacent to a portion of the heat transfer element that at the opposite end of the heating chamber to the heating assembly.

[0084] The additional heater may compensate the temperature gradient across the heat transfer element by heating the heating chamber at the opposite end to the heating assembly.

[0085] The additional heater may any electrical heater, such as a resistive heater, inductive heater, radiation heater.

[0086] In examples, the heater forms a part of the heat transfer element. This configuration ensures a good thermal contact of the heater to the heat transfer element which may allow for more precise adjustment of the temperature gradient within the heat transfer element.

[0087] In examples, the aerosol generating device comprises two or more temperature sensors. The two or more temperature sensors are configured to measure temperatures of at least two locations of the heating chamber. Preferably, the two or more temperature sensors may be arranged to measure temperatures at different longitudinal positions of the heating chamber or the heat transfer element. This allows to precisely detect the temperature gradients within the heating chamber or the heating transfer element. In examples, the two or more temperature sensors are in thermal contact a wall defining the heating chamber. Alternatively, or additionally, the two or more temperature sensors may be in thermal contact with the heat transfer element. As discussed with respect to the first aspect, the temperature sensors may be used to effectively control the temperature gradient of the heating chamber.

[0088] According to a fifth aspect, there is provided an aerosol generating system comprising: the aerosol generating device according to preceding claim; and an aerosol generating article configured to be at least partially received in the heating chamber.According to a sixth aspect, there is provided a method of aerosol generation comprising steps of: providing the aerosol generating system according to the previous examples; and operating the heating assembly to heat the aerosol generating article.

[0089] It will be understood that any of the features of any of the aspects may be combined as appropriate.

[0090] Brief Description of the Drawings

[0091] Examples of the present disclosure will now be described with reference to the accompanying drawings.

[0092] Figure 1 shows a schematic drawing of an aerosol generating device;

[0093] Figure 2 shows a drawing of a heating chamber of an aerosol generating device according to an example;

[0094] Figure 3 shows a drawing of a heating chamber of an aerosol generating device according to an example;

[0095] Figure 4 shows a schematic drawing of an aerosol generating system; and

[0096] Figure 5 shows a schematic drawing of a method of operating an aerosol generating system.

[0097] Detailed Description

[0098] As used herein, the term “aerosol precursor material”, “vapour precursor material” or “vaporizable material” are used synonymously and may refer to a material and / or composition, which may for example comprise nicotine or tobacco and a vaporising agent. The aerosol precursor material is configured to release an aerosol when heated or otherwise mechanically stimulated, such as by vibrations. Tobacco may take the form of various materials such as shredded tobacco, granulated tobacco, tobacco leaf and / or reconstituted tobacco. Nicotine may be in the form of nicotine salts. Suitable vaporising agents include: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin or vegetable glycerin. In some examples, the aerosol precursor material is substantially a liquid or a gel that holds or comprises one or more solid particles, such as tobacco particles extracted from tobacco materials or suspended in a solution or gel.

[0099] An aerosol generating device is configured to aerosolise an aerosol precursor material without combustion in order to facilitate delivery of an aerosol to a user. Furthermore, and as is commonin the technical field, the terms “vapour” and “aerosol”, and related terms such as “vaporize”, “volatilize” and “aerosolise”, may generally be used interchangeably.

[0100] As used herein, the term “aerosol generating device” is synonymous with “aerosol generation device” or “device” and may include a device configured to heat an aerosol precursor material and deliver an aerosol to a user, typically without combusting the aerosol precursor material. The device may be portable. “Portable” may refer to the device being for use when held by a user. The device may be adapted to generate a variable amount of aerosol, which can be controlled by a user input.

[0101] As used herein, the term “aerosol” may include a suspension of vaporizable material as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to / include a vapour. Aerosol may include one or more components of the vaporizable material.

[0102] The disclosure generally relates to an aerosol generating device 100 for heating an aerosol generating article 300. The aerosol generating device 100 comprises a heating chamber 108. The heating chamber 108 is configured to receive at least part of an aerosol generating article 300. The aerosol generating device 100 comprises a light source assembly 200 configured to emit light for heating the aerosol generating article 300 received in the heating chamber 108. The aerosol generating device 100 comprises an elongated light guide 210. The elongated light guide 210 is arranged at least partially within the heating chamber 108. The light guide 200 is configured to receive light emitted from the light source assembly 200 at a first end 212 of the light guide, and direct the light, such that the light is emitted from a lateral surface along a length of at least part of the light guide 210. In other words, the light from the light source assembly 200 is spread or diffused laterally along the guide 210, to advantageously more uniformly heat the article 300 along its length.

