EP1831461B1 - Security structure and article incorporating such a structure - Google Patents

Abstract

A security structure intended to be incorporated or fastened, at least partially, in or on an article, for example a security document and/or a document of value, includes at least one first fluorescent zone capable of emitting by fluorescence, under a predefined illumination condition, visible light of a first color; and at least one second fluorescent zone capable of emitting by fluorescence, under the predefined illumination condition, visible light of a second color that differs from the first, the first and second fluorescent zones being observable from the respective opposed faces of the structure.

Description

Security structure and article incorporating such a structure

The present invention particularly relates to a security structure and an article incorporating such a structure.

• une première zone florescente capable d'émettre pas fluorescence, dans une condition d'éclairage prédéfinie, une lumière visible d'une première couleur,
• une deuxième zone fluorescente capable d'émettre par fluorescene, dans une condition d'éclairage prédéfinie, une lumière visible d'une deuxième couleur, les première et deuxième zones fluorescentes étant respectivement observables depuis des faces opposées de la structure.

We know WO 03/061980 , EP 0319157 , EP 1036 665 and GB 2300596 describing a security structure comprising:

• a first florescent zone capable of emitting fluorescence, in a predefined lighting condition, a visible light of a first color,
• a second fluorescent zone capable of fluorescently emitting, in a predefined lighting condition, a visible light of a second color, the first and second fluorescent zones being respectively observable from opposite faces of the structure.

There is a need to further improve the protection of security and / or value documents against forgery.

The present invention aims in particular to meet this need.

• au moins une première zone fluorescente capable d'émettre par fluorescence, dans une condition d'éclairage prédéfmie, une lumière visible d'une première couleur,
• au moins une deuxième zone fluorescente capable d'émettre par fluorescence, dans la condition d'éclairage prédéfinie, une lumière visible d'une deuxième couleur, différente de la première, les première et deuxième zones fluorescentes étant respectivement observables depuis des faces opposées de la structure.

According to one of its aspects, the subject of the invention is a security structure intended to be incorporated or fixed at least partially in or on an article, for example a security and / or value document, the structure comprising:

• at least a first fluorescent zone capable of fluorescently emitting, in a predefined lighting condition, a visible light of a first color,
• at least one second fluorescent zone capable of fluorescently emitting, in the predefined lighting condition, a visible light of a second color, different from the first, the first and second fluorescent zones being respectively observable from opposite sides of the structure.

Thus, in the predefined lighting condition, the color of the structure may vary from one face to the other, the structure appearing for example at least partially in blue on one side and at least partially in yellow on the other. Authentication and / or identification of an article comprising such a structure can thus use two observation steps from respectively two opposite faces of the article, which reinforces the protection of the article against forgery.

In addition, the invention makes it possible, because of the presence of fluorescent zones of different colors, to create new optical effects.

The predefined lighting condition may correspond to ultraviolet illumination, in particular of near-visible wavelength, for example around 365 nm. Alternatively, the predefined lighting condition corresponds to infrared illumination.

At least one of the first and second fluorescent zones, in particular both, are at least partially non-opaque, at least in the predefined lighting condition.

In an exemplary implementation of the invention, at least one of the first and second fluorescent zones, in particular both, are, in addition, substantially colorless in color. White light.

The first and second fluorescent zones are superimposed at least partially so that, in the predefined lighting condition, a light passing successively through the two fluorescent zones has a third color, different from the first and second colors.

Thus, the authentication and / or identification of an article or document incorporating such a structure may comprise, in addition to two observation steps, in the predefined lighting condition, in reflection, first and second colors, at least one observation step in transmitted light to observe the third color.

Advantageously, the first and second fluorescent zones have absorption spectra chosen so that, in the predefined lighting condition, their superposition appears in transmitted light of a third or fourth color, each different from the first ones. and second colors, according to the order of the fluorescent zones traversed by the incident light.

The difference ΔE between the third and fourth colors, in the CIEL * C * h 1976 color space, may be at least 2, especially at least 5, which makes it easily observable.

Authentication and / or identification of an article or document can thus pass through the detection of four different colors, which further enhances security.

For example, under UV light, in reflection, the first fluorescent zone appears yellow and the second blue fluorescent zone, and, observed in transmitted light, the structure has a violet color when it is observed from a first face and appears substantially white when it is observed from a second side, opposite to the first.

The colors and their number may be different from those described above.

As a variant, the first and second fluorescent zones have absorption spectra chosen so that, in the predefined lighting condition, the superposition of the two fluorescent zones appears in transmitted light of substantially the same color, whatever the observation side.

