Heating method for a plate-shaped heating chamber of an aerosol generation device, and related aerosol generation device

Abstract

A heating method (100) for a plate-shaped heating chamber of an aerosol-generating device configured to operate with a plate-shaped tobacco article comprising a substrate portion, the substrate portion defining two opposite heating surfaces, the heating chamber comprising two heating elements arranged to face each other, each heating element being designed to extend along substantially the entire area of the respective heating surface, the method comprising: - performing a preheating phase (110) comprising powering only one of the heating elements until a target temperature is achieved; - performing a vaping phase (120) by powering each heating element according to a different heating profile, at least one heating profile comprising powering the corresponding heating element within a predetermined heating interval (122) according to a predetermined power supply value.

Description

Technical Field

[0001] The present invention relates to a heating method for a plate-shaped heating chamber of an aerosol generating device.

[0002] Specifically, an aerosol generating device configured to implement the heating method according to the present invention is configured to operate, for example, with a plate-shaped tobacco article including a solid substrate capable of forming an aerosol when heated. Thus, such a type of aerosol generating device, also known as a heat-not-burn device, is adapted to heat rather than burn the substrate by conduction, convection, and / or radiation to generate an aerosol for inhalation.

[0003] The present invention also relates to an aerosol generating device configured to implement this heating method.

Background Art

[0004] (Also known as a vaporizer) The popularity and use of risk reduction devices or risk modification devices have grown rapidly in recent years as an aid to assist habitual smokers who wish to quit smoking conventional tobacco products such as cigarettes, cigars, cigarillos, and roll-your-own tobacco. In contrast to burning tobacco in conventional tobacco products, various devices and systems for heating or warming vaporizable substances are available.

[0005] Generally available risk reduction devices or risk modification devices are substrate heated aerosol generation devices or heat non-combustion devices. This type of device typically generates an aerosol or vapor by heating an aerosol substrate, typically containing moist tobacco or other suitable vaporizable material, to a temperature in the range of typically 150°C to 350°C. By heating the aerosol substrate rather than burning or igniting it, an aerosol is released that contains the components desired by the user but does not contain toxic and carcinogenic by-products resulting from combustion and ignition. Furthermore, the aerosol generated by heating tobacco or other vaporizable material typically does not contain the burnt or bitter taste resulting from combustion and ignition that can be unpleasant to the user, and thus the substrate does not require sugars and other additives typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0006] To provide high user comfort, it is desirable to obtain rapid heating of the aerosol substrate. However, some known aerosol generation devices operating with tobacco articles are equipped with heaters that consume a lot of energy to raise the heater to a predetermined temperature and thus heat the tobacco article to the target temperature.

[0007] High energy consumption can lead to design constraints of the aerosol generation device, such as the need for a large-capacity battery. Also, high energy consumption may not provide optimal user comfort, as this may require frequent recharging of the battery of the aerosol generation device. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] One object of the present invention is to provide a heating method for a plate-shaped heating chamber of an aerosol generation device that requires less electrical energy. MEANS FOR SOLVING THE PROBLEMS

[0009] For this purpose, the present invention relates to a heating method for a plate-shaped heating chamber of an aerosol-generating device configured to operate with a plate-shaped tobacco article comprising a substrate portion, the substrate portion defining two opposite heating surfaces, the heating chamber comprising two heating elements arranged to face each other, each heating element being designed to extend along substantially the entire area of the respective heating surface, The method comprises - performing a preheating phase comprising powering only one of the heating elements until a target temperature is achieved; - performing a vaping phase by powering each heating element according to a different heating profile, at least one heating profile comprising powering the corresponding heating element within a predetermined heating interval according to a predetermined power supply value; and

[0010] Thanks to these features, the heating performed by the aerosol-generating device according to the heating method of the present invention requires less electrical energy than in known methods. Specifically, the heating method according to the present invention makes it possible to reduce the consumed electrical energy in both the preheating phase and the vaping phase.

[0011] During the preheating phase, only one heating element is powered until the target temperature is achieved, so that, for example, less energy is required to carry out the preheating phase compared to a method comprising powering both heating elements during the preheating phase. In addition, the maximum current required from the device's battery is lower, for example, than when two heating elements are powered simultaneously.

[0012] The preheating phase of the present invention enables, for example, saving approximately 10% of the electrical energy. Furthermore, in the preheating phase according to the present invention, one heating element is heated very rapidly, so it is possible to reduce the duration of the preheating phase. Therefore, the first puff during the vaping phase can be performed after a very short preheating time. This improves user comfort.

[0013] Thanks to the vaping phase according to the present invention, the energy consumption is also reduced by supplying power to each heating element according to different heating profiles. For example, the energy consumption is reduced by approximately 7% compared to constantly heating both heating elements during the vaping phase.

[0014] The combination of the preheating phase and the vaping phase makes it possible to significantly reduce the energy consumption, especially compared to methods that include heating both heating elements.

[0015] In addition, since each heating element is designed to extend along substantially the entire area of its respective heating surface, this heating method enables utilization of substantially the entire area of each heating surface for heat transfer. This makes it possible to obtain high efficiency especially in heat transfer from the heating element to each heating surface.

[0016] According to some embodiments, this heating section is defined by the temperature of the corresponding heating element.

