Method and system for optical analysis of components of an aerosol-generating article - Patent Application 20070123633

Abstract

The present invention relates to a method for optical analysis of components of an aerosol-generating article, the method comprising: - providing a component of an aerosol-generating article defining a first end and a second end, the component comprising: · Aerosol-forming substrate; providing a susceptor in thermal contact with the aerosol-forming substrate; - providing a first polarization camera including a sensor for detecting polarization information of electromagnetic radiation; - Irradiating the component with electromagnetic radiation; - detecting, with a first polarized camera, electromagnetic radiation transmitted, reflected or refracted from the component; - generating a first image of the first end of the component with a first polarization camera, the first image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information about the detected electromagnetic radiation; and - detecting the position of the susceptor in the first image.

Description

[Technical field]

[0001] The present invention relates to a method and system for optical analysis of a component of an aerosol-generating article, in particular the method and system are adapted to detect the position of a susceptor included in the component of an aerosol-generating article. [Background technology]

[0002] Aerosol generating devices are known and include an aerosol-forming substrate and an induction heating device. The induction heating device includes an induction source that generates an alternating electromagnetic field that induces eddy currents and hysteresis losses that generate heat in a susceptor. The susceptor is in thermal proximity to an aerosol-forming substrate, such as a tobacco substrate. The heated susceptor then heats the aerosol-forming substrate, which includes a material capable of releasing volatile compounds capable of forming an aerosol.

[0003] In some configurations, the susceptor is positioned within the aerosol-generating article, which also includes an aerosol-forming substrate.

[0004] Due to manufacturing tolerances, it may occur that the susceptor in a component is not in the desired location or does not have the proper orientation.

[0005] If the susceptor remains in an incorrect position or orientation, a lack of product compatibility may occur with respect to aerosol delivery when the component is used in an aerosol generating device.

[0006] It is therefore desirable to detect such defects as early as possible to ensure that only conforming components are manufactured, avoiding unnecessary costs and waste. Summary of the Invention

[0007] In one aspect, the present invention relates to a method for optical analysis of a component of an aerosol-generating article. The method includes providing a component of the aerosol-generating article defining a first and a second end, the component including an aerosol-forming substrate and a susceptor in thermal contact with the aerosol-forming substrate. The method preferably further includes providing a first polarization camera including a sensor for detecting polarization information of the electromagnetic radiation. The method may include illuminating the component with the electromagnetic radiation. The method may include detecting electromagnetic radiation transmitted, refracted or reflected from the component by the first polarization camera. The method may include generating a first image of a first end of the component by the first polarization camera, the first image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information related to the detected electromagnetic radiation. Additionally, the method includes detecting a position of the susceptor in the first image.

[0008] In another aspect, the invention relates to a system for generating a component of an aerosol-generating article, the component comprising a longitudinal axis, a first end and a second end, an aerosol-forming substrate, and a susceptor in thermal contact with the aerosol-forming substrate. The system also comprises a first electromagnetic radiation source adapted to irradiate the component. The system may also comprise a first polarization camera comprising a sensor for detecting polarization information of the electromagnetic radiation, the first polarization camera defining a first field of view, the first polarization camera being positioned such that the first end of the component is within the first field of view, the first polarization camera being adapted to generate a first image of the first end of the component, the first image being formed by a plurality of pixels, each pixel of the plurality of pixels comprising polarization information of the electromagnetic radiation being detected by the camera. The system may also comprise a control unit adapted to process the first image and adapted to detect a position of the susceptor in the first image.

[0009] It has been found that taking an image of the edge of an aerosol-generating article component, that is a component that includes a susceptor, with a polarized camera improves the visibility of the position of the susceptor in the image compared to images taken with any other camera. By checking the correct position of the susceptor while the aerosol-generating article component is being manufactured, defective components can be removed as soon as possible, limiting material waste. Polarized cameras are fast enough to allow processing of images during manufacturing.

[0010] The term "aerosol-generating article" as used herein refers to an article comprising an aerosol-forming substrate which, upon heating, releases a volatile compound capable of forming an aerosol. The aerosol-generating article is preferably a heated aerosol-generating article. A heated aerosol-generating article is an aerosol-generating article comprising an aerosol-forming substrate that is intended to be heated, rather than burned, to release a volatile compound capable of forming an aerosol. The aerosol-generating article may be a consumable product, in particular a consumable product that is discarded after a single use. The aerosol-generating article may be an article similar to a conventional cigarette, in particular a tobacco article.

[0011] The term "aerosol-forming substrate" as used herein refers to a substrate formed from or including an aerosol-forming material capable of releasing volatile compounds upon heating to form an aerosol. The aerosol-forming substrate may include tobacco material, or may include non-tobacco material, or may include a combination of both tobacco and non-tobacco materials. The aerosol-forming substrate may be a cellulosic material impregnated with nicotine, and preferably includes one or more flavors. Advantageously, the aerosol-forming substrate includes tobacco material, preferably homogenized tobacco material, preferably one or more aerosol formers. The term "homogenized tobacco material" as used herein refers to a material formed by agglomerating particulate tobacco.

[0012] The aerosol-forming substrate preferably comprises a volatile tobacco flavour compound that is released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise or consist of a blended tobacco cut filler, or may comprise a homogenised tobacco material. The homogenised tobacco material may be formed by agglomerating particulate tobacco. The aerosol-forming substrate may further comprise a non-tobacco-containing material, for example a homogenised plant-based material other than tobacco.

[0013] The aerosol-forming substrate is preferably a tobacco sheet, preferably crimped, comprising tobacco material, fibers, binders, and aerosol formers. The tobacco sheet is preferably a cast leaf. Cast leaf is a form of reconstituted tobacco formed from a slurry containing tobacco particles, fiber particles, aerosol formers, binders, and, for example, flavors.

[0014] The tobacco particles may be in the form of tobacco dust having particles of about 30 micrometers to 250 micrometers, preferably about 30 micrometers to 80 micrometers, or about 100 micrometers to 250 micrometers, depending on the desired sheet thickness and casting gap, and typically the sheet thickness is determined by the casting gap. The size of the tobacco particles refers to their Dv95 size in the volume distribution.

[0015] The fiber particles may include tobacco stem material, stalk, or other tobacco plant material, and other cellulosic fibers, such as wood fibers with low lignin content. The fiber particles may be selected based on the requirement to produce sufficient tensile strength in the cast leaf for a low content, for example, about 2 percent to 15 percent. Alternatively, fibers such as plant fibers may be used in conjunction with or in place of the above-mentioned fiber particles, including hemp and bamboo.