In an exemplary implementation of the invention, the structure comprises at least a third fluorescent zone having a color different from the first fluorescent zone and observable on the same face, in the predefined lighting condition.

• au moins une troisième zone fluorescente apparaissant de la deuxième couleur précitée, dans la condition d'éclairage prédéfinie, les première et troisième zones étant observables depuis une première face de la structure,
• au moins une quatrième zone fluorescente apparaissant de la première couleur précitée, dans la condition d'éclairage prédéfinie, les deuxième et quatrième zones étant observables depuis une deuxième face de la structure, opposée à la première, chaque zone fluorescente d'une face se superposant au moins partiellement, de préférence sensiblement exactement, avec une zone fluorescente de couleur différente de l'autre face.

The structure advantageously comprises:

• at least one third fluorescent zone appearing from the aforementioned second color, in the predefined lighting condition, the first and third zones being observable from a first face of the structure,
• at least a fourth fluorescent zone appearing from the aforementioned first color, in the predefined lighting condition, the second and fourth zones being observable from a second face of the structure, opposite to the first, each fluorescent zone of a face superimposed at least partially, preferably substantially exactly, with a fluorescent zone of different color of the other face.

When the order of superposition of the fluorescent zones is not without effect on the result produced during the observation in transmitted light, it is possible to observe on each side of the structure, in transmitted light, in the predefined lighting condition, an alternation of fluorescent zones appearing respectively of the third and fourth colors. Thus, whatever the face that is observed, the structure generally has the same appearance in the predefined lighting condition, which can facilitate authentication and / or identification.

Preferably, the third fluorescent zone, respectively the fourth fluorescent zone, is adjacent to the first zone, respectively the second zone, these zones overlapping preferably substantially exactly. The structure is advantageously non-opaque in a junction region of the first and third fluorescent zones, respectively of the second and fourth fluorescent zones.

Such a structure provides enhanced tamperproofing insofar as a defect in the arrangement of the fluorescent zones can be detected relatively easily. Indeed, when the fluorescent zones of the opposite faces of the structure are superimposed exactly, an observation of the structure by transparency, in the predefined lighting condition, reveals only one or two colors. On the other hand, when fluorescent zones of the opposite faces are not superimposed exactly and overflow on neighboring fluorescent zones, other colors are revealed.

In an exemplary implementation of the invention, the structure has at least one face, in particular two opposite fully fluorescent faces. Alternatively, the structure has at least one face, in particular two opposite faces, not entirely fluorescent (s), for example with fluorescent zones alternating with non-fluorescent areas.

In an exemplary implementation of the invention, the structure comprises a support at least partially, in particular entirely, transparent or translucent, and carrying the fluorescent zones. The support may be flexible, being in particular made of plastic, for example polyester.

At least one of the fluorescent zones may be formed by depositing a fluorescent composition on one side of the support.

Preferably, the structure, for example the support, comprises at least first and second adjacent portions, the first portion having an ability to oppose the passage of light, under a given light, greater than that of the second portion.

The first portion may be substantially opaque and / or reflective at least in the predefined lighting condition, for example under UV illumination and / or at least in ambient lighting.

The second portion may be substantially transparent and / or translucent at least in the predefined lighting condition, for example under UV illumination and / or at least in ambient lighting.

Preferably, the aforesaid second portion is superimposed at least partially with at least one fluorescent zone or, where appropriate, with the superposition of two fluorescent zones, so that, in the predefined lighting condition, in transmitted light, the second portion appears with a color corresponding to the fluorescent zone or the superposition of the fluorescent zones.

In an exemplary implementation of the invention, the second portion has a shape chosen to define a pattern, which appears, in transmitted light, brighter than adjacent regions of the structure.

The second portion may, where appropriate, be entirely surrounded by the first.

In another embodiment of the invention, the first portion has a shape chosen to define a pattern, which appears, in transmitted light, darker than adjacent regions of the structure.

The first portion may, where appropriate, be entirely surrounded by the second.

The pattern can be chosen from one of the following elements: a letter, a drawing, a symbol, a logo, this list not being limiting.

In an exemplary implementation of the invention, the aforementioned first portion is formed by a metal layer, in particular a metal deposit, and the second aforementioned portion by a demetallization of this layer.

In a variant, the structure comprises a negative or positive printing of an ink, the first portion comprising the ink and the second portion being devoid of it.

Advantageously, the aforesaid second portion and the fluorescent zone at least partially covering it are non-opaque in white light so as to allow the observation, in ambient light, by transparency, of patterns present on the structure, thus providing additional security.