[0103] In brief overview, and with reference to Figure 1 , an aerosol generating device 100 may comprise a housing 102. Within the housing 102, the aerosol generating device 100 comprises a battery unit 104 to supply power to the aerosol generating device 100. The aerosol generating device 100 may also include a controller 106, otherwise known as a processor or control unit, that is configured to control operation of the aerosol generating device 100 in use. The controller 106 may comprise control circuitry that is configured to control operation of a light source assembly, one or more heaters, and / or one or more temperature sensors, as will be described.The aerosol generating device 100 comprises the heating chamber 108. The heating chamber 108 is configured to receive an aerosol generating article comprising aerosol generating material (not shown in Figure 1). The heating chamber 108 may be elongated. The heating chamber 108 may be provided as a cylindrical cavity with a circular cross section. In use, the aerosol generating article is received at least partially in the chamber 108 within the housing 102. The aerosol generating material may be in a solid form or a liquid form.

[0104] The heating chamber 108 may be accessible via an opening 110. The opening 110 is an opening in the housing 102 of the aerosol generating device 100. The opening may be closable by a lid 122. The lid 122 forms part of the housing 102. The lid 122 is movable between a first configuration, where the opening 110 to the chamber 108 is covered and a second configuration, where the opening 110 to the chamber 108 is open and accessible. In examples, the lid 122 may comprise a user interface.

[0105] The aerosol generating device 100 comprises a light source assembly 200. The light source assembly 200 is configured to heat an aerosol generating article 300 received in the heating chamber 108.

[0106] The aerosol generating device 100 may comprise an elongated light guide 210. The elongated light guide 210 is within the heating chamber 108. The elongated light guide 210 may be provided as a circular cylinder, a circular frustoconical shape, or a circular conical shape that extends within the heating chamber 108.

[0107] The aerosol generating device 100 may comprise heat transfer element 250. The heat transfer element 250 may be in thermal contact with the light source assembly 200 and at least partially surround the heating chamber 108

[0108] Referring to Figure 2, the heating chamber 108 is shown. The heating chamber 108 comprises the light source assembly 200 and the light guide 210.

[0109] The heating chamber 108 may comprise a cylindrical cavity, having an open end and a closed end, and defining a receiving volume 182. The heating chamber 108 may have a circular cross section. The heating chamber 108 may be defined by a wall 180. The wall 180 may be parallel to the longitudinal direction of the heating chamber 108. The wall 180 may comprise an inner wall 182 which may be in thermal contact with an outer surface of an aerosol generating article received therein.The heating chamber may have a first end 114 proximal to the opening 110, and a second end 116 opposite to the first end 114. The receiving volume 182 of the heating chamber 108 may be elongate and extend between the first end 114 and the second end 116. The second end 116 may be arranged towards a distal end of the device 100. In examples, the heating chamber 108 may be elongate but not cylindrical. Advantageously, the heating chamber 108 is convenient for use with a typical aerosol generating article (a heat-not-burn stick). In examples, the heating chamber 108 is convenient for use with an aerosol generating article adapted for use with the aerosol generating device 100 described herein.

[0110] The light source assembly 200 is configured to emit light. The light source assembly 200 comprises a light source 202 that is arranged to emit light therefrom. The emitted light is suitable for heating aerosol generating material to generate aerosol. In examples, the light source 202 may be arranged to emit laser light. That is, the light source 202 of the light source assembly 200 may comprise a laser. In examples, the light source 202 is configured to emit ultraviolet or infrared light. In examples, the light source 202 is arranged to emit visible light, for example light within the red, green, blue (RGB) spectrum. In examples, the light source may be an LED, LEP, or noncoherent light source.

[0111] The light source assembly 200 is arranged at the second end 116 of the heating chamber 108. That is, the light source assembly 200 is arranged at the opposite end of the heating chamber 108 to the opening 110. As such, light is emitted form the second end 116 in a direction towards the first end 114. The light emitted from the light source assembly 200 may be emitted in a direction parallel to the longitudinal axis of the heating chamber 108.

[0112] The light source assembly 200 may comprise additional components. In examples, the light source assembly 200 may comprise an optical component 220 configured to diverge light emitted from the light source 202. The optical component 220 may be provided above the light source 202. In examples, the light source assembly 200 may comprise more than one light source 202. The light source assembly 200 may be a connected to a power supply of the device 100. In examples, the light source assembly 200 may be controllable by a user input to the device 100. In examples, the light emission from the light source assembly 200 may be preset for a specific heating profile of the device.

