EP2501554B1 - Security document including patterns with variable optical effect - Google Patents

Description

The present invention relates to the technical field of security elements for securities documents, such as fiduciary documents or similar.

For the purposes of the invention, "fiduciary document" means all documents such as banknotes, checks, bank cards, used to transmit a sum of money.

"Assimilated document" means any document issued by an administration of the State to prove the identity of a person, his rights to drive a vehicle, such as, in particular, the identity card, the passport, driving license, etc. By this expression is also meant any document used to authenticate an object of value such as for example a label affixed to a luxury garment. We also hear any document used to authenticate the payment of a tax such as tax stamps.

To date, there is a strong demand for security documents comprising security elements that are easily identifiable with the naked eye while being particularly complex to reproduce. Such security features are also referred to as "first level security".

The complexity of producing such an element generally resides in a diverse combination of printing techniques difficult to reproduce with consumer copying equipment (scanner, laser or color ink jet printers, etc.) and / or standard printing equipment.

Generally, security elements produce optical effects consisting of optical animations such as contrast sets, color changes, optical illusions, and so on.

Thus, we already know in the state of the art, including the document WO 2006/133512 , a security document comprising a substrate and a security element able to change color according to an angle of observation. This security element is formed in a transparent area of the security document and is able to change color according to an observation angle in reflection.

However, it is sometimes difficult for an uninformed observer to control unambiguously that the animation he observes corresponds to that prescribed for an authentic document. Indeed, such animation is often observable in specific configurations that the observer may have difficulty determining and there may ultimately remain a doubt as to the authenticity of the document.

WO 2009010714 A1 relates to a security document disclosing the features of the preamble of claim 1. There is therefore a need for new means of identification and / or authentication that may possibly contribute to the aesthetics thereof and whose compliance is easily and unambiguously verifiable, while being difficult to reproduce in such a way as to guarantee a great difficulty of counterfeiting.

For this purpose, the subject of the invention is, in particular, a security document, characterized in that the document comprises a substrate and a security element comprising first and second patterns carried by the substrate, in which the substrate further comprises a zone translucent, or even transparent, within which the first and second patterns extend at least partially, the first and second patterns are able to produce, within the transparent area, respectively at least first and second colors during an observation of the document in reflection and to swap these first and second colors during an observation of the document in transmission, so as to compose together a final image producing a variable color inversion optical effect according to configurations of transmissive and reflective observation and in that the element comprises a third pattern, extending at least partially in the zo not transparent, able to stain at least one color during an observation in reflection and to disappear substantially during a transmission observation in the transparent zone.

With the security document according to the invention, the user has no difficulty in understanding that the inversion optical effect that he observes is that expected.

Indeed, the final image produces a very intuitive optical effect since it is a color inversion in two very different and easily identifiable optical observation configurations.

Thus, since the color variation occurs during the passage from a reflection observation to a transmission observation, the user quickly determines the variable optical effect to be observed.

In addition, the user is not likely to misposition the document. Indeed, the user is usually spontaneously led to look through transmission and reflection security document, especially because it is strongly encouraged by the presence of the translucent or transparent area.

Colors include all possible colors including white, black, and gray.

In a preferred embodiment, the element comprises a third non-optically variable pattern extending at least partially within the window. This makes it possible to highlight the optical variation of the two patterns with respect to the third optically invariable pattern. Preferably, the first and second patterns extend within the third pattern to further emphasize the enhancement of the optical variation of the first and second patterns.