[0016] The aerosol formers included in the slurry forming the cast leaf, or used with other aerosol-forming substrates, may be selected based on one or more properties. Functionally, the aerosol formers provide a mechanism that allows the aerosol former to volatilize and deliver nicotine or flavorings or both in an aerosol state when heated above the particular volatilization temperature of the aerosol former. Different aerosol formers typically vaporize at different temperatures. The aerosol formers may be any suitable known compound or mixture of compounds that, in use, promotes the formation of a dense, stable aerosol and is substantially resistant to thermal decomposition at the operating temperature of the induction heating device used with the induction heating tobacco substrate. The aerosol formers may be selected based on their ability to remain stable at or near room temperature, but volatilize at higher temperatures, e.g., between 40 degrees Celsius and 450 degrees Celsius.

[0017] The aerosol former may have humectant properties that help maintain a desired level of moisture within the aerosol-forming substrate when the substrate is comprised of a tobacco-based product, particularly a tobacco-based product that includes tobacco particles. In particular, some aerosol formers are hygroscopic materials that function as humectants, i.e., materials that help keep the tobacco substrate, including the humectant, moist.

[0018] One or more aerosol formers may be combined to take advantage of one or more properties of the combined aerosol formers, for example, triacetin may be combined with glycerin and water to take advantage of triacetin's ability to carry active ingredients and the humectant properties of glycerin.

[0019] The aerosol former may be selected from polyols, glycol ethers, polyol esters, esters, and fatty acids, and may include one or more of the following compounds: glycerin, erythritol, 1,3-butylene glycol, tetraethylene glycol, triethylene glycol, triethyl citrate, propylene carbonate, ethyl laurate, triacetin, meso-erythritol, diacetin mixtures, diethyl suberate, triethyl citrate, benzyl benzoate, benzyl phenylacetate, ethyl vanillate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene glycol.

[0020] The aerosol-forming substrate may contain other additives and ingredients, such as flavourants, etc. Preferably, the aerosol-forming substrate comprises nicotine and at least one aerosol former.

[0021] Crimped tobacco sheets, such as cast leaves, may have a thickness ranging between about 0.5 and about 2 millimeters, preferably between about 0.8 and about 1.5 millimeters, and for example, 1 millimeter. Thickness variations of up to about 30 percent may occur due to manufacturing tolerances.

[0022] The aerosol-forming substrate may comprise a gel. The aerosol-forming substrate may comprise a porous medium loaded with a gel. The porous medium forms a substrate for adsorbing the gel. The gel is inserted into a component of the aerosol-generating article.

[0023] In combination with certain embodiments, the gel is a mixture of materials that can release volatile compounds into the aerosol passing through the aerosol-generating article, preferably upon heating of the gel. Advantageously, the gel is solid at room temperature. In this context, "solid" means that the gel has a stable size and shape and does not flow. In this context, room temperature means 25 degrees Celsius.

[0024] The gel may include an aerosol former. Ideally, the aerosol former is substantially resistant to thermal decomposition at the operating temperature of the component. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols such as triethylene glycol, 1,3-butanediol, glycerin, and the like; esters of polyhydric alcohols such as glycerol monoacetate, diacetate, or triacetate; and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanedioate, dimethyl tetradecanedioate. The polyhydric alcohol or mixtures thereof may be one or more of triethylene glycol, 1,3-butanediol, and glycerin or polyethylene glycol.

[0025] Advantageously, the gel comprises, for example, a thermoreversible gel. This means that the gel becomes fluid when heated to the melting temperature and becomes a gel again at the gelling temperature. The gelling temperature may be at room temperature and atmospheric pressure or above. Atmospheric pressure means a pressure of 1 atmosphere. The melting temperature may be higher than the gelling temperature. The melting temperature of the gel may be above 50 degrees Celsius, or 60 degrees Celsius, or 70 degrees Celsius, or even above 80 degrees Celsius. The melting temperature in this context means the temperature at which the gel is no longer solid and starts to flow.

[0026] Alternatively, in certain embodiments, the gel is a non-melting gel that does not melt during use of the component, hi these embodiments, the gel may at least partially release the active agent at or above the operating temperature of the tubular element during use, but below the melting temperature of the gel.

[0027] In combination with certain embodiments, the gel comprises a gelling agent, hi certain embodiments, the gel comprises agar or agarose or sodium alginate or gellan gum, or a mixture thereof.

[0028] In certain embodiments, the gel comprises water, eg, the gel is a hydrogel.

[0029] Alternatively, in certain embodiments, the gel is non-aqueous.

[0030] The gel preferably includes an active agent. In combination with certain embodiments, the active agent includes nicotine (e.g., nicotine in powder or liquid form), or a tobacco product or another target compound, for example, for release in an aerosol. In certain embodiments, nicotine is included in the gel together with an aerosol former.

[0031] In certain embodiments, the gel includes solid tobacco materials that release flavor compounds upon heating. According to certain embodiments, the solid tobacco materials are one or more of powders, granules, pellets, pieces, spaghetti, strips, or sheets, including one or more of plant materials such as herb leaves, tobacco leaves, tobacco stem fragments, reconstituted tobacco, homogenized tobacco, extruded tobacco, and expanded tobacco.

[0032] Additionally or alternatively, there are embodiments in which the gel includes other flavors, such as, for example, menthol, which may be added either to the water or to the aerosol former prior to formation of the gel.

[0033] The gel preferably comprises a gelling agent, which is capable of forming a solid medium in which the aerosol former can be dispersed.

[0034] The gel may include any suitable gelling agent. For example, the gelling agent may include one or more biopolymers, such as two or three biopolymers. When the gel includes more than one biopolymer, it is preferred that the biopolymers are present in substantially equal amounts by weight.

[0035] The biopolymer may be formed of a polysaccharide. Suitable biopolymers for the gelling agent include, for example, gellan gum (natural, low acyl gellan gum, high acyl gellan gum, with low acyl gellan gum being preferred), xanthan gum, alginate (alginic acid), agar, guar gum, etc. The gel preferably comprises agar.

[0036] The gel may include divalent cations. The divalent cations preferably include calcium ions, such as calcium lactate in solution. Divalent cations (such as calcium ions) may aid in gel formation in compositions including biopolymers (polysaccharides), such as gellan gum (native gellan gum, low acyl gellan gum, high acyl gellan gum), xanthan gum, alginate (alginic acid), agar, guar gum, and the like. Ionic effects may aid in gel formation. Divalent cations may be present in the gel composition in the range of about 0.1 to about 1 weight percent, or about 0.5 weight percent. In some embodiments, the gel does not include divalent cations.