• premier niveau : observation en éclairage ambiant, par transparence, de la ou des deuxièmes portions, avec reconnaissance du ou des motifs correspondants,
• deuxième niveau : observation des zones fluorescentes, par réflexion, dans la condition d'éclairage prédéfinie,
• troisième niveau : observation, en lumière transmise, dans la condition d'éclairage prédéfinie, de la ou des deuxièmes portions, avec reconnaissance du ou des motifs et, le cas échéant, des couleurs formées par la superposition des zones fluorescentes.

The invention can thus make it possible to have, for a document, the following security levels:

• first level: observation in ambient lighting, by transparency, of the second portion or portions, with recognition of the corresponding pattern or patterns,
• second level: observation of the fluorescent zones, by reflection, in the predefined lighting condition,
• third level: observation, in transmitted light, in the predefined lighting condition, of the second or portions, with recognition of the pattern (s) and, where appropriate, the colors formed by the superposition of the fluorescent zones.

Advantageously, the second portion extends over a junction region between adjacent first and third adjacent fluorescent zones, respectively second and fourth adjacent fluorescent zones.

The first portion opaque and / or reflective above may optionally comprise a composition containing or not fluorescent pigments or dyes.

In an exemplary implementation of the invention, the aforementioned first and second portions form a plurality of patterns or groups of patterns repeating, regularly or randomly, in a predetermined direction.

• une puce électronique,
• un élément holographique ou diffractif,
• un revêtement magnétique ou cristallin,
• des cristaux liquides,
• une impression d'un vernis,
• un marqueur, notamment biologique, minéral ou synthétique,
• une encre ou une substance luminescente,
• un pigment thermochromique et/ou piézochromique.

In order to further improve the protection, the structure may include one of the following:

• an electronic chip,
• a holographic or diffractive element,
• a magnetic or crystalline coating,
• liquid crystals,
• an impression of a varnish,
• a marker, in particular a biological, mineral or synthetic marker,
• an ink or a luminescent substance,
• a thermochromic and / or piezochromic pigment.

The structure can be in various forms, for example strip, and constitute for example a security thread. The structure may have a width for example greater than 0.7 mm and preferably less than 60 mm, in particular between 1 mm and 40 mm.

In an exemplary implementation of the invention, the structure is arranged to be fully incorporated in or on the security article and / or value.

As a variant, the structure comprises a support forming a carrier strip arranged to be separated from at least one fluorescent layer after application of the structure to an article, in particular a security and / or value document, the structure possibly comprising, where appropriate between the support and the fluorescent layer, at least one release layer. The structure may constitute for example a security patch.

The invention further relates, in another of its aspects, an article, for example a security document and / or value, comprising a security structure as mentioned above.

The structure may be at least partially embedded in a layer of the article, and may comprise for example alternately zones embedded in a layer of the article and exposed portions. The structure may alternatively come flush with one face of the article or be entirely embedded therein.

The article may comprise, in contact with the structure, at least one fibrous layer, for example containing paper fibers, in particular cellulose fibers and / or fibers of synthetic nature.

Alternatively, the article may comprise, in contact with the structure, at least one non-fibrous layer, for example plastic.

In an exemplary implementation of the invention, the security structure extends from a first edge of the article to a second edge, opposite the first.

The article may be intended to receive an impression, in particular to form a document.

The item may be one of the following: a bank note, security paper, passport slip or cover, visa, coupon, valuable document other than a bank note for example a check or a credit card, a protection and / or authentication label, a traceability label, an optical disc, a ticket.

The article preferably comprises a region of sufficiently transparent and / or translucent fluorescent zones so that at least a portion of the fluorescent zones is visible through said region when the article is observed, by transparency.

The aforementioned region may correspond, for example, to an opening in the article or to at least one layer of a transparent and / or translucent material.

• fournir une structure telle que précitée,
• incorporer ou transférer au moins partiellement la structure dans ou sur l'article.

The invention further relates, in another of its aspects, to a method of manufacturing an article, comprising the following steps:

• provide a structure as mentioned above,
• at least partially incorporating or transferring the structure into or onto the article.

• former la couche fibreuse par dépôt de fibres sur une surface immergée dans une dispersion de matière fibreuse,
• amener la structure au contact de la couche fibreuse en formation.

When the article comprises a fibrous layer, the method may comprise the following steps:

• forming the fibrous layer by deposition of fibers on a surface immersed in a dispersion of fibrous material,
• bring the structure into contact with the fibrous layer in formation.

