Aerosol generation device with optical heating

Abstract

In a first aspect, the invention is an aerosol-generating device comprising a first illumination means for generating and directing a first light beam and a second light beam onto at least one same portion of an aerosol-generating substrate received by the aerosol-generating device, for generating an aerosol, wherein the first light beam and the second light beam are arranged to generate a first interference pattern on the at least one same portion of the aerosol-generating substrate.

Description

[0001] AEROSOL GENERATION DEVICE WITH OPTICAL HEATING

[0002] FIELD OF INVENTION

[0003] The present invention relates to an aerosol generation device, in particular an aerosol generation device comprising one or more light sources for optically heating an aerosolgenerating substrate.

[0004] TECHNICAL BACKGROUND

[0005] Aerosol generation devices of the prior art commonly found on the market employ thermal heating, wherein a heating system generates heat and contacts and transfers the generated heat to an aerosol-generating substrate, typically either directly via conduction or via convection by heating air drawn into the aerosol-generating device.

[0006] As an alternative, non-contact heating such as optical heating can be employed. In optical heating, only the parts of the aerosol-generating substrate that absorb generated light are heated. Optical heating can therefore selectively target localized portions of the aerosol-generating substrate, and thus allows faster generation of an aerosol.

[0007] Current devices and methods for optical heating of an aerosol-generating substrate employ light sources such as lasers to heat an aerosol-generating substrate. However, due to the small beam size of lasers, optical heating can be concentrated onto a portion of the aerosol-generating substrate, and that portion of the aerosol-generating substrate can be overheated and thus burnt by a laser. Yet overheating of the aerosolgenerating substrate cannot be easily prevented by simple adjustment of operational parameters of the laser.

[0008] It is therefore an object of the present invention to provide an aerosol-generating device and method employing optical heating with light sources that overcomes the problem of overheating.

[0009] SUMMARY OF THE INVENTION

[0010] Some, or all the above issues of the prior art are addressed by the invention as defined by the features of the independent claims. Preferred embodiments of the invention are defined by the features of the dependent claims. Preferred embodiments are now described, by way of example only, with reference to the accompanying drawings.

[0011] In a 1st aspect, the invention is an aerosol-generating device comprising a first illumination means for generating and directing a first light beam and a second light beam onto at least one same portion of an aerosol -generating substrate received by the aerosol-generating device, for generating an aerosol, wherein the first light beam and the second light beam are arranged to generate a first interference pattern on the at least one same portion of the aerosol-generating substrate.

[0012] The istaspect of the invention is advantageous since a first illumination means configured for emitting light beams allows precise targeting of well-defined portions of an aerosol-generating substrate without generating wasted thermal energy. Light sources, in particular those having a small beam size with a beam intensity distribution with a peak in the center of the beam and decreasing intensity towards the edges of the beam, can lead to hotspots on the at least one same portion of the aerosol-generating substrate. By creating an interference pattern on the at least one same portion of the aerosol-generating substrate 210, the beam intensity distribution of an individual light source is changed to an interference pattern with brighter spots due to constructive interference and darker spots due to destructive interference. According to an embodiment, the interference pattern distributes the light onto a portion of the aerosolgenerating substrate that is substantially larger than a portion of the aerosol-generating substrate that can be illuminated by the beam size of individual light sources. In general, the interference pattern is different from, and in particular increased with respect to, the sum of the patterns of the individual sources of light. In general, the interference pattern allows to obtain a more uniform heating of the aerosol-generating substrate, and hotspots and insufficiently heated parts of the at least one same portion of the aerosol-generating substrate can be prevented.

[0013] According to a 2ndaspect, in the preceding aspect, the first light beam and the second light beam have a wavelength within a first range of 380 nm to 500 nm, a preferably of 430 nm to 470 nm, more preferably of 440 nm to 460 nm, most preferably of about 450 nm.

[0014] Using light in the first range is advantageous as it improves the heating performance of the light emitted by the aerosol-generating device. According to a 3rdaspect, in any one of the preceding aspects, the aerosol-generating device further comprises a second illumination means for generating and direction a third light beam and a fourth light beam onto the at least one same portion of the aerosol-generating substrate, wherein the third light beam and the fourth light beam are arranged interfere with each other at the at least one same portion of the aerosolgenerating substrate to generate a second interference pattern on the at least one same portion of the aerosol-generating substrate.

[0015] The 3rdaspect is advantageous as using a further illumination means further improves the heating performance of the aerosol-generating device.

[0016] According to a 4thaspect, in preceding aspect, the third light beam and the fourth light beam have wavelength within a second range of 520 nm to 590 nm, preferably of 540 nm to 570 nm, most preferably of about 555 nm, or the third light beam and the fourth light beam have wavelength within a third range of 590 nm to 635 nm, preferably of 590 nm to 600 nm, most preferably of about 595 nm.

[0017] The applicant has found that many substrates, including tobacco substrates, have optical absorption properties that are enhanced at a wavelength, preferably within the first range, compared to other wavelengths that lie preferably within the second range or the third range. Consequently, by providing a first light beam and a second light beam with wavelengths within the first range, and a third light beam and a fourth light beam with wavelengths within the second or third range, optical heating of the aerosolgenerating substrate can be controlled to be more efficient, effective, and flexible.

[0018] According to a 5thaspect, in any one of claims 2ndto 4thaspects, the aerosol-generating device further comprises a third illumination means for generating and directing a fifth light beam and a sixth light beam onto the at least one same portion of the aerosolgenerating substrate, wherein the fifth light beam and the sixth light beam are arranged to interfere with each other at the at least one same portion of the aerosol-generating substrate to generate a third interference pattern on the at least one same portion of the aerosol-generating substrate.

[0019] The 5thaspect is advantageous since, as described in analogous fashion for the 3rd aspect, heating of the aerosol-generating substrate can be improved and optimized.

[0020] According to a 6thaspect, in the preceding aspect, the third light beam and the fourth light beam have wavelengths within a second range of 520 nm to 590 nm, preferably of 540 nm to 570 nm, most preferably of about 555 nm, and the fifth light beam and the sixth light beam have wavelengths within a third range of 590 nm to 635 nm, preferably of 590 nm to 600 nm, most preferably of about 595 nm.

[0021] As described for the 4thaspect, the applicant has found that many substrates, including tobacco substrates, have optical absorption properties that are enhanced at a wavelength, preferably within the first range, compared to other wavelengths that lie preferably within the second range or the third range. Consequently, according to the 6thaspect, by providing a first light beam and a second light beam with wavelengths within the first range, a third light beam and a fourth light beam with wavelengths within the second range, and a fifth light beam and a sixth light beam with wavelengths within the third range, optical heating of the aerosol-generating substrate can be controlled to be even more efficient, effective, and flexible.

[0022] According to a 7thaspect, in any one of the preceding aspects, the first illumination means comprises a first light source for generating the first light beam and a second light source for generating the second light beam. Additionally, or alternatively, the second illumination means comprises a third light source for generating the third light beam and a fourth light source for generating the fourth light beam. Additionally, or alternatively, the third illumination means comprises a fifth light source for generating the fifth light beam and a sixth light source for generating the sixth light beam.

[0023] The 7haspect is advantageous as having an individual light source for each individual beam improves the energy output of the aerosol-generating device and thus improves and optimizes heating of the aerosol-generating substrate.

[0024] According to an 8thaspect, in the preceding aspect, first light source and the second light source are arranged to emit light onto the at least one same portion of the aerosolgenerating substrate. Additionally, or alternatively, the third light source and the fourth light source are arranged to emit light onto the at least one same portion of the aerosolgenerating substrate. Additionally, or alternatively, the fifth light source and the sixth light source are arranged to emit light onto the at least one same portion of the aerosolgenerating substrate.

[0025] The 8thaspect is advantageous as it allows respective light sources to be arranged in a simple and cost-efficient manner for generating a respective interference pattern.

