Patent Description:
Electronic cigarettes based on aerosol-generating consumable articles have gained popularity in the recent years. There are mainly two types: liquid vaporizers and heated tobacco inhaler devices. Heated tobacco inhaler devices are referred to as "heat-not-burn" systems (HNB). They provide a more authentic tobacco flavour compared to electronic cigarettes, which deliver an inhalable aerosol from heating of a liquid charge comprising aerosol formers, flavorants, and often nicotine. The HNB system's working principle is to heat a tobacco material comprising an aerosol-forming substance (such as glycerine and/or propylene glycol) which vaporises during heating and creates a vapour that extracts nicotine and flavour components from the tobacco material. The tobacco substance is heated to between <NUM> and <NUM>, which is below the normal burning temperatures of a conventional cigarette. The inhaler device is typically a hand-held heater, which is configured to receive rod-shaped consumable articles.

Illicit trade of aerosol-generating articles, be it standard cigarettes, e-liquids, or HNB articles, is a problem, as counterfeit articles in particular may be of inferior quality or, may not be suited to a specifically dedicated aerosol-generating system. In order to identify if an aerosol-generating consumable article is an authentic one, a code or equivalent marking containing information about the article may be arranged onto an outer surface of the article, for it to be detected in use or prior use with a certain device. This allows to check for authenticity of the consumable article and in case of negative check, to provide an appropriate control, such as to power off the heating system with which it is used.

Moreover, there may be also a need for distinguishing a consumable article from another article for the purpose of adapting the aerosol generating conditions. For example, certain consumable articles within a range of articles may contain different constituents (e.g. different tobacco blends, forming agents, nicotine levels, etc.) which so require different parameter settings for the device to optimize the consumer experience.

To provide accurate authentication of a code on a consumable article such as an HNB article, the recognition probability should be very high so that suitable articles will not be rejected. However, existing indicia are limited by the low density of information that they may be contained, and most known indicia rely on conventional codes such as <NUM>-Dimensional or <NUM>-Dimensional barcodes that may be easily be forged.

Various attempts at providing authenticatable aerosol-generating articles have been proposed in the prior art already.

<CIT> discloses an aerosol generating apparatus having a cavity for receiving an article (such as aerosol-generating consumable article). The article has marker elements arranged in the form of lines on its outer surface. The marker elements consist of an encoded parameter associated with the article. The apparatus includes a sensor arrangement to monitor the marker elements (such as indicium) after the article has been inserted in the cavity, i.e. when the article does not undergo any movement anymore. The apparatus comprises an optical sensor arrangement and a non-optical sensor arrangement such as capacitive sensor to monitor the presence of these markers. Due to lack of space only simple markers can be arranged over a small length , limited to low density information. In the optical configurations light has to be directed with several light sources that have to be arranged with an array of detectors, which is cumbersome and leading to easily reproducible codes. <CIT> also describes that in the case optical sensors are used they must have a certain field of view to detect markers.

In another document <CIT> a small camera having a wide field of view is implemented to read a code on an article that has been fully inserted into a cavity of an aerosol generating device. The system described in <CIT> requires a wide field of view lens to assure that the image of a significant portion of the surface of the smoking article is required, so that the image covers at least the area of the code. Implementing a vision camera requiring a uniform illumination system and a very wide aperture lens to cover the angular span of a code on an article is cumbersome and expensive. Also, as the system may only capture one side of a smoking article it requires a precise angular orientation of the inserted article relative to the optical axis of the vision system. In order to avoid a user to have to turn the smoking article so that the code comes into the view angle of the imaging system, <CIT> discloses an embodiment based on a mirror system which would lead to a complex system that is not adapted for low cost smoking devices and their inserted smoking articles.

<CIT> discloses a tubular aerosol-generating article, marked with an identifier. The identifier is arranged on the inner surface of the article or can be anywhere. The tubular aerosol generating article comprises a mouthpiece, a proximal end and a distal end configured to receive the heating portion of the main unit. The identity of the tubular aerosol-generating article comprises a sensor system and the detection is done by optical scanner and electric circuitry. The system disclosed in <CIT> is limited to either a variation of an intensity or change of electrical current or resistive information when a stick has been introduced. For example, the system may detect a single resistance value that may be compared by values stored into a lookup table. Therefore, the system is limited to low density codes and would be easy to reproduce.