• amener au contact d'une face d'un article un support d'au moins une couche fluorescente,
• transférer la couche fluorescente,
• après le transfert, séparer le support de la couche fluorescente.

Alternatively, the method may comprise the following steps:

• bringing into contact with a face of an article a support of at least one fluorescent layer,
• transfer the fluorescent layer,
• after the transfer, separate the support from the fluorescent layer.

• exposer l'article à la condition d'éclairage prédéfinie,
• vérifier l'authenticité et/ou l'identité de l'article à partir de la ou des couleurs révélées par les zones fluorescentes.

According to another of its aspects, the subject of the invention is also a method for authenticating and / or identifying an article comprising a structure as defined above, the method comprising the following steps:

• expose the item to the predefined lighting condition,
• verify the authenticity and / or the identity of the article from the color or colors revealed by the fluorescent zones.

• observer la première zone fluorescente en lumière réfléchie, dans la condition d'éclairage prédéfinie,
• observer la deuxième zone fluorescente en lumière réfléchie, dans la condition d'éclairage prédéfinie,
• observer la structure en lumière transmise, dans la condition d'éclairage prédéfinie,
• vérifier l'authenticité et/ou l'identité de l'article à partir des couleurs observées dans les étapes ci-dessus.

When the first and second fluorescent zones are non-opaque, observable from opposite faces of the structure and overlapping at least partially, the method advantageously comprises the following steps:

• observe the first fluorescent zone in reflected light, in the predefined lighting condition,
• observe the second fluorescent zone in reflected light, in the predefined lighting condition,
• observe the structure in transmitted light, in the predefined lighting condition,
• check the authenticity and / or the identity of the article from the colors observed in the steps above.

• observer la structure en lumière transmise, dans la condition d'éclairage prédéfinie, depuis une première face de l'article,
• observer la structure en lumière transmise, dans la condition d'éclairage prédéfinie, depuis une deuxième face de l'article, opposée à la première,
• vérifier l'authenticité et/ou l'identité de l'article à partir des couleurs observées dans les étapes ci-dessus.

When the first and second fluorescent zones have absorption spectra chosen so that, in the predefined lighting condition, a light passing successively through the two fluorescent zones has third and fourth colors, different from the first and second colors, according to the order of the fluorescent zones traversed by the incident light, the method advantageously comprises the following steps:

• observe the transmitted light structure, in the predefined lighting condition, from a first face of the article,
• observe the structure in transmitted light, in the predefined lighting condition, from a second face of the article, opposite to the first,
• check the authenticity and / or the identity of the article from the colors observed in the steps above.

• la figure 1 représente, schématiquement et partiellement, un exemple d'article réalisé conformément à l'invention,
• les figures 2 et 3 représentent, schématiquement et partiellement, en coupe, la structure incorporée dans l'article de la figure 1, conformément à deux exemples de mise en oeuvre de l'invention,
• les figures 4 à 13 représentent, schématiquement et partiellement, d'autres exemples de mise en oeuvre de la structure,
• les figures 14 à 16 représentent, schématiquement et partiellement, en coupe transversale, des articles respectivement conformes à divers exemples de mise en oeuvre de l'invention,
• la figure 17 illustre schématiquement une étape d'un procédé de fabrication de l'article de la figure 1,
• la figure 18 représente, schématiquement et partiellement, en coupe transversale, une structure de sécurité conforme à un autre exemple de mise en oeuvre de l'invention,
• la figure 19 représente, schématiquement et partiellement, en coupe transversale, un article incorporant la structure de la figure 18, et
• la figure 20 illustre schématiquement une étape du procédé de fabrication de l'article de la figure 19, conformément à un exemple de mise en oeuvre de l'invention.

The invention will be better understood on reading the following detailed description, non-limiting examples of implementation thereof, and on examining the appended drawing, in which:

• the figure 1 represents, schematically and partially, an example of an article produced according to the invention,
• the Figures 2 and 3 represent, schematically and partially, in section, the structure incorporated in the article of the figure 1 according to two examples of implementation of the invention,
• the Figures 4 to 13 represent, schematically and partially, other examples of implementation of the structure,
• the Figures 14 to 16 show schematically and partially, in cross-section, articles respectively complying with various examples of implementation of the invention,
• the figure 17 schematically illustrates a step of a method of manufacturing the article of the figure 1 ,
• the figure 18 represents, schematically and partially, in cross-section, a security structure according to another example of implementation of the invention,
• the figure 19 represents, schematically and partially, in cross section, an article incorporating the structure of the figure 18 , and
• the figure 20 schematically illustrates a step of the manufacturing process of the article of the figure 19 according to an exemplary implementation of the invention.