[0017] Thanks to this feature, this heating method enables, for example, reliable control of the heating element according to a given temperature profile. Also, the control of the aerosol generating device by considering the temperature of the corresponding heating element is simple.

[0018] Specifically, this feature enables, for example, realizing control independent of the number of puffs, which leads to a control that can be easily reproduced, for example, during the operation of the aerosol generating device.

[0019] According to some embodiments, each heating period is carried out until a predetermined temperature is achieved, preferably the predetermined temperature is substantially equal to the target temperature.

[0020] Thanks to this feature, this heating method makes it possible to control each heating element regardless of some characteristics of the aerosol generating device, for example, regardless of the material characteristics of the heating element and regardless of the current intensity supplied to the corresponding heating element.

[0021] According to some embodiments, this heating period is defined by time.

[0022] Thanks to this feature, since the heating period is carried out in a predictable manner for a given time, it is particularly easy to implement this method. Specifically, this feature enables the realization of a predictable behavior of the heating of the element, for example, regardless of external conditions or measured values of physical quantities. This feature also makes it possible to achieve control regardless of, for example, the number of puff cycles, which leads to a control that can be easily reproduced during the operation of the aerosol generating device.

[0023] According to some embodiments, the heating periods are equally spaced by a predetermined time value, and the predetermined time value is preferably included in 20 to 30 seconds.

[0024] Thanks to this feature, the heating periods are carried out regularly in a predetermined manner. This enables the realization of an energy-efficient operation of the aerosol generating device.

[0025] Furthermore, this feature enables simple control by providing a stable interval between the heating periods.

[0026] Also, thanks to the feature that the predetermined time value is included in 20 to 30 seconds, the user comfort is very high. Because even during the 20 - 30 seconds of heating pause of one of the heating elements, the heating element can provide certain aerosol characteristics for the user.

[0027] According to some embodiments, the heating intervals are substantially equal within the heating interval, and preferably, the duration of each heating interval is substantially equal to a predetermined time value.

[0028] Thanks to this feature, the heating is controlled in an easy manner. Specifically, this feature enables the realization of heating in a certain heating interval of the substrate portion. For example, when a constant power is supplied during each heating interval, the same amount of heat is supplied from the corresponding heating element to the substrate portion during each heating interval.

[0029] When the duration of each heating interval is substantially equal to a predetermined time value, this makes it possible to achieve an equally spaced distribution of the heating intervals and a pause between the heating intervals for a given heating element. Therefore, the control of the heating element is very simple and at the same time energy efficient.

[0030] According to some embodiments, during the heating intervals, the corresponding heating profile - supplies power to the corresponding heating element according to a minimum power supply value that is strictly smaller than a predetermined power supply value, or - cuts off the power, is included.

[0031] When the corresponding heating profile includes supplying power to the corresponding heating element according to a minimum power supply value that is strictly smaller than a predetermined power supply value during the heating intervals, this makes it possible to reduce the energy consumption of the heating element, but still some heat is supplied to the substrate portion. Therefore, less energy is required to reach the target temperature, for example, during the next heating interval.

[0032] When the corresponding heating profile includes cutting off the power during the heating intervals, this makes it possible to reduce the energy consumption.

[0033] According to some embodiments, during the preheating phase, the corresponding heating element is powered according to a predetermined power supply value, and advantageously, the predetermined power supply value is the maximum power supply value.

[0034] Thanks to this feature, the target temperature is reached very rapidly, and the vaporizing phase can be carried out simply after a very short preheating phase. Thus, user comfort is improved.

[0035] According to some embodiments, the preheating phase further includes powering only one of the heating elements until the target temperature is achieved, in addition to powering the other heating element until the target temperature is achieved.

[0036] Thanks to this feature, the energy consumption during the preheating phase is reduced, and the method still enables heat to be supplied to both heating surfaces.

[0037] According to some embodiments, each heating profile includes powering the corresponding heating element within a predetermined heating interval according to a predetermined power supply value.

[0038] Thanks to this feature, each heating profile has the same power value provided, so the control of power supply is very simple. Furthermore, thanks to this feature, when the predetermined power supply value corresponds to the maximum power supply value, the maximum amount of heat per unit time is supplied by the heating element.

[0039] According to some embodiments, the heating profiles of different heating elements are configured to alternately power the corresponding heating elements according to a predetermined power supply value.

[0040] Thanks to this feature, the heating elements are alternately powered, so the heating elements cooperate to heat the heating surfaces on both sides, and thus the substrate part. When one of the heating elements is not powered, the other heating element is powered according to a predetermined power supply value, thereby making it possible to keep a given temperature of the substrate part constant during the vaporizing phase.

[0041] According to some embodiments, the heating profiles have substantially the same shape, and one of the heating elements is offset with respect to the other heating profile so as to ensure alternating power supply to the heating profiles.

[0042] Thanks to this feature, the control is very easy. This feature also makes it possible to provide the same amount of heat during the implementation of each heating profile. Furthermore, thanks to one of the heating profiles being offset with respect to the other heating profile, the heating elements cooperate to heat the heating surfaces on both sides, and thus the substrate part.

[0043] According to some embodiments, the target temperature is included in the range of 260°C to 300°C, preferably substantially equal to 280°C.