• les premier et deuxième motifs sont portés respectivement par des première et deuxième faces du substrat en repérage l'un de l'autre afin de se compléter pour former l'image finale ;
• le substrat comprend une autre zone sensiblement opaque et dans laquelle s'étend au moins partiellement un des motifs ;
• les premier et deuxième motifs sont imprimés avec une encre, telle qu'une encre iridescente à effet optique interférentiel ;
• l'encre comprend des traceurs de sécurité, par exemple des particules fluorescentes, des particules luminescentes, des particules de type à réaction à une longueur d'onde prédéfinie et/ou des particules thermochromes ;
• le document comprend un troisième motif réalisé par impression taille-douce pour former une image latente;
• l'élément comprend un troisième motif, s'étendant au moins partiellement dans la zone transparente, apte à changer de couleur en fonction d'un angle d'observation en réflexion et à disparaître sensiblement lors d'une observation en transmission dans la zone transparente ;
• le troisième motif est réalisé par impression avec une encre optiquement variable ;
• les motifs sont adjacents, voire contigües ;
• le substrat est réalisé dans un matériau comprenant essentiellement du papier à base de fibres naturelles et/ou synthétiques, du papier poreux et/ou du papier carton.
• le document est choisi parmi un billet de banque et un passeport ;
• au moins les premier et deuxième motifs sont portés par une première face et le troisième motif est porté par une deuxième face opposée à la première face, le troisième motif est agencé au moins partiellement en vis-à-vis avec chacun des premier et deuxième motifs de manière à ce que les premier et deuxième motifs soient au moins partiellement dissimulés par le troisième motif en observation en réflexion de la deuxième face et révélés par transparence du troisième motif en observation en transmission à partir de la deuxième face.

A document according to the invention may further comprise one or more of the features according to which:

• the first and second patterns are carried respectively by first and second faces of the substrate in register with each other in order to complete each other to form the final image;
• the substrate comprises another substantially opaque zone and in which at least partially extends one of the patterns;
• the first and second patterns are printed with an ink, such as an iridescent ink with optical interference effect;
• the ink comprises security tracers, for example fluorescent particles, luminescent particles, reaction type particles at a predefined wavelength and / or thermochromic particles;
• the document comprises a third pattern made by intaglio printing to form a latent image;
• the element comprises a third pattern, extending at least partially in the transparent zone, able to change color according to an observation angle in reflection and to disappear substantially during a transmission observation in the transparent zone ;
• the third pattern is achieved by printing with an optically variable ink;
• the patterns are adjacent, even contiguous;
• the substrate is made of a material essentially comprising paper based on natural and / or synthetic fibers, porous paper and / or paperboard.
• the document is selected from a bank note and a passport;
• at least the first and second patterns are carried by a first face and the third pattern is carried by a second face opposite the first face, the third pattern is arranged at least partially vis-a-vis with each of the first and second patterns so that the first and second patterns are at least partially concealed by the third pattern in reflection observation of the second face and revealed by transparency of the third pattern observed in transmission from the second side.

• les figures 1 et 2 représentent des vues d'une même face du document de sécurité selon un premier mode de réalisation de l'invention respectivement en observation réflexive et en observation transmissive ;
• la figure 3 représente une vue en coupe du document de la figure 1 selon la ligne 3-3 ;
• les figures 4 et 5 représentent des vues d'une même face du document de sécurité selon un deuxième mode de réalisation de l'invention respectivement en observation réflexive et en observation transmissive ;
• les figures 6 et 7 représentent respectivement des vues d'une première face et d'une deuxième face du document de sécurité selon un troisième mode de réalisation de l'invention en observation respectivement transmissive et réflexive;
• la figure 8 représente une vue en coupe du document de la figure 6 selon la ligne 8-8 ;
• les figures 9 à 11 représentent des vues d'une même face d'un document selon un quatrième mode de réalisation de l'invention respectivement selon différents angles d'inclinaisons du document et en observation réflexive ;
• les figures 12 à 14 représentent des vues d'une même face d'un document selon un sixième mode de réalisation de l'invention selon différents points de vue en observation en réflexion et en transmission.

Other characteristics and advantages of the invention will become apparent in the light of the description which follows, made with reference to the appended drawings in which:

• the Figures 1 and 2 represent views of the same face of the security document according to a first embodiment of the invention respectively in reflexive observation and in transmissive observation;
• the figure 3 represents a sectional view of the document of the figure 1 along line 3-3;
• the Figures 4 and 5 represent views of the same face of the security document according to a second embodiment of the invention respectively in reflexive observation and in transmissive observation;
• the Figures 6 and 7 respectively represent views of a first face and a second face of the security document according to a third embodiment of the invention in respectively transmissive and reflexive observation;
• the figure 8 represents a sectional view of the document of the figure 6 along line 8-8;
• the Figures 9 to 11 represent views of the same face of a document according to a fourth embodiment of the invention respectively according to different angles of inclination of the document and in reflexive observation;
• the Figures 12 to 14 represent views of the same face of a document according to a sixth embodiment of the invention according to different points of view in observation in reflection and in transmission.