In the drawing, for the sake of clarity, the relative proportions of the various elements represented have not always been respected, the views being schematic.

We have shown on the figure 1 an article 1, for example a bank note, comprising a fibrous layer 2, in which is incorporated a security structure 3 according to the invention.

Section 1 may still be a security paper, a passport slip or cover, a visa, a coupon, a document of value other than a ticket bank, for example a check or a credit card, a protection and / or authentication label, a traceability label or an optical disc.

Article 1 may be constituted by the structure itself, if necessary, for example in the case of a plastic banknote.

In the example under consideration, the structure 3 is in the form of a longitudinal axis strip X, with a width smaller than that of the article 1, for example being about 15 mm or less.

Structure 3 can be completely embedded in Article 1, as can be seen in figure 14 . Alternatively, as illustrated on the figure 15 , the structure 3 comes flush with a face 4 thereof. In another variant, as illustrated on the figure 16 , the structure 3 is partially embedded in the fibrous layer 2, so as to present alternately embedded and uncovered portions. For this purpose, the fibrous layer 2 may include recesses 5 leaving portions of the structure 3 discovered. The fibrous layer 2 may comprise, if appropriate, bosses 7, shown in dotted lines on the figure 16 , located between the recesses 5.

Article 1 may have, where appropriate, openings facilitating observation in transmitted light.

The structure 3 comprises for example a support 10 made of transparent plastic, in particular polyester, as illustrated in FIG. figure 2 .

The structure 3 comprises a first portion 13 substantially opaque and / or reflective surrounding second portions 12 substantially transparent.

In the example under consideration, the second portions 12 form groups of patterns 11 such as texts, as illustrated in FIGS. Figures 6 and 7 , repeating in the longitudinal direction of structure 3.

The patterns may alternatively represent a drawing, a symbol or a logo.

The first portion 13 may be formed by a metal deposit and the portions 12 by a demetallization of this deposit.

In a variant, the first portion 13 is formed by a deposit of an ink obtained by negative printing and the second portions 12 correspond to the zones that are devoid of ink.

The portions 12 and 13 may be made on only one side of the support 10, as shown in FIG. figure 2 , or, alternatively, on two opposite sides of the support 10, as illustrated in FIG. figure 3 .

The support 10 with the portions 13 is covered on at least one of its faces with at least one fluorescent composition.

In the example of Figures 2 and 3 , the support 10 and the portions 13 are covered by fluorescent compositions 15 and 16 appearing respectively in fluorescence of a first color C ₁ and a second color C ₂ , under a predefined lighting condition, for example under UV illumination , in particular of wavelength close to 365 nm.

In addition, the fluorescent compositions 15 and 16 have absorption spectra chosen so that, in the predefined lighting condition, their superposition appears from a third color C ₃ or a fourth color C ₄ , different first and second colors C ₁ and C ₂ , according to the order of the fluorescent compositions traversed by the incident light.

The fluorescent compositions 15 and 16 are, for example, those marketed by HONEYWELL.

The compositions 15 and 16 are non-opaque, so that the second portions 12 can be observed in daylight, by transparency.

We will now describe, with reference to Figures 4 to 7 , different steps to authenticate and / or identify the article 1.

When the article 1 is observed from the face 18 of the structure 3, in the predefined lighting condition, in reflection, the structure 3 appears with the first color C ₁ , as illustrated in FIG. figure 4 .

By observing the article 1 from the opposite face 19, still in the predefined lighting condition, in reflection, the structure 3 appears with the second color C ₂ , as shown in FIG. figure 5 .

In the predefined illumination condition, when the article 1 is observed in light transmitted from the face 18, the portions 12 appear with the third color C ₃ , as can be seen in FIG. figure 6 , and an observation by transparency from the other face 19 reveals the portions 12 with the fourth color C ₄ , as illustrated in FIG. figure 7 .

Thus, the authentication and / or the identification of the article 1 can go through the observation of four different colors.

In the example just described, the structure 3 has on each face 18 or 19 a single color, in the predefined lighting condition.

It is not beyond the scope of the present invention when the security structure comprises on each face fluorescent zones of different colors.

We have shown on Figures 8 and 9 a structure 3 'according to the invention, having on opposite sides 20 and 23 an alternation of adjacent fluorescent zones 21 and 22, respectively 24 and 25. The zones 21 and 25, respectively 22 and 24, are capable of emitting fluorescence a light of a first color C ₁ , respectively of a second color C ₂ , in the predefined lighting condition.