[0026] According to a 9thaspect, in the 7thaspect, the first light source and the second light source are arranged to emit light onto different portions of the aerosol-generating substrate, wherein the first illumination means comprises first means for changing the position and / or orientation of the first light source and / or the second light source to direct the first light beam and the second light beam onto the at least one same portion of the aerosol-generating substrate. Additionally, or alternatively, third light source and the fourth light source are arranged to emit light onto different portions of the aerosolgenerating substrate, wherein the second illumination means comprises second means for changing the position and / or orientation of the third light source and / or the fourth light source to direct the third light beam and the fourth light beam onto the at least one same portion of the aerosol-generating substrate. Additionally, or alternatively, the fifth light source and the sixth light source are arranged to emit light onto different portions of the aerosol-generating substrate, wherein the third illumination means comprises third means for changing the position or orientation of the fifth light source and / or the sixth light source to direct the fifth light beam and the sixth light beam onto the at least one same portion of the aerosol-generating substrate.

[0027] The 9thaspect is advantageous as it allows the generation of interference patterns on the at least one same portion of the aerosol-generation device even when respective individual light sources of respective illumination means are not initially arranged to emit light onto the at least one same portion. It also allows the respective illumination means to switch between a first state in which an interference pattern is generated, and a second state in which respective individual light sources cannot emit light onto the at least one same portion and thus cannot generate an interference pattern. light According to a iothaspect, in any one of the preceding aspects, the aerosolgenerating device further comprises a control unit for changing operational parameters the first and the second light beam and / or the third and the fourth light beam and / or the fifth and the sixth light beam, wherein the operational parameters comprise at least one of phase, amplitude, and frequency of the light beams generated and directed by the first and / or the second and / or the third illumination means.

[0028] According to a 11thaspect, in the preceding aspect, the control unit is configured for changing the phase of the first light beam and the phase of the second light beam relative to each other, and / or changing the phase of the third light beam and the phase of the fourth light beam relative to each other, and / or changing the phase of the fifth light beam and the phase of the sixth light beam relative to each other.

[0029] According to a 12thaspect, in any one of the 10thor 11thaspects, the control unit is configured for changing the amplitude of the first and / or the second and / or the third and / or the fourth and / or the fifth and / or the sixth light beam. According to a 13thaspect, in any one of the 10thto 12thaspects in combination with the 4thor 6thaspect, the control unit is configured for changing the wavelength of the first light beam and or the second light beam within the first range, and / or changing the wavelength of the third light beam and / or the fourth light beam within the second range or within the third range.

[0030] According to a 14thaspect, in any one of the 10thto 12thaspects in combination with 6thaspect, the control unit is configured for changing the wavelength of the first light beam and or the second light beam within the first range, and / or changing the wavelength of the third light beam and / or the fourth light beam within the second range, and / or changing the wavelength of the fifth light beam and / or the sixth light beam within the third range.

[0031] The 10thto 14thaspects are advantageous as they further improve the uniformity of the heating of the at least one same portion of the aerosol-generating substrate. By changing the phase and / or amplitude and / or wavelength of respective light beams that generate a respective interference pattern relative to each other, the respective interference pattern can be changed, wherein the location and / or magnitude of interference maxima and minima change.

[0032] In a 15thaspect, the invention is an aerosol-generating system comprising the aerosolgenerating device according to any one of the preceding aspects, and an aerosolgenerating article comprising an aerosol-generating substrate, wherein the aerosolgenerating article is received by the aerosol-generating device.

[0033] The advantages of the 15thaspect correspond to the advantages of any one of the preceding aspects.

[0034] In a 16thaspect, the invention is a method of generating an aerosol, the method comprising receiving an aerosol-generating article by an aerosol-generating device, the aerosol-generating device comprising a first illumination means. The method comprises generating and directing, using the first illumination means, a first light beam and a second light beam onto at least one same portion of an aerosol-generating substrate received by the aerosol-generating device, for generating an aerosol, wherein the third light beam and the fourth light beam are made to interfere with each other at the at least one same portion of the aerosol-generating substrate to generate a second interference pattern on the at least one same portion of the aerosol-generating substrate. According to a 17thaspect, in the preceding aspect, the first light beam and the second light beam have a wavelength within a first range of 380 nm to 500 nm, a preferably of 430 nm to 470 nm, more preferably of 440 nm to 460 nm, most preferably of about 450 nm.

[0035] According to an 18thaspect, in any one of the 16thto 17thaspects, the aerosol-generating device further comprises a second illumination means, the method further comprising generating and directing, using the second illumination means, a third light beam and a fourth light beam onto the at least one same portion of the aerosol-generating substrate, wherein the third light beam and the fourth light beam are made to interfere with each other at the at least one same portion of the aerosol-generating substrate to generate a second interference pattern on the at least one same portion of the aerosolgenerating substrate.

[0036] According to a 19thaspect, in preceding aspect, the third light beam and the fourth light beam have wavelength within a second range of 520 nm to 590 nm, preferably of 540 nm to 570 nm, most preferably of about 555 nm, or the third light beam and the fourth light beam have wavelength within a third range of 590 nm to 635 nm, preferably of 590 nm to 600 nm, most preferably of about 595 nm.

[0037] According to a 20thaspect, in any one of claims 17thto i9mdaspects, the aerosolgenerating device further comprises a third illumination means, the method further comprising generating and directing, using the third illumination means, a fifth light beam and a sixth light beam onto the at least one same portion of the aerosolgenerating substrate, wherein the fifth light beam and the sixth light beam are made to interfere with each other at the at least one same portion of the aerosol-generating substrate to generate a third interference pattern on the at least one same portion of the aerosol-generating substrate.

[0038] According to a 21staspect, in the preceding aspect, the third light beam and the fourth light beam have wavelength within a second range of 520 nm to 590 nm, preferably of 540 nm to 570 nm, most preferably of about 555 nm, and the fifth light beam and the sixth light beam have a wavelength within a third range of 590 nm to 635 nm, preferably of 590 nm to 600 nm, most preferably of about 595 nm.

[0039] According to a 22ndaspect, in any one of the 16thto 21staspects, the first illumination means comprises a first light source for generating the first light beam and a second light source for generating the second light beam. Additionally, or alternatively, the second illumination means comprises a third light source for generating the third light beam and a fourth light source for generating the fourth light beam. Additionally, or alternatively, the third illumination means comprises a fifth light source for generating the fifth light beam and a sixth light source for generating the sixth light beam.

[0040] According to a 23rdaspect, in the preceding aspect, the method further comprises arranging the first light source and the second light source in the aerosol-generating device such that the first light source and the second light source can emit light onto the at least one same portion of the aerosol-generating substrate. Additionally, or alternatively, the method further comprises arranging the third light source and the fourth light source such that the third light source and the fourth light source can emit light onto the at least one same portion of the aerosol-generating substrate. Additionally, or alternatively, the method further comprises arranging the fifth light source and the sixth light source such that the that the fifth light source and the sixth light source can emit light onto the at least one same portion of the aerosol-generating substrate.

[0041] According to a 24thaspect, in the 22ndaspect, the method further comprises arranging the first light source and the second light source such that the first light source and the second light source can emit light onto different portions of the aerosol-generating substrate, and changing, using a first changing means of the first illumination means , the position and / or orientation of the first light source and / or of the second light source to direct the first light beam and the second light beam onto the at least one same portion of the aerosol-generating substrate. Additionally, or alternatively, the method further comprises arranging first third source and the fourth light source such that the third light source and the fourth light source can emit light onto different portions of the aerosol-generating substrate, and changing, using a second changing means of the second illumination means , the position and / or orientation of the third light source and / or of the fourth light source to direct the third light beam and the fourth light beam onto the at least one same portion of the aerosol-generating substrate. Additionally, or alternatively, the method further comprises arranging a fifth light source and the sixth light source such that the fifth light source and the sixth light source can emit light onto different portions of the aerosol-generating substrate, and changing, using a third changing means of the third illumination means , the position and / or orientation of the fifth light source and / or of the sixth light source to direct the fifth light beam and the sixth light beam onto the at least one same portion of the aerosol-generating substrate. According to a 25thaspect, in any one of the 16thto 24thaspects, the method further comprises changing, using a control unit of the aerosol-generating device, operational parameters of the first and the second light beam and / or of the third and the fourth light beam and / or of the fifth and the sixth light beam, wherein the operational parameters comprise at least one of a phase, an amplitude, and a frequency of the respective light beam generated and directed by the first and / or by the second and / or by the third illumination means.