There is shown in the Figures 1 to 3 a security document according to a first embodiment of the invention. The security document is designated by the general reference 10.

In this first embodiment, the document 10 is a bank note. Alternatively, the document 10 may be a passport, a driver's license or any other document that may require security.

This document 10 comprises a substrate 12 made for example of a material essentially comprising plastic, paper or a mixture both but the invention is not limited to a particular material. The substrate material may also have a multilayer structure, where appropriate, with several layers laminated together.

The substrate 12 further comprises a translucent zone 14, preferably transparent, designated in the following description by "window". This zone 14 is preferably surrounded by an opaque zone 16.

The presence of such a window 14 in a security document 10 allows in particular the incorporation of a security element of the type of transvision (in English "see-through") that is to say comprising an image observable in transmitted light or even reflected light in the window 14 from one or other of the faces of the document 10.

In this first embodiment, the substrate 12 is made of a transparent plastic material. The plastics material comprises for example essentially a polymer belonging to the family of bi-oriented polypropylenes (BOPP). To obtain the transparent window 14, the substrate 12 is for example covered with a layer of opaque white ink around the location of the window 14 while sparing the latter.

Alternatively, the substrate 12 may be made of a substantially opaque material and may be provided with a hole at the location of the window. A strip of transparent material is then deposited on one of the faces of the substrate to cover the hole and thus form the window. The strip is for example made of a material essentially comprising polyester. Such an embodiment is illustrated for example in the Figures 9 to 11 . We can see in these figures a strip 18 deposited on the document 10.

The document 10 further comprises a security element 20 carried by the substrate 12. More specifically, the security element 20 comprises first 22A and second 22B patterns extending at least partially in the window 14 and in this first embodiment. realization illustrated by the Figures 1 to 3 , the patterns 22A, 22B extend entirely inside the window 14.

These first and second patterns 22A, 22B are able to produce, within the transparent zone 14, respectively at least first and second colors during an observation of the document in reflection and to to swap these first and second colors during an observation of the document in transmission ( Figures 1 and 2 ).

The two patterns 22A and 22B together compose a final image producing a variable color inversion optical effect according to a transmissive and reflective observation.

In this first embodiment and as illustrated by the figure 3 , the two patterns 22A and 22B are carried by the same face F1 of the substrate 12. However, because of the transparency properties of the zone 14, the image is observable in transmission and reflection from one or other of the F1 and F2 faces of the substrate 12.

Preferably, the first 22A and second 22B patterns are printed with an interferential optical interference iridescent ink.

It has thus been discovered that an iridescent ink of particular formulation printed in a transparent area of a substrate produces hue variations when the viewing conditions in transmission and reflection vary.

This ink, also known as pearl effect ink, incorporates, for example, pigments with small semi-transparent plates that reflect light. These small plates give depth and shine in ink. The size of the pigments makes it possible to vary the satin or scintillating effect of the ink. Thus, a satin effect is obtained with fine pigments and a flicker effect with coarse pigments. Preferably, the pigments are based on mica and are prepared by grinding mica chips on which is deposited a metal layer such as for example titanium oxide or iron oxide. In this case, the color and the optical effect obtained depend in particular on the thickness of this layer. The pigments are also at the origin of color interference obtained by reflection of the incident light either by the semi-transparent pigments or by a film deposited on these pigments. However, the invention is not limited to an iridescent ink obtained from this technique.

Alternatively, other inks capable of producing a color change depending on a reflective or transmissive observation may be suitable.

In this first embodiment, the first pattern 22A is printed with a first iridescent ink and the second pattern 22B is printed with a second iridescent ink.

For example, the first ink is the ink referenced 75U008P marketed by the SICPA company which produces a turquoise color in reflection and red in transmission and the second ink is the ink referenced 73U022P also marketed by the SICPA company which produces a red color in reflection and turquoise in transmission.