In the example considered, the fluorescent zones 21, 22, 24 and 25 have a rectangular shape. Of course, these fluorescent zones may have a different shape, for example trapezoidal.

Each zone 21, respectively 22, is superimposed exactly with a zone 24, respectively 25, of the other face. In the example considered, each pair of fluorescent zones 21, 24 and 22 completely covers a group of portions 12.

The color C ₃ or C ₄ produced by the observation in transmitted light of the fluorescent zones depends on the order in which the light passes through them.

• observer la structure 3' depuis la face 20, respectivement 23, dans la condition d'éclairage prédéfinie, en réflexion, de manière à détecter l'alternance de couleurs C1 et C2 sur la face 20, respectivement 23, comme illustré sur les figures 8 et 9,
• observer la face 20, respectivement la face 23, de la structure 3' dans la condition d'éclairage prédéfinie, par transparence, comme illustré sur les figures 10 et 11, afin de détecter la succession de groupes de portions 12 présentant alternativement des couleurs C3 et C4.

Authentication and / or identification of an article comprising the structure 3 'may thus comprise the following steps:

• observe the structure 3 'from the face 20, respectively 23, in the predefined lighting condition, in reflection, so as to detect the alternation of colors C1 and C2 on the face 20, respectively 23, as illustrated on the Figures 8 and 9 ,
• observe the face 20, respectively the face 23, of the structure 3 'in the predefined lighting condition, by transparency, as illustrated on the Figures 10 and 11 to detect the succession of groups of portions 12 having alternately C3 and C4 colors.

In order to reinforce the safety of the 3 'structure, it is possible to foresee, as illustrated on the figure 12 , transparent and / or translucent intermediate portions 27 between two groups of portions 12, these intermediate portions 27 revealing the joining two adjacent fluorescent zones 21 and 22, respectively 24 and 25, at least by transparency.

Thus, in the predefined illumination condition, when the structure 3 'is observed in transparency from the face 20 for example, the intermediate portions 27 each have the colors C ₃ and C ₄ .

It is found that, in the case where the fluorescent zones 21, 22 and 24, 25 do not coincide exactly, because for example one of the fluorescent zones 22 is wider than the zone 25 opposite, the intermediate portion 27 would not only the two colors C ₃ and C ₄ , but also a portion with the color C ₂ corresponding to the superposition of the zone 22 with the neighboring zone 24, which involves the falsification of the structure 3 '.

The intermediate portions 27 may form patterns 28, for example, patterns, revealing the junction between two adjacent fluorescent zones 21 and 22, respectively 24 and 25, as shown in FIG. figure 13 .

Diagrammatically and partially, on the figure 17 , a paper machine of round shape.

This machine comprises a tank 40 comprising a suspension 41 of fibers, for example cellulose fibers and / or cotton linters and / or synthetic and / or artificial fibers in which is partially immersed a cylinder of rotating fabric 42 defining a surface 43 in contact with which the fibrous layer 2 is formed.

The formation of the structure 3 can be incorporated in the fibrous layer 2 during its formation.

When the fibrous layer 2 has bosses 7, as described above, the cylinder 42 has reliefs 44, shown in dashed lines on the figure 17 these reliefs 44 being constituted for example by bosses on the cylinder 42 or by one or more masks.

We have shown on the figure 18 a security structure 50, according to another example of implementation of the invention.

• un support 51, par exemple en polyester,
• une couche de libération 52, par exemple en cire,
• éventuellement une couche de vernis 53,
• une première couche d'une première composition fluorescente 54, les couches 53 et 54 pouvant encore être confondues,
• une couche dans laquelle sont réalisées une ou plusieurs portions 13, par exemple une couche de métal partiellement démétallisée,
• une deuxième couche d'une deuxième composition fluorescente 55, et
• une couche d'adhésif 56, les couches 55 et 56 étant éventuellement confondues.

This structure 50, also called "foil" or "patch", comprises:

• a support 51, for example of polyester,
• a release layer 52, for example wax,
• optionally a layer of varnish 53,
• a first layer of a first fluorescent composition 54, the layers 53 and 54 still being confused,
• a layer in which one or more portions 13 are made, for example a partially demetallized metal layer,
• a second layer of a second fluorescent composition 55, and
• an adhesive layer 56, the layers 55 and 56 possibly being merged.

The optional layer of varnish 53, the first fluorescent composition 54, the layer defining the portion or portions 13 and the second fluorescent composition 55 form an assembly 60 to be transferred to a fibrous layer 2, for example on the surface thereof as illustrated on the figure 19 .