[0042] According to a 26thaspect, in the preceding aspect, the method comprises changing, using the control unit, the phase of the first light beam and the phase of the second light beam relative to each other, and / or changing the phase of the third light beam and the phase of the fourth light beam relative to each other, and / or changing the phase of the fifth light beam and the phase of the sixth light beam relative to each other.

[0043] According to a 27thaspect, in any one of the 25thor 26thaspects, the method further comprises changing, using the control unit, the amplitude of the first and / or of the second and / or of the third and / or of the fourth and / or of the fifth and / or of the sixth light beam.

[0044] According to a 28thaspect, in any one of the 25thto 27thtaspects in combination with the 18thor 20thaspect, the method further comprises changing, using the control unit, the wavelength of the first light beam and / or of the second light beam within the first range, and / or changing the wavelength of the third light beam and / or of the fourth light beam within the second range or within the third range.

[0045] According to a 29thaspect, in any one of the 25thto 27thtaspects in combination with 20thaspect, the method further comprises changing, using the control unit, the wavelength of the first light beam and / or of the second light beam within the first range, and / or changing the wavelength of the second third light beam and / or of the fourth light beam within the second range, and / or changing the wavelength of the fifth light beam and / or the of sixth light beam within the third range.

[0046] The advantages of the 16thto 29thaspects respectively correspond to the advantages of the 1stto 14thaspects.

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Fig. 1 shows a schematic illustration of the electronic configuration of an aerosolgenerating device, according to embodiments of the invention. IO

[0049] Figs. 2A and 2B respectively show schematic illustrations of aerosol-generating devices and aerosol-generating articles for use with the aerosol-generating devices, according to embodiments of the invention.

[0050] Figs. 3A and 3Brespectively show a schematic illustration of interior cross-sectional views of aerosol-generating devices and aerosol-generating articles in use with the aerosol-generating devices, according to embodiments of the invention.

[0051] Figs. 4A and 4B respectively show schematic illustrations of a side view of aerosolgenerating units configured to emit light onto aerosol-generating substrates, according to preferred embodiments of the invention.

[0052] Figs. 5A and 5B respectively show schematic illustrations of a plan view of aerosolgenerating units configured to emit light onto aerosol-generating substrates of the preferred embodiments shown in Figs. 4A and 4B.

[0053] Figs. 6A, 6B, and 6C respectively show schematic illustrations of a side view, a plan view, and a side view of aerosol-generating units configured to emit light onto aerosolgenerating substrates, according to different embodiments of the invention.

[0054] Figs. 7A and 7B show schematic illustrations of an aerosol-generating device, according to preferred embodiments of the invention.

[0055] Fig. 8 shows a schematic illustration of a method of operating an aerosol-generating device according to preferred embodiments of the invention.

[0056] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0057] In the description of the present invention, it should be understood that the terms "one end", "the other end", "outer side", "upper", "above", "inner side", "under", “below”, "horizontal", "coaxial", "central", "end" "part", "length", "outer end" etc., which indicate the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings. The terms such as "upper", "above", "below", "under" and the like used in the present invention to indicate a relative position in space are used for the purpose of facilitating explanation to describe a unit or feature shown in the drawings relative to the relationship of another unit or feature. The term of the relative position in space may be intended to include different orientations of the device in use or operation other than those shown in the figures. For example, if the device in the figure is turned over, the unit described as being "below" or "under" other units or features will be "above" the other units or features. Therefore, the exemplary term "below" can encompass both the above and below orientations. The device can be oriented in other ways (rotated by 90 degrees or other orientations), and the space- related descriptors used herein are explained accordingly. More specifically, the word “above” means that one unit, layer or element is arranged or configured relatively in an exterior direction of the device towards the (an)other unit(s), layer(s) or element(s); the word “below” means that one unit, layer or element is arranged or configured relatively in an interior direction of the device towards the other units, layers or elements.

[0058] [Overview of the aerosol-generating device and system]

[0059] Aerosol-generating devices according to the invention are preferably portable devices. For this purpose, they are of limited size. According to preferred embodiments of the invention, the portable aerosol-generating devices are hand-held devices that fit into a hand of a user and that can be operated by hand.

[0060] The aerosol-generating device too comprises an outer housing or casing within which components of the aerosol-generating device are arranged. The aerosol-generating device according to the invention houses an aerosol generation unit that is configured to generate an aerosol from an aerosol generation substrate using light.

[0061] [Electronic configuration]

[0062] Fig. 1 illustrates an electronic configuration of an aerosol-generating device too according to embodiments of the invention. As a preferably portable and handheld device, the aerosol-generating device too further comprises a power source 150, such as, for example, a rechargeable and / or replaceable battery. The power source is configured to provide power to electronic components of the aerosol-generating device too. In preferred embodiments, a control unit 140 is provided with the aerosolgenerating device too, wherein the control unit is configured for controlling various functions for the functioning of the aerosol-generating device too. In preferred embodiments, the control unit is configured to control operation of the aerosolgenerating unit 110 for heating the aerosol-generating substrate 210 to generate an aerosol. The aerosol-generating unit 110 is shown exemplary in Fig. 1 to comprise a first illumination means 111, a second illumination means 112, and a third illumination means 113, wherein each illumination means comprises one or more light sources. However, the number of illumination means may be more or less. While each of the light sources of aerosol-generating unit 110 can be pre-programmed or set to emit light with predetermined operational parameters, it is preferred that the control unit 140 is configured to control operational parameters of the aerosol-generating unit 110 comprising the at least two light sources. Operational parameters of some or all of the illumination means can be controlled by the control unit 140 comprise one or more of: beam-on time during which light is emitted, beam-off time during which light is not emitted, amplitude of the emitted light / light beam intensity, phase of the emitted light, beam profile of the emitted light, and wavelength of the emitted light. It is to be noted that the above reported operational parameters of some or all of the light sources can be controlled independently one from another or two or more of them can be controlled simultaneously.

[0063] As shown in Figs. 2A to 2B, the aerosol generation device may have a generally longitudinal shape in the longitudinal direction y, and a substantially circular or elongated cross-section in the transverse direction x. However, other shapes of the aerosol-generating device too and with different cross-sections are possible. The longitudinal direction y is parallel to the inhalation direction, i.e., the direction in which the aerosol-generating device too is inserted or brought to a user’s mouth for inhaling a generated aerosol, and the transverse direction x is perpendicular to the inhalation direction.

[0064] In an embodiment, the aerosol-generating substrate is a solid substrate such as, for example, a tobacco substrate. A tobacco substrate comprises tobacco which may be in the form of ground or milled tobacco leaves. Additionally, the tobacco substrate may comprise gellan gum, and additionally, or alternatively a CMC binder. Both gellan gum and CMC binder can act binders, thickeners, and / or stabilizers.

[0065] In an embodiment the aerosol-generating substrate is liquid substrate, such as, for example, an e-liquid or a t-liquid. An e-liquid typically comprises vegetable glycerin (VG), propylene glycol (PG) nicotine, and flavoring. A T-liquid typically comprises vegetable glycerin (VG), propylene glycol (PG) and tobacco material such as ground tobacco.

[0066] Liquid aerosol-generating substrates are stored in a reservoir. The aerosol-generating device too unit is provided with extraction means configured for extracting the aerosolgenerating substrate. In an embodiment, the extraction means comprises an element, such as, for example, a wicking element, that is in contact with the liquid aerosolgenerating substrate stored in the reservoir and that is configured to draw the liquid aerosol-generating substrate 210 from the reservoir. The reservoir can be provided as part of the aerosol-generating device 100, wherein an opening is provided to allow liquid aerosol-generating substrate to be filled into the reservoir.