In addition, in order to enhance the protection of the document against attempts at fraudulent copying or copying, the ink incorporates, for example, security tracers, such as, for example, fluorescent particles, luminescent particles, reaction-type particles. at a predefined wavelength and / or thermochromic particles.

Preferably, the first and second patterns are adjacent or even contiguous as shown in the figures. This makes it possible to accentuate the variable optical effect.

In a second embodiment illustrated by the Figures 4 and 5 , the security element 20 further comprises a third optically invariable pattern 22C. When changing the observation conditions, this third pattern does not vary. For example, this third pattern 22C is printed with a traditional colored ink but having no remarkable optical effect, such as for example an ink for offset printing, letterpress, gravure, flexography, screen printing, intaglio, etc.

In a third embodiment illustrated by the Figures 6 to 8 the first and second patterns 22A, 22B are respectively carried by first F1 and second F2 faces of the substrate 12 in register with each other in order to complete each other to form the final image. This makes it possible to enhance the security of the document-value 10 by making particularly complex any attempt at fraudulent reproduction of the document. Indeed, the reproduction of document requires a high accuracy of identification between the two faces F1 and F2 of the substrate 12. Thus, in the transparent zone 14, the least inaccuracy of identification is particularly visible and detectable by any informed observer.

In addition, as illustrated on the figure 6 it is seen that the first pattern 22A extends partially outside the transparent window 14, inside the opaque zone 16. Thus, the first pattern 22A comprises a first region R1, representing the number '100' in the window 14 and a second region R2, representing the symbol '€' in the opaque zone 16.

During a transmission observation of the F1 face ( figure 6 ), the region R2 of the first pattern 22A extending in the opaque zone 16 appears in the same color as the region R1 of the same pattern 22A extending in the transparent window 14 but less contrasting (the difference in contrast between the two regions R1, R2 is schematized on the figure 6 a dashed outline for low contrast and a solid outline for strong contrast). In reflexive observation of the second face F2 ( figure 7 ), the region R2 of the first pattern 22A extending in the opaque zone 16 is not observable.

In a fourth embodiment illustrated by the Figures 9 to 11 , the security element comprises a third pattern 22C producing an optically variable effect depending on the inclination of the document. In addition, the third pattern 22C becomes invisible in transmission ( figure 11 ). For example, the third pattern 22C is printed with an optically variable ink such as the ink referenced 75U009V OVI Green / Blue or the ink referenced 73U021 V Sicpastar pink / green marketed by SICPA.

In a fifth embodiment not shown in the figures, the security element further comprises a third pattern printed in relief to form a latent image. For example, the third pattern is obtained by deformation of the substrate by means of a press generating a dry stamp. Optionally, alternatively, at least one of the patterns, the first or the second pattern, can be achieved by intaglio printing inked to form a tactile mark and provide an additional degree of security to the document.

In a sixth embodiment illustrated on the Figures 12 to 14 , The element 20 comprises a third pattern 22C extending at least partially in the transparent area 14. This third pattern 22C is adapted to appear when viewed in reflection ( Figures 12 and 13 ) and to disappear substantially during a transmission observation in the transparent zone 14 ( figure 14 ).

The third pattern 22C is preferably adapted to change color depending on a viewing angle in reflection and substantially disappear when viewed in transmission in the transparent area 14, as is illustrated in Figures 12 and 13 which represent the face F2 carrying the third pattern 22C seen under two distinct observation observation configurations. Thus, according to a first point of view in reflection of the face F2 illustrated by the figure 1 2 , the third pattern 22C takes a first color and according to a second point of view in reflection of the face F2 illustrated by the figure 13 the third pattern 22C takes a second color.

Preferably, at least the first 22A and second 22B patterns are carried by a first face F1 and the third pattern 22C is carried by the second face F2 opposite to the first face F1. In this case, the third pattern 22C is arranged at least partially facing each of the first 22A and second 22B patterns so that the first and second patterns 22A, 22B are at least partially concealed by the third pattern. 22C in reflective observation of the second face F2 and revealed by transparency of the third pattern 22C in transmissive observation from the second face F2.

