WO2021122524A1

WO2021122524A1 - An electrically operated smoking device including a system for identifying smoking articles comprising an indicium

Info

Publication number: WO2021122524A1
Application number: PCT/EP2020/086114
Authority: WO
Inventors: Patrick Debergh
Original assignee: Jt International S.A.
Priority date: 2019-12-20
Filing date: 2020-12-15
Publication date: 2021-06-24

Abstract

The present invention relates aerosol-generating system comprising an aerosol-generating device (200) comprising an optical reader system (200) and an aerosol generating article (1) extending along a longitudinal axis (3) and comprising at least one indicium (10) containing information about the article (1) arranged on a surface (5) of said article (1). The indicium (10) comprises at least one array of structures having greatest dimensions smaller than 5μm that are readable upon illumination by the optical reader system (200), said array of structures being arranged according to an optically readable pattern or code, said optical reader system comprising at least one light source (300, 302, 304, 306) emitting light having wavelengths between 250 nm and 5 μm The present invention further relates to an aerosol-generating consumable article (1) comprising at least one indicium (10) containing information about the article (1) arranged on its surface. The indicium (10) comprises at least one array of structures having dimensions smaller than 5μm that are readable upon illumination by an optical reader system (200).

Description

AN ELECTRICALLY OPERATED SMOKING DEVICE INCLUDING A SYSTEM FOR IDENTIFYING SMOKING ARTICLES COMPRISING AN

INDICIUM

Technical field of the invention

The present invention relates to the field of tobacco, in particular to reconstituted tobacco as well as aerosol-generating article. The present invention further relates to smoking devices, especially to an electrically heated e-liquid system or an electrically heated aerosol-generating system.

Background of the invention 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 200 and 400°C, 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, in the case of e-liquids or HNB consumable articles, may not be suited to a determined smoking 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 on 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 power off the heating system with which it is used. 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 may be contained in them, and most known indicia rely on classic codes such as 1 -dimensional or 2-Dimensional barcodes that may be easily be copied without using specific optical instruments, for example by simply visualizing the code by the human eye. Various attempts at providing authenticatable aerosol-generating articles have been proposed in the prior art already. For instance, US20190008206A1 discloses a smoking article comprising an indicium on an outer surface of the smoking article and represents a type of smoking article and may be in the form of pattern or one/two-dimensional barcode. The indicium includes different grey levels that can be generated by printing in dots which have smaller size. Such indicium is easily detectable and reproducible and may contain only a small density of information, or to be provided with an unacceptably large size.

In US20160302488A1 , a smoking article is described comprising an indicium on an outer surface of the smoking article. The indicium may be in the form of one/two dimensional barcodes. The code comprises an identifiable spectroscopic signature but requires the application of a layer by a spray and requires a spectroscope. Also, the signature produced by a spectrum depends on the concentration that may be between 1ppm and lOOOppm, the precision of which is difficult to control. A taggant based on a spectroscopic signature is also linked to a spectroscopic measurement and interpretation and calibration issues that may make the taggant not very reliable and there may be issue related to the stability of such a taggant.

In WO 2019129378A1 an aerosol-generating consumable article is described for an inhaler comprising an indicium containing information about a consumable. The indicium provides information on the temperature threshold as the indicium is altered after it has been exposed to a temperature exceeding the temperature threshold. The indicium is formed from a heat-sensitive composition. The stability of such type of indicium is questionable as a consumable article may be transported in harsh conditions. Also, the indicium is in the form of a simple readable code that is visible to the human eye and the code can thus be easily copied and would have little use as an anti-counterfeit taggant.

There is thus a need for an improved technique to allow authentication of aerosol-generating articles such as HNB, vaping and smoking articles. Authentication based on codes or indicia comprising a much higher information density would be preferable to improve authentication quality and harden counterfeiting of the articles.

Summary of the invention

The inventors of the present invention have found solutions to the above-discussed problems by providing a consumable article comprising an indicium that contains a high-density of micro and/or nanostructures forming a code that cannot be visualized by the unaided human eye. The invention also provides a device designed to detect and identify information contained in the high-density coded information contained in the indicium. Apart from anti counterfeit properties it is desired that the indicium may also contain information of specific parameters that should be used by the inhaler devices such as the ideal temperature range, or the heating profile in function of time, or parameters which allow to provide to the smoker different smoking tastes or intensities.

In a first aspect, the invention thus relates to an aerosol-generating system comprising an optical reader system and an aerosol generating article extending along a longitudinal axis and comprising at least one indicium containing information about the article arranged on a surface of said article,

The indicium comprises at least one array of structures having greatest dimensions smaller than 5 pm that are readable upon illumination by the optical reader system, said array of structures being arranged according to an optically readable pattern or code, said optical reader system comprising at least one light source emitting light having wavelengths between 250 nm and 5pm. The provision of an optical reader system configured to detect an indicium comprising micro and/or nanostructures on a consumable article thus allows for accurate authentication of the consumable article and thus, to ensure that said consumable article is from an authorized source and origin and also that it is compatible for use with the aerosol-generating device. The optical reader system is designed to read details in the indicium born by the consumable articles of the invention that may not be detected by non-aided human eye or by simple optics. The aerosol-generating device of the invention thus provides a high-performance authentication system, which can detect a high density of information in a structured indicium provided on a consumable article, such as type and/or format of the consumable article and required functional parameters of the aerosol generating device in relation with said consumable article.