The assembly 60 may in particular be transferred hot to the fibrous layer 2, as illustrated in FIG. figure 20 .

The layer 2 and the structure 50 are then driven in displacement in the same direction by means of a machine comprising first 61 and second 62 rotating cylinders. After this passage, the support 51 and the release layer 52 are separated from the assembly 60, which remains integral with the layer 2.

In the example considered, the layer 2 has a relatively small thickness making it possible to observe, by transparency, the assembly 60 from the face of the layer 2 opposite to the assembly 60.

Alternatively, the layer 2 may for example be made of a transparent material, for example a transparent plastic material.

Of course, the invention is not limited to the embodiments which have just been described.

The structure according to the invention may be made otherwise than in band, for example in the form of a patch. The structure according to the invention may comprise compositions having a fluorescence other than in the UV, for example in the infrared.

• une puce électronique,
• un élément holographique ou diffractif,
• un revêtement magnétique ou cristallin,
• des cristaux liquides,
• une impression d'un vernis,
• un marqueur, notamment biologique, minéral ou synthétique,
• une encre ou une substance luminescente,
• un pigment thermochromique et/ou piézochromique.

The structures 3 and 3 'and the "foil" 50 may comprise, if desired, one of the following elements:

• an electronic chip,
• a holographic or diffractive element,
• a magnetic or crystalline coating,
• liquid crystals,
• an impression of a varnish,
• a marker, in particular a biological, mineral or synthetic marker,
• an ink or a luminescent substance,
• a thermochromic and / or piezochromic pigment.

Throughout the description, including the claims, the phrase "having one" should be understood as being synonymous with the phrase "having at least one", unless the contrary is specified.

Claims (34)

1. A security structure (3 ; 3'; 50) intended to be incorporated or fastened, at least partially, in or on an article (1), for example a security document and/or a document of value, the structure comprising:

   - at least one first fluorescent zone capable of emitting by fluorescence, under a predefined illumination condition, visible light of a first color (C₁); and

   - at least one second fluorescent zone capable of emitting by fluorescence, under the predefined illumination condition, visible light of a second color (C₂) that differs from the first, the first and second fluorescent zones being observable from the respective opposed faces (18; 19) of the structure,
   the structure being characterized in that at least one of the first and second fluorescent zones, in particular both, are at least partially nonopaque, at least under the predefined illumination condition, and in that the first and second fluorescent zones are superposed at least partially so that, under the predefined illumination condition, light passing in succession through the two fluorescent zones has a third color (C₃) that differs from the first and second colors (C₁, C₂).
2. The structure as claimed in the preceding claim, characterized in that the predefined illumination condition corresponds to ultraviolet illumination, in particular with a wavelength close to the visible.
3. The structure as claimed in claim 1, characterized in that the predefined illumination condition corresponds to infrared illumination.
4. The structure as claimed in any one of the preceding claims, characterized in that at least one of the first and second fluorescent zones, in particular both, are substantially colorless in white light.
5. The structure as claimed in any one of the preceding claims, characterized in that the first and second fluorescent zones have absorption spectra chosen so that, under the predefined illumination condition, light passing in succession through the two fluorescent zones has third (C₃) and fourth (C₄) colors that differ from the first and second colors (C₁, C₂), depending on the order of the fluorescent zones through which the incident light passes.
6. The structure as claimed in any one of the preceding claims, characterized in that it comprises at least one third fluorescent zone (22) observable on the face of the first fluorescent zone (21), having a color (C₂) that differs from the first fluorescent zone (C₁) under the predefined illumination condition.
7. The structure as claimed in the preceding claim, characterized in that it comprises:

   - at least one third fluorescent zone (22) having said second color (C₂) under the predefined illumination condition, the first and third zones being observable from a first face (20) of the structure; and