[0113] The light guide 210 is elongated. That is, the light guide 210 is extends in a direction such that it extends along the length of the heating chamber 108. The light guide 210 is provided in the heating chamber 108. At least part of the light guide 210 may be arranged adjacent to the lightsource assembly 200. In examples, the light guide 108 is provided partially within the heating chamber 108. In these examples, a portion of the light guide 108 may extend outside of the heating chamber 108. In examples, the light guide 108 may extend from the second, closed end 116 of the heating chamber 108 along a longitudinal direction of the heating chamber 108.

[0114] The light guide 210 has a first end 212 and a second end 214. The second end 214 is opposite the first end 212. The second end 214 of the light guide 210 is arranged within the heating chamber 108. The first end 212 of the light guide 210 is arranged proximal to the light source assembly 200. The light guide 210 is arranged to receive light emitted by the light source assembly 200 at its first end 212. The second end 214 may be arranged within the receiving volume 182 of the heating chamber 108.

[0115] The light guide 210 may be provided as a cylinder, for example a circular cylinder, a circular frustoconical or conical shape, or other elongated shape with a polygonal base.

[0116] The light guide 210 has a lateral surface that extends along the length of the elongated light guide 210 between its first end 212 and its second end 214. In other words, the lateral surface may refer to a side wall 216 that extends between the first end 212 and the second end 214. In examples where the light guide 212 has a polygonal base, the side wall 216 defining the lateral surface may comprise various flat segments.

[0117] In use, the light guide 210 is configured to receive light at its first end 212 and direct the received light such that the light is emitted from the lateral surface along the length of the light guide 210. The light guide 210 may be arranged in the center of the heating chamber 108 when viewed from the horizontal cross section of the heating chamber 108.

[0118] In examples, the light guide 210 is a pillar. The pillar may be provided centrally within the heating chamber 108. That is, the pillar may extend from the center of the second end 116 of the heating chamber 108. Advantageously, this means that an aerosol generating article received in the heating chamber 108 may be evenly heated by the emitted light. In examples where the cross section of the cavity heating chamber 108 is circular, the pillar may be provided radially centrally within the circular cross section of the cavity. In use, an aerosol generating article may be shaped to surround the light guide 210, as will be described. In examples, the aerosol generating article may be pierced by the light guide 210.In examples, the aerosol generating article for use with the aerosol generating device 100 may be provided in the form of a hollow tube. That is, the center of the aerosol generating article may be empty such that it may be provided over or around the light guide 210. The aerosol generating substrate may be provided in the body of the hollow tube. In use, the light guide 210 may be configured to be inserted in the hollow tube when the aerosol generating article is received in the heating chamber 108. In use, the aerosol generating substrate in the aerosol generating article may be heated from the inside, i.e. from the hollow portion of the aerosol generating article. The light guide 210 may comprise one or more optical components 218. The one or more optical components may be arranged along the length of the elongated light guide 210 between its first end 212 and its second end 214. In examples, where the light guide 210 is a pillar, the optical components are arranged within the pillar. In examples, the optical components 218 may comprise fibre optical efficient material.

[0119] In examples, the optical components 218 may comprise a plurality of lenses. The plurality of lenses may be arranged along the length of the light guide 210. In examples, the plurality of lenses are convex lenses. As such, the emitted light received at the first end 212 of the light guide 210 is directed by the plurality of convex lenses to be emitted from the lateral surface of the light guide 210.

[0120] In examples, each of the plurality of lenses has optical properties that vary based on its distance from the first end 212 of the light guide 210. Advantageously, this means that the divergence of light is highly controlled along the length of the light guide 210. In examples where each of the plurality of lenses is a convex lens, the convex lenses may have different curvatures. These lenses may be arranged such that the curvature of the array of the plurality of concave lenses vary across the length of the light guide. In examples, each of the convex lenses has a curvature that increases with an increase of the distance from the first end 212 of the light guide 210. As such, the light emitted from the light source assembly 200 and received by the convex lenses of the light guide 210 may be directed to a direction substantially perpendicular to the longitudinal direction of the heating chamber 108. This means that the light incidents aerosol generating material in an aerosol generating article received in the heating chamber 108 with an angle of incidence of substantially zero. Advantageously, this allows for a more precise control of heating across different portions of the aerosol generating article.

[0121] The light is emitted from the lateral surface of the light guide 210 in a direction substantially perpendicular to the direction in which the elongated light guide 210 extends. This is illustrated by the arrows shown in Figure 2. In examples, the light emitted by the light source assembly 202may be split and directed by different lenses within the plurality of lenses. As such, the emitted light is distributed along the length of the light guide 210, along its lateral surface.