In an embodiment the structures have greatest dimensions smaller than 1 pm, preferably smaller than 500 nm, still preferably smaller than 200 nm. In an embodiment at least one array of structures is arranged as light reflecting structures and/or light diffractive structures.

In an embodiment said pattern consists in a plurality of light beams provided by said indicium upon the illumination with a light beam of at least a portion of said indicium. The indicium comprises at least one array of structures are micro and/or nanostructures having maximal dimensions smaller than 5pm that are readable upon illumination by an optical reader system. The indicium may comprise at least one array of micro and/or nanostructures having maximal dimensions smaller than 5 pm, preferably maximal dimensions between 1 pm and 5 pm, more preferably between 100 nm and 1 pm, even more preferably between 20nm and 100nm.

The consumable article according of the system of the invention is particularly advantageous and fit for allowing proper authentication in that the micro and/or nanostructures provide a huge information density in the coded indicium. The information contained in the layout of the micro and/or nanostructures may be detected by imaging the light effects produced by the indicium upon illumination at a determined wavelength, or wavelength band, such as predetermined color effects, or by detection of emitted light beams that may have different apertures and/or different wavelength compositions. The micro and/or nanostructures may be illuminated in a device providing large band light or narrow band light, providing as such a huge design flexibility of the indicium.

In an embodiment, said array of micro and/or nanostructures is arranged according to an optically readable pattern or code. The advantage of using patterns, which comprise microstructures and/or nanostructures is that the code is not identifiable by the human eye without using at least an optical magnification system and/or a system that may detect a plurality of light beams that may be diffracted light beams having predetermined properties. At least two of said plurality of light beams may have a different color or have different spectra consisting in a single wavelength or a plurality of distinct wavelengths. In an embodiment, said array of micro and/or nanostructures is arranged on a support or substrate fixed on the surface. Arranging a support applied on the outer surface allows to use existing low cost and highspeed techniques of applying preformed layers such as thin polymer layers that are preferably pre-structured with micro and/or nanostructures. In an embodiment said support is a lacquer layer provided on an outer surface of the aerosol-generating article.

In an embodiment said outer surface is a surface of a wrapper of said article.

In an embodiment said support is made at least partially of a material chosen from: glasses, T1O2, or HfC , or Ta20s, or ZrC , or AIN, or AI2O3, or ZnO, or S1O2, or S13N4, or CaF2 or MgO, or combinations thereof.

In an embodiment said support is made at least partially of transparent polymer chosen from: Polyethylene terephthalate (PET), Polycarbonate (PC), Polyethylene naphtholate (PEN), Polymethyl methacrylate (PMMA), polyesters, polyethylene (PE), polypropylene (PP), Polyethylene furanoate, Polymethyl methacrylate (PMMA), polymers based on poly (bis - cyclopentadiene) condensates, colorless polyimide (CP), cellulose, PEEK polymers, a combination thereof. In an embodiment, said array of structures is realized on or inside a waveguide that is arranged on at least a portion of the surface of the article. The portion may be a circumferential and/or axial portion of a surface of an aerosol generating article. The waveguide is at least partially configured to guide light and has at least one incoupling surface and at least one outcoupling surface. Using waveguides that comprise lateral incoupling and outcoupling surfaces allows to use a detection device that provides a light beam into the waveguide, without any contact and similarly to detect outcoupled light by directing it to a detector of the device as further described.

In an embodiment, at least a portion of said waveguide is a leaky waveguide and is arranged to behave, upon illumination with an incident light, as a zero-order filter. Using leaky waveguides and more precisely zero-order waveguides, defined as resonant gratings, allows to provide unique incoupling and outcoupling effects and so a high level of information density and provides security indicia that are extremely difficult to copy and which contain information provided in a form that is difficult to duplicate.

In an embodiment, said incoupling surface and/or said outcoupling surface has an area that is greater than 10%, preferably greater than 30%, even more preferably greater than 50% of a greatest surface area of said support. By using incoupling and/or outcoupling surfaces that are an important fraction of the surface of their substrate or support, allows providing solutions of indicia which optical effects are less sensitive or not sensitive at all to the axial orientation of said article relative to required incident light beams.

In an embodiment, said indicium has a plurality of incoupling surfaces. In variants the plurality of incoupling surfaces may be distributed continuously or discontinuously. By using a predetermined distribution of a plurality of incoupling and/or outcoupling surfaces allows providing even more complicated indicia that are difficult to copy.

In an embodiment, said indicium has a plurality of outcoupling surfaces. In variants, the plurality of outcoupling surfaces may be distributed continuously or discontinuously. Using continuously arranged incoupling and/or outcoupling surfaces allows to provide a solution that provides effects that are independent of the rotational position of the aerosol-generating consumable article in an aerosol-generating device as further described.