[0037] The gel may include a carboxylic acid. The carboxylic acid may include a ketone group. The carboxylic acid preferably includes a ketone group with less than 10 carbon atoms. The carboxylic acid preferably includes five carbon atoms (such as levulinic acid). Levulinic acid may be added to neutralize the pH of the gel. It may also aid in gel formation with biopolymers (polysaccharides) such as gellan gum (low acyl gellan gum, high acyl gellan gum), xanthan gum, especially alginates (alginic acid), agar, guar gum, and the like. Levulin may also enhance the sensory profile of the gel formulation. In some embodiments, the gel does not include a carboxylic acid.

[0038] Preferably, the gel further comprises 0.1 to 2 weight percent nicotine. Preferably, the gel further comprises 30 to 90 weight percent (or 70 to 90 weight percent) glycerin. In certain embodiments, the remainder of the gel comprises water and flavorings.

[0039] Additionally or alternatively, in some particular embodiments, the aerosol-forming substrate comprises a porous medium loaded with a gel, the gel being adsorbed by the porous medium which acts as a substrate for the gel.

[0040] As used herein, the term "aerosol-generating device" is used to describe a device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device is preferably a smoking device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol that is directly inhalable by a user through the user's mouth.

[0041] "Component" of an aerosol-generating article means an element used to form the aerosol-generating article. The component is preferably rod-shaped. The component is preferably substantially cylindrical. In certain embodiments, the component has an outer diameter of 5 millimeters to 12 millimeters, for example 5 millimeters to 10 millimeters, or 6 millimeters to 8 millimeters. Typically, the component has an outer diameter of 7.2 millimeters plus or minus 10%. Preferably, the component is surrounded by a wrapper. Typically, the component has a length of 5 millimeters to 15 millimeters. The component has a length of 6 millimeters to 12 millimeters, preferably the component has a length of 7 millimeters to 10 millimeters, and preferably the component has a length of 8 millimeters.

[0042] As used herein, the term "susceptor" refers to a material capable of converting electromagnetic energy into heat. When located in an alternating electromagnetic field, eddy currents are induced in the susceptor and hysteresis losses occur, causing the susceptor to heat up. When the susceptor is located in thermal contact or in close thermal proximity to the aerosol-forming substrate, the susceptor heats the aerosol-forming substrate such that an aerosol is formed. The susceptor is preferably disposed in direct physical contact with the aerosol-forming substrate, for example within the aerosol-forming tobacco substrate.

[0043] The susceptor may be formed of any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptors include metal or carbon. Preferred susceptors may include or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel, or stainless steel. Suitable susceptors may be or include aluminum. Preferred susceptors may be heated to temperatures above 250 degrees Celsius. Suitable susceptors may include a non-metallic core having a metal layer disposed thereon, such as a metal track formed on the surface of a ceramic core. The susceptor may have a protective outer layer, such as a protective ceramic layer or a protective glass layer, that encapsulates the susceptor. The susceptor may include a protective coating formed of glass, ceramic, or an inert metal formed over a core of susceptor material.

[0044] The susceptor may be a multi-material susceptor and may include a first susceptor material and a second susceptor material. The first susceptor material is placed in close physical contact with the second susceptor material. The second susceptor material preferably has a Curie temperature below 500° C. The first susceptor material is preferably used primarily to heat the susceptor when it is placed in an oscillating electromagnetic field. Any suitable material may be used. For example, the first susceptor material may be aluminum or a ferrous material such as stainless steel. The second susceptor material is preferably used primarily to indicate when the susceptor has reached a particular temperature, which is the Curie temperature of the second susceptor material. The Curie temperature of the second susceptor material may be used to regulate the temperature of the entire susceptor during operation. Therefore, the Curie temperature of the second susceptor material should be below the ignition point of the aerosol-forming substrate. Suitable materials for the second susceptor material may include nickel and certain nickel alloys.

[0045] The susceptor preferably has the shape of a filament, rod, sheet or band. When the susceptor profile has a constant cross section, e.g. a circular cross section, it has a preferred width or diameter between about 1 mm and about 5 mm. When the susceptor profile has the form of a sheet or band, the sheet or band preferably has a rectangular shape with a width preferably between about 2 mm and about 8 mm, more preferably between about 3 mm and about 5 mm, e.g. 4 mm, and a thickness preferably between about 0.03 mm and about 0.15 mm, more preferably between about 0.05 mm and about 0.09 mm, e.g. 0.07 mm.

[0046] According to the method of the present invention, a component for an aerosol-generating article is provided. The component preferably has a rod shape. The component preferably defines a longitudinal axis. The component defines a first end and a second end. The longitudinal axis connects the first end and the second end.

[0047] The cross-section of the components along a plane perpendicular to the longitudinal axis is preferably circular or elliptical, however the components may also have a rectangular or polygonal cross-section.

[0048] Further, the component comprises an aerosol-forming substrate. The aerosol-forming substrate may comprise homogenized tobacco material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a substrate that adsorbs gel. Preferably, the majority of the component is formed by the aerosol-forming substrate. The aerosol-forming substrate preferably completely fills the component, i.e. no voids, cavities or holes are desired in the component.

[0049] The component further comprises a susceptor. The susceptor is preferably made of metal. The susceptor is in thermal contact with the aerosol-forming substrate. The thermal contact is made to heat the aerosol-forming substrate. Upon heating, the aerosol-forming substrate emits an aerosol. The susceptor is preferably surrounded by the aerosol-forming substrate. Preferably, the susceptor defines a longitudinal axis. Preferably, the susceptor is completely contained within the component. Preferably, the susceptor is located near a first end of the component. Preferably, the susceptor extends from the first end to the second end of the component. Preferably, the longitudinal axis of the susceptor is parallel to the longitudinal axis of the component or forms an angle of less than 20 degrees with the longitudinal axis of the component. Preferably, the susceptor is inserted within the component. Preferably, the susceptor is located at a predetermined position within the component. Preferably, the susceptor has the shape of a blade.

[0050] The components are preferably wrapped in a wrapping sheet.

[0051] A first polarization camera is also provided that includes a sensor that detects polarization information of electromagnetic radiation. The sensor preferably includes a polarizer array. Preferably, the polarizer array includes a plurality of polarizing filters at a plurality of different polarization angles. The sensor preferably includes a CMOS sensor. The sensor may incorporate a layer of polarizing filters above the photodiodes. The polarizer array layer may be disposed on-chip and may include an air-gap nanowire grid coated with an anti-reflective material that suppresses flare and ghosting. This on-chip arrangement reduces polarization crosstalk and improves the extinction ratio.