[0122] In examples, the optical component 220 provided as part of the light source assembly 200 may be provided above the light source 202. In examples, the optical component may comprise a convex or concave lens, to focus and / or diverge the emitted light. In such examples, the light beam emitted into the heating chamber 108 at the second end 116 may have an angle of deviation that is greater than the light beam received at the first end 114 of the heating chamber 108. In other words, an angle between the path of the original light beam emitted by the light source 202, i.e. in the longitudinal direction of the heating chamber 108, and the path of the light beam after the light is diverged by the optical component may be greater towards the second end 116 of the heating chamber 208. As such, light may incident in the light guide 210 at a greater angle of incidence at the first end 114 of the heating chamber 108, adjacent to the opening 110, than the second end 116 of the heating chamber 108, adjacent to the light source assembly 200. In order to direct the light in the direction perpendicular to the longitudinal direction of the heating chamber 200, the convex lens at each longitudinal position in the light guide 210 may be adjusted. When the light incidents at a greater angle of incidence, a greater curvature of the lens is provided. In examples, the light guide 210 comprises one or more beam splitters. The beam splitters may be arranged along the lengths of the light guide 210 such that at least part of the emitted light that enters the light guide at the first end 212 is reflected towards the lateral surface of the light guide 210. This is illustrated by the arrows shown in Fig. 2. In use, the beam splitters are configured to split a single beam of light emitted form the light source assembly 200 into various beams that are spread evenly across the length of an aerosol generating article that may be received in the heating chamber 108.

[0123] In examples, the light guide 210 may be used to heat specific portions of an aerosol generating article received in the heating chamber 108. For example, the light guide 210 may be arranged such that defined portions of an aerosol generating article are heated differently. A specified heating profile may be provided through use of the light guide 210 arrangement to suit specific aerosol generating articles. Advantageously, this may provide for an improved and customisable user experience.

[0124] Referring to Fig. 3, the heating chamber 108 may comprise a heat transfer element 250. The heat transfer element 250 may also be known as a heat sink structure. In examples, the heat transfer element 250 comprises a thermally conductive material, such as a metal or alloy, for example copper or aluminium, or alloys thereof.The heat transfer element 250 is in thermal contact with the light source assembly 200. The heat transfer element 250 may be adjacent to at least part of the light source assembly. In examples, at least part of the light source assembly 200 may be embedded in the heat transfer element 250. The heat transfer element at least partially surrounds the heating chamber 108. In examples, part of the heat transfer element 250 defines part of the heating chamber 108. That is, the heat transfer element 250 defines at least one wall of the heating chamber. In examples, the heat transfer element 250 is integrated into part of the wall defining the heating chamber 108.

[0125] In examples, the heat transfer element 250 comprises a cup shaped structure to surround the heating chamber 108. The heat transfer element 250 may comprise a bottom part 256 and a sidewall part 254. As shown in Fig. 3, the heat transfer element 250 may surround the heating chamber 108 on all sides except for the opening 110. This means that the heat transfer element 250 may provide thermal benefits, while not compromising how the aerosol generating device 100 is used, for example by not impacting how an aerosol generating article may be inserted into the heating chamber 108.

[0126] In use, heat loss from heating from the light source assembly 200 is reduced. Excess heat that is generated in heating the aerosol generating article may be transferred to the heat transfer element 250. Since the heat transfer element 250 at least partially surrounds the heating chamber 108, at least some of the heat transferred to the heat transfer element 250 may heat the outside, or a peripheral surface, of an aerosol generating article.

[0127] As such, the heat transfer element 250 may act as an external heater. Advantageously, the heat transfer element 240 may help to suitably distribute heat in and around the heating chamber 108. Further, the heat transfer element 250 may act as a heat sink to prevent the light source assembly from heating up or overheating. A bottom part 256 of the cup shaped structure of the heat transfer element 250 may be arranged in thermal contact with the light source assembly 200 such that the heat generated at the light source as it emits light may be transferred to the heat transfer element 250 at the regions adjacent to the light source assembly 250. The heat collected at these regions of the heat transfer element 250 may then transferred to a sidewall part of the heat transfer element 250. Advantageously, this may reduce energy consumption, efficiency of light emission and prolong the lifespan of the light source assembly 200.