In an embodiment, at least a portion of one of the surfaces of said waveguide is arranged as an incoupling surface and/or an outcoupling surface. The advantage of the incoupling surface and/or an outcoupling surface over most of the circumference of the article is to provide an indicium that may be read independent of its axial orientation relative to said virtual longitudinal axis. In variants at least one of the surfaces of said waveguide is arranged, over at least 50% of its entire length, as an incoupling surface and/or an outcoupling surface.

In an embodiment said indicium provides at least two projected light beams upon illumination by at least two different light beams, said tow projected light beams having a different projection angle, defined relative to the local normal N of the incidence area of the indicium . In an embodiment, the consumable article comprises a plurality of optically readable indicia. In a variant said optically readable indicia are different from one another. Using a plurality of indicia allows to provide an even greater information content and may provide a redundant and so very reliable security code. In an embodiment, said array of structures is arranged to provide reflected and/or diffracted light upon direct illumination of a predetermined portion of said array by a light beam. Using reflection diffraction effects allows to provide an indicium that is simpler to manufacture. In a variant a resonant waveguide may be configured to provide a high-density information indicium provided by reflected and diffracted light. In an embodiment said support is made of a flexible and at least partially transparent material. Using a flexible material allows to prefabricate a structured waveguide and apply it on the outer surface during the manufacturing process of the article. In an embodiment said flexible material is resistant to temperatures up to 250°C, preferably up to 400 °C. The advantage of using flexible materials that are heat resistant is that they have optical properties that are robust against high temperatures or varying temperatures.

Brief description of the drawings Figure 1 shows a schematic representation of a manufactured aerosol generating consumable article according to an embodiment of the present invention wherein an indicium comprises micro-and/or nanostructures.

Figure 2 shows a schematic representation of a manufactured aerosol generating consumable article, according to an embodiment of the present invention wherein an indicium is made of a waveguide comprising an incoupling and an outcoupling surface.

Figure 3 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article wherein an indicium is configured to convert a broad band incoming light beam into a projected light beam has predetermined light spectrum.

Figure 4 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article wherein an indicium is configured to convert an coming light beam into at least two projected light beams having each a predetermined light spectrum and/or a predetermined projection angle .

Figure 5 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article wherein an indicium is configured to convert at least two incoming light beams into at least two projected light beams that may have different predetermined light spectra and/or different predetermined projection angles.

Figure 6 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article wherein an indicium is configured to convert a incoming broad band light beam into a plurality of light beams that may be projected on a detector so as to provide the image of a code having a predetermined arrangement of code elements that may have different spectral properties.

Figure 7a and 7b illustrate an arrangement of a waveguide, arranged on the outer surface of an article, comprising a discontinuous arrangement of incoupling and outcoupling surfaces.

Figure 8 illustrates an indicium of the invention that is configured to project at least one light beam upon illumination by a grating-incidence light beam propagating parallel to the outer surface of an aerosol-generating consumable article.

Figure 9 illustrates an aerosol-generating device according to an embodiment of the invention.

Figure 10 illustrates an aerosol-generating device according to another embodiment of the invention. Figure 11 illustrates a process to realize arrays of structures having greatest dimensions smaller than 5pm, possibly smaller than 1pm, on wrappers such as paper wrappers suitable for manufacturing aerosol-generating articles.

Detailed description of the invention

The present invention will be described with respect to embodiments and with reference to the appended drawings, but the invention is not limited thereto. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. 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..

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.

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 may preferably comprise a cellulose based material such as paper and may also be made of a biodegradable polymer or may be made of glass or a ceramic. The wrapper may be a porous material and may have a smooth or rough outer surface 5 and may be a flexible material or a hard material.

As used herein, the term "structure" refers to a portion of a surface or an element that has a dimension smaller than 5pm covering the field of micro- and nanostructures, and that may have any 2D or 3D shape and which may be a surface feature or an element that is embedded at least partially inside a layer or that is deposited on a surface. The term “array” means broadly a plurality of microstructures and/or nanostructures that may be arranged in a specific order such as a series of lines or dots and may also be a random distribution of structures. The term “magnification”, as used herein, means providing optical and/or digital means allowing detection, reading and deciphering of a code embedded in an indicium arranged on an aerosol-generating article. The means provided to achieve magnification may be geometric optical amplification means such as the use of projection lenses but may also be means detect the angles and/or colors of emitted light beams from the indicia.

Figure 1 shows an exemplary embodiment of a manufactured aerosol generating consumable article 1. The article 1 extends preferably along a virtual longitudinal axis 3 and comprises at least one indicium 10 containing information about the article 1. The indicium 10 is arranged on an outer surface 5 of said article 1. The manufactured aerosol-generating consumable article 1 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 said longitudinal axis 3. The indicium 10 of the article 1 of the invention comprises at least one array of structures that is readable upon illumination by an optical reader system 200. The structures of the indicium 10 are individually difficult or impossible to detect or identify by the human eye so that the indicium may not be easily be read or copied without using an optical system. The structures are typically microstructures, having larger dimensions that are smaller than 5pm, preferably smaller than 1pm, or nanostructures, having larger dimensions that are typically smaller than 200nm. An indicium 10 may be arranged according to a 2D or 3D arrangement of structures and may have any shape such as a square, a rectangular band that may be arranged on a complete circumference of the outer surface 5 of a wrapper.