[0067] Solid aerosol-generating substrates can be provided in different shapes and sizes. As shown in Fig. 2A, the aerosol-generating article can be an aerosol-generating substrate 210 that is a tobacco substrate that may also have a shape that is elongated in the longitudinal direction y with a circular or elliptical base shape in the transverse direction x, the shape of the aerosol-generating substrate 210 emulating the shape of a traditional cigarette. Alternatively, as shown for a preferred embodiment illustrated in Fig. 2B, the solid aerosol-generating substrate 210 may be disk-shaped, or, alternatively, half-spherical, spherical, or ellipsoidal. In many cases, the aerosolgenerating article 200 may substantially correspond to the aerosol-generating substrate 210.

[0068] As shown in Figs. 3A and 3B, for use of the solid aerosol-generating substrate, it is preferred the aerosol-generating device 100 is provided with receiving means for receiving the solid aerosol-generating substrate. The receiving means may be a cavity or chamber 105 into which the solid aerosol-generating substrate 210 can be partially or fully inserted. The size and shape of the cavity or chamber 105 can be adapted depending on the size and shape of the solid aerosol-generating substrate 210. For example, in case the solid aerosol-generating substrate 210 is of the shape emulating a traditional cigarette, the cavity or chamber 105 is preferably of a tubular shape. The cavity or chamber 105 is preferably also a vaporization chamber. The vaporization chamber encloses the vaporization space within which an aerosol is generated when heated.

[0069] Alternatively, for liquid aerosol-generating substrates, the reservoir for storing the liquid aerosol-generating substrates can be provided with an aerosol-generating article 200, such as, for example, a cartridge that comprises an outer housing or casing within which the reservoir is provided. In use, the aerosol-generating article can detachably connect to the aerosol-generating device. When the aerosol-generating article 200 is attached to the aerosol-generating device 100, the aerosol-generating unit 110 is configured to extract the liquid aerosol-generating substrate 210 from the reservoir of the aerosol-generating article 200 and heat the drawn aerosol-generating substrate 210.

[0070] Alternatively, the solid aerosol-generating substrate 210 may be provided as part of an aerosol-generating article 200 that is in the form of a cartridge. The cartridge comprises an outer housing or casing within which the solid aerosol-generating substrate 210 is provided. The cartridge, and additionally, or alternatively, the aerosolgenerating device 100 is / are configured such that, when the cartridge is received by the aerosol-generating device 100, the aerosol-generating unit 110 of the aerosolgenerating device 100 can heat the solid aerosol-generating substrate 210 that is provided as part of the cartridge.

[0071] According to the invention, the aerosol-generating unit 110 is configured to emit light onto an aerosol-generating substrate 210 for heating the aerosol-generating substrate 210 to generate an aerosol. The configuration and arrangement of the aerosolgenerating unit 110 in the aerosol-generating device 100 depends on the type of aerosol-generating article 200 as well as the manner, in which an aerosol-generating article 200 comprising the aerosol-generating substrate 210 is received. The configuration and arrangement of the aerosol-generating unit 110 may also depend on the way an aerosol-generating substrate 210 is to be heated.

[0072] As can be seen in Figs. 3A and 3B, the aerosol-generating article 200 that is exemplified as a disk shape but may have any shape described in the context of Figs. 2A and 2B, is partially or fully received in a cavity or chamber 105 of the aerosol-generating device too. For heating the aerosol-generating substrate 210, the aerosol-generating unit 110 is preferably arranged at an inner surface of the cavity or chamber 105 as a vaporization space to allow the aerosol-generating unit 110 to emit light directly onto the aerosolgenerating substrate 210 to generate an aerosol within the cavity or chamber 105. For this purpose, the aerosol-generating unit 110 may be arranged inside a groove or cutout provided at the inner surface of the cavity or chamber 105 so that protrusion of the aerosol-generating unit 110 from the inner surface of the cavity of chamber 105 is minimized or eliminated. Alternatively, as a configuration that is simpler to manufacture, the aerosol-generating unit 110 can be provided on the inner surface of the cavity or chamber 105. Furthermore, the aerosol-generating unit 110 maybe arranged to be distanced from the aerosol-generating substrate 210 in a transverse direction x, as shown in Fig. 3A, or alternatively, the aerosol-generating unit 110 may be arranged to be distanced from the aerosol-generating substrate 210 in the longitudinal direction y, as shown in Fig. 3B. Additionally, and irrespective of the positioning and orientation of the at least two light sources of the aerosol-generating unit 110 relative to the aerosol-generating substrate 210, In both cases, one or more of the at least two light source may be arranged on an inner surface of the chamber 105, or may be recessed into an inner surface of the chamber 105. Notably, the aerosol generating unit 110 may be configured as described below in the context of Figs. 4Ato 6C.

[0073] In a case where the aerosol-generating substrate 210 is comprised by an aerosolgenerating article 200 that is in the form of a cartridge, the aerosol-generating unit 110 is preferably arranged at or proximate the interface between the aerosol-generating device 100 and the aerosol-generating article 200 when, in use, the aerosol-generating article 200 is attached to the aerosol-generating device 100. Additionally, or alternatively, it is preferred that the aerosol-generating substrate 210 comprised by the aerosol-generating article 200 is arranged at or proximate the interface between the aerosol-generating device 100 and the aerosol-generating article when, in use, the aerosol-generating article 200 is attached to the aerosol-generating device too. When the aerosol-generating article 200 is attached to the aerosol-generating device too, the aerosol-generating substrate 210 comprised by the aerosol-generating article, and the aerosol-generating unit 110 are arranged such that light emitted from the aerosolgenerating unit 110 is incident onto the aerosol-generating substrate 210.

[0074] Considering that all light sources have a certain spectral bandwidth, it is to be noted that the term wavelength of light emitted by a light source according to the present invention refers to peak wavelength, i.e., the wavelength at which the optical spectrum the light emitted by the light source has its maximum.

[0075] When referring to the “blue” light or light within the “blue range”, it is be noted that this corresponds to light within the visible spectrum that is from 380 nm to 500 nm, preferably from 430 nm to 470 nm, more preferably from 440 nm to 460 nm, most preferably of about 450 nm.

[0076] When referring to the “green” light or light within the “green range”, it is be noted that this corresponds to light within the visible spectrum that is from 520 nm to 590 nm, preferably from 540 nm to 570 nm, most preferably of about 555 nm

[0077] When referring to the “orange” light or light within the “orange range”, it is be noted that this corresponds to light within the visible spectrum that is from 590 nm to 635 nm, preferably from 590 nm to 600 nm, most preferably of about 595 nm.

[0078] According to possible embodiments, the wavelength of light emitted by one light source being different than the wavelength of light emitted by another light source means that the peak wavelengths of the one light source is different from the peak wavelength of the other light source. According to possible embodiments, there could be substantially no overlap in the optical spectrum of the two light sources, or there could be a small or negligible percentage of overlap at the end part of the optical spectrum. According to possible embodiments, the peak wavelength of the one light source does not lie within the full width at half maximum (FWHM) of the spectrum of the other light source, and that the peak wavelength of the other light source does not lie within the FWHM of the one light source.

[0079] To create an interference pattern from two light beams, in some preferred embodiments, each of the two light beams has a same or similar wavelength such that they may create interference patterns comprising one or more constructive and / or destructive interference portions. In some preferred embodiments, the wavelength of one light beam corresponds to the wavelength of the other light beam. According to possible embodiments, the wavelengths correspond to each other if there is a spectral overlap between the optical spectrum of the one light beam and the optical spectrum of the other light beam. According to possible embodiments, the wavelengths correspond to each other if the peak wavelength of the one light beam is within the FWHM of the optical spectrum of the other light, and / or vice versa.