[0128] In examples, the heat transfer 250 element may comprise phase change materials (PCM). The PCM may be arranged on a surface of the heat transfer element 250 and / or it may be embedded in the heat transfer element 250 or be comprised in the material of the heat transfer element 250.Advantageously, the PCM may aid in reduce energy consumption, efficiency of light emission and prolong the lifespan of the light source assembly 200, by helping to maintain a desired temperature by absorbing and releasing large amounts of latent heat during their phase transitions (e.g., from solid to liquid and vice versa). In this way, the PCM may contribute to maintaining the heat transfer element at the predetermined temperature in use.

[0129] The heat transfer element 250 may comprise one or more fins 252. The fins 252 may be arranged in an array. The array of fins 252 may extend from a sidewall part 254 of the heat transfer element 250. The fins 252 may improve heat transfer via the heat transfer element 250 by providing for improved heat dissipation. The fins 252 may be arranged on at east half of the length of the sidewall part 254 of the heat transfer element 250.

[0130] The fins 252 may be arranged such that the density of the fins 252 or the size of the fins 252 varies across a length of the heat transfer element 250. In examples, the geometry, thickness and length of the fins 252 may vary across a length of the heat transfer element 250. In examples, the fins 252 are arranged such that the length of the fins 252 varies along the length of the heat transfer element 250. In examples, the length of each fin 252 may sequentially reduce from the second end 116 of the heating chamber 108 towards the first end 114 of the heating chamber 108. The fins 252 may be arranged in groups of similarly sized fins 252. The length of each group of fins 252 may reduce from the second end 116 of the heating chamber 108 towards the first end 114 of the heating chamber. In examples, the size of each of the fins 252, or the length of each fin 252 within a group of fins 252, may reduce towards the first end 114 of the heating chamber 108. The size of the fins 252 may relate to the length, width, or surface area of each of the fins 252. In examples, the density of the fins 252 may reduce along a sidewall 254 of the heat transfer element 250. In examples where the fins 252 are arranged in groups, the groups of fins 252 towards the first end 114 of the heating chamber 108 may comprise fewer fins than the groups towards the second end 116. As such, the heat transfer in the heat transfer element 250 may be greater towards the second end 116, i.e. closest to the light source assembly 200. This may advantageously work to compensate a temperature gradient in the heat transfer element 250 that arises due to the positioning of the light source assembly 200 at the second end 116 of the heating chamber 108.

[0131] In examples, the fins 252 in each array of fins may have consistent dimensions. In examples, the fins 252 in each array of fins may be consistently spaced. In examples, the total surface area of each array of fins may decreases towards an opening of the heating chamber. This may allow for controllable thermal management as required for an aerosol generation device 100.In examples, the heat transfer element 250 may be provided as part of an aerosol generating device comprising a different type of heating, rather than heating using a light source assembly. The heat transfer element 250 may be used in any aerosol generating device comprising a heating assembly. For example, the heat transfer element 250 may be used in aerosol generating devices that use resistive or induction heating assemblies comprising a heating source, as an alternative to heating assemblies that comprise a light source assembly. The heat transfer element 250 may be used in devices with any type of contactless heating assembly. Advantageously, the heat transfer element 250 may contribute to improving heating efficient in any such devices.

[0132] In examples, the aerosol generating device 100 may comprise an additional heater 260. The heater 260 may be provided adjacent to, or embedded in, the heat transfer element 250. The heater 260 may form part of the heat transfer element 250. Advantageously, the heater 260 is in good thermal contact with the heat transfer element 250 such that the temperature of the heating chamber 108 may be suitably controlled.

[0133] In examples, the heater 260 may be any suitable electrical heater. In examples, the additional heater 260 may be a resistive heater. In examples, the additional heater 260 may be an induction heater. In examples, the additional heater 260 may be a radiation heater. In examples, more than one heater 260 may be provided.

[0134] In examples, two heaters 260 may be provided on opposing sides of the heating chamber 108. Advantageously, this may provide for consistent heating of the heating chamber 108.

[0135] The heater 260 may be provided towards the second end 116 of the heating chamber. In other words, the heater 260 may arranged such that the distance between the heater 260 and a second end 214 of the light guide 210, opposite to the first end 212 of the light guide 210, is closer than the distance between the heater 260 and the first end 212 of the light guide 210. In examples, the heater 260 may be arranged adjacent to a portion of the heat transfer element 250 that is away, or at the opposite end of the heating chamber 108, from the light source assembly 200. In examples where the heat transfer element 250 comprises a cup shaped structure, the heater may be arranged around at a top part of the sidewall 254. Advantageously, the heater 260 may compensate the temperature gradient across the heat transfer element 250 by heating the heating chamber 108 at the opposite end to the light source assembly 200.