In an embodiment, the array of structures is arranged according to an optically readable pattern or code. The code may be a linear code, or a 2D code or a 3D code. To the contrary of codes that may be easily viewed and interpreted by the naked or unaided human eye, such as the barcodes described in the document US2019/0008206A1 , the indicia of the invention may not be detected nor identified by the non-aided human eye as they consist in invisible structures that have dimensions smaller than smaller than 5pm, possibly smaller than 1000 nm or smaller than 500 nm or smaller than 200 nm.

In embodiments, said array of structures is arranged on a support fixed on said outer surface 5. The support may be made of any material that can be produced at low cost in great quantities, such as for example a lacquer layer deposited by for example spray technique or a polymer layer that may be deposited on said out surface by gluing or thermal techniques. The array of structures may be embedded in said layer before or after its application to said outer surface. The structures may be formed on at least one of the surfaces of said layer or may be embedded in said layer.

The indicium 10 may be of different types, some of which are described in further details below. Typical classes of indicia 10 applicable to the aerosol-generating articles 1 according to the invention comprise:

- a reflecting indicium 10; - a diffracting indicium 10;

- a reflecting and diffracting indicium 10;

- an indicium 10 that comprises at least one waveguide;

- an indicium 10 comprising at least one resonating waveguide;

- a partially transparent indicium 10; - an indicium 10 that comprises an adaptation layer to assure the adhesion on said outer surface 5;

- a combination of different types of said typical classes of indicia 10.

The indicium 10 may be arranged to provide predetermined direct reflection effects such as providing, upon illumination by a light beam, a plurality of light beams that may have different spectra and/or different reflection angles. The reflected light beams may be diffracted light beams projected in any diffraction order.

In other variants, the indicium 10 comprises structures on at least one of its surfaces or sides and may comprise structures imbedded inside a layer of the indicium 10. For example, diffractive structures may be provided on an outer surface of the indicium 10, away from said wrapper and may be realized by embossing techniques on a polymer layer.

The indicium 10 may be incorporated onto or inside said wrapper. For example, in the case of a paper wrapper the indicium may be realized as a coating applied on the outer surface 5 of the paper wrapper. A process to realize arrays of structures according to the invention is described in detail further herein. The indicium 10 may be also arranged on said wrapper to the inner side thereof, which may be used to hide the indicium. In such a variant infrared light may be used to provide an optical effect by the indicium 10. In another variant the wrapper may be made of a transparent material and the indicium 10 may be imbedded inside the wall of such transparent wrapper that may be an at least partially glass wrapper.

In an embodiment, schematically illustrated in Fig.2, said array of nanostructures is realized on or inside a waveguide 100 that is arranged on at least a portion of a circumference of said outer surface 5 of the article, 1 said waveguide 100 being configured to guide light and having at least one incoupling surface 110 and at least one outcoupling surface 120. Said at least one incoupling surface 110 and at least one outcoupling surface 120 are configured to respectively incouple an incident light beam lin and outcouple a light beam lout that is at least a fraction of said incident light beam lin. Said waveguide layer is typically a multimode waveguide and is preferably made of a flexible polymer layer and comprises preferably a core layer configured to guide light that propagates in the waveguide by internal reflections. The waveguide may have a circular shaped cross section or a rectangular cross section, defined in a plane orthogonal to the longitudinal axis of the waveguide. In variants said waveguide may comprise a plurality of parallel layers. At least one of the layers of the waveguide may be a doped layer to provide a different refractive index as its neighboring layers.

The materials used for the waveguides must be chosen so that the waveguide may be realized before or during the fabrication process of said article. Said optical waveguide may be made of a material chosen from a dielectric group comprising common or special glasses or T1O2, or HfC , or Ta20s, or ZrC , or AIN, or AI2O3, or ZnO, or S1O2, or S13N4, or CaF2 or MgO, or combinations thereof. Material may also be chosen from a substantially transparent polymer comprising Polyethylene terephthalate (PET), Polycarbonate (PC), Polyethylene napthalate (PEN), Polymethyl methacrylate (PMMA), polyesters, polyethylene (PE), polypropylene (PP), Polyethylene furanoate, Polymethyl methacrylate (PMMA), polymers based on poly (bis - cyclopentadiene) condensates, colorless polyimide (CP), cellulose, PEEK polymers, and their combination. The polymers or composite materials based on a polymer matrix have the advantage of being elastic and thus providing flexibility for thin structures such as the waveguides described here. The polymer or dielectrics can also include additives such as chemicals or nanoparticles. Semiconductors such as Si and Ge or a combination of them may also be chosen as materials for the waveguide, especially is infrared light is used for illumination and imaging. The wide range of possible materials allows to design indicia 10 that may be used in the UV, visible and infrared parts of the electromagnetic spectrum.