[0080] It is to be noted that deconstructive and constructive interference effects in interference patterns within the context of the present invention are not limited to total deconstructive and constructive interference. Rather, deconstructive and constructive interference effects also comprise partial deconstructive and constructive interference. This is the case, for example, when the amplitude of one light beam is different from the maximum amplitude of another light beam.

[0081] Fig. 4A illustrates a first preferred embodiment of the present invention. The aerosolgenerating unit no comprises first illumination means m. The first illumination means in comprises a first light source ma configured to emit a first light beam, and a second light source mb configured to emit a second light beam. The first light source ma and the second light source mb are preferably configured to emit light in the blue, green, or in the orange range. Additionally, the aerosol-generating unit 100 may comprise a second illumination means 112, as illustrated in Fig. 4B. The second illumination means 112 is configured to emit a third light beam and a fourth light beam. The second illumination means 112 may be configured as the first illumination means 111 and comprise two individual light sources for generating the third light beam and the fourth light beam. Alternatively, optical elements maybe used to generate the third light beam and the fourth beam from a single light source. The third light beam and the fourth light beam have a wavelength preferably in the blue, green, or orange range, wherein it is preferable that the third light beam and the fourth light beam have a wavelength within a range that is different from the wavelengths of the first light beam and the second light beam. It is particularly preferred that the first light beam and the second light beam are within the blue range, and the light beam and the third light beam are within the green range or the orange range. It is preferred that, when at least three illumination means are provided, that a first illumination means m is configured to emit a first and second light beam within the blue range, a second illumination means 112 is configured to emit a third and fourth light beam within the green range, and a third illumination means 113 is configured to emit a fifth and sixth light beam within the orange range. It is to be noted that the above-described different configurations of the illumination means can be applied to any illumination means.

[0082] In the preferred embodiment, the first and second light sources 111a, mb are configured to emit light such that the emitted lights are incident onto the same portion of the aerosol-generating substrate 210. In the context of the present invention, at least two light sources are configured to emit light onto a same portion of an aerosolgenerating substrate 210 when the main emission directions of the at least two light sources intersect within the same portion, or preferably at the surface of that same portion of the aerosol-generating substrate 210 onto which light from the at least two light sources are incident. Within the context of embodiments shown in Figs. 4A and 4B, this means that the first light source 111a and the second light source mbof the first illumination means 111, as shown in Fig. 4A, or the first light source 111a and the second light source mb of the first illumination means 111, and the second illumination means 112, as shown in Fig. 4B, are oriented such that the main emission directions of the first light source 111a and the second light source mb, or the main emission directions (illustrated as solid lines) of the first light source ma, the second light source mb, and the second illumination means 112 intersect as described above. However, this arrangement is generally applicable to a plurality of illumination means comprising a plurality of light sources.

[0083] With the above-described configurations, an interference pattern can be generated on the same portion of the aerosol-generating substrate 210.

[0084] The type of light source can be chosen depending on the requirements of the aerosolgenerating device too regarding heating performance, energy consumption, spatial constraints within the aerosol-generating device too, size and shape of the aerosolgenerating substrate 210, and other factors known to the person skilled in the art.

[0085] According to an aspect, in any one of the preceding aspects, one or more of the light sources are coherent light sources.

[0086] This aspect is advantageous, since coherent light sources, such as, for example, lasers, usually have a small beam divergence that allows specific portions of a substrate to be accurately targeted without the focusing optics.

[0087] According to an aspect, in any one of the preceding aspects, one or more of the light sources are non-coherent light sources.

[0088] This aspect is advantageous as non-coherent light sources, such as, for example, LEDs, are smaller and require less power.

[0089] In other words, the light sources are coherent light sources, such as, for example, one or more lasers. Lasers, in particular, have a small beam divergence and thus narrow beam that allows heating of the aerosol-generating substrate 210 to be focused on and limited to a precise and well-defined portion of the aerosol-generating substrate 210. This provides improved control over the heating process and allows targeted and selective heating of the aerosol-generating substrate 210. The lasers maybe surface-emitting lasers, such as, for example, vertical cavity surface emitting lasers (VCSEL), photonic crystal surface-emitting lasers (PCSEL), and topological cavity surface emitting lasers (TCSEL). Compared to other types of lasers, such as, for example, edge-emitting laser, surface-emitting lasers are easier to manufacture and install in the aerosol-generating device too. In addition, surface-emitting lasers require less power, which is particularly advantageous in portable or handheld aerosol-generating devices that have a limited and non-constant constant power supply.

[0090] However, as mentioned above, the type of light source is not limited to coherent light sources. Additionally, or alternatively, one or more, or all of the at least two light sources may be non-coherent light sources, such as, for example, such as LEDs, filament bulbs or plasma / flame radiation devices. LEDs, in particular, are energyefficient and requires less power to operate when compared to coherent light sources, such as, for example, lasers. As described, decreased power consumption is particularly advantageous in portable or handheld devices. According to an aspect, in any one of the preceding aspects, the interference pattern is changing with time, for example due to the spectrum related to the light sources. This could help at dissipating the heat through the tobacco substrate in a more uniform manner.

[0091] As can be seen in Figs. 4A and 4B, the light sources maybe arranged within the aerosol-generating device 100 such that their distance to at least one same portion of the aerosol-generating substrate 210, onto which the at least two light sources are configured to emit light, are equal. While Fig. 4A illustrates the aerosol-generating substrate 210 as a rectangular shape, the shape of the aerosol-generating substrate 210 is not limited and may have a circular, spherical, ellipsoidal, or cigarette-like shape, as described above in the contexts of Figs. 2Ato 2B.

[0092] In case the aerosol-generating substrate 210 has a disk-like shape with flat surface on opposite sides of the disk-like shape, as exemplified in Figs. 2B and 3B, the at least two light sources may be arranged to be at a same distance from a portion of one of the two flat surfaces. In case the aerosol-generating substrate 210 has a cylindrical shape emulating a cigarette, as shown in Fig. 2A, the at least two light sources may be arranged to be at a same distance from the base of the aerosol-generating substrate 210 that is inserted into the cavity or chamber 105 of the aerosol-generating device too. Alternatively, the at least two light sources may be arranged to be at a same distance from a curved portion of the lateral surface of the cylindrical shape of a cigarette. In case the aerosol-generating substrate 210 is comprised in an aerosol-generating article 200 in the form of a cartridge, the at least light sources are arranged in the aerosolgenerating device too such that when the aerosol-generating article 200 is attached to the aerosol-generating device too, the at least two light sources are arranged at a same distance from at least one same portion of the aerosol-generating substrate 210 onto which the at least two light source are configured to emit light.

[0093] Since any light source has a non-zero beam divergence, the distance of the light source to the aerosol-generating substrate 210 affects the parameters of beam size, coherence, and intensity of light that is incident on the aerosol-generating substrate 210. If individual light sources of the at least two light sources are arranged at different distances from a same portion of the aerosol-generating substrate 210, differences in the above parameters must be accounted for when setting operational parameters of the individual light sources. For example, due to beam divergence, if a first and a second laser of the same type are arranged at different distances, the beam size incident on the aerosol-generating substrate 210 from the first laser, positioned at a larger distance from the aerosol-generating substrate 210, is larger than the beam size of the second laser that is positioned at a smaller distance from the aerosol-generating substrate 210. As a consequence, even if the first and the second laser are arranged to emit light onto a same portion of the aerosol-generating substrate 210, the area and / or volume of the aerosol-generating substrate 210 that is illuminated by the first laser is larger than the area and / or volume of the aerosol-generating substrate 210 that is illuminated by the second laser, thus leading to non-uniform heating of the aerosolgenerating substrate 210 by the first laser and the second laser. Consequently, when the at least light sources are of a same type of light sources, such as, lasers of a same type, it is therefore preferred to arrange the at least two light sources at a same distance from the aerosol-generating substrate 210, since it minimizes deviations in the above parameters and affords improved control over the heating process

[0094] Additionally, or alternatively, as shown in Figs. 5A and 5B, when viewing an outer surface portion of the aerosol-generating substrate 210 onto which the light sources are configured to emit light, from a plan view, the light sources may be arranged to emit light onto the portion of the aerosol-generating substrate 210 from different directions, i.e., the emission directions of the at least two light sources are non-parallel to each other. This facilitates the arrangement of the at least two light sources within the spatial constraints of the aerosol-generating device too and allows the light sources to be arranged in close proximity to the aerosol-generating substrate 210 while allowing the light sources to emit light directly onto a same portion of the aerosol-generating substrate 210. This is particularly advantageous for portable or handheld devices. Additionally, or alternatively, the light sources may be arranged, in plan view, on a curved, preferably arced, or even more preferably circular or elliptical line. The arrangement on a circular or elliptical line is particularly advantageous for an aerosolgenerating device too that is of an elongated shape with a circular or elliptical base shape, as described in the context of embodiments illustrated in Figs. 2A to 2B.