[0044] Thanks to this feature, the user comfort is very high. Specifically, a target temperature of 280°C enables the realization of optimal heating rather than combustion of the substrate part. Furthermore, this feature makes it possible to achieve low energy consumption.

[0045] The present invention also relates to an aerosol generating device configured to operate with a plate-shaped tobacco article comprising a substrate part, the substrate part defining two opposite heating surfaces, and the aerosol generating device comprises - a heating chamber configured to accommodate the plate-shaped tobacco article and comprising two heating elements arranged to face each other, each heating element being designed to extend along substantially the entire area of its respective heating surface, - a controller configured to operate the heating elements according to the heating method described above. comprises

[0046] According to some embodiments, each heating element is made of ceramic.

[0047] Thanks to this feature, heating is very efficient because a large amount of heat is supplied to the substrate portion by consuming only a small amount of electrical energy.

[0048] The present invention and its advantages will be better understood by reading the following description, given as a non-limiting example only, with reference to the accompanying drawings.

Brief Description of the Drawings

[0049]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0050] Before describing the present invention, it should be understood that the present invention is not limited to the details of the structures described in the following description. It will be apparent to those skilled in the art who enjoy the benefits of this disclosure that other embodiments are possible and that the present invention can be practiced or carried out in various ways.

[0051] As used herein, the terms "aerosol generating device" or "device" may include a vaping device for delivering to a user an aerosol containing an aerosol for vaping, using a heater element described in more detail below. The device may be portable. "Portable" may refer to a device that is used when held by a user. The device may be adapted to produce a variable amount of aerosol (as opposed to a fixed amount of aerosol), for example, by operating a heater element over a variable amount of time, which may be controlled by a trigger. The trigger may be something that the user actuates, such as a vaping button and / or an inhalation sensor. The inhalation sensor may be highly sensitive to inhalation intensity and duration of inhalation and may be capable of providing a variable amount of vapor (to mimic the smoking effect of conventional combustible smoking articles such as cigarettes, cigars, or pipes). The device may include a temperature control unit for driving the temperature of the heater and / or the heated aerosol product substance (aerosol precursor) to a specific target temperature and then maintaining that temperature at the target temperature that enables efficient generation of the aerosol.

[0052] As used herein, the term "aerosol" can include a suspension of a vaporizable material as one or more of solid particles, droplets, and gases. This suspension can be in a gas including air. The aerosols herein can generally refer to / can include vapors. An aerosol can include one or more components of a vaporizable material.

[0053] As used herein, the term "vaporizable material" or "precursor" can refer to a smokable material that can include, for example, nicotine or tobacco and an aerosol-forming agent. Tobacco can take various material forms such as shredded tobacco, granular tobacco, tobacco leaves and / or reconstituted tobacco. Suitable aerosol-forming agents include polyols (such as sorbitol, glycerol, and glycols such as propylene glycol or triethylene glycol), non-polyols (such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, and triethyl citrate, glycerin or vegetable glycerin). In some embodiments, the aerosol-generating agent can be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol. The substrate can also include at least one of a gelling agent, a binder, a stabilizer, and a humectant.

[0054] As used herein, "substantially equal" can refer to a deviation from being equal of less than ±10%, preferably less than ±5%, even more preferably less than ±1%.

[0055] Figure 1 shows an aerosol-generating assembly 10 comprising an aerosol-generating device 11 and a tobacco article 12. The aerosol-generating device 11 is intended to operate with the tobacco article 12 shown in more detail in Figure 2.

[0056] In the example of this Figure 2, the tobacco article 12 is a plate-shaped tobacco article presenting a rectangular parallelepiped extending along the article axis X and having external dimensions L×W×D. In a typical example, the length L of the article 12 along the article axis X is substantially equal to 33 mm, while its width W and depth D are respectively substantially equal to 12 mm and 1.2 mm. According to another example, the values L, W and D can be selected, for example, within a range of ±40%. The depth D of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B hereinafter called narrow walls 13A, 13B, and the width W of the tobacco article 12 is formed by a pair of parallel walls 14A, 14B hereinafter called wide walls 14A, 14B. In some embodiments, the edges between the wide walls and the narrow walls 13A, 13B, 14A, 14B may be rounded. According to other embodiments of the present invention, the tobacco article 12 can have any other suitable plate shape and / or external dimensions. According to still other embodiments, the tobacco article 12 can present any other suitable shape, such as, for example, a stick shape.

[0057] The tobacco article 12 comprises a substrate portion 15 and a mouthpiece portion 16 arranged along the article axis X. The substrate portion 15 may be, for example, slightly longer than the mouthpiece portion 16. For example, the length L2 of the substrate portion 15 along the article axis X may be substantially equal to 18 mm, and the length L1 of the mouthpiece portion 16 along the article axis X may be substantially equal to 15 mm. The substrate portion 15 defines the abutment end 18 of the article 12, and the mouthpiece portion 16 defines the mouth-side end 20 of the article 12. The substrate portion 15 and the mouthpiece portion 16 may be fixed to each other by a wrapper 21 extending around the substrate axis X. The wrapper 21 forms the narrow walls and the wide walls 13A, 13B, 14A, 14B of the tobacco article 12. In some embodiments, the wrapper 21 is formed from the same packaging sheet. In some other embodiments, the wrapper 21 is formed by separate packaging sheets that separately package the portions 15, 16, and one is fixed to the other by any other suitable means. The wrapper 21 may include, for example, paper, and / or non-woven fabric, and / or aluminum foil. The wrapper 21 may be porous or air-impermeable and forms a plurality of air flow paths extending inside the article 12 between the abutment end 18 and the mouth-side end 20.