[0136] In use, the heater 260 may also be controlled to generate a temperature gradient across the heating chamber 108. In use, aerosol may be generated more significantly from a portion of the aerosol generating article close to the mouthpiece end of the heating chamber 108, as a userinhales aerosol. As such, aerosol generating material in an aerosol generating article may be consumed faster at that end when the aerosol generating article is heated uniformly. Since the heater 260 may be controlled to provide a temperature gradient across the heating chamber 108, the temperature at the first end 114 may be less than the temperature at the second end 116. In examples, the heater 260 may be controllable to reduce the temperature at the first end 114 once the aerosol generating material is depleted at the mouth end of an aerosol generating article. For example, the aerosol generating device 100 may be configured to stop power supply to the heater 260. In examples, the aerosol generating device 100 is configured to reduce power supply to the heater 260. In examples, the aerosol generating device 100 may first reduce power supply to the heater 260 and later stop power supply to the heater 260. In examples, power supply to the heater 260 may be controlled to be decreased or stopped based on a progress of a session of use, for example a predetermined time and / or number of puffs by a user. In examples, power supply to the heater 260 may be controlled by a user input.

[0137] In examples, the aerosol generating device 100 may comprise a temperature sensor 270. The temperature sensor 270 is configured to measure the temperature at a location within the heating chamber. In examples, the aerosol generating device 100 may comprise at least two temperature sensors. The two or more temperature sensors 270 may be configured to measure the temperatures of at least two different locations of the heating chamber.

[0138] The two or more temperature sensors 270 may be in thermal contact with the heating chamber 108 and / or the heat transfer element 250. In examples, the two or more temperature sensors 270 may be provided as part of the heating chamber 108 or as part of the heat transfer element 250. In examples, one or more temperature sensors 270 may be proved in the heating chamber 108 and one or more may be provided in the heat transfer element 250. Specifically, the temperature sensors 270 may be in thermal contact with a wall 180 of the heating chamber 108 or a sidewall part 254 of the heat transfer element 250.

[0139] In examples, a first of the two or more temperature sensors 270 may be provided at a first end 114 of the heating chamber 108. A second of the two or more temperature sensors may be provided at a second end 116 of the heating chamber 108. As such, a difference between temperatures of the first end 114 and the second end 116 of the heating chamber 108 may be measured. In examples, the first and second of the two or more temperature sensors 270 may be provided at different longitudinal positions of the heating chamber 108. As such, the temperature gradient along the longitudinal length of the heating chamber 108 may be accurately determined.This means that the device 100 and, for example, the heater 260, may be controlled appropriated to provide for efficient heating of the aerosol generating article.

[0140] In examples, more than two temperature sensors 270 may be provided to measure the temperature of the heating chamber 108 at different locations.

[0141] In use, each of the two or more temperature sensors 270 may provide a signal indicative of the temperature of each corresponding location of the heating chamber. The power supply to the heater 260 may be controlled based on the signals obtained from the two or more temperature sensors 270. Advantageously, this means that the temperature may be monitored during use to provide for optimum heating of an aerosol generating article and a highly controllable device. In examples where the heater 260 is integrated within or arranged on the heat transfer element 250, the temperature gradient of the heating chamber 108 or the heat transfer element 250 may be directly modulated based on signals from the temperature sensors 270.

[0142] Referring to Fig. 4, an aerosol generating system 500 is provided. The aerosol generating system 500 comprises an aerosol generating device 100 as described and an aerosol generating article 400.

[0143] The aerosol generating article 400 is configured to be at least partially received in the heating chamber 108 of the aerosol generating device 100. The aerosol generating article 400 comprises an aerosol generating substrate. At least a part of the aerosol generating substrate of the aerosol generating article 400 is inserted in a gap between an inner wall 182 of the heating chamber 108 and the light guide 210.

[0144] The aerosol generating article 400 may be an aerosol generating stick, also known as a heat-not-burn stick. The aerosol generating article 400 may have a first, also known as the mouth or proximal end, 401 and a second end, also known as the distal end 402. The aerosol generating article 400 comprises an aerosol generating substrate arranged at least at a distal end of the aerosol generating article 400. The aerosol generating article may be in the form of a hollow tubular structure. As such, the aerosol generating substrate may also be in the form of a hollow tubular structure. That is, a hollow portion 404 extends through at least part of the aerosol generating article 400. In examples, the hollow portion 404 extends from the second end 402 towards the first end 401, longitudinally thought the aerosol generating article 400.