[0095] Additionally, or alternatively, the light sources are arranged such that the lights emitted by the light sources are incident on the same portion of the aerosol-generating substrate 210 from different directions that, when view in plan view, are spaced apart by equal angular distances from each other. This can be achieved by arranging the light sources, when viewed in plan view and based on the point, at which the main emission directions of the light sources intersect, as the origin point, at equal angular distances from each other. Additionally, or alternatively, the sources are arranged such that the lights emitted by the light sources have a same angle of incidence onto the surface of a same portion of the aerosol-generating substrate 210. Since light sources in general have a non-zero beam divergence, parameters such as size and intensity of the emitted lights that are incident onto the portion of the aerosol-generating substrate 210 are dependent on the incidence angle. A larger incidence angle of a light source (relative to the local surface normal) leads to a larger surface area or volume of the aerosol-generating substrate 210 being illuminated by light emitted from the light source than a smaller incidence angle, and thus changing the beam intensity onto the aerosol-generating substrate 210. For example, a light with a circular beam profile that is incident onto a surface at a nonzero incidence angle (relative to the local surface normal) will result not in a circular, but an elliptical illuminated area on the surface of the aerosol-generating substrate 210. By emitting light onto the aerosol-generating substrate 210 at a same incidence angle minimizes differences between the beam intensity distribution of the lights of the at least two sources on the aerosol-generating substrate 210, which is particularly advantageous for light sources of a same type with a same or similar beam profile. This affords more uniform heating of the aerosol-generating substrate 210 via the at least two light sources and provides improved control over the heating process.

[0096] While Figs. 4A, 4B, 5A, and 5B illustrate an aerosol-generating unit 110 with two light sources or three light sources, the number is light sources is only limited by spatial constraints and / or power supply limitations of the aerosol-generating device too, and the aerosol-generating unit 110 may comprise four or more light sources. In an embodiment, as shown in Figs. 6A and 6B, the aerosol-generating unit 110 may comprise six light sources. While in Fig. 6A, the arrangement of the six light sources is illustrated in relation to a rectangular or disk-shaped aerosol-generating substrate 210, the arrangement described in the following can be applied to any suitable shape of the aerosol-generating substrate 210, such as, for example, spherical, ellipsoidal, or cylindrical aerosol-generating substrates. The aerosol-generating substrates may preferably be aerosol-generating substrates as described in the context of embodiments shown and illustrated in Figs 2A to 5B. Furthermore, the light sources of the embodiment illustrated in Figs. 6A and 6B may preferably be light sources as described above in the context of embodiments illustrated in Figs. 3A to 5B.

[0097] In embodiments illustrated in Figs. 6A and 6B, a first light source 111a and a second light source mb are provided to form a first pair of light sources. The first light source 111a and the second source mb may be arranged on opposite sides of the aerosol- generating substrate 210. Alternatively, the first light source 111a and the first further light source 111b may be arranged adjacent each other. A third light source 112a and a fourth light source 112b may be provided to form a second pair of light sources. Furthermore, a fifth light source 113a and a sixth light source 113b may be provided to form a third pair of light sources. As described above, any pair of light sources maybe exchanged for a configuration with a single light source and an optical element such as a beam splitter.

[0098] The arrangement of the third light source 112a and the fourth light source 112b, and additionally, or alternatively, the arrangement of the fifth light source 113a and the sixth light source 113b may be as described for the first light source 111a and the second light source mb. The first light source 111a, the third light source 112a, and the fifth light source 113a maybe arranged on one side of the aerosol-generating substrate 210 as described above in the context of embodiments illustrated in Figs. 4A to 5B. The first light source 111a, the third light source 112a, and the fifth light source 113a may be arranged with distances to the aerosol-generating substrate 210, and / or with an incidence angle, and / or with an arrangement in plan view as described in the context of embodiments illustrated in Figs. 4A to 5B.

[0099] The first light source 111a, the third light source 112a, and the fifth light source 113 may be configured to emit light in a blue range, and / or green range, and / or orange range as described above in the context of embodiments illustrated above in Figs. 3A to 5B. For example, the first light source 111a may be configured to emit light in the blue range, the third light source 112a may be configured to emit light in the green range, and the fifth light source 113a maybe configured to emit light in the orange range. The second light source 111b, the fourth light source 112b, and the sixth light source 113b may be configured to emit light with a wavelength substantially and respectively corresponding to the wavelength of the light emitted by the first light source 111a, the third light source 112a, and the fifth light source 113a.

[0100] As shown in Fig. 6A, the light sources are configured to emit light onto at least one same portion of the aerosol-generating substrate 210. As described in the context of Figs. 4A and 4B, the light sources are configured such that the main emission directions of the six emitted lights intersect at a common point within the aerosol-generating substrate 210. Alternatively, the first light source 111a, the third light source 112a, and the fifth light source 113a may be configured such that their respective main emission directions intersect on one surface of the aerosol-generating substrate 210, while the second source mb, the fourth light source 112b, and the sixth light source 113b are configured such that their respective main emission directions intersect at the other, opposite surface of the aerosol-generating substrate 210.

[0101] Alternatively, as shown in Fig. 6B, all light sources may be arranged on a same side of the aerosol-generating substrate 210. In such case, the first light source 111a maybe arranged to be neighboring the second light source mb, the third light source 112a may be arranged to be neighboring the fourth light source 112b, and the fifth light source 113a may be arranged neighboring the sixth light source 113b.

[0102] Alternatively, as shown in Fig. 6C, and as previously described, instead of forming a first / second / third pair of light sources using two light sources, a single light source in conjunction with an optical element, such as, for example, a beam splitter 120 can be provided. Instead of providing a first light source 111a and second light source mb to form a first pair of light sources to emit a first light beam and a second light beam, a first light source 111a can be provided in conjunction with a beam splitter 120 so that a light beam emitted from the first light source 111a is split into a first light beam and a second light beam. This allows the generation of a pair of light beams using only a single light source. This configuration can be utilized for any one of the second, and / or third, and / or any further pair of light sources.

[0103] [2ndPREFERRED EMBODIMENT: INTERFERENCE HEATING]

[0104] A second preferred embodiment corresponds to the first preferred embodiment of the invention. The first illumination means 110 is configured for directing the generated first light beam and second light beam onto at least one same portion of an aerosolgenerating substrate 210, wherein the first light beam has an optical spectrum that corresponds to the optical spectrum of the second light beam. Consequently, an interference pattern caused by constructive interference effects and deconstructive interference effects occurring between the first light beam and the second light beam is generated. While the wavelength of the first light beam and the second light beam need not be limited to a specific range, it is preferred that the first light beam and the second light beam have a wavelength within the blue range as previously defined.

[0105] Additionally, the aerosol-generating device too may further comprise a second illumination means 112 for generating and directing a third light beam and a fourth light beam onto the at least one same portion of the aerosol-generating substrate 2iolightlight. Consequently, a second interference pattern can be generated on the at least one same portion of the aerosol-generating substrate 210. The wavelength of the third light beam and of the fourth light beam are different from the wavelength of the first light beam and of the second light beam. Additionally, it is preferred that the third light beam and the fourth light beam have a wavelength within the green range or the orange range as previously defined.