[0058] The substrate portion 15 defines two opposite heating surfaces 17A, 17B. The two opposite heating surfaces 17A, 17B may extend parallel to each other. The two opposite heating surfaces 17A, 17B may each be formed by a portion of the wide walls 14A, 14B, in particular, a portion of the wide walls 14A, 14B that define the boundary of the substrate portion 15.

[0059] As will be described in more detail below, the substrate portion 15 contains a vaporizable material and is intended to be heated by a heating chamber.

[0060] The mouthpiece portion 16 comprises a core 27 which is intended to function, for example, as a cooler for slightly cooling the vapor before the user inhales. The core 27 may, for this purpose, include, for example, corrugated paper. The core 27 can be formed into a stable shape by an extrusion process and / or a rolling process. Advantageously, the core 27 is arranged inside the mouthpiece portion 16 so as to be in complete contact with the inner surface of the wrapper 21 and defines the boundary of this mouthpiece portion 16.

[0061] Referring again to FIG. 1, the aerosol generating device 11 comprises a device body 40 extending along a device axis Y and a mouthpiece 42. According to one example, the mouthpiece 42 and the device body 40 may form two different parts. Specifically, according to this example, the mouthpiece 42 is designed to be fixed to the fixed end of the device body 40.

[0062] As shown in FIG. 3, the mouthpiece 42 includes a central portion 43 and a peripheral portion 44 extending around the central portion 43. The peripheral portion 44 defines, for example, a collar that partially covers the outer surface of the device body 40 when the mouthpiece 42 is fixed to the fixed end of the device body 40. For example, the peripheral portion 44 can be designed to cooperate with a gasket 45 disposed at the fixed end of the device body 40 to seal the space formed between the peripheral portion 44 and the outer surface of the device body 40. The peripheral portion 44 also defines an intermediate portion that extends, for example, laterally with respect to the device axis Y and forms a transition portion between the central portion 43 of the mouthpiece 42 and the collar defined by the peripheral portion 44. The central portion 43 of the mouthpiece 42 defines a through hole 46 adapted to at least partially receive the tobacco article 12. Specifically, the through hole 46 can be adapted to receive at least a part of the mouthpiece portion 16 of the tobacco article 12, as shown in FIG. 3. Advantageously, the through hole 46 can be adapted to tightly fit with the mouthpiece portion 16 of the tobacco article 12 so as to avoid or minimize the leakage of the flow between the wall defining the boundary of the through hole 46 and the outer surface of the tobacco article 12. In some embodiments, the tobacco article 12 can be held within the through hole 46, for example, by friction. In this case, for example, it is possible to first insert the mouthpiece portion 16 of the tobacco article 12 into the interior of the through hole 46 and then fix both elements to the fixed end of the device body 40.

[0063] As also shown in FIG. 3, an internal volume 47 is formed between the inner surface 48 of the mouthpiece 42 and the fixed end of the device body 40. This internal volume 47 is traversed by the tobacco article 12 when the tobacco article 12 is inserted into the interior of the device body 40. For example, the tobacco article 12 can divide the internal volume 47 into two symmetric portions.

[0064] The device body 40 defines the boundary of the internal space of the device 11 that houses various elements designed to perform different functions of the device 11. This internal space can accommodate, for example, a battery (not shown) for powering the device 11, one or more temperature sensors (not shown), a heating chamber 50 for heating the base portion 15 of the tobacco article 12, a controller 51, particularly shown in FIG. 1, for controlling the operation of the device 11, and the like.

[0065] An example of the heating chamber 50 will be described with reference to FIGS. 3 and 4. The heating chamber 50 can form a cup shape adapted to accommodate at least the base portion 15 of the tobacco article 12 and, in some cases, at least a part of the mouthpiece portion 16. Similar to the tobacco article 12, the heating chamber 50 also extends along the device axis Y and includes a pair of parallel narrow walls 53A, 53B (shown in FIG. 4) that extend along the device axis Y, a pair of parallel wide walls 54A, 54B that also extend along the device axis Y, and a bottom wall 58 that extends perpendicular to the device axis Y adjacent to each wall, forming a rectangular parallelepiped shape. Thus, the bottom wall 58 forms the closed end of the chamber 50. The heating chamber 50 defines an opening 59 configured to accommodate the tobacco article 12 on the side opposite the bottom wall 58, such that the corresponding wide walls 14A, 14B of the tobacco article 12 face the corresponding wide walls 54A, 54B of the heating chamber 50, the corresponding narrow walls 13A, 13B of the tobacco article 12 face the corresponding narrow walls 53A, 53B of the heating chamber 50, and the abutting end 18 of the tobacco article 12 abuts against the bottom wall 58 or at least a rib extending from this bottom wall 58. Alternatively, the abutting end 18 faces the bottom wall 58 without contacting it. Thus, the heating chamber 50 is configured to accommodate the tobacco article 12 such that the narrow wall 13A (or 13B) of the tobacco article 12 faces the narrow wall 53B (or 53A) of the heating chamber 50 and the wide wall 14A (or 14B) of the tobacco article 12 faces the wide wall 54B (or 54A) of the heating chamber 50. The opposing wide walls 14A, 14B, 54A, 54B and the opposing narrow walls 13A, 13B, 53A, 53B can contact each other or be spaced apart from each other.