   - at least one fourth fluorescent zone (25) having said first color (C₁) under the predefined illumination condition, the second (24) and fourth (25) zones being observable from a second face (23) of the structure, on the opposite side from the first,
   each fluorescent zone on one face being at least partially, preferably exactly, superposed with a fluorescent zone of different color on the other face.
8. The structure as claimed in the preceding claim, characterized in that the third fluorescent zone (22), or the fourth fluorescent zone (25), is adjacent to the first fluorescent zone (21), or the second fluorescent zone (24), respectively.
9. The structure as claimed in the preceding claim, characterized in that the structure is nonopaque in a joining region between the first (21) and third (22) fluorescent zones, or second (24) and fourth (25) fluorescent zones, respectively.
10. The structure as claimed in any one of the preceding claims, characterized in that it has at least one entirely fluorescent face, in particular two opposed entirely fluorescent faces.
11. The structure as claimed in any one of the preceding claims, characterized in that it comprises a support (10; 51) which is at least partially, in particular entirely, transparent or translucent and bears the fluorescent zones.
12. The structure as claimed in the preceding claim, characterized in that the support (10 ; 51) is flexible, in particular being made of a plastic, for example a polyester.
13. The structure as claimed in either of claims 11 and 13, characterized in that at least one of the fluorescent zones is formed by depositing a fluorescent composition (15; 16) on one face of the support.
14. The structure as claimed in any one of the preceding claims, characterized in that it comprises at least first (13) and second (12) adjacent portions, the first (13) having a greater capability of preventing the passage of light, for a given illumination, than the second (12), the first portion (13) being in particular substantially opaque and/or reflective, at least under said predefined illumination condition, and the second portion (12) being substantially transparent and/or translucent, at least under said predefined illumination condition.
15. The structure as claimed in the preceding claim, characterized in that the second portion (12) is at least partially superposed with at least one fluorescent zone (15, 16).
16. The structure as claimed in either of the two preceding claims, characterized in that the second portion (12) has a shape chosen so as to define a pattern (11), the second portion being in particular entirely surrounded by the first.
17. The structure as claimed in either of claims 14 and 15, characterized in that the first portion (13) has a shape chosen so as to define a pattern (11), the first portion being in particular entirely surrounded by the second.
18. The structure as claimed in claim 19, characterized in that the pattern (11) is chosen from one of the following elements: a letter, a drawing, a symbol, a logo.
19. The structure as claimed in any one of claims 14 to 18, characterized in that the first portion (13) is formed by a metal layer, in particular a metal coating, and the second portion (12) is formed by demetallizing this layer.
20. The structure as claimed in any one of claims 14 to 18, characterized in that it includes printing, in negative or positive, with an ink, the first portion (13) having the ink and the second portion (12) having no ink.
21. The structure as claimed in any one of the preceding claims, characterized in that it furthermore includes one of the following elements:

    - an electronic chip;

    - a holographic and/or diffractive element;

    - a magnetic or crystalline coating;

    - liquid crystals;

    - printing with a varnish;

    - a marker;

    - a luminescent ink or substance;

    - a thermochromic and/or piezochromic pigment.
22. The structure as claimed in any one of the preceding claims, characterized in that it is in the form of a strip and constitutes for example a security thread.
23. The structure as claimed in any one of the preceding claims, characterized in that it has a width of at least 0.7 mm but preferably less than 60 mm, in particular between 1 mm and 40 mm.
24. The structure as claimed in any one of the preceding claims, characterized in that it is designed to be entirely incorporated into or onto the security article and/or the article of value.
25. The structure as claimed in any one of claims 1 to 23, which includes a support (51) bearing at least one fluorescent layer, characterized in that the support (51) is designed to be separated from the fluorescent layer (53) after the structure has been applied on a security document and/or document of value, the structure constituting for example a security patch.
26. An article at least partially comprising a security structure as defined in any one of the preceding claims.
27. The article as claimed in the preceding claim, characterized in that the structure is at least partially, in particular entirely, embedded in a layer of the article.
28. The article as claimed in the preceding claim, characterized in that the structure comprises, alternately, zones embedded in a layer of the article and portions that are exposed.
29. The article as claimed in any one of claims 26 to 28, comprising at least one fibrous layer (2).
30. The article as claimed in any one of claims 26 to 29, characterized in that the security article extends from a first edge of the article to a second edge, opposite the first.
31. The article as claimed in any one of claims 26 to 30, characterized in that it is intended to receive printing.
32. The article as claimed in any one of claims 26 to 31, characterized in that it is intended to constitute one of the following elements: a banknote; a security paper; a passport sheet or cover; a visa; a coupon; a document of value other than a banknote, for example a check or a credit card; a protective and/or authenticating label; a traceability label; a ticket.
33. A method of manufacturing an article, which includes the following steps:

    - provision of a structure as claimed in any one of claims 1 to 25,

    - at least partial incorporation or transfer of the structure into or onto the article.
34. A method of authenticating and/or identifying an article, for example a security document and/or a document of value, comprising a structure as claimed in any one of claims 1 to 25, the method including the following steps:

    - the article (1) is exposed to the predefined illumination condition; and

    - the authenticity and/or identity of the article is checked on the basis of the color or colors (C₁; C₂; C₃; C₄) revealed by the fluorescent zone.

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