In an advantageous embodiment, at least a portion of said waveguide is arranged according to a resonant waveguide grating (RWG). RWG’s are described in for example: - A.Sharon et al.:”Resonating grating-waveguide structures for visible and near-infrared radiation”: J.Opt.Soc.Am” vol.14, nr.11 , pp.2985-2993, 1997.

RWG’s are made by using a multilayer configuration and combine subwavelength gratings and a thin waveguide. A resonance occurs when incident light is diffracted by a grating and matches a mode of the waveguide. As most of the spectrum of incoupled light does not couple into the waveguide, strong spectral effects are provided in reflection and/or transmission. This to the fact that RWG’s are corrugated waveguides and behave as a waveguide-grating. The use of RWG in indicia allows to provide unique optical effects that are extremely difficult to identify and to duplicate. RWG’s are generally designed to have spatial periodicity shorter than the wavelength they operate with and are therefore called “subwavelength” structures or subwavelength devices. Eventually they have periodicities closed to the wavelength they are operating with and just above it. Quite often, the periods are significantly smaller than the free-space wavelength they are working with, for example a third of it. Because of their small periodicity, they do not allow various diffractive orders, which distinguishes them from much simpler diffractive optical elements (DOE). In an embodiment an indicium 10 is designed to operate only in zero-diffractive order, which allows light filtering and redirection only between the zero-order transmission and reflection, this last one is also called specular reflection, and with a leaky-guided mode incoupled and outcoupled continuously, eventually with non-guided plus or minus first diffraction order, exceptionally with non-guided plus or minus second diffraction order.

In embodiments said incoupling surface 110 and/or said outcoupling surface 120 has an area that is greater than 10%, preferably greater than 30%, even more preferably greater than 50% of a greatest surface area of said support.

In advantageous embodiments said indicium 10, 11 has a plurality of incoupling surfaces and/or may have a plurality of outcoupling surfaces.

In embodiments at least one of the surfaces of said waveguide is arranged, over at least 50% of its entire length, as an incoupling surface and/or an outcoupling surface. The waveguide may comprise arrays of RWG’s as described further herein. In a particular case at least 80% or the whole surface of said waveguide is arranged so that at any localization light, provided by a fixed light source, may be incoupled and outcoupled. In a preferred arrangement the waveguide is present on more than 80%, preferably a whole circumference of an article, illustrated in the embodiment of Fig.7A, 7B. This allows to provide optical effects that are not sensitive to the axial orientation of the article 1 relative to a light source or light sources such as arranged in a device 2 as described further herein. In advantageous embodiment said array of structures is arranged to provide reflected and/or diffracted light upon direct illumination of a predetermined portion of said array by a light beam.

In variants the indicium may comprise a meta-surface and may be configured to project a hologram-type image of at least a portion of the indicium 10.

By using micro-and nanostructured elements special optical effects can be obtained, especially when the micro-and nanostructured elements are realized on waveguides, more particularly on resonant waveguides. Some exemplary embodiments and their variants are now briefly described (Fig.2- Fig.8). In advantageous embodiments of the indicium is arranged so that the desired effect is obtained independent of the rotational position of the article 1 relative to an incident light beam.

Figure 2 shows an embodiment of the present invention wherein an indicium 10 is made of a waveguide comprising an incoupling surface 110 and an outcoupling surface 120. In a variant the waveguide may be a RWG.

Figure 3 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article wherein an indicium 10 is configured to convert a broad band incoming light beam into a projected light beam has predetermined light spectrum. The graphs in the figure illustrate the incoupled and outcoupled intensities, lin and lout, in function of the wavelength l. In a preferred embodiment, illustrated in Fig.3, the angles of the incident and projected light beams are different, relative to the local normal N of the indicium 10.

Figure 4 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article 1 wherein an indicium 10 is configured to convert an coming light beam 11 into at least two projected light beams I2, I3 having each a predetermined light spectrum and/or a predetermined projection angle a, b. This configuration may be implemented by using a reflection grating or a RWG structure. Figure 5 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article wherein an indicium 10 is configured to convert at least two incoming light beams I4, I5 into at least two projected light beams I4’, I5’ that may have different predetermined light spectra and/or different predetermined projection angles Q1 , Q2, Q3, Q4. This configuration is advantageously implemented by using a waveguide or a RWG structure.