[0145] In examples, the aerosol generating article 400 may further comprise a mouthpiece 406 at the first end 401. In examples, the mouthpiece 406 may comprise a filter. In examples, the aerosol generating article 400 may comprise a cooling section arranged between the mouthpiece and theaerosol generating substrate. In examples, components of the aerosol generating stick may be held by a wrapper to form a stick.

[0146] The hollow tubular structure of the aerosol generating article 400 and / or substrate may have an inner diameter which is sufficiently large such that the light guide may be inserted into the hollow portion 404. The aerosol generating article 400 may have an outer diameter which is smaller than the diameter of the heating chamber 108 for inserting the aerosol generating article into the heating chamber 108. As such, when the aerosol generating article 400 is received in the heating chamber 108, at least a portion of the aerosol generating substrate is sandwiched between the inner wall 182 of the heating chamber 108 and the light guide 210.

[0147] In examples, the aerosol generating article 400 is configured such that an entire portion of the aerosol generating substrate is sandwiched between the inner wall 182 of the heating chamber 108 and the light guide 210. In such an example, the hollow portion 404 may extend through the length of the aerosol generating article 400. Advantageously, this means that the aerosol generating substrate may be uniformly heated.

[0148] In examples, the aerosol generating article 400 is configured such that the aerosol generating article may have a diameter substantially the same or a slightly smaller than the diameter of the heating chamber 108. This way, the aerosol generating article may receive heat from the heat transfer element most efficiently.

[0149] Referring to Figure 5, there is provided a method 600 of aerosol generation.

[0150] The method 600 comprises a first step 610 of providing the aerosol generating system 500 and a second step 620 of operating the light source assembly 200 to emit light.

[0151] In examples, providing the aerosol generating system 500 comprises inserting the aerosol generating article 400 into the heating chamber 108 of the device 100. The aerosol generating device 100 may be configured to detect initiation of use of the aerosol generating device by a user. In examples, this may be through a sensor or user input.

[0152] In examples, the aerosol generating device 100 may be configured to activate (i.e. , supply power to) the light source assembly 200 upon detecting insertion of the aerosol generating article 400 into the heating chamber 108. In examples, a user input may be detected. A user input may be, for example, a user pushing a button arranged on the aerosol generating device 100. The power supply to the light source assembly 200 may be controlled to heat the aerosol generating substrate in the aerosol generating article 400 to a predetermined target temperature.In examples, the light source assembly 200 may be controlled based on the signals of the two or more sensors 270 which may be arranged in the device 100. For controlling the power supply to the heater, at least one of the two or more sensors may be selected to be used for feedback control. In examples, the measured temperatures determined by the two or more sensors may be used to inform operation of the device 100. In examples, one of the two or more sensors 270 may be used for feedback control at a time. In examples, the temperature sensor 270 used for the feedback control may be altered during the progress of the vaping session, as required.

[0153] In examples, the aerosol generating device 100 comprises a first temperature sensor 270 configured to measure a temperature at a first end 114 (top portion) of the heating chamber 108, a second temperature sensor 270 configured to measure a temperature at a middle portion of the heating chamber 108, and a third temperature sensor 270 configured to measure a temperature at a second end 116 (bottom portion) of the heating chamber 108. In examples, the feedback control for operating the light source may be based on at least one of the first, second and third sensors 270. In examples, the aerosol generating device may be configured such that one of the first, second and third sensors for the feedback control of the power supplied to the light source at a time and the temperature sensors to be used is changed sequentially based on the progress of the session. Advantageously, this may relate to requirements as the amount of aerosol generating substrate in the article 400 depletes during a session of use.

[0154] Specifically, during a session of use, the aerosol tends to be generated more significantly from a first end 401 of the article 400. Therefore, aerosol generating material of the aerosol generating article 400 may be consumed faster at that portion. In examples, the first sensor 270 may be used to control the power to the light source assembly 200 at an initial stage of a session of use. Then, after a first predetermined time and / or number of puffs of the session is expired, the second temperature sensor may used for feedback control of the power of the light source assembly 200. Finally, when a second predetermined time and / or number of puffs of the session is expired, the third temperature sensor may be used to adjust the power to the light source assembly 200. Therefore, once the aerosol precursor in the proximal side portion is depleted, the heater may be controlled to reduce the temperature at that part. Advantageously, this means that the aerosol generating material within the aerosol generating article 400 is used efficiently. Advantageously, the depleted portion of the aerosol generating substrate is not heated or heated at lower temperatures, thereby preventing overheating of that portion, leading to an improvement in user experience.In examples of the method 600, the aerosol generating device 100 may start supplying power to the additional heater 260 only once the initiation of a session of use of the aerosol generating device 100 by a user is detected and / or the light source assembly 200 is activated. During use, the power supply to the heater 260 may be adjusted such that the temperature gradient within the heating chamber 108 or the heat transfer element 250 is compensated during operation of the light source assembly 200.