<CIT> discloses an inhaler for heated cigarette rods (such as consumable article), having an indicium which is only readable by the optical reader after the consumable has been exposed to a temperature exceeding a temperature threshold. The system is limited to detect of the consumable has been overly heated or has been used a second time. Due to lack of space, only simple codes can be detected by the system, or the detection has to be done by the human eye which checks if the code on the articles has been altered. There is thus a need for an improved technique to allow authentication of aerosol-generating articles such as HNB, vaping and smoking articles. In particular, authentication based on codes that comprise a much higher information density detectable by a- non cumbersome detection system would be preferable to improve authentication quality and harden counterfeiting of the articles.

Also, the use of complex detection and/or imaging optics to detect complex codes should be avoided. Imaging optics to detect complex codes require most often complex or voluminous optical paths and optical parts, which lead to devices that are too heavy or which have unacceptable dimensions. Also, the use of chemicals, in the form of liquids or gases, to realize indicia have to be avoided during the manufacturing process of a consumable article.

The inventors of the present invention have found solutions to the above-discussed problems by providing an authentication method that simplifies the detection system required to detect indicia, by using the insertion movement of an aerosol-generating article into an aerosol-generating device. The invention profits of the insertion movement of a consumable article into an aerosol-generating device, which is a movement that has to occur anyhow at consumption of an article.

In a first aspect the invention is achieved by a method according to claim <NUM>.

The detection may require the movement of insertion being an accelerated movement or a movement having a constant speed. By detecting an indicium during the introduction movement of a coded indicium, allows to use an indicium that may have a considerable length on a consumable. This allows to provide a distributed code that may be read by a simple and non-voluminous detector system that is arranged in a reduced space next to or along a cavity of an aerosol-generating device Also, the indicium may have a length that is much larger than the width of the detection area defined at a surface of a consumable. Furthermore, as the detection is performed while the indicium is in movement, optical sensors with relatively narrow field of view to detect the markers can be used or optical sensors that do not require focusing or redirecting optical elements, e.g. micro lenses or mirrors.

In an embodiment, the indicium is made of an array of optical layers arranged in the insertion length of the article. The layers may be aligned along a line parallel to the insertion direction. The layers are separated by a distance which may be constant or variable between neighbouring layers.

In advantageous embodiments, the layers:.

The indicium detection system may comprise several optical detectors. Using more than one indicium layer allows to enhance the authentication detection probability of a consumable. In variants, indicia may be arranged in different orientations which must not be necessarily the direction of the insertion of an article. Preferably, the insertion length of the article corresponds to the longitudinal direction of extension of the article. If the article is a rod-shaped article, the longitudinal direction is the central axis of the article.

In an embodiment at least two of said optical layers have different optical transmission or reflection properties. Such layers must not be parallel layers and may present an angle relative to each other. The layers may also be crossing layers or layers arranged in a matrix arrangement, or layers that are arranged according to a helicoidal arrangement over a length on the circumference of an article. By using optical layers as indicia that have different optical properties it is possible to complexify the identification code of a consumable and make the detection of the embedded code information more difficult. It allows also to provide a denser code information, such as information related to the desired parameters of operation of a device.

In an embodiment an indicium or indicium layer may be made of an array of electrically conductive layers arranged in the length of said insertion direction Z and wherein said indicium detection system comprises at least one electrical detector. Similar detection methods as the ones used in the case of optical detection schemes may be applied, such as the use of conductive conical shaped indicia.

In an embodiment said conductive layers are metallic layers. Thin metallic layers such as thin wires may be easily integrated in an article. These layers may be arranged for example as an array of metallic wire parts. Metallic wires or layers may have a rigidifying function. Because of their rigidity metallic wires or layers may be easily introduced into the article for example in glue or bond or as separation layers on an article.

In an embodiment said conductive layers are conductive ink layers. Applying conductive ink layers may be applied by deposition that are easily adaptable to the manufacturing of articles. For example, the ink layers are deposited as thin metal film onto the surface of the article by evaporation under vacuum. Using ink layers allow to provide bar-code type indicia which may be read sequentially in the insertion direction of an article during its insertion in an aerosol-generating device. In variants, glue or seam or bond layers may comprise conducting dopants or particles to provide an at least partial electrically conductive property to the layer.