Figure 6 shows a schematic representation of an embodiment of a manufactured aerosol-generating consumable article 1 wherein an indicium 10 is configured to convert a incoming broad band light beam I6 into a plurality of light beams I60-I70 that may be projected on a detector 260 so as to provide the image 260’ of a code, provided by the indicium 10, having a predetermined arrangement of the imaged code elements S60-S70, of which at least two may have different spectral properties. Figure 7a and 7b illustrate an arrangement of an indicium 10 comprising a waveguide, arranged on the outer surface of an article 1 , comprising a discontinuous arrangement of incoupling surfaces 11 and outcoupling surfaces 13. The incoupling surfaces 11 and/or outcoupling surfaces 13 may be separated by gaps G. In variants the distribution of the incoupling and outcoupling surfaces 11, 13 may be non-uniform. As illustrated in Fig.7a an incident light beam I7 may have a wide aperture W so that at least two adjacent incoupling surfaces 11 are illuminated, providing an outcoupled beam I7’ that is always directed into a predetermined direction Out”. This allows to provide optical effects that are insensitive to the axial orientation of the article 1. In an embodiment, not illustrated in the figures, the indicium comprises a high density of arrays of pairs of Resonant Waveguide Gratings (RWG). The pairs are preferably adjacent pairs but not necessarily so. Each pair forms a light redirection unit consists of two adjacent RWGs having two different periods or grating orientations. The corrugated waveguide thickness and the modulation depth of the supporting grating are smaller than the wavelength, enabling almost no direct free-space diffraction. The light from a broadband light source such as a white LED incident on the first RWG of each pair can be partly coupled into leaky guided modes. Since the RWG has a finite length, the coupled modes have a spectral band whose width depends on the grating length. The in-coupled leaky modes propagate in the first and later second RWG of said pairs, being trapped in the waveguiding layer. While propagating into the second RWG of said pairs, the coupled mode is outcoupled in a direction that differs from the incoming light because the periods or the orientation of the two RWGs of each said pair are different. It is possible to tune the direction of the out-coupled modes by changing the period or the orientation of the second RWG of each pair of RWG. In an exemplary realization, more than 100 of RWG pairs may be comprised in 1mm2 of an indicium. This allows to provide unique color effects that are extremely difficult to reproduce.

Figure 8 illustrates an indicium 10 of the invention that is configured to project at least one light beam upon illumination by a grazing-incidence light beam I8 propagating substantially parallel to the outer surface of an aerosol- generating consumable article. The grazing-incidence light beam I8 provides, by optical interaction, with the indicium at least one reflected or outcoupled light beam I8’, I9’, preferably having wide spectral widths Dl1, Dl2. This configuration is advantageously implemented by using a waveguide or a RWG structure. In a variant at least two light sources 304, 306 providing two similar or different light beams I8, I9 may be used.

In advantageous embodiments the indicium is made of a flexible material is resistant to temperatures up to 250°C, preferably up to 300 °C, more preferably up to 400°C.

It is understood that the indicium 10 may be configured so that it may be illuminated by a light beam that may be, at least partially, be transmitted at least partially through said smoking article, i.e. from one side of its outer surface 5 to an opposite side of its outer surface 5.

The invention is also achieved by a manufacturing method of the indicium 10. The indicium 10 may be manufactured on an indicium portion of the surface of a wrapper and comprises the steps of: - proving a wrapper;

- realizing nanostructures on said indicium portion

In an embodiment of the manufacturing method said nanostructures are realized on or in a waveguide. In a variant of said method the waveguide is realized on a support and is adapted to the wrapper and comprises the steps of:

- realizing a waveguide;

- realizing on said wrapper an intermediate support layer;

- fixing said waveguide onto said intermediate layer; In an embodiment the waveguide is fixed to an intermediate layer before the intermediate layer is applied on the wrapper. In variants of said manufacturing process the wrapper is made of paper.

In a variant said step of fixing is made by a gluing and/or thermal process step. In variants of said manufacturing process said waveguide comprises at least one RWG.

In variants in which said wrapper is made of a porous material, such as paper, the fabrication method may comprise a step to smoothen at least one of the surfaces of the wrapper. For example, in the case of a paper wrapper it is preferable that the surface area on which an indicium has to be deposited or fixed, is smoothed. This may be made by for example chemical processes or a mechanical process for example a calendaring process which consist in running a paper substrate onto a frictional area between tow steel reels under pressure. By such a process the compressed area undergoes a plasticization and compression, increasing the surface softness, and is affected by parameters related to the humidity content, the applied pressure and the number of reels between the paper sheets pass. Softening of an area of paper may also be realized by the deposition of a lacquer layer. Treating paper so to smooth its surface is known in the paper printing industry and is not further described here. The smoothening process should be adapted in function of the type of indicium to be applied on a rough surface such as a paper surface or the like.

Figure 11 illustrates an exemplary process for treating aerosol generating article wrappers, which allows to realize arrays of structures as necessary according to the present invention having greatest dimensions that are smaller than 5 pm, preferably smaller than 1 pm, even more preferably smaller than 200 nm cannot be realized with simple processes that are used in the case of visual detectable barcodes such as barcodes described and shown in Figure 4 of the document US2019/0008206A1 .

The process illustrated in Figure 11 is designed to form optically active structures onto aerosol-generating wrappers before manufacturing of aerosol generating articles. It uses a deposition system 500 comprising at least one UV lamp 600 and a cylinder 502 provided with a shim 504 comprising a master consisting of arrays of microstructures smaller than 5000 nm. Aerosol generating wrapper sheet material 5, preferably provided from a paper bobbin for instance, is covered first with varnish layer, for example through bathing in a bath 506 containing varnish or lacquer material or more preferably through standard offset or dye printing method. The varnish wrapper material is then passed onto said cylinder 505, so as to impart said structures master onto the varnish layer and subsequently instantly curing the lacquer after having imparted said master.