[0052] The polarizer array may include four different orientation polarizing filters. The polarizing filters may be disposed on each pixel. Each polarizing filter polarizes light along a polarization direction. Preferably, the four different polarization directions are 90 degrees, 45 degrees, 135 degrees, and 0 degrees. A calculation unit is defined for each block of four pixels. A sensor using different orientation polarizers in a four-pixel block design preferably allows for calculation of both the angle and direction of polarization of electromagnetic radiation.

[0053] The first polarization camera is preferably sensitive to electromagnetic radiation having a wavelength range from about 200 nanometers to about 2500 nanometers, more preferably from 400 nanometers to 1000 nanometers.

[0054] Preferably, the first polarization camera is an XCG-CP series polarization machine vision camera manufactured by Sony. Preferably, the first polarization camera uses the XPL-SDKW polarization camera software development kit.

[0055] The component is illuminated, for example, by an electromagnetic radiation source emitting electromagnetic radiation. Preferably, the entire component is illuminated or only a portion of the component. Preferably, a first end of the component is illuminated by the electromagnetic radiation. The electromagnetic radiation may be a focused beam of electromagnetic radiation. The electromagnetic radiation may be diffuse electromagnetic radiation. The electromagnetic radiation source preferably emits electromagnetic radiation having a wavelength range of about 200 nanometers to about 2500 nanometers, more preferably 400 nanometers to 1000 nanometers. The electromagnetic radiation preferably has a wavelength in the visible range. The electromagnetic radiation source preferably comprises an LED. The LED may be a white LED. Preferably, the electromagnetic radiation may comprise a suitable optical device to focus the electromagnetic radiation on the first end of the component. The electromagnetic radiation source is preferably positioned such that it can illuminate the first end of the component.

[0056] The first polarization camera defines a field of view and the component is positioned such that it is positioned or adapted to be within the field of view of the first polarization camera. Preferably, the component is positioned such that all or a portion of it is positioned or adapted to be within the field of view of the first polarization camera. Preferably, the component is positioned such that a first end of the component is positioned or adapted to be within the field of view of the first polarization camera.

[0057] The field of view of the polarization camera has a central axis, which is the optical axis of the optical system contained in the first polarization camera.

[0058] The electromagnetic radiation may be reflected, refracted or transmitted by the component, for example by a part of the component. The part of the component that may reflect, refract or transmit the electromagnetic radiation preferably comprises a first end of the component. A part of the electromagnetic radiation arriving from the component strikes a sensor of the first polarization camera, to be detected by the first polarization camera. In the following, by "electromagnetic radiation arriving from the component" is intended electromagnetic radiation reflected, refracted or transmitted by a part of the component. The first polarization camera is adapted to generate a first image having a plurality of pixels. Each pixel of the first image comprises polarization information of the detected electromagnetic radiation. Thus, the first image comprises polarization information of the electromagnetic radiation arriving from the component.

[0059] For example, each pixel of the image may contain information about polarization along a given direction, e.g., a direction defined by one of the polarizing filters included in the camera's sensor. For example, a first image may be divided into a cluster of four pixels, and each pixel of the cluster may contain polarization information, e.g., a polarization value, along one of the four directions identified by the polarizing filter. Thus, the cluster of four pixels may contain polarization values ​​along the four directions.

[0060] The first image may contain sophisticated polarization information: different quantities may be calculated from the polarization values ​​along one or more directions.

[0061] The first image may include a degree of polarization (DOP) for each pixel. The degree of polarization may be calculated for each pixel and displayed globally as a polarization degree image. The degree of polarization (DOP) is a quantity used to describe the portion of electromagnetic radiation that is polarized. Fully polarized radiation has a DOP of 100 percent, while unpolarized radiation has a DOP of 0 percent. Radiation that is partially polarized, and thus may be represented by a superposition of polarized and unpolarized components, has a DOP between 0 percent and 100 percent. DOP is generally calculated as the percentage of the total power carried by the polarized components of the electromagnetic radiation.

[0062] The first image may include for each pixel information regarding polarization values ​​along a single direction, the same direction for all pixels, which may be one of the polarization directions of the filter. The first polarization camera may generate four different images, one for each direction of polarization defined by the polarizing filters included in the camera sensor.

[0063] The first image may include, for each pixel information regarding polarization values ​​along a single direction, the same direction for all pixels, different from all directions defined by the polarizing filter, the first image being acquired by refining the polarization values ​​along the different directions defined by the polarizing filter acquired by the sensor.

[0064] The first image may include polarization information that includes, for each pixel, an average of polarization values ​​along multiple directions, e.g., for four different directions defined by four polarizing filters, the first image may include a value for each pixel that is the average of the four polarizations along the four different directions.

[0065] The first image may include polarization information, including the direction of polarization, for each pixel. This information may be processed and used to display a surface normal image, which indicates the direction of the normal to the surface of the component at each pixel.

[0066] Based on the polarization information present in the first image, the location of the susceptor may be identified. With a standard camera, the location of the susceptor is not easily found. Using the polarization information displayed in the first image, the location of the susceptor within the component may be easily identified. The location of the susceptor within the component may be easily identified. Preferably, the identification of the susceptor location is done automatically using known image processing software or algorithms.

[0067] The position of the susceptor is identified using a control unit, for example a computer, which may include software suitable for digital image analysis.

[0068] If the susceptor is covered by another material, such as a gel, other information obtained by refining the first image can be used to determine the location of the susceptor. Additionally, information about the dimensions of the susceptor can be used to determine the location of the susceptor.

[0069] Additional information about the component may be obtained by refining the first image, for example the diameter dimension of the component at the first end may be measured.

[0070] Preferably, the method includes determining whether the position of the susceptor is correct. Determining whether the position is correct preferably includes comparing the detected position of the susceptor with an expected position of the susceptor. Determining whether the position is correct preferably includes comparing the detected position of the susceptor with a range of expected positions of the susceptor. The susceptor is preferably positioned within the component such that it is completely surrounded by the aerosol-forming substrate. Furthermore, the susceptor defines a susceptor axis. Preferably, the susceptor axis is substantially parallel to the longitudinal axis of the component. Thus, if the axis of the susceptor is not parallel to the longitudinal axis, the susceptor is considered to be incorrectly positioned. If the axis of the susceptor and the longitudinal axis form an angle of more than 20 degrees, the susceptor is considered to be incorrectly positioned.