In embodiments, said conductive layers may be layers made of intrinsic conducting polymers (ICP). This allows to provide conductive layers that do not contain metallic compounds or metallic particles. In variants, different types of conductive layers may be implemented on or into the same consumable article <NUM>.

In embodiments the detection may be based on the detection of electrical and/or magnetic properties of the indicium. Electrical detection methods may be based on the detection or measurement of a capacitance, an inductance, or a resistance. Using electrical and/or magnetic detection of a moving indicium is simpler than optical detection because it requires less space.

In an embodiment the detector is configured to detect an electrical capacitance and/or an inductance effect between said conductive layers and said electrical detector. Using a method to detect and measure electrical effects provided by an indicium, one may provide simpler detection than optical detection, as they are less sensitive to surface contaminations. In variants, optical detection may be combined with electrical detection. In an embodiment said indicium detection system comprises more than one electrical detector and more than one optical detector. By using a combination of different detection methods such as combining electrical and optical detection of a code while introducing an article in a device it is possible to complexify the code imbedded in an indicium considerably and impose more data encoding requirements.

In an embodiment said electrical detector is configured to detect an electrical resistance between said conductive layers and said electrical detector. For this, the electrical detector contacts the indicium for the detection of a resistance. The electrical contacts may be flexible to ensure increased adaptability between the article and the detection system.

In an embodiment the indicium is made of an array of magnetic layers arranged in the length of said insertion direction Z, and wherein said indicium detection system comprises at least one magnetic detector configured to detect a magnetic field generated by said magnetic layers. Using magnetic detection methods allows to provide a detection method that is quite insensitive to particle or moisture contamination of the detection system.

In an embodiment said the article comprises an indicium made of at least a first and a second array of detectable layers that are parallel and extending in said the insertion direction Z. The signals provided by each of the first and second arrays of detectable layers provide at least two signals S1, S2 that may be detected by a single detector or a plurality of detectors. In variants a first detector is configured to provide a first signal S1 and a second detector is configured to provide a second signal. In variants said at least a first and a second array of detectable layers may be layers that present an angle relative to each other and may be crossing layers.

Preferably, the signals S1, S2 provided by each of the first and second arrays of detectable layers are detected by at least one optical detector and are superposed to provide a superposed signal S3 that provides a unique identification code identifying the aerosol-generating consumable article. Using a configuration wherein at least two different codes are superposed allows to make the detection system independent of the acceleration of the insertion movement of an article into a device. So, in an advantageous variant said indicium may comprise at least one electrically detectable layer and at least one optically detectable layer, both layers being separately arranged in parallel along the insertion direction Z, said indicium detection system comprising at least one electrical detector and at least one optical detector.

In variants, additional information on the article may be retrieved during the movement of withdrawal of the article <NUM> out of said aerosol-generating device.

In a second aspect the invention is achieved by an aerosol-generating device according to claim <NUM>.

Preferably the movement is executed from a proximal end to a distal end thereof. The detection system may comprise a single detector and may comprise a slit arranged in front of the detector, allowing to provide a simple detection system that relies on the detection of varying optical and/or optical effects, such as varying light intensities provided by the passing of the indicium in front of the detector system. In other variants the detector system comprises an imaging system to provide an image of the indicium or a portion of it while it passes in front of the detection system at the introduction of the consumable article in the aerosol-generating device.

In variants the detector is an electric and/or magnetic detector and is configured to detect and/or measure the value or variation of: an electrical capacitance, an inductance a magnetic field, a resistance, an electric field, an electrical potential, an electrical current, a micro-electrical discharge. In variants the device comprises a microwave source and the detector is a microwave detector.

There is also provided an aerosol-generating article for aerosol generating device comprising a cavity; the article defining an insertion direction Z and comprising at least one indicium containing coded information about the article, said indicium being arranged in the insertion direction Z, for being read by an indicium detection system of an aerosol-generating device upon insertion of said aerosol-generating article in the cavity as the article moves in or through the aerosol-generating device. In embodiments the article comprises different types of layers as described above. In a variant a first layer is optical detectable, and a second layer is electrically detectable by said detection system. Also, in variants during insertion of the article in a device an optical detection signal may be provided, in function of time, before or after an electrical detection signal. In another configurations, a layer is made of a fist layer comprising a plurality of first layer elements and a second layer comprising a second array of second layer elements. The layer may be arranged as a sequence of successive first and second layer elements. In variants said first layer and said second layer are arranged on a common longitudinal axis, or in parallel in contact or in close proximity. In advantageous embodiment said first and/or second layer is partially optically detectable and partially electrically detectable.