[0066] The heating chamber 50 further includes at least two heating elements 60A, 60B configured to face each other.

[0067] Each heating element 60A, 60B is configured to heat the substrate portion 15 of the tobacco article 12. According to different embodiments of the present invention, each heating element 60A, 60B can exhibit, for example, a resistive element disposed adjacent to at least one of the walls 53A, 53B, 54A, 54B of the heating chamber 50. Advantageously, each heating element 60A, 60B comprises, for example, a resistive heater such as a heating track or a polyimide film heater. According to other embodiments of the present invention, each heating element 60A, 60B comprises any other suitable means, for example, a heating plate facing the respective heating surfaces 17A, 17B. According to yet another embodiment, each heating element 60A, 60B comprises a magnetic element capable of causing heating of a plurality of susceptors included in the substrate portion 15 by magnetic induction.

[0068] Each heating element 60A, 60B is designed to extend along substantially the entire area of the respective heating surfaces 17A, 17B of the substrate portion 15. "Extending along substantially the entire area of the respective heating surfaces 17A, 17B" is specifically understood to mean that each heating element 60A, 60B extends along at least 95%, preferably more than 100%, of the respective heating surfaces 17A, 17B.

[0069] Specifically, each heating element 60A, 60B extends along at least the entire length L2 of the substrate portion 15 and along at least the entire width W of the substrate portion 15. According to a specific example, the length of each heating element 60A, 60B along the device axis Y is greater than the length of the substrate portion 15 along the article axis X. Accordingly, each heating element 60A, 60B protrudes from both ends of the substrate portion 15 defined along the device axis Y. According to one embodiment, the width of each heating element 60A, 60B is greater than the width W of the substrate portion 15.

[0070] Each of the heating elements 60A, 60B is designed to face, in particular, one of the heating surfaces 17A, 17B. For example, each of the heating elements 60A, 60B may be in contact with one of the heating surfaces 17A, 17B. According to another embodiment, a gap is defined between each of the heating elements 60A, 60B and the respective heating surfaces 17A, 17B.

[0071] For example, as shown in FIG. 3, each of the heating elements 60A, 60B may form at least a part of the corresponding wall of the heating chamber 50. For example, the heating elements 60A, 60B may at least partially form the opposite walls of the heating chamber 50. According to one embodiment, each of the heating elements 60A, 60B may integrally form the corresponding wall of the heating chamber 50. For example, such a wall is one of the wide walls 54A, 54B of the heating chamber 50. As also shown in FIG. 3, the substrate portion 15 is disposed sandwiched between the two heating elements 60A, 60B.

[0072] Each of the heating elements 60A, 60B may include ceramic. For example, each of the heating elements 60A, 60B is made of ceramic.

[0073] Referring to FIG. 1, the controller 51 is shown in dotted lines, which shows an example of its arrangement within the internal space of the device body 40.

[0074] The controller 51 may be disposed at any feasible location within the internal space, for example, at a location a predetermined distance from the heating chamber 50.

[0075] The controller 51 is configured to control the operation of the heating elements 60A, 60B. Specifically, the controller 51 includes a memory for storing software instructions for controlling the operation of the aerosol generating device 11, and a processor configured to execute the software instructions. Alternatively, the controller 49 may be implemented in the form of a programmable logic component such as an FPGA (Field Programmable Gate Array), or in the form of an application-specific integrated circuit such as an ASIC (Application Specific Integrated Circuit).

[0076] According to an embodiment, the aerosol generating device 11 may include a temperature sensor (not shown) configured to provide a measurement signal of the temperature of the corresponding heating elements 60A, 60B for each of the heating elements 60A, 60B. For example, each temperature sensor may be of the type of an NTC thermistor (from a Negative Temperature Coefficient thermistor).

[0077] Here, an example of the operation of the aerosol generating device 11 will be described with reference to FIG. 5 showing a flowchart of a heating method 100 for the heating chamber 50 of the aerosol generating device 11.

[0078] The heating method 100 includes a step of performing a preheating phase 110 and a step of performing a vaping phase 120.

[0079] The preheating phase 110 may be started by the user when the user activates the aerosol generating device 11. For example, the preheating phase 110 may be started when the corresponding command is received from the switch.

[0080] During the preheating phase 110, the controller 51 preferably powers only one of the heating elements 60A, 60B until the target temperature is achieved. For example, the controller 51 powers only the element 60A during the preheating phase 110. According to an alternative form, the controller 51 powers only the element 60B during the phase 110.

[0081] "The controller powers" is understood to mean that the controller commands the battery of the device 11 or the switch connecting the battery and the corresponding heating elements 60A, 60B to supply current to these elements 60A, 60B.

[0082] Specifically, the target temperature is a predetermined temperature. The target temperature may be predetermined as a function of the characteristics of the heating elements 60A, 60B and / or as a function of the type of the vaporizable material included in the substrate portion 15.