[0071] Preferably, the method includes issuing an alert. If the susceptor is misplaced or not properly aligned, i.e. the position of the susceptor is incorrect, preferably the method includes issuing an alert, e.g. to an operator. Alternatively, the alert or warning is sent to a feedback loop device. The feedback loop device may change the position of the susceptor within the component based on the alert.

[0072] Preferably, the method includes estimating either the degree of polarization or the polarization angle from the polarization information present in the first image. More preferably, either the degree of polarization or the polarization angle is calculated for each pixel of the first image. More preferably, both the degree of polarization and the polarization angle are calculated. Thus, the first image may include, for each pixel, a DOP value or an angle value of the polarization. Preferably, the first image includes, for each pixel, a DOP value and an angle value of the polarization. The susceptor may be realized in metal. Since electromagnetic radiation is relatively highly polarized by metals, the degree of polarization image enhances the contrast of metallic objects compared to other materials. Localization of the susceptor and determining whether the susceptor is correctly positioned is relatively simple.

[0073] Preferably, the first polarized camera defines a first field of view having a first central axis, and the method includes providing a second polarized camera including a sensor for detecting polarization information of the electromagnetic radiation, the second polarized camera defining a second field of view having a second central axis, the second central axis forming an angle with the first central axis different from zero; detecting the electromagnetic radiation transmitted, reflected or refracted from the component by the second polarized camera; generating a second image of the first end of the component by the second polarized camera, the second image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information regarding the detected electromagnetic radiation; and combining the polarization information included in the first image with the polarization information included in the second image to obtain a single combined image of the first end of the component. More preferably, the step of detecting the electromagnetic radiation transmitted, reflected or refracted from the component by the second polarized camera includes detecting the electromagnetic radiation transmitted, reflected or refracted from the first end of the component by the second polarized camera. Preferably, a second polarized camera is provided. The second polarized camera obtains a second image of the first end of the component. Preferably, the second polarized camera is substantially identical to the first polarized camera. The second polarized camera defines a second field of view having a second central axis. The angle formed between the first axis of the first field of view of the first polarized camera and the second axis of the second field of view of the second polarized camera is different from zero or 180 degrees. The polarization information contained in the first image is preferably of the same type as the polarization information contained in the second image. For example, if the first image includes all pixel information on the DOP, the second image also includes information on the DOP. The first image and the second image are preferably taken substantially simultaneously. The first axis of the first field of view of the first polarized camera and the second axis of the second field of view of the second polarized camera form an angle therebetween, so that the first image and the second image can be combined to obtain a substantially three-dimensional image. The angle formed between the first axis and the second axis is preferably comprised between about 5 degrees and about 60 degrees. A stereoscopic algorithm may be used to combine the first image and the second image.By comparing information about the components from two angles, three-dimensional information can be extracted by examining the relative positions of the elements in the first and second images. The three-dimensional image may allow for better identification of the location of the susceptor in the aerosol-forming substrate. The three-dimensional image improves the recognizability of structures within the aerosol-forming substrate, such that the susceptor becomes more visible.

[0074] Preferably, the method includes providing an X-ray sensor; illuminating the component between the first end and the second end with an X-ray field; generating an X-ray image; and combining information contained in the X-ray image with information contained in the first image. A first polarized light camera generates an image of the first end of the component. The polarized light camera may not be capable of generating an image of the interior of the component, but may have the ability to generate an image of only its surface. Thus, defects present inside the component that do not appear on the surface of the component cannot be detected by use of the polarized light camera. To generate an image of the inside of the component, an X-ray sensor may be provided. The X-ray sensor detects a transmitted or reflected X-ray field impinging on the component between the first end and the second end. The X-ray sensor is adapted to generate an X-ray image. This allows for the detection of defects located inside the component that are not visible on the surface of the component.

[0075] Preferably, the method includes providing a third polarization camera including a sensor for detecting polarization information of the electromagnetic radiation; detecting the transmitted, reflected or refracted electromagnetic radiation from the component by the third polarization camera; and generating a third image of the second end of the component by the third polarization camera, the third image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information regarding the detected electromagnetic radiation; and detecting the location of the susceptor in the third image. More preferably, the first image and the third image are generated substantially simultaneously. Even more preferably, the step of illuminating the component with the electromagnetic radiation includes illuminating the first end and the second end of the component by the electromagnetic radiation. More preferably, the step of detecting the transmitted, reflected or refracted electromagnetic radiation from the component by the third polarization camera included detecting the transmitted, reflected or refracted electromagnetic radiation from the first end of the component by the third polarization camera. In this way, the location of the susceptor can be identified at both the first end and the second end of the component. Misalignment of the susceptor at both ends of the component can be identified. The presence of two polarization cameras (a first polarization camera and a third polarization camera) allows for simultaneous inspection of the first and second ends, reducing production time, which can also be useful when two different susceptors are present at two opposite ends of a component.

[0076] Preferably, the method includes illuminating the component with a first electromagnetic radiation; detecting the first electromagnetic radiation transmitted, reflected or refracted from the component by a first polarization camera; generating a first image of a first end of the component, the first image formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information about the detected first electromagnetic radiation; illuminating the component with a second electromagnetic radiation different from the first electromagnetic radiation; detecting the second electromagnetic radiation transmitted, reflected or refracted from the component by the first polarization camera; generating a fourth image of the first end of the component by the first polarization camera, the fourth image formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information about the detected second electromagnetic radiation; combining the polarization information in the first image with the polarization information in the fourth image to obtain a single combined image of the first end of the component.

[0077] The first electromagnetic radiation may differ from the second electromagnetic radiation in any characteristic. For example, the second electromagnetic radiation is diffuse while the first electromagnetic radiation is focused. The wavelength of the first electromagnetic radiation may differ from the wavelength of the second electromagnetic radiation. The angle at which the first electromagnetic radiation hits the first end of the component may differ from the angle at which the second electromagnetic radiation hits the first end of the component. Having two different light settings, such as the first electromagnetic radiation and the second electromagnetic radiation, allows the optimum electromagnetic radiation to be used for a given analysis. For example, the first electromagnetic radiation is selected such that the position of the susceptor can be easily detected in the first image, the fourth image, or a composite image, while the second electromagnetic radiation is selected such that another characteristic of the first image, the fourth image, or a composite image can be easily detected.