The invention is also achieved by an aerosol-generating system according to claim <NUM>.

The present invention will be described with respect to particular embodiments and with reference to the appended drawings, but the invention is not limited thereto. The drawings described are only schematic and are nonlimiting. The dimensions and the relative dimensions do not correspond to actual reductions to the practice of the invention.

The invention will be described in the following examples in relation to tobacco-based consumable articles but the scope of the invention shall not be construed as limited to tobacco based consumable articles but shall encompass any aerosol-generating consumable articles, such as smoking articles, heat-not-burn articles, e-liquid cartridges and cartomizers, which comprises an aerosol-generating substrate capable to generate an inhalable aerosol upon heating. Aerosol-generating articles <NUM> of the invention are also defined herein as articles or consumables or consumable articles.

As used herein, the term "aerosol-generating material" refers to a material capable of releasing upon heating volatile compounds, which can form an aerosol. The aerosol generated from aerosol-generating material of aerosol-generating articles described herein may be visible or invisible and may include vapours (for example, fine particles of substances, which are in a gaseous state, that are ordinarily liquid or solid at room temperature) as well as gases and liquid droplets of condensed vapours. Detailed composition of the aerosol generating substance may be tobacco, aerosol formers, binders, flavouring agents, nicotine and combinations thereof. An aerosol-forming substrate may be provided in a stable support. Such a support may be in the form of a powder, granules, strands, small strips, sheets or foam.

The term "wrapper" is defined broadly as any structure or layer that protects and contains a charge of aerosol-generating material, and which allows to handle them. It has an inner surface that may be in contact with the aerosol-generating material and has an outer surface away from the aerosol-generating material. The wrapper <NUM> may preferably comprise a cellulose based material such as paper and/or cellulose acetate. The wrapper <NUM> may also be made of a biodegradable polymer or may be made of glass or a ceramic, and/or cellulose acetate. The wrapper <NUM> may be a porous material and may have a smooth or rough outer surface <NUM> and may be a flexible material or a hard material.

The manufactured aerosol-generating consumable article <NUM> may have a cross section of any regular or irregular shape, and can have, for example, an elliptical or circular cross-section, defined in a plane orthogonal to a longitudinal axis.

Herein the term "indicium" is a broad term that encompasses any layer or structure or element or configuration or layer or any geometrical and/or physical and/or or chemical property that may be used to identify the aerosol-generating article. The indicium is meant to be an element applied to or part of the aerosol-generating article that has the ability to de detected or read by a detection device for providing a signal of analog or digital form.

The indicium of the invention is particularly configured to be readable during the introduction movement of the indicium in a device, by passing typically in front of or next to a detector system <NUM>.

Information in the indicium may be encoded in digital (e.g. binary) or analog manner.

As used herein, the term "electrical effect" encompasses any effect produced by an electrical field or resistance of voltage or current or magnetic or induction effect. As used herein "an optical effect" encompasses any of: a colour, an intensity, a polarisation, a spectral, an interferometric, a transmission, a deviation or a reflection effect.

There is provided a method to identify coded information arranged on an aerosol-generating consumable article <NUM>. The article <NUM> defines an insertion direction Z and comprises at least one indicium <NUM> containing coded information about the article <NUM> arranged on or inside said article <NUM>.

It is understood that a movement of the aerosol-generating article may be realized after the full insertion of the article in said cavity. The movement may be, for example, any back-and-forward movement of the aerosol-generating article after it has been inserted in the cavity <NUM>.

The detection of the indicium <NUM> is realized by any optical and/or electrical effect as defined before. The detection of the indicium <NUM> is fully finished when the aerosol-generating article <NUM> does not move anymore. In variants additional information on the article <NUM> may be retrieved during the movement of withdrawal of the article <NUM>.

Indicia <NUM> may have a continuous shape (<FIG>, <FIG>) in the length of an article or may be arranged according to a plurality of indicia elements <NUM>-<NUM> (<FIG>, <FIG>, <FIG>).