[0083] The target temperature specifically indicates the temperatures of the corresponding heating elements 60A and 60B. For example, "feeding power to one of the heating elements 60A and 60B until the target temperature is achieved" indicates that the corresponding heating elements 60A and 60B are fed power until their temperature, for example, their surface temperature, achieves the target temperature.

[0084] The target temperature can be included in the range of 260°C to 300°C. For example, the target temperature may be substantially equal to 280°C.

[0085] Heating element 60A can be fed power according to a predetermined power supply value during the preheating phase 110.

[0086] The predetermined power supply value may be predetermined as a function of the characteristics of the heating elements 60A and 60B, the battery of the aerosol generating device 11, the electrical connection between the battery and the corresponding heating elements 60A and 60B, and / or the type of the vaporizable material. The predetermined power supply value is generally a power value that is strictly greater than 0 and preferably less than 35W for each of the heating elements 60A and 60B.

[0087] According to an embodiment, the predetermined power supply value can be the maximum power supply value. The "maximum power supply value" is specifically understood to be the maximum power that the battery of the aerosol generating device 11 can supply to the corresponding heating elements 60A and 60B.

[0088] FIG. 6 shows an example of the energy consumption E in joules J of the aerosol generating device 11 as a function of the time t in seconds. In this figure, the preheating phase 110 is emphasized by the ellipse P. The first curve S represents an example of the energy consumption E when the preheating phase 110 according to the present invention is carried out, that is, by supplying power to only one of the heating elements 60A or 60B. The second curve D represents an example of the energy consumption E when the preheating phase is carried out by supplying power to both heating elements 60A and 60B simultaneously. As can be seen from this example, the preheating phase 110 including supplying power to only one of the heating elements 60A or 60B enables the saving of electrical energy as compared with the preheating phase including heating both elements 60A and 60B.

[0089] FIG. 7 shows an example of the temperature T in degrees Celsius of one of the heating elements 60A, 60B as a function of the time t in seconds. The first curve S represents an example of the temperature of one of the heating elements 60A, 60B that is being powered during the preheating phase 110. In this example, the other of the elements 60A, 60B is not being powered. Thus, the curve S corresponds to an example of the implementation of the preheating phase 110 according to the present invention. The second curve D represents the temperature T when both heating elements 60A and 60B are being powered simultaneously. As can be seen from this example, here, the target temperature, which is substantially equal to 280° C., is reached at approximately t = 20 seconds in the case of the first curve S, whereas in the case of the second curve D, it is reached at approximately t = 25 seconds at this temperature. Thus, the preheating phase 110 according to the present invention enables reaching the target temperature very rapidly, particularly more rapidly than when both heating elements 60A and 60B are heated.

[0090] Preferably, the preheating phase 110 includes supplying power to only one of the heating elements 60A and 60B until the target temperature is achieved, in addition to supplying power to the other heating element 60A and 60B until the target temperature is achieved. For example, during the preheating phase 110, only the heating element 60A is supplied with power until the target temperature is achieved, and when this target temperature is achieved by the heating element 60A, the heating element 60B is supplied with power until the target temperature is achieved. According to another embodiment, the preheating phase 110 may include first supplying power to only the heating element 60B until the target temperature is achieved, and then supplying power to the heating element 60A until the target temperature is achieved.

[0091] According to an embodiment, during the preheating phase 110, after supplying power to only one of the heating elements 60A and 60B, for example, the heating element 60A, until the target temperature is achieved, the other of the heating elements 60A and 60B, for example, the heating element 60B, is supplied with power. During the power supply to the heating element 60B, the heating element 60A may be supplied with power according to a predetermined power supply command. The predetermined power supply command may correspond to, for example, supplying power to the heating element 60A so as to substantially maintain the target temperature, for example, by power and / or temperature control. According to another embodiment, when the heating element 60B is being supplied with power, the predetermined power supply command may correspond to cutting off the power of the heating element 60A.

[0092] The preheating phase 110 may include, for example, a first stage and a second stage. Preferably, the preheating phase 110 consists of a first stage and a second stage. During the first stage, only one of the heating elements 60A, 60B is powered, and during the second stage, only the other of the heating elements 60A, 60B is powered or both of the heating elements 60A, 60B are powered simultaneously. When the first stage is completed, the second stage can be carried out directly, i.e., without any interruption. For example, during the first stage, only the heating element 60A is powered. The achievement of the target temperature of this heating element 60A can correspond to the completion of the first stage, which triggers the power supply to the heating element 60B until the target temperature is achieved.

[0093] According to other embodiments, the preheating phase 110 consists of powering only one of the heating elements 60A, 60B until the target temperature is achieved. That is, during the preheating phase 110, the other of the heating elements 60A, 60B is not powered.

[0094] When at least one, preferably both, of the heating elements 60A, 60B reach the target temperature, the controller 51 may switch from the preheating phase 110 to the vaporizing phase 120.

[0095] During the vaporizing phase 120, the controller 51 powers each of the heating elements 60A, 60B according to different heating profiles. At least one heating profile includes powering the corresponding heating element 60A, 60B within a predetermined heating interval according to a predetermined power supply value, for example, the maximum power supply value.