In the first and second observation patterns, the first and second patterns 22A and 22B are partially concealed by the third pattern 22C. In the third transmission observation configuration illustrated by the figure 14 the two patterns 22A, 22B are revealed by the transparency of the third pattern 22C.

Alternatively, the third pattern 22C may completely conceal the first and second patterns 22A, 22B ( Figures 12 and 13 ).

The main aspects of the invention according to the first embodiment will now be described.

First, the observer places the substrate 12 with respect to a light source S to observe the substrate 12 in reflection. It observes two distinct colors each produced by the first and second patterns 22A, 22B, for example turquoise for the first pattern 22A and red for the second pattern 22B.

Then, the observer then directs the substrate 12 with respect to the light source to observe in transmission the substrate 12. In the transparent zone 14, the image takes on a different appearance by changing the color very clearly. Thus, more particularly, the colors of the patterns 22A, 22B permute. The first pattern 22A turns red while the second pattern 22B becomes turquoise. This change is clearly identifiable to the observer.

This optical effect varies in a very intuitive way which removes any ambiguity concerning the authenticity of the document. In addition, it is possible to obtain particularly aesthetic images and easily identifiable optical animations without requiring prior knowledge of the optical effect prescribed. Having two distinct and clearly identifiable orientations for observing a color change also makes it possible to avoid any mispositioning of the document with respect to a light source.

It is understood that the embodiments which have just been described are not limiting and they can receive any desirable modification without departing from the scope of the invention.

Claims (12)

1. A security document (10), document comprising a substrate (12) and a security element (20) having first and second patterns (22A, 22B) carried by the substrate (12), wherein the substrate (12) further includes a zone (14) that is translucent or even transparent, within which the first and second patterns (22A, 22B) extend at least in part, characterized in that the first and second patterns (22A, 22B) are suitable for producing within the transparent zone (14) respectively at least first and second colors when the document (10) is observed in reflection and for interchanging the first and second colors when the document (10) is observed in transmission, so that together they make up a final image producing an optical effect of color inversion that varies as a function of the observation configuration in transmission or in reflection, and in that the element (20) includes a third pattern (22C) extending at least in part in the transparent zone (14) and suitable for being colored with at least one color during observation in reflection and for substantially disappearing during observation in transmission in the transparent zone (14).
2. A document (10) according to the preceding claim, wherein the third pattern (22C) is suitable for changing color as a function of angle of observation in reflection.
3. A document (10) according to either preceding claim, wherein at least the first and second patterns (22A, 22B) are carried by a first face (F1) and the third pattern (22C) is carried by a second face (F2) opposite from the first face (F1), the third pattern (22C) being arranged at least in part to overlap each of the first and second patterns (22A, 22B) in such a manner that the first and second patterns (22A, 22B) are hidden at least in part by the third pattern (22C) when observing the second face (F2) in reflection, and are revealed by the transparency of the third pattern (22C) when observing in transmission from the second face (F2).
4. A document (10) according to any preceding claim, wherein the first and second patterns (22A, 22B) are carried respectively by first and second faces (F1, F2) of the substrate (12) in register with each other so that together they form the final image.
5. A document (10) according to any preceding claim, wherein the substrate (12) includes another zone (16) that is substantially opaque and in which one of the patterns (22A, 22B) extends at least in part.
6. A document (10) according to any preceding claim, wherein the first and second patterns (22A, 22B) are printed using an ink such as an iridescent ink having an interference optical effect.
7. A document (10) according to the preceding claim, wherein the ink includes security tracers, for example fluorescent particles, luminescent particles, particles of the type that react at a predefined wavelength, and/or thermochromic particles.
8. A document (10) according to any preceding claim, wherein the third pattern (22C) is made by copperplate printing so as to form a latent image.
9. A document (10) according to any preceding claim, wherein the third pattern (22C) is made by printing using an optically-variable ink.
10. A document (10) according to any preceding claim, wherein the patterns (22A, 22B, 22C) are adjacent, or indeed contiguous.
11. A document (10) according to any preceding claim, wherein the substrate (12) is made of a material that essentially comprises paper based on natural and/or synthetic fibers, porous paper, and/or card.
12. A document according to any preceding claim, the document being selected from a bank note and a passport.

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