In an embodiment said indicium <NUM> is made of an array of optical layers arranged in the length of said insertion direction Z, and wherein said indicium detection system <NUM> comprises at least one optical detector <NUM>, <NUM>. As further described, and illustrated in <FIG>, a detector system <NUM> may comprise two different detectors. In an embodiment at least one of said two detectors <NUM>,<NUM> may be a non-optical detector. For instance, a first detector is an optical detector and a second detector is an electrical detector, e.g. a capacitive, inductive or resistive detector.

Layers that may be used as a code or a support of an indicium <NUM> are advantageously chosen amongst article layers such as one of: glue layers, bond, seam, separation layers, joining layers, overlapping layers. A layer may have also a single function as support layer of an indicium or array of indicia.

In advantageous embodiments indicia <NUM> are realized onto or into layers that may have typically one of the functions of:.

Indicia may also be arranged on parts or inserts or layers that are incorporated into or onto an article for the mere purpose of proving an indicium.

In variants, a layer of an article may be used as an indicium <NUM>. Indeed, it is understood that typical manufacturing layers of an article <NUM>, such as a paper wrapper or a glue layer, may be manufactured so that they conform to a predetermined shape, such as a triangular shape that may be identified during the introduction of an article in a device. The shaped part of such a layer may thus be used as an indicium <NUM> without requiring an added indicium layer onto or into an article <NUM>.

In variants (not illustrated), an indicium <NUM> may be formed by at least two straight lines or stripes that are arranged according to an angle relative to a longitudinal axis of an article <NUM>. For example, an indicium <NUM> may comprise two thin lines or strips that are separated by a small distance or be in contact at the side of the consumable portion of an article, and having a greater separation at the side to the mouthpiece of an article. Such lines or stripes may have a curved shape and/or have a variable width. Said at least two straight lines or stripes may have an angle relative to each other or may even be crossing lines or stripes. In variants an indicium may comprise two thin lines that present a relative angle of less than <NUM>°, preferably less than <NUM>°, which is difficult to detect by the un-aided human eye. Such variant can also be combined with the embodiment of <FIG>, further described, that comprises an additional longitudinal code, possible a bar code extending in the length of said two lines or strips.

In variants of all embodiments herein, the layers <NUM> may have at least one of the following characteristics:.

Indicia <NUM> may also be formed by a chemical treatment of a portion of a layer of a consumable <NUM>. For instance, a predetermined surface area of a wrapper may undergo a chemical etching or vapor deposition this partially etched or vapor deposited area may serve as an indicium <NUM>. For example, etching may be used to realize a seam layer that has a variable width along a length of an article so that it may be detected when the article is introduced along a central axis <NUM> of a cavity of a device.

In variants, indicia <NUM> may be formed by a thickened predetermined area of a surface of an article <NUM>.

In an embodiment, an indicium <NUM> may be formed by at least two optical or electrical layers <NUM>, <NUM>' that have different optical transmission or reflection properties, or different electrical properties.

In an embodiment said indicium <NUM> is made of an array of successive conductive layers arranged in the length of said insertion direction Z and wherein said indicium detection system <NUM> comprises at least one electrical detector <NUM>.

In an embodiment said conductive layers are metallic layers. In an alternative, the layer is a graphite layer or a conductive ink layer. In variants a layer of an article may have a directional conductivity. For example, the conductivity may be different in two orthogonal directions. This may be realized for example by directional doping of the layers.

In an embodiment said conductive layers are conductive ink layers <NUM>.

In embodiments, said conductive layers may be layers made of intrinsic conducting polymers (ICP). This allows to provide conductive layers that do not contain metallic compounds or metallic particles.

In variants, different types of conductive layers may be implemented on or into the same consumable article <NUM>.

In an embodiment said electrical detector is configured to detect at least electrical capacitance between said conductive layers and said electrical detector.

In an embodiment said electrical detector is configured to detect at least electrical inductance generated between said conductive layers <NUM> and said electrical detector.

In an embodiment an electrical detector <NUM> of the invention is configured to detect at least an electrical resistance between said conductive layers <NUM> and said electrical detector.