[0106] Additionally, the aerosol-generating device 100 may further comprise a third illumination means 113 for generating and directing a fifth light beam and a sixth light beam onto the at least one same portion of the aerosol-generating substrate. Consequently, a third interference pattern can be generated on the at least one same portion of the aerosol-generating substrate 210. The wavelength of the fifth light beam and of the sixth light beam are different from the wavelength of the first light beam and of the second light beam and are preferably also different from the wavelength of the first light beam and of the second light beam. Additionally, when the third illumination means 113 is provided, it is preferred that the third light beam and the fourth light beam have a wavelength within the green range, and the fifth light beam and the sixth light beam have a wavelength within the orange range, as previously respectively defined.

[0107] In a first configuration, the first illumination means 111 comprises a first light source 111a and a second light source mb. For example, first illumination means 111 maybe configured as the first light source 111a and the second light source mb as described within the context of embodiments illustrated in Fig. 6Blight. For directing the first light beam and the second light beam onto the at least one same portion of the aerosolgenerating substrate 210, the first light source 111a and the second light source mb may simply be arranged and oriented such that first light beam and the second light beam are directly emitted onto the at least one same portion of the aerosol-generating substrate 210.

[0108] Alternatively, as shown in Fig. 7A, the same light sources 111a, mb of the first configuration are arranged and oriented such that arranged and oriented such that the first light beam is emitted onto a portion of the aerosol-generating substrate 210 that is different from a portion of the aerosol-generating substrate 210 onto which the second light beam is emitted. To cause the first light beam and the second light beam to be directed onto the at least one same portion of the aerosol-generating substrate 210 to generate the first interference pattern, the first illumination means 111 is provided with first changing means for changing the position and / or orientation of the first light source ma and / or of the second light source mb.

[0109] For this, the changing means may be configured to cause translational movement of the first light source ma and / or the second light source mb, wherein the caused translational movement causes the first light beam and the second light beam to be directed onto the at least one same portion of the aerosol-generating substrate 210. The first changing means may be configured to change the orientation of the first light source 111a and / or of the second light source mb, wherein the caused change in orientation causes the first light beam and the second light beam to be directed onto the at least one same portion of the aerosol-generating substrate 210. For example, the first changing means can be one or micromechanical or piezo actuators to which the first light source 111a and / or the second light source mb are attached. The piezo actuator may be configured to oscillate between a first orientation in which no interference is caused, and a second orientation in which interference is caused on the at least one same portion of the aerosol-generating substrate 2io.The first changing means may comprise an optical element configured for diverting the first light beam and / or second light beam, wherein translational movement and / or rotation of the optical element 130 causes the first and / or the second light beam to be diverted such that the first light beam and the second light are directed onto the at least one same portion of the aerosol-generating substrate 210. In a simple configuration, the optical element 130 may be a moveable and / or rotatable mirror.

[0110] In a second configuration, the first illumination means 111 comprises a first light source ma in combination with a beam splitter 120 to split light emitted from the first light source ma into a first light beam and a second light beam. The second configuration may a configuration as described in the context of embodiments illustrated in Fig. 6C. An optical element such as a mirror 130 may be provided for directing the first light beam or the second light beam such that both the first light beam and the second light are directed onto the at least one same portion of the aerosol-generating substrate 210. The beam splitter 120, and optionally the other optical element, such as a mirror 130, may be moveable to change the travelling distance of the first light beam to the at least one same portion of the aerosol-generating substrate 210 and the travelling distance of the second light beam to the at least one same portion of the aerosol-generating substrate 210, relative to each other. The aerosol-generating device too preferably comprises a control unit 140 for controlling operational parameters of the first illumination means. Notably, the control unit 140 may be configured to changing operational parameters of the first illumination means 111 to change the first interference pattern generated on the at least one same portion of the aerosol-generating substrate 210. Parameters that can be changed by the control unit 140 comprise phase, amplitude, frequency of a light beam, and position of a light source.

[0111] For example, the control unit 140 may be configured for changing the phase of the first light beam relative to the phase of the second light beam. For this purpose, as shown in Fig. 7B, in case of the first configuration, the first light source 111a and / or the second light source mb may be moveable, and the control unit 140 may be configured to move the first light source 111a and / or the second light source mb to, for example, increase the travelling distance of the first and / or second light beam to the at least one same portion of the aerosol-generating substrate 210. Additionally, or alternatively, the control unit 140 may be configured to change operational parameters of the first 111a and / or the second light source mb to cause a change in phase difference between the first and the second light beam. In case a beam splitter 120 is provided, the control unit 140 may be configured to operate the changing means described in the context of Figs. 7A, 7B) to change a position or positions of the first light source 111a and / or the second light source mb and hence a travelling distance, of the first light beam and / or the second light beam to the at least one same portion of the aerosol-generating substrate 210.

[0112] Additionally, or alternatively, the control unit 140 may be configured to change the amplitude of the first light beam and / or the amplitude of the second light beam. For this, the control unit 140 may be configured to directly change operational parameters of the first ma and / or the second light source mb as such.

[0113] Additionally, or alternatively, the control unit 140 may be configured to change the wavelength of the first light beam and / or the wavelength of the second light beam. Preferably, the wavelength of the first light beam and / or the second light beam are changed within the blue range. Notably, the wavelength of the first light beam and the wavelength of the second light beam may be changed relative to each other.

[0114] To effectively generate a first interference pattern, a first beam-one time, during which the first illumination means 111 is configured to emit and direct the first light beam on the at least one same portion of the aerosol-generating substrate 210, is at least partially or fully overlapping or the same as a second beam-on time, during which the first illumination means is configured to emit and direct the second light beam onto the at least one same portion of the aerosol-generating substrate 210. While the first beam- on time may be the same as the second beam time, the first beam on time may be different from the second beam-on time. For example, the first beam-on time may be longer than the second beam-on time, and the first light beam is emitted and directed onto the at least one same portion of the aerosol-generating substrate 210 while the second light beam is not emitted and directed onto the at least one same portion of the aerosol-generating substrate 210 to heat the at least one same portion without generating an interference pattern. This can be achieved by, for example, switching the second light source mb off and leaving the first light source 111a on. Alternatively, the second light beam may be blocked from traveling to the at least one same portion of the aerosol-generating substrate 210 while the second light beam is still being emitted and directed onto the at least one same portion.

[0115] It is to be noted that the above-described configurations and controls of the control unit 140 are described merely exemplarily for the first illumination means 111 and are equally applicable to the second 112 and / or the third illumination means 113. It is also to be noted that different illumination means may have different configurations and may be controlled by different ways be the control unit 140. In case a beam splitter 120 is provided, the first 111 and / or the second 112 and / or the third illumination 113 means may be provided with a common beam splitter. In case the wavelength of the third light beam and / or of the fourth light is changed, the changes are preferably within the green or orange range. In case the wavelength of the fifth light beam and / or of the sixth light is changed, the changes are preferably within the orange range.

[0116] Any change in phase, frequency, and amplitude changes the interference pattern. Therefore, the control unit 140 may be configured to gradually change any one of the above-described parameters to gradually shift the interference pattern, and notably interference maxima and minima, over the least one same portion of the aerosolgenerating substrate 210.