The curing of the lacquer master can be obtained with two 600, 602 or even more UV lamps 600, 602, 604 . A third UV lamp 604 may be required to finalize the curing of the deposited layer. At the level of the third UV lamp 604 any type of additional layer 606 may be arranged to the cured structured layer. In the embodiment of Figure 11 the UV light passes with high transmittance through the wrapper as its thickness is typically smaller than 10Opm, typically smaller than 70 or 50 pm. In variants, the shim may be a transparent shim and at least one UV lamp may be arranged inside said cylinder and may cure the lacquer directly without passing UV light through the wrapper.

In an embodiment of the method illustrated in Figure 11, a coating layer may further be deposited on the realized array of structures. This may be realized by passing the structured wrapper into or through a second bath 508. The coating may be a metallic ink or a high-refractive index layer, both being suited to enhance the optical reflection effects of the microstructures realized on the wrapper.

In embodiments said shim 504 is selected from a group consisting of a nickel sleeve, an etched drum, or a laser processed drum. The shim may be made in metal or other materials or may be a cylinder containing a master of microstructures.

In variants, colored inks may be deposited on the realized structures on said wrapper. Diffraction requires that the medium in which said array structures are made of, and the media that border the array of structures have a difference in optic index. The larger this difference, the greater the diffraction effects will be. To create the greatest optical effects from the array of structures according to the invention, full reflective materials such as metals like aluminum, copper or gold are thin fil coated onto the surface of the array of structures. Alternatively, the array of structures may be coated with a film of transparent material having a high refractive index.

In variants, metallic layers or a layer of transparent high refractive index material may be deposited by physical vapour deposition but are preferably formed by depositing a metallic or transparent ink onto the coded array of structures.

In variants, in case the UV varnish or lacquer is easily permeable to said wrapper, a first coating may be applied to the wrapper before its passing through the UV varnish reservoir. The invention further relates to an aerosol-generating device 100 configured to work in conjunction with an aerosol-generating consumable article 1 as previously described, in particular configured to illuminate and read the indicium 10 on such consumable article 1 to authenticate it before consumption by a user. The aerosol-generating device 100 thus comprises, arranged in an outer body part 110, a power supply section 120 and a cavity 112. The cavity 112 has an opening accessible at the outer body part and being configured to receive a consumable article 1, as described above, upon insertion of said article along its longitudinal axis in the cavity 112. The aerosol-generating device 2 further comprises an optical reader system 200 arranged in the outer body part 110 and configured to read the at least one indicium 10 located on the consumable article 1. Also, the aerosol-generating device 100 further comprises a control unit 250 configured to determine authenticity of the consumable article based on the content of the information read by the optical reader system in the indicium arranged on the consumable article 1.

The illumination of the indicium 10 may be made, in embodiments, by different types of light sources, preferably by a broad band and cheap light source such as a white LED. In an example, a white LED illuminates at least a portion of an indicium and provides at least 5 different light beams having 5 different directions and 5 different spectra. The light source may also be a VCSEL or VCSEL array or any other type of semiconductor laser, for example a visible or infrared semiconductor laser. In embodiments the light source may comprise different types of light sources or light sources that have different emission intensities and/or emitted beam shapes and/or emitted light beam directions. The reflected and/or diffracted light beams may be detected by a small camera or by using an optical projection system. The specific angular distribution and color distribution of the light beams contain information on the article.

Said optical reader system 200 may comprise at least one optical magnification system as illustrated in Fig.9, which shows a concave focusing mirror 240 that reflects a projected light beam 320 which is reflected so as to provide a secondary light beam 340 onto a detector 260. Fig.9 illustrates an exemplary detected spectrum illustrating how the varying output intensities of the light beam provided by the indicium may vary according to the wavelength l, and so provide information on the article 1. The detector 260 may be a single detector or a detector array, preferably a CCD detector array. The detector 260 may be an imaging camera such as a miniaturized camera. In variants a plurality of detectors may be arranged at different locations in the device 2 as illustrated in the embodiment of Fig. 10 which illustrates the use of two light sources 300, 302 and two detectors 260, 262.

In variants the walls of the cavity 112 may comprise apertures 222 (Fig.9) that may contain a transparent window. In variants at least a portion of one wall of the cavity 112 is made of a transparent material. It is generally understood that the optical reader system 200 may comprise addressable optical elements, such as a flipping mirror or MEMS components that may be located in one of the incident or projected light paths. Other variants comprising for example optical filters or miniaturized spectrometers may be integrated in said aerosol-generating device 100. In a variant the aerosol-generating device 100 comprises a display that is configured to display information provided by the indicium 10 of the article of the invention.