In an embodiment said indicium <NUM> is made of an array of magnetic layers <NUM> arranged in the length of said insertion direction Z, and wherein said indicium detection system <NUM> comprises at least one magnetic detector configured to detect a magnetic field generated by said magnetic layers.

In an embodiment, illustrated in <FIG> said indicium <NUM> is made of at least a first array <NUM>' and a second array <NUM>" of detectable layers that are both extending along or parallel to said insertion direction Z. As schematically illustrated in <FIG> the signals S1, S2 provided by the optical or electrical effect each of said at least a first array <NUM>' and a second array <NUM>" of detectable layers are detected by at least one detector <NUM>, <NUM>' and are superposed to provide a superposed signal S3 that provides a unique identification code identifying the aerosol-generating consumable article <NUM>. Said detector <NUM>, <NUM>' may be an optical or electric or magnetic sensor but may also be a sensor that is configured to measure optical and electrical effects at the same time. For example, a sensor may detect a polarisation state and at the same time be configured as a Faraday effect sensor wherein the polarisation state changes upon an induced current, for example induced in a metallic layer or wire.

<FIG> illustrates a detailed view of two superposed signals S1, S2. The signal shape of the superposed signal S1+S2 presents a unique shape which is independent of the acceleration of the insertion movement of an article, as may be seen by comparing the shapes of the signal S1+S2 at speeds different V1 and V2 as illustrated in <FIG>. The shape of the signal S1+S2 at a speed V2, which is greater than the speed V1, is identical. For example, even if the introduction movement of the article in a device is an accelerated movement, it is still possible to determine the over-all shape of the superposed signal S1+S2 , for example by counting the number of peaks and valleys.

In variants, detector schemes may be implemented to detect and correct for sudden backward movement , i.e. in the -Z direction, i.e. away from the end 2b of the cavity <NUM>. Such correction techniques are well known in the field of rotational or linear encoders and are not further described here.

In an embodiment wherein said indicium detection system <NUM> comprises at least one electrical detector <NUM> and at least one optical detector <NUM>.

In advantageous variants, illustrated in <FIG>, said indicium <NUM> comprises at least one electrical detectable layer 10a and at least one optical detectable layer 10b, both layers being arranged along or parallel to said insertion direction Z, said indicium detection system <NUM> comprising at least one electrical detector <NUM> and at least one optical detector <NUM>. In a variant of the configuration of <FIG>, said indicium <NUM> comprises at least two different optical detectable layer 10a, 10b and the two detectors <NUM>, <NUM> are different optical detectors. A detector <NUM>, <NUM> may be detector comprising a color filter or an interference filter. In all embodiments of the invention an optical detection system <NUM> may comprise optical means to measure spectral characteristics, such as a spectrometer or refractive or diffractive dispersion elements. An optical detection system may comprise mirrors to send collected light to a detector <NUM>, <NUM> that is placed at a distance to the portion of the layer that provides optical information such as its spectral characteristic. In a variant a detector may be arranged to a distal end 2b of the cavity <NUM>.

In embodiments the indicium may be made so that it comprises at least two codes that may be codes that have a predetermined angle. For example, <FIG> illustrates a conical shaped indicium that has a varying width. A code, such as a bar-code , may be incorporated into or onto the layer of the indicium so that not only the longitudinal distribution of code elements constitutes a readable code, but the code may be complexified by adding information on the variation of the width of the indicia, as illustrated schematically in <FIG>.

In an advantageous variant, an indicium may have a wedge shape and at least one of its sides may comprise step structure such as illustrated in the example of <FIG> illustrates how a first signal Sz may be provided in relation with the longitudinal distribution of code elements <NUM>, <NUM>, <NUM>, <NUM> of the indicium <NUM>. <FIG> shows exemplary signals Sz1, Sz4, Sz7, Sz10 corresponding to longitudinal-oriented code elements <NUM>, <NUM>, <NUM>, <NUM>. The variations of the widths of the steps of the indicium may provide an addition signal Sy, which maxima area aligned with the centre of the steps as illustrated in <FIG>. The sum of the signals Sx related to the longitudinal code elements and the signals Sy related to the information on the variation of width or presence of steps constitute a code signal S1+S2 that comprises much more information than simpler codes such as the one illustrated in <FIG>.