[0155] In examples, the method 600 may further comprise a step of measuring the temperature variations in the heating chamber 108 by the two or more temperature sensors 270, in order to control the power of the heater 260. In examples, the heater 260 may be activated only when temperature variations in the heating chamber 180 measured by the one or more temperature sensors exceed a predetermined value.

[0156] In examples, the method of aerosol generation may further comprise a step of controlling power supply to the heater 260 based on progress of a session of use. The progress of a session of use may relate to a predetermined time and / or number of puffs. In this step, the power to the heater may be adjusted based on the measurement of the temperature by the two or more temperature sensors 270. The feedback control of the heater 260 may employ a similar method as that for the light source assembly 200 as described earlier.

[0157] In examples where the aerosol generating device 100 comprises a first, second and third temperature sensors 270, the feedback control for the power of the heater 260 may be based on measurements of one of the first, second and third sensors 270. Furthermore, the aerosol generating device 100 may be configured to use one of the first, second and third sensors 270 for the feedback control of the heater 260 at a time. In examples, the aerosol generating device 100 may be configured to change the temperature sensors to be used for the feedback control sequentially based on the progress of the session.

[0158] In examples, the heat transfer element 250 may be used in aerosol generating devices where the primary energy provision system could take any form configured to provide energy to the consumable to generate aerosol from the consumable. That is, use of the heat transfer element as described herein is not limited to use with light source assemblies. For example, a compatible energy provision system could take the form of a resistive or inductive heater or the like. It may also comprise a wick and coil arrangement configured to absorb liquid aerosol precursor material and generate an aerosol. Other arrangements of the energy provision system and the aerosol generating device are envisaged.Although a few example embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

[0159] All the features disclosed in this specification, including any accompanying claims, abstract and drawings, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0160] Each feature disclosed in this specification, including any accompanying claims, abstract and drawings, may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Claims

Claims1. An aerosol generating device for heating an aerosol generating article comprising:a heating chamber configured to receive at least part of the aerosol generating article; a light source assembly configured to emit light for heating the aerosol generating article when received in the heating chamber; andan elongated light guide arranged at least partially within the heating chamber, the light guide configured to:receive light emitted from the light source assembly at a first end of the light guide, anddirect the light, such that the light is emitted from a lateral surface along a length of at least part of the light guide.

2. An aerosol generating device according to claim 1, wherein the aerosol generating device further comprises a heat transfer element in thermal contact with the light source assembly and arranged to at least partially surround the heating chamber.

3. An aerosol generating device according to any preceding claim, wherein the aerosol generating device comprises an additional heater.

4. An aerosol generating device according to claim 3, wherein the heater is arranged such that the distance between the heater and a second end of the light guide, opposite to the first end of the light guide, is closer than the distance between the heater and the first end of the light guide.

5. An aerosol generating device according to claim 3 or 4, wherein the heater forms part of the heat transfer element.

326. An aerosol generating device according to any preceding claim, wherein the aerosol generating device comprises two or more temperature sensors.

7. An aerosol generating device according to any preceding claim, wherein the light source assembly comprises a light source.

8. An aerosol generating device according to any preceding claim, wherein the light source assembly comprises an optical component configured to diverge the light from the light source assembly.

9. An aerosol generating device according to any preceding claim, wherein the light guide comprises a plurality of lenses arranged along one or more lateral surfaces of the light guide.

10. An aerosol generating device according to claim 9, wherein each of lenses of the plurality of lenses has optical properties that vary based on a distance from the first end of the light guide.

11. An aerosol generating device according to claim 10, wherein the plurality of lenses comprises convex lenses, and each of the convex lenses has a curvature that increases with an increase in distance from the first end of the light guide.

12. An aerosol generating device according to any preceding claim, wherein the heating chamber comprises a cylindrical cavity having an open end and a closed end, and wherein the light guide extends from the closed end along a longitudinal direction of the chamber such that a second end of the light guide, opposite to the first end, is arranged within the heating chamber.

13. An aerosol generating device according to claim 12, wherein the light source assembly is arranged adjacent to the first end of the light guide.

14. An aerosol generating system comprising:the aerosol generating device according to any preceding claim; and an aerosol generating article configured to be at least partially received in the heating chamber of the aerosol generation device.

15. A method of aerosol generation comprising:providing the aerosol generating system according to claim 14; and operating the light source assembly to emit light.

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