[0096] According to an embodiment, each heating profile, i.e., all of the heating profiles, includes supplying power to the corresponding heating elements 60A, 60B within a predetermined heating period according to a predetermined power supply value, for example, according to a maximum power supply value. Specifically, each heating profile may include at least one predetermined heating period, during which the corresponding heating elements 60A, 60B are supplied with power by applying power to this element according to a predetermined power supply value, for example, according to a maximum power supply value.

[0097] According to an embodiment, during the heating period, the corresponding heating profile may include supplying power to the corresponding heating elements 60A, 60B according to a minimum power supply value or cutting off the power. Each period during the heating period may also be referred to as an idle period.

[0098] The minimum power supply value is preferably strictly smaller than the predetermined power supply value. The minimum power supply value is specifically predetermined.

[0099] Referring to FIG. 5, the vaporizing phase 120 may include a heating period 122 and an idle period 124 directly following the heating period 122. After the implementation of the idle period 124, specifically, as indicated by the arrow R1, the same heating period 122 may be repeated, and then the same idle period 124 may follow again. For example, the vaporizing phase 120 may include a plurality of consecutive implementations of the heating period 122 and the idle period 124 according to the duration of the vaporizing phase 120. The number of implementations of each of the periods 122, 124 may be, for example, at least 5, preferably at least 10.

[0100] Preferably, each heating profile consists only of a heating section 122 and an idle section 124 between these heating sections 122. Each heating section 122 of each heating profile may correspond, for example, to feeding the corresponding heating elements 60A, 60B according to a predetermined power supply value, for example, according to the maximum power supply value. Each idle section 124 of each heating profile may correspond to feeding the corresponding elements 60A, 60B with the minimum power supply value, or may correspond to cutting off the power.

[0101] According to an embodiment, the heating profiles of the different heating elements 60A, 60B are configured to alternately supply power to the corresponding heating elements 60A, 60B according to a predetermined power supply value, for example, according to the maximum power supply value. Specifically, the heating profiles of the heating elements 60A, 60B are configured such that either the heating element 60A or the heating element 60B is supplied with power at a given time using a predetermined, i.e., maximum, power supply value. For example, the controller 51 operates as a bang-bang controller. That is, the controller 51 commands either to supply power to the element 60A or to supply power to the element 60B using a predetermined, i.e., maximum, power supply value.

[0102] According to an embodiment, the heating profiles have substantially the same shape. "Substantially the same shape" is understood to mean, in particular, that for each heating profile, the time-dependent curve of the power supplied to the corresponding heating elements 60A, 60B exhibits substantially the same geometric shape.

[0103] In embodiments with heating profiles having substantially the same shape, preferably, one of the heating profiles is offset with respect to the other heating profile so as to ensure alternating power supply to the heating elements 60A, 60B. "Alternating power supply" is understood to mean that, in particular, at a given instant, only one of the heating elements 60A, 60B is powered. According to a specific example of this embodiment, the heating profile of element 60A may be configured to power this element from t = 0 to t = 25 seconds and again from t = 50 seconds to t = 75 seconds, but not from t = 25 seconds to t = 50 seconds and from t = 75 seconds to t = 100 seconds. The heating profile of element 60B may be configured to power this element from t = 25 to t = 50 seconds and again from t = 75 seconds to t = 100 seconds, but not to power element 60B from t = 0 to t = 25 seconds and from t = 50 seconds to t = 75 seconds.

[0104] According to an embodiment, the heating section 122 is defined by the temperatures of the corresponding heating elements 60A, 60B. For example, each heating section 122 is carried out until a predetermined temperature is achieved. According to a specific example, the controller 51 may command to power element 60A until a predetermined temperature is reached, then stop power supply to element 60A, start power supply to element 60B, and continue until the predetermined temperature is achieved.

[0105] The predetermined temperature is, for example, substantially equal to the target temperature.

[0106] For example, the controller 51 receives a measurement signal from each temperature sensor of the device 11 and powers the corresponding heating elements 60A, 60B until the measurement signal indicates the predetermined temperature of the corresponding elements 60A, 60B.

[0107] According to an embodiment, the heating section 122 is defined by time.

[0108] For example, the heating intervals 122 are spaced at equal intervals by a predetermined time value. Specifically, each heating interval 122 of the heating profile exhibits the same time space (or idle interval) with a predetermined time value between the previous heating interval 122 and / or the next heating interval 122. For example, the time space with a predetermined time value is defined from the end of a given heating interval 122 to the start of the heating interval 122 following that given heating interval 122.

[0109] For example, the predetermined time value is included in the range of 20 to 30 seconds and, for example, is substantially equal to 25 seconds.

[0110] According to one example, the heating intervals 122 are substantially equal among them. Specifically, this means that the duration of each heating interval 122 is the same. Preferably, the duration of each heating interval 122 is substantially equal to the predetermined time value.