[0078] Preferably, the third polarization camera defines a third field of view having a third central axis, and the method includes providing a fifth polarization camera including a sensor for detecting polarization information of the electromagnetic radiation, the fifth polarization camera defining a fifth field of view having a fifth central axis, the fifth central axis forming an angle different from zero with the third central axis; detecting transmitted, reflected or refracted electromagnetic radiation from the component by the fifth polarization camera; generating a fifth image of the second end of the component by the fifth polarization camera, the fifth image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information of the detected electromagnetic radiation; and combining the polarization information contained in the third image with the polarization information contained in the fifth image to obtain a single combined image of the second end of the component. As with the first end, a substantially three-dimensional image of the second end of the component may be obtained by combining the third image and the fifth image taken at different angles.

[0079] Preferably, the components define a longitudinal axis and the first polarized camera has a first field of view, the method comprising: providing a movable transport; providing a plurality of components on the movable transport with their longitudinal axes substantially parallel to one another; generating a first image of a first end of some of the plurality of components that enter the first field of view of the first camera by the movement of the movable support. Preferably, the components are moved. During the production of the aerosol-generating article, the components are moved from one machine to another to be produced. In order to produce the components in a limited time, for example during processing, a determination of the position of the susceptor is made while the components are moving. Interruptions of production can be avoided or minimized. For this purpose, a moving element is provided that is adapted to move a plurality of components arranged with their longitudinal axes parallel to one another. The components are moved with parallel longitudinal axes so that their first ends can be easily illuminated and enter the field of view of the first polarized camera. The first polarized camera can take first images of the components in succession. The first polarized camera generates the first image as soon as the components enter its field of view.

[0080] Preferably, the system also includes a trigger element adapted to identify the approach of a component and to send a signal to the electromagnetic radiation source to switch on the electromagnetic radiation source and illuminate the component. If multiple components are considered, the trigger element is actuated and switches on the electromagnetic radiation source each time a new component enters the field of view of the first polarized camera. The electromagnetic radiation source may be a strobe.

[0081] Preferably, the components define a longitudinal axis and the first polarized camera has a first field of view, and the method includes providing a drum; positioning a plurality of components on the drum with their longitudinal axes substantially parallel to one another; rotating the drum; and generating first images of first ends of some of the plurality of components that fall within a first field of view of the first camera due to the rotation of the drum. The movable elements can be of any type. Polarized cameras are positioned at several locations within the system to form the components of the aerosol-generating article.

[0082] Preferably, the method includes discarding components based on the position of the susceptor. If the susceptor is not correctly positioned within a component, the component including the incorrectly positioned susceptor is preferably discarded. For example, compressed air can be used to push out the undesired components.

[0083] Preferably, the system includes a moving element adapted to move a plurality of components arranged with their longitudinal axes parallel to one another.

[0084] Preferably, the system includes a rejection unit adapted to reject components based on the position of the susceptor.More preferably, the movable element includes a drum or a conveyor belt.

[0085] Preferably, the first source of electromagnetic radiation comprises a strobe light adapted to illuminate the component at a given frequency, and more preferably, the strobe light comprises optics that focus the electromagnetic radiation onto the component.

[0086] Preferably, the system comprises a second source of electromagnetic radiation adapted to irradiate the component, the second source being different from the first source.

[0087] The invention will now be described in more detail with reference to the accompanying drawings. [Brief description of the drawings]

[0088] [Figure 1] FIG. 1 is a schematic perspective view of a first embodiment of a system for the manufacture of a component of an aerosol-generating article. [Diagram 2] FIG. 2 is a schematic side view of a second embodiment of a system for the production of a component of an aerosol-generating article. [Diagram 3] FIG. 3 is a schematic perspective view of a third embodiment of a system for the production of a component of an aerosol-generating article. [Figure 4] FIG. 4 is a schematic perspective view of a fourth embodiment of a system for the production of a component of an aerosol-generating article. [Diagram 5] FIG. 5 is a schematic perspective view of a fifth embodiment of a system for the manufacture of a component of an aerosol-generating article. [Figure 6] FIG. 6 is a schematic front view of the components of an aerosol-generating article. [Figure 7] FIG. 7 is a schematic side view of the components of FIG. [Figure 8] Figure 8 shows an image of the components taken with a polarized camera. [Figure 9] FIG. 9 is a detail of the image of FIG. 8 according to the method of the present invention. [Figure 10] FIG. 10 is a detail of the image of FIG. 9 according to the method of the present invention. [Figure 11] Figure 11 is an image of the components taken with a polarized camera. [Figure 12] FIG. 12 is a detail of the image of FIG. 11 according to the method of the present invention. [Figure 13] FIG. 13 is a detail of the image of FIG. 12 according to the method of the present invention. [Figure 14] FIG. 14 is a detail of the image of FIG. 13 according to the method of the present invention. [Figure 15] FIG. 15 is a photograph of the components taken with a standard camera. [Figure 16] FIG. 16 is a front view of a detail of the system of FIG. [Figure 17] Figure 17 is a schematic side view of a general system for the manufacture of a component of an aerosol-generating article. (Figure 18) Figure 18 shows a flow chart of the method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0089] A general system for the manufacture of components 50 for aerosol-generating articles is shown in FIG. 17 and is generally designated 20.

[0090] Component 50 is represented diagrammatically in Figures 6 and 7. Component 50 is rod-shaped and defines a longitudinal axis 51. Component 50 includes a first end 52 and a second end 53, one opposite the other. First end 52 is shown in a front view in Figure 6.

[0091] Component 50 includes an aerosol-forming substrate 54, indicated by a dot on component 50. Within aerosol-forming substrate 54, a susceptor 55 is inserted.

[0092] As shown in the front view of the first end 52 of the component shown in Figure 15, in this embodiment the aerosol-forming substrate 54 includes a medium loaded with gel. The medium may be cotton. Figure 15 shows the medium 56, a portion of the gel 57 separated from the medium 56, a hole 58 (i.e., a volume that does not contain any elements), and a susceptor 55. As can be seen from this image of Figure 15 taken with a standard camera, the susceptor 55 is barely visible and may be confused with other elements such as the hole.

[0093] In the general side view illustration of FIG. 17 , the system 20 includes a first polarization camera 4. The first polarization camera 4 is adapted to generate a first image defining a first field of view and including information regarding the polarization of the electromagnetic radiation detected by the camera. The first polarization camera 4 is positioned such that a first end 52 of a component conveyed by the conveyor belt 2 falls within the field of view of the first polarization camera 4. For example, the first polarization camera is positioned in front of the first end 52 of the component 50. Additionally, the system 20 includes a source of electromagnetic radiation 6 for illuminating the first end 52 of the component 50.