Claims

1. An aerosol-generating system comprising an optical reader system (200) and an aerosol generating article (1) extending along a longitudinal axis (3) and comprising at least one indicium (10) containing information about the article (1 ) arranged on a surface (5) of said article (1 ), wherein the indicium (10) comprises at least one array of structures having greatest dimensions smaller than 5pm that are readable upon illumination by the optical reader system (200), said array of structures being arranged according to an optically readable pattern or code, said optical reader system comprising at least one light source (300, 302, 304, 306) emitting light having wavelengths between 250 nm and 5 pm.

2. The aerosol-generating system according to claim 1 , wherein structures have greatest dimensions smaller than 1 pm, preferably smaller than 500 nm, still preferably smaller than 200 nm.

3. The aerosol-generating system according to claim 1 or 2, wherein said at least one array of structures are arranged as light reflecting structures and/or light diffractive structures.

4. The aerosol-generating system according to any one of claims 1 to 3, wherein said pattern consists in a plurality of light beams provided by said indicium upon the illumination with a light beam of at least a portion of said indicium.

5. The aerosol-generating system according to any one of claims 1 to 4, wherein said array of structures is arranged on a support fixed on an outer surface (5) of the aerosol-generating article (1).

6. The aerosol-generating system according to claim 5, wherein said support is a lacquer layer provided on an outer surface (5) of the aerosol-generating article (1).

7. The aerosol-generating system according to claim 6, wherein said outer surface (5) is a surface of a wrapper of said article (1 ).

8. The aerosol-generating system according to any one of claims 5 to 7, wherein said support is made at least partially of a material chosen from: glasses, T1O2, or Hf02, or Ta20s, or Zr02, or AIN, or AI2O3, or ZnO, or S1O2, or S13N4, or CaF2 or MgO, or combinations thereof.

9. The aerosol-generating system according to claims 5 to 7, wherein said support is made at least partially of transparent polymer chosen from: Polyethylene terephthalate (PET), Polycarbonate (PC), Polyethylene naphtholate (PEN), Polymethyl methacrylate (PMMA), polyesters, polyethylene (PE), polypropylene (PP), Polyethylene furanoate, Polymethyl methacrylate (PMMA), polymers based on poly (bis - cyclopentadiene) condensates, colorless polyimide (CP), cellulose, PEEK polymers, a combination thereof.

10. The aerosol-generating system according to claims 1 or 2, wherein said array of structures is realized on, or inside, a waveguide (100) that is arranged on at least a portion of a circumference of said outer surface (5) of the article (1 ), said waveguide (100) being configured to guide light and having at least one incoupling surface (110) and at least one outcoupling surface (120).

11. The aerosol-generating system according to claim 10, wherein at least a portion of said waveguide is a leaky waveguide and is arranged to behave, upon illumination with an incident light, as a zero-order filter.

12. The aerosol-generating system according to claim 10 or claim 11 , wherein said incoupling surface (110) and/or said outcoupling surface (120) has an area that is greater than 10%, preferably greater than 30%, even more preferably greater than 50% of a greatest surface area of said support.

13. The aerosol-generating system according to any one of claims 10 to 12, wherein said indicium (10, 11) has a plurality of incoupling surfaces.

14. The aerosol-generating system according to any one of claims 10 to 13, wherein said indicium (10, 11) has a plurality of outcoupling surfaces.

15. The aerosol-generating system according to any one of claims 10 to 14, wherein at least one of the surfaces of said waveguide is arranged, over at least 50% of its entire length, as an incoupling surface and/or an outcoupling surface.

16. The aerosol-generating system according to any one of claims 1 to 15, wherein said indicium (10, 11) provides at least two projected light beams (I4’, I5’) upon illumination by at least two different light beams (I4, I5) , said two projected light beams having a different projection angle (Q1-Q4), defined relative to the local normal N of the incidence area of the indicium (10,11 ) .

17. The aerosol-generating system according to any one of the preceding claims, comprising a plurality of optically readable indicia (10, 11, 13).

18. The aerosol-generating system according to claim 17, wherein said optically readable indicia (10, 11, 13) are different from one another.

19. The aerosol-generating system according to claim 17 or 18, wherein said optically readable indicia (10, 11, 13) are arranged according to parallel strips.

20. The aerosol-generating system according to any one of claims 1 to 19, wherein said array of structures is arranged to provide reflected and/or diffracted light upon direct illumination of a predetermined portion of said array by a light beam.

21. The aerosol-generating system according to any one of claims 5 to 20 , wherein said support is made of a flexible and at least partially transparent material.

22. The aerosol-generating system according claim 21, wherein said flexible material is resistant to temperatures up to 250°C, preferably up to 300 °C, more preferably up to 400°C.

23. An aerosol-generating system according to any one of the preceding claims, wherein further comprising a control unit (250) configured to read and decipher said optically readable pattern or code to determine authenticity of the consumable article.

24. An aerosol generating article (1) extending along a longitudinal axis (3) and comprising at least one indicium (10), containing information about the article (1 ), arranged on a surface (5) of said article (1 ), the indicium (10) comprising at least one array of structures having greatest dimensions smaller than 5pm, said array of structures being arranged according to an optically readable pattern or code.