[0117] Fig. 8 illustrates how the aerosol-generating device too according to embodiments of the invention may be operated by the control unit 140. At time t0, no light, or a first light beam is directed onto the at least one same portion of the aerosol-generating substrate 210 while the second light beam is not directed onto the at least one same portion of the aerosol-generating substrate 210, and hence no interference pattern is generated. Hence, the central portions of the first light beam heat the at least one same portion of the aerosol-generating substrate 210 more than the edge portions of the first light beam. At time ti, the first and the second light beam are emitted and directed onto the at least one same portion of the aerosol-generating substrate 210 to generate the first interference pattern Hb. At or before time t2, the first and the second light beam are turned off, and at time t2, the third light beam and the fourth light beam are emitted and directed onto the at least one same portion of the aerosol-generating substrate 210 to generate the second interference pattern Hg. At or before time t3, the third and the fourth light beam are turned off, and at time t3, the fifth light beam and the sixth light beam are emitted and directed onto the at least one same portion of the aerosolgenerating substrate 210 to generate the third interference pattern Ho. At or before time t4, the fifth and the sixth light beam are turned off, and the step at ti may be repeated. When repeated, one or more of the operational parameters of the first illumination means being changed, either instantly, or gradually. As can be seen in Fig. 8, the first interference pattern Hb at time ti differs from the interference pattern at time t4, and interference maxima and minima are shifted to different positions. This provides more uniform heating of the at least one same portion of the aerosol-generating substrate 210. The same may be performed at time t5with the step at t2.

[0118] As a further example of how the aerosol-generating device too can be operated, at t0, only the first light beam is directed onto the at least one same portion of the aerosolgenerating substrate 210 without generating an interference pattern. At time ti, the first and the second light beam are directed onto the at least one same portion to generate the first interference pattern. At t2, only the third light beam is directed onto the at least one same portion of the aerosol-generating substrate 210 without generating an interference pattern. At time t3, the third and the fourth light beam may be directed onto the at least one same portion to generate the second interference pattern. Then at t4, only the fifth light beam is directed onto the at least one same portion of the aerosolgenerating substrate 210 without generating an interference pattern. At time t5, the fifth and the sixth light beam may be directed onto the at least one same portion to generate the third interference pattern.

[0119] While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the scope of this disclosure, as defined by the independent and dependent claims.

[0120] LIST OF REFERENCE SIGNS USED

[0121] 100 aerosol-generation device

[0122] 105 cavity / chamber

[0123] 110 aerosol-generation unit

[0124] 111 first illumination means ma first light source mb second light source

[0125] 112 second illumination means

[0126] 112a third light source

[0127] 112b fourth light source

[0128] 113a fifth light source

[0129] 113b sixth light source

[0130] 120 beam splitter

[0131] 130 optical element

[0132] 140 control unit

[0133] 150 power source

[0134] 200 aerosol-generating article

[0135] 210 aerosol-generating substrate to, ti, t2, t3, t4, t5points of time

[0136] Hbfirst interference pattern

[0137] Hg second interference pattern Ho third interference patter

Claims

Claims for PCT1. An aerosol-generating device comprising: a first illumination means for generating and directing a first light beam and a second light beam onto at least one same portion of an aerosol-generating substrate received by the aerosol-generating device, for generating an aerosol, wherein the first light beam and the second light beam are arranged to generate a first interference pattern on the at least one same portion of the aerosol-generating substrate.

2. The aerosol-generation device according to the preceding claim, wherein the first light beam and the second light beam have a wavelength within a first range of 380 nm to 500 nm, a preferably of 430 nm to 470 nm, more preferably of 440 nm to 460 nm, most preferably of about 450 nm.

3. The aerosol-generating device according to any one of the preceding claims, further comprising: a second illumination means for generating and directing a third light beam and a fourth light beam onto the at least one same portion of the aerosol-generating substrate, wherein the third light beam and the fourth light beam are arranged to interfere with each other at the at least one same portion of the aerosol-generating substrate to generate a second interference pattern on the at least one same portion of the aerosolgenerating substrate.

4. The aerosol-generating device according to the preceding claim, wherein the third light beam and the fourth light beam have wavelength within a second range of 520 nm to 590 nm, preferably of 540 nm to 570 nm, most preferably of about 555 nm, or wherein third light beam and the fourth light beam have wavelength within a third range of 590 nm to 635 nm, preferably of 590 nm to 600 nm, most preferably of about 595 nm.

5. The aerosol-generating device according to any one of claims 2 to 4, further comprisinga third illumination means for generating and directing a fifth light beam and a sixth light beam onto the at least one same portion of the aerosol-generating substrate, wherein the fifth light beam and the sixth light beam are arranged to interfere with each other at the at least one same portion of the aerosol-generating substrate to generate a third interference pattern on the at least one same portion of the aerosolgenerating substrate.

6. The aerosol-generating device according to the preceding claim, wherein the third light beam and the fourth light beam have wavelengths within a second range of 520 nm to 590 nm, preferably of 540 nm to 570 nm, most preferably of about 555 nm, and wherein the fifth light beam and the sixth light beam have wavelengths within a third range of 590 nm to 635 nm, preferably of 590 nm to 600 nm, most preferably of about 595 nm.

7. The aerosol-generating device according to any one of the preceding claims, wherein the first illumination means comprises a first light source for generating the first light beam and a second light source for generating the second light beam; and / or wherein the second illumination means comprises a third light source for generating the third light beam and a fourth light source for generating the fourth light beam; and / or wherein the third illumination means comprises a fifth light source for generating the fifth light beam and a sixth light source for generating the sixth light beam.

8. The aerosol-generation device according to the preceding claim, wherein first light source and the second light source are arranged to emit light onto the at least one same portion of the aerosol-generation substrate; and / or wherein third light source and the fourth light source are arranged to emit light onto the at least one same portion of the aerosol-generation substrate; and / or wherein the fifth light source and the sixth light source are arranged to emit light onto the at least one same portion of the aerosol-generation substrate.9- The aerosol-generation device according to claim 7, wherein first light source and the second light source are arranged to emit light onto different portions of the aerosol-generation substrate, wherein the first illumination means comprises first changing means for changing the position and / or orientation of the first light source and / or of the second light source to direct the first light beam and the second light beam onto the at least one same portion of the aerosolgeneration substrate; and / or wherein third light source and the fourth light source are arranged to emit light onto different portions of the aerosol-generation substrate, wherein the second illumination means comprises second changing means for changing the position and / or orientation of the third light source and / or of the fourth light source to direct the third light beam and the fourth light beam the at least one same portion of the aerosol-generation substrate; and / or wherein the fifth light source and the sixth light source are arranged to emit light onto different portions of the aerosol-generation substrate, wherein the third illumination means comprises third changing means for changing the position or orientation of the fifth light source and / or of the sixth light source to direct the fifth light beam and the sixth light beam onto the at least one same portion of the aerosolgeneration substrate.

10. The aerosol-generating device according to any one of the preceding claims, further comprising a control unit for changing operational parameters of the first and the second light beam and / or of the third and the fourth light beam and / or of the fifth and the sixth light beam, wherein the operational parameters comprise at least one of phase, amplitude, and frequency of the light beams generated and directed by the first and / or the second and / or the third illumination means.

11. The aerosol-generating device according to the preceding claim, wherein the control unit is further configured for: changing the phase of the first light beam and the phase of the second light beam relative to each other, and / orchanging the phase of the third light beam and the phase of the fourth light beam relative to each other, and / or changing the phase of the fifth light beam and the phase of the sixth light beam relative to each other, and / or changing the amplitude of the first and / or the second and / or the third and / or the fourth and / or the fifth and / or the sixth light beam.

12. The aerosol-generating device according to any one of claims 10 to 11, when dependent on claim 4 or 6, wherein the control unit is further configured for: changing the wavelength of the first light beam and or the second light beam within the first range; and / or changing the wavelength of the third light beam and / or the fourth light beam within the second range or within the third range.

13. The aerosol-generating device according to any one of claims 10 to 11, when dependent on claim 6, wherein the control unit is configured for: changing the wavelength of the first light beam and or the second light beam within the first range; and / or changing the wavelength of the third light beam and / or the fourth light beam within the second range; and / or changing the wavelength of the fifth light beam and / or the sixth light beam within the third range.

14. An aerosol-generating system comprising: the aerosol-generating device according to any one of the preceding claims, and an aerosol-generating article comprising an aerosol-generating substrate, wherein the aerosol-generating article is received by the aerosol-generating device.

15. A method of generating an aerosol, the method comprising generating an aerosol using an aerosol-generating system according to the preceding claim.

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