[0094] In Figure 1, a first embodiment of a general system 20 is designated by the reference numeral 1. The same reference numerals are used to indicate the same elements as described with reference to the system 20 of Figure 17.

[0095] 1 includes a moving element, such as a conveyor belt 2, adapted to carry components 50. The components 50 are mounted on the conveyor belt 2 with their longitudinal axes 51 substantially parallel to one another. The system 1 further includes a first polarization camera 4. The first polarization camera 4 defines a first field of view and is adapted to generate a first image that includes information regarding the polarization of electromagnetic radiation detected by the camera.

[0096] The first polarization camera 4 is positioned such that a first end 52 of the component transported by the conveyor belt 2 can be in the field of view of the first polarization camera 4 during the movement of the conveyor belt 2. In the illustrated embodiment, the component 50 is aligned such that the first polarization camera 4 forms a field of view at an angle of approximately 0 degrees, i.e. parallel, to the surface of the first end 52 of the component 50. The system 1 also includes a mirror 5 to split the optical path of the electromagnetic radiation coming from the component 50 into two components. In this way, the first polarization camera 4 can be mounted perpendicular to the longitudinal axis 51 of the component 50 (i.e. the central optical axis of the first polarization camera and the longitudinal axis 51 of the component 50 are perpendicular), providing a compact solution. The mirror 5 can be movable so that possible inaccuracies in the relative position of the component 50 can be corrected without the need to move the first polarization camera 4. The system 1 also includes a first electromagnetic radiation source 6 adapted to illuminate the first end 52 of the component 50. The first source 6 may emit only one specific wavelength. The first source preferably emits white light. An example of the first source 6 can be an LED spotlight that flashes a bright white light. The first source 6 can be constituted by one, preferably several spotlights, or an LED ring light, arranged to obtain a uniform light and a specific illumination angle.

[0097] The system 1 includes a control unit 30 adapted to control the first polarization camera 4 and to refine a first image generated by the first polarization camera 4 .

[0098] In figures 2 and 16, a second embodiment of the general system 20 is shown with reference number 40. The same reference numbers are used to indicate the same elements described with reference to system 1 in figure 1. The difference between system 1 and system 40 lies in the moving elements. Instead of a conveyor belt, component 50 is located in a drum 8 that rotates in the direction indicated by arrow 9. The first polarization camera 4 is placed on one side of the drum 8 such that a first end 52 of component 50 is in the field of view of the first polarization camera 4 while the drum 8 rotates. The drum 8 may be part of a combiner. As shown in figure 16, preferably system 40 also includes a mirror 5 that is used to direct the electromagnetic radiation arriving from component 50 to the first polarization camera 4. A first source 6 may also be present in system 40 (not shown in figures 2 and 16).

[0099] In FIG. 3, a third embodiment of the general system 20 is shown with reference numeral 60. The same reference numerals are used to denote the same elements described with reference to the system 1 in FIG. 1. The system 60 includes a first polarization camera 4 and a second polarization camera 7, which is preferably identical to the first polarization camera 4. The second polarization camera 7 is adapted to generate a second image of the first end 52 of the component 50, including polarization information for each pixel. The second polarization camera 7 defines a field of view. In FIG. 3, the central axis 14 of the field of view of the first polarization camera 4 and the central axis 17 of the field of view of the second polarization camera 7 are shown. As shown, the first polarization camera and the second polarization camera are positioned such that one is slightly horizontally offset from the other, i.e., the central axes of the respective fields of view form an angle therebetween. In this way, the first and second images of the first end 52 of the component 50 generated by the first and second polarization cameras, respectively, are taken from different angles. By overlaying the first and second images, a "stereoscopic" combined image can be created that contains many more three-dimensional features than either the single first or second image. In this manner, three-dimensional structures located at the first end 52 of the component 50 can be made discernible.

[0100] The second polarization camera 7 is also controlled by the control unit 30 and the second image may be refined by the control unit 30 .

[0101] In FIG. 4, a fourth embodiment of the general system 20 is shown with reference numeral 70. The same reference numerals are used to denote the same elements as described with reference to the system 1 of FIG. 1. The system 70 includes a third polarization camera 11 adapted to generate a third image of the second end 53 of the component 50. Thus, while the conveyor belt 2 moves, the first polarization camera 4 generates a first image of the first end 52 of the component and the third polarization camera 11 generates a third image of the second end 53 of the component. The first and third images are preferably taken simultaneously. Thus, misalignment of the susceptor 55 at the first end 52 and the second end 53 can be detected.

[0102] The third polarization camera 11 is also controlled by the control unit 30 and the third image may be refined by the control unit 30 .

[0103] In Fig. 5, a fifth embodiment of the general system 20 is indicated with the reference numeral 80. The system 80 includes the same elements as the system 70 of Fig. 4, and further includes an additional X-ray imaging unit 12. The X-ray imaging unit 12 is suitable for taking a non-destructive image of the component 50 over the entire length of the component 50 between the first end 52 and the second end 53. The X-ray imaging unit 12 is adapted to generate an X-ray image. The X-ray image may visually show different densities, and thus the resolution and gradation of individual elements such as paper, cotton, gel, holes, tobacco, and susceptors within the component 50 can be obtained.

[0104] The X-ray imaging unit 12 is also controlled by the control unit 30, and the X-ray image may be refined by the control unit 30. The X-ray imaging unit 12 may also fit into the systems 1, 40, 60, 70.

[0105] The systems 1, 40, 60, 70 or 80 operate according to the method of the present invention illustrated generally in FIG.

[0106] A number of components 50 are placed on a movable element such as a conveyor belt 2 or a drum 8 in step 100, with their longitudinal axes 51 parallel to each other. While the movable element 2 or 8 moves, a first end 52 of each of the components 50 successively enters the field of view of the first polarization camera 4 in step 101. In the same step 101, a second end 53 of the component may enter the field of view of the third polarization camera 11. In step 102, the first end 52 is illuminated by a first light source 6. The first light source 6 may be switched on by the approach of the component. In step 103, a first image of the first end 52 is generated by the first polarization camera 4. In the same step, a third image of the second end 53 may be generated by the third polarization camera 11. A first image 90 is formed by a number of pixels. Each pixel contains the polarization information of the electromagnetic radiation arriving from the first end of the component. An example of the first image 90 is shown in FIG. 8. In this image, each pixel indicates a value of polarization along a given direction. Since there are four directions of polarized light, each pixel provides a value for the polarized light along one of these four directions. A third image (not shown) having the same characteristics of the first image 90 can be generated for the second end 53. Another example of the first image 90 is shown in FIG.