In variants, to further complexify a code, information on the variable thickness of successive indicia elements having different thicknesses may be provided, such as illustrated in <FIG>. The indicia elements are positioned in an array in the direction of direction Z, e.g. parallel to the longitudinal axis of the article as illustrated in <FIG>. The thickness of each element is determined orthogonally to the insertion direction Z or to a tangent to the surface of the article, e.g. radial to the surface of a rod-shaped article. In variants, indicia elements <NUM>-<NUM> may be realized directly into the material of the layer <NUM>. Indicia may be realized inside or onto at least one side of the material of the layer <NUM> for example by a pressing tool during the manufacturing of an article. The thickness may also vary between two parallel arrays of layers. For example, a first array may have layers with first thicknesses t1, t2, t3 and the second array have layers with second thicknesses t4, t5, t6.

<FIG> illustrates an indicium that is made of a layer that is configured to provide internal reflected light, similar to the reflection inside a prism or a pentaprism. This allows to provide signals that depend on the way an article is introduced in a device, for example it may provide information on the depth of introduction of an article in a cavity <NUM>. The light source <NUM> and the detector system <NUM> in the embodiment of <FIG> may be configured so that it detects a layer <NUM> arranged at the distal end of an article. For example, as long as the distal end comprising the layer does not provide a signal to the detector <NUM>, the device <NUM> may not allow to trigger the start of use of the device <NUM>.

In variants, indicia <NUM> of the invention may have optical properties such as light focusing, light diverging properties. In variants, indicia may provide a signal related to changes of color, polarization and optical scattering effects, or a combination of such optical effects. It is generally understood herein that a variety of detection schemes or imaging methods may be applied to detect and/or image the indicium <NUM> or indicium layer <NUM> of the invention image processing techniques in the invention may be simple contrast enhancing techniques or very advanced. Image processing methods such as used in any high security detection systems, for example as used in banking or in fingerprint recognition. In variants 2D and/or 3D imaging may be used to detect and interpret the information imbedded in the indicium <NUM>. For example, 3D imaging techniques may be used to detect the height variations of indicia elements, such as the elements <NUM>-<NUM> illustrated in <FIG>. In variants, optical depth probes may be applied to detect the indicia. Such probes are optical devices that provide information on a depth or a depth profile of a structures, here an indicium structure. Also, interferometric optical techniques may be used in the detection system <NUM>, <NUM>' of the invention.

Any advanced imaging and/or imaging processing technique may be used to detect an indicium. Image processing comprising feature extraction techniques are well known in the field of 2D and 3D image processing and are not further described here.

It is referred therefor to the following publications:.

There is also provided an aerosol-generating device <NUM> comprising, arranged in an outer body a power supply section (not illustrated) and a cavity <NUM> defining a cavity axis <NUM>, said body having an opening accessible at the outer body and being configured to receive a consumable article <NUM> defining an insertion direction Z.

The aerosol-generating device <NUM> further comprises an indicium detection system <NUM> configured arranged in the device <NUM> to detect said readable code optically and/or electrically during the insertion movement of said article <NUM> into said cavity <NUM> from a proximal end 2a to a distal end 2b thereof.

There is also provided an aerosol-generating article <NUM> defining an insertion direction Z and comprising at least one indicium <NUM> containing coded information about the article <NUM>, said indicium <NUM> and said coded information being arranged along or parallel to said insertion direction Z for being readable by an indicium detection system <NUM> of an aerosol-generating device <NUM> during the movement of insertion of said aerosol-generating article <NUM> into said aerosol-generating device <NUM>.

Claim 1:
Method for identifying coded information arranged on an aerosol-generating consumable article (<NUM>) to be consumed by using an aerosol generating device, the article (<NUM>) defining an insertion direction (Z) and comprising at least one indicium (<NUM>) containing coded information about the article (<NUM>) arranged on or inside said article (<NUM>), the aerosol-generating device (<NUM>) comprising a cavity (<NUM>) arranged for insertion of the article (<NUM>) along the insertion direction (Z) and comprising an indicium detection system (<NUM>), the method comprising:
reading the coded information of said indicium (<NUM>) by the indicium detection system (<NUM>) only during the lapse of time of the movement of insertion of said aerosol-generating article (<NUM>) in the cavity (<NUM>), as the article (<NUM>) is moved in or through the cavity (<NUM>) of said aerosol-generating device (<NUM>).