[0111] An example of a heating profile including a heating section 122 defined by time is described with reference to FIG. 8, which represents the energy consumption E in joules J of the aerosol generating device 11 as a function of time t in seconds. In this figure, the vaping phase 120 starts at t = 25 seconds and ends at t = 275 seconds. The first curve S represents an example of the energy consumption E when the vaping phase 120 is carried out according to an example of the invention. In this example, the heating element 60A is constantly powered, and the heating element 60B is powered only during the following sections: from t = 50 seconds to t = 75 seconds, from t = 100 seconds to t = 125 seconds, from t = 150 seconds to t = 175 seconds, from t = 200 seconds to t = 225 seconds, and from t = 250 seconds to t = 275 seconds. During these sections, the heating element 60B is not powered. The second curve D represents an example of the energy consumption E when a vaping phase including constantly powering both heating elements 60A and 60B is carried out. As can be seen from this example, the embodiment (curve S) of the vaping phase 120 according to an example of the invention enables a saving of electrical energy compared to a vaping phase including heating both elements 60A, 60B. Specifically, the power consumption during each section where the heating element 60B is not powered (curve S) is lower than during these sections of curve D. This leads to a total energy consumption E that is approximately 200 J lower after the implementation of the vaping phase 120 (curve S) compared to the constant powering of both elements 60A, 60B (curve D).

[0112] Method 100 may be repeated, particularly after an interruption, as represented by arrow R2 in FIG. 5, in which case it is necessary to carry out the preheating phase 110 once again before the implementation of the vaping phase 120.

[0113] For example, when a preheating phase 110 including powering only one of the heating elements 60A, 60B until a target temperature is achieved, as shown in FIG. 6, is combined with a vaporizing phase 120 according to the method of the present invention, the present invention can be understood to be particularly advantageous. This combination makes it possible to reduce the battery capacity and / or size, which is, firstly, because the maximum required current during the preheating phase 110 is reduced, and secondly, because the total energy consumption during phases 110 and 120 is reduced, especially due to different heating profiles being carried out during the vaporizing phase 120. Thus, a combination of a low maximum current and a low total power consumption as compared to the methods of the prior art makes it possible to reduce the battery capacity and / or size.

Claims

**Claim 1** A heating method (100) for a plate-shaped heating chamber (50) of an aerosol generation device (11), configured to operate with a plate-shaped tobacco article (12) comprising a substrate portion (15), wherein the substrate portion (15) defines two opposite heating surfaces (17A, 17B), and the heating chamber (50) comprises two heating elements (60A, 60B) arranged to face each other, each heating element (60A, 60B) being designed to extend along substantially the entire area of the respective heating surface (17A, 17B). The method comprises - performing a preheating phase (110) including powering only one of the heating elements (60A, 60B) until a target temperature is achieved; - performing a vaping phase (120) by powering each heating element (60A, 60B) according to different heating profiles, at least one heating profile including powering the corresponding heating element (60A, 60B) within a predetermined heating period (122) according to a predetermined power supply value; The heating method (100) comprising the above steps. **Claim 2** The heating method according to claim 1, wherein the heating period (122) is defined by the temperature of the corresponding heating element (60A, 60B). **Claim 3** The heating method according to claim 2, wherein each heating period (122) is performed until a predetermined temperature is achieved, preferably the predetermined temperature being substantially equal to the target temperature. **Claim 4** The heating method according to claim 1, wherein the heating period (122) is defined by time. **Claim 5** The heating method according to claim 4, wherein the heating periods (122) are equally spaced by a predetermined time value, preferably the predetermined time value being included in the range of 20 to 30 seconds. **Claim 6** The heating method according to claim 5, wherein the heating periods (122) are substantially equal within the heating periods (122), preferably the duration of each heating period (122) being substantially equal to the predetermined time value. **Claim 7** During the heating period (122), the corresponding heating profile comprises - powering the corresponding heating element (60A, 60B) according to a minimum power supply value strictly smaller than the predetermined power supply value, or - cutting off the power; The heating method according to claim 1. **Claim 8** In the preheating phase (110), the corresponding heating elements (60A, 60B) are powered according to the predetermined power supply value, and advantageously, the predetermined power supply value is the maximum power supply value. The heating method according to claim 1.

9. The preheating phase (110) further includes powering only one of the heating elements (60A, 60B) until the target temperature is achieved, in addition to powering the other heating element (60A, 60B) until the target temperature is achieved. The heating method according to claim 1.

10. Each heating profile includes powering the corresponding heating element (60A, 60B) within a predetermined heating section (122) according to the predetermined power supply value. The heating method according to claim 1.

11. The heating profiles of different heating elements (60A, 60B) are configured to alternately power the corresponding heating elements (60A, 60B) according to the predetermined power supply value. The heating method according to claim 10.

12. The heating profiles have substantially the same shape, and one of the heating profiles is offset with respect to the other heating profile so as to ensure alternating power supply to the heating elements (60A, 60B). The heating method according to claim 11.

13. The target temperature is included in the range of 260 °C to 300 °C, and preferably is substantially equal to 280 °C. The heating method according to claim 1.

14. An aerosol generating device (11) configured to operate with a plate-shaped tobacco article (12) comprising a substrate portion (15), wherein the substrate portion (15) defines two opposite heating surfaces (17A, 17B), and the aerosol generating device (11) A heating chamber (50) configured to accommodate the plate-shaped tobacco article (12) and comprising two heating elements (60A, 60B) arranged to face each other, wherein each heating element (60A, 60B) is designed to extend along substantially the entire area of the respective heating surface (17A, 17B). The heating chamber (50) A controller (51) configured to operate the heating elements (60A, 60B) according to the heating method (100) according to any one of claims 1 to 13 An aerosol generating device (11) comprising.

15. Each heating element (60A, 60B) is an aerosol generating device (11) according to claim 14, made of ceramic.

Images