[0107] In step 104, the control unit 30 refines the first image 90 to generate a refined image 91. The refined image is shown in FIG. 9. The refined image 91 for each pixel may show the DOP of the electromagnetic radiation detected by the first polarization camera 4. The same refinement can be performed for the third image. In FIG. 9, it is clear that the susceptor 55 is more visible in the refined image 91 than in the first image 90. The refined image 91 can be further refined in step 105 using standard machine vision algorithms to obtain a further refined image 92 as shown in FIG. 10. These algorithms may include one or more of blob detection, edge detection, region growing. From the further refined image, in step 106, the position of the susceptor 55 can be identified.

[0108] Another example of the refinement of the first image 900 acquired by the first polarization camera 4 is illustrated with reference to Figs. 11 to 14. Fig. 11 is a first image 900 in which each pixel indicates the value of the polarization along a given direction. Since there are four directions of polarization, each pixel gives the value of the polarization along one of these four directions. The refined image 901 of Fig. 12 for each pixel may indicate the DOP of the electromagnetic radiation detected by the first polarization camera 4. A rectangle is used to highlight the location of the susceptor 55. The image 901 of Fig. 12 may be further refined with a further refined image 902 of Fig. 13 to further strengthen the definition of the susceptor. In Fig. 14 a segmented image 903 of the first edge 52 of the component is shown. The susceptor 55 is identified and located at the first edge 52.

Claims

1. 1. A method for optical analysis of a component of an aerosol-generating article, the method comprising: providing a component of an aerosol-generating article defining a first end and a second end, said component comprising: - an aerosol-forming substrate; comprising a susceptor in thermal contact with said aerosol-forming substrate; providing a first polarimetric camera including a sensor for detecting the polarimetric information of electromagnetic radiation; - irradiating said component with electromagnetic radiation; - detecting, by said first polarized camera, electromagnetic radiation transmitted, reflected or refracted from said component; generating a first image of the first end of the component with the first polarization camera, the first image being formed by a plurality of pixels, each pixel of the plurality of pixels containing polarization information about the detected electromagnetic radiation; and detecting the position of said susceptor in said first image.

2. said polarization information in said first image, degree of polarization; or The method of claim 1 , comprising estimating from: a polarization angle.

3. The first polarization camera defines a first field of view having a first central axis, and the method includes: providing a second polarization camera including a sensor for detecting polarization information of electromagnetic radiation, said second polarization camera defining a second field of view having a second central axis, said second central axis forming an angle with said first central axis different from zero; - detecting electromagnetic radiation transmitted, reflected or refracted from said component by said second polarized camera; generating a second image of the first end of the component with the second polarized camera, the second image being formed by a plurality of pixels, each pixel of the plurality of pixels containing polarization information about the detected electromagnetic radiation; - combining the polarization information contained in the first image with the polarization information contained in the second image to obtain a single combined image of the first end of the component.

4. providing a third polarimetric camera including a sensor for detecting the polarimetric information of the electromagnetic radiation; - detecting electromagnetic radiation transmitted, reflected or refracted from said component by said third polarized camera; generating a third image of the second end of the component with the third polarization camera, the second image being formed by a plurality of pixels, each pixel of the plurality of pixels containing polarization information about the detected electromagnetic radiation; The method of claim 3, further comprising: detecting the position of the susceptor in the third image.

5. - irradiating said component with a first electromagnetic radiation; - detecting, by said first polarized camera, a first electromagnetic radiation transmitted, reflected or refracted from said component; generating the first image of the first end of the component, the first image being formed by a plurality of pixels, each pixel of the plurality of pixels comprising polarization information relating to the detected first electromagnetic radiation; - irradiating said component with a second electromagnetic radiation different from said first electromagnetic radiation; - detecting, by said first polarized camera, a second electromagnetic radiation transmitted, reflected or refracted from said component; generating a fourth image of the first end of the component by the first polarization camera, the fourth image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information related to the detected second electromagnetic radiation; - combining the polarization information contained in the first image with the polarization information contained in the fourth image to obtain a single combined image of the first end of the component.

6. the component defines a longitudinal axis, the first polarization camera has a first field of view, and the method comprises: - Providing mobile transport; - positioning a plurality of components on said movable transport with their longitudinal axes substantially parallel to one another; A method according to any one of claims 1 to 5, comprising generating the first image of the first edge for a portion of the plurality of said components that falls within the first field of view of the first polarized camera by the movement of the movable support.

7. the component defines a longitudinal axis, the first polarization camera has a first field of view, and the method comprises: - Providing drums; - positioning a plurality of components on said drum with their longitudinal axes substantially parallel to one another; - rotating said drum; A method according to any one of claims 1 to 6, comprising generating the first image of the first edge for a portion of the plurality of components that fall within the first field of view of the first polarized camera by the rotation of the drum.

8. The method according to one or more of claims 1 to 7, comprising discarding said components based on said position of said susceptor.

9. 1. A system for manufacturing a component of an aerosol-generating article, the component comprising: - Longitudinal axis; - a first end and a second end; - an aerosol-forming substrate; a susceptor in thermal contact with said aerosol-forming substrate. The system further comprises: a first electromagnetic radiation source adapted to irradiate said component; a first polarization camera including a sensor for detecting polarization information of electromagnetic radiation, the first polarization camera defining a first field of view, the first polarization camera being positioned such that the first end of the component is within the first field of view, the first polarization camera being adapted to generate a first image of the first end of the component, the first image being formed by a plurality of pixels, each pixel of the plurality of pixels including polarization information of the electromagnetic radiation detected by the first polarization camera; a control unit adapted to process said first image and to detect the position of said susceptor in said first image.

10. A system according to claim 9, comprising a moving element adapted to move a plurality of components arranged with their respective longitudinal axes parallel to one another.

11. The system of claim 9 or 10, comprising a rejection unit adapted to reject the component based on the position of the susceptor.

12. The system of claim 10 , wherein the moving element comprises a drum or a conveyor belt.

13. A system according to one or more of claims 9 to 12, wherein the source of electromagnetic radiation comprises a strobe light adapted to illuminate the component at a given frequency.

14. The system of claim 13 , wherein the strobe light includes optics for focusing the electromagnetic radiation onto the component.

15. The system according to one or more of claims 9 to 14, comprising a second electromagnetic radiation source adapted to irradiate the component, the second electromagnetic radiation source being different from the first electromagnetic radiation source.

Images