FR3045890A1 - DOCUMENT PROVIDED WITH A SAFETY PATTERN MARKED BY A GHOST IMAGE - Google Patents

Abstract

The invention relates to a security document comprising a laminated multilayer structure (1,2) of which at least one layer (1,2) comprises a first security pattern (6; 6 '; 6 ") visible to the naked eye, characterized in that it comprises on a layer (3) intermediate distinct from that which carries said security pattern (6; 6 '; 6 ") and opposite thereof, a second pattern (5; 5'; 5 5 '' ') made slightly raised or recessed with respect to the surface of said layer (3), so that the lamination of the layers (1,2,3) produces by transfer of said second pattern (5). 5'5 ''; 5 '' '), the appearance on said first security pattern (6; 6'.6 "), a latent and indelible security mark (9).

Description

FIELD OF THE INVENTION The invention relates to the field of security documents such as contact or contactless smart cards, or data sheets called "Data Page". in English terminology, or even security documents in the form of a card or "Data Page" without a chip. The "Data Page" are rigid inserts usually in polycarbonate, forming the page of a passport where the biometric data of the holder of the passport are registered.

State of the art

In the state of the art, security documents are already known, in particular in the form of a smart card, comprising one or more visual security reasons.

Thus, documents containing security reasons of hologram type, OVI (acronym for "Optical Variable Ink"), OVD (acronym for "Optically Variable Device"), CLI (acronym for "Changeable Laser Image" or MU (acronym for "Multiple Laser Image").

OVIs are anti-counterfeiting devices commonly used on some banknotes and using inks that have two distinct colors depending on the angle at which they are observed.

OVDs are iridescent images based on diffractive optical structures and they exhibit various optical effects such as motion or color change impressions, depending on the amount of light that reaches them, and the angle of incidence of the light.

CLIs and MLIs are images that change their appearance depending on the viewing angle, and are impossible to reproduce by photocopying and require specialized equipment. The insertion of a security reason of the above type into a document makes it possible, of course, to reinforce the security and the traceability of this document, but it does not offer perfect security, insofar as it is often possible with appropriate tools to extract these security reasons for posting in another document, or even replace them with counterfeit security reasons.

It is recalled in this respect that security levels for security reasons are classified on several levels:

A safety reason is said to be level 1 if it is visible to the naked eye in ambient light.

A security reason is called level 2 if it is not detectable to the naked eye and if its detection requires simple external detection tools (magnifying glass, ultraviolet lamp or infrared).

A safety reason is said to be level 3 if it is not detectable to the naked eye or with simple means, and if its detection or revelation requires important technical means such as a microscope or very specific equipment .

Of course, Level 1 security features are very popular because they allow you to evaluate the authenticity of a document at a glance, which helps to speed up the implementation of controls, for example on ePassports.

In fact, the market is increasingly demanding that documents carry Level 1 or Level 2 security elements, in order to facilitate checks by security forces or security chain operators.

A disadvantage to the ease of detection is that Level 1 or Level 2 security elements are also the easiest to counterfeit, so there is a trade-off between the security level offered by a security element and its security level. ease of detection.

In order to improve this compromise, it has been proposed in document FR 2917871 A1 to make a visual security reason by creep of an outer layer of a smart card into the material of a chip card insert, so that to achieve a nested security pattern between two layers, making removal much more difficult.

It has also been proposed in document FR 2932910 A1 to use superimposed security elements, arranged on the electronic module of a smart card. But the obtained superposition is a simple stack, which does not change the appearance of security reasons and in particular does not create visual interaction between the superimposed patterns.

Purpose of the invention

The general object of the present invention is to propose visual security reasons for security documents, in particular of the smart card type, or of the Data Page type for electronic passports or the like, which are easily detectable with the naked eye, while offering increased resistance to counterfeiting.

A particular object of the invention is to propose documents intended for the identity market (cards and Data Page) and comprising in combination on the one hand elements known per se as holograms, OVI, OVD CLI or MLI, and comprising on the other hand a visual modification of these known elements, able to modify the visual aspect of the hologram, OVI, OVD, or CLI / MLI after lamination of the layers composing the card or the Data Page.

Object of the invention

According to the principle of the invention, visual security elements are superimposed so as to obtain a visual interaction due to the lamination of the layers of material containing the various visual elements, and to create, because of this interaction, a latent image or ghost ("ghost image" or "latent image" in English terminology).

More precisely, a visual and embossed irregularity is produced under a known security element of the hologram, OVI, OVD, CLI, MLI type, so that the lamination of the various layers together causes a purely visual effect, with no detectable relief by hand. or with the naked eye. Indeed, the relief of the irregularity becomes encrusted during the lamination of the layers, in an adjacent layer, but the irregularity remains visible in the form of a latent or ghost image. The subject of the invention is therefore a security document comprising a laminated multilayer structure of which at least one layer has a first security pattern visible to the naked eye, characterized in that it comprises on an intermediate layer distinct from that which carries said security motif and facing it, a second pattern slightly raised or recessed with respect to the surface of said layer, such that the lamination of all the layers produces the appearance on said first security reason of a security mark (9) latent and indelible, corresponding to the transfer of said second pattern on said first security pattern.

Preferably, said intermediate layer is dimensionally stable and without creep during lamination.

According to an alternative embodiment, said second security pattern is constituted by an engraved, wound or printed antenna portion, in relief relative to said intermediate layer, and its thickness is between 10 and 30 microns.

According to another variant embodiment, said second security pattern is constituted by a localized perforation of said intermediate layer, and its depth is between 25 and 50 micrometers.

According to another variant embodiment, said second security pattern consists of a localized printing on one of the layers constituting the structure and its thickness is between 10 and 30 micrometers.

According to embodiments of the invention, said first security reason is constituted by a hologram, an OVI, an OVD, a CLI or a MLI.

The security document according to the invention is for example in the form of a smart card, contact or contactless, but other form factors are of course possible, such as a data sheet ("Data"). Page "), or a" Data Page "without electronic. The invention also relates to a method for producing a laminated multilayer security document as described above, comprising a step of arranging on at least one of the layers of said document, a first hologram-type security element. , OVI, OVD, CLI or PWM, this method being characterized in that it further comprises a step of modifying one of the layers to be rolled, to provide a second security element made in relief or recessed representing a recognizable pattern, said second security element being disposed opposite said first security element and capable of appearing therein, by transfer during lamination of the various layers together, an indelible ghost mark. The invention will be better understood on reading the detailed description and on examining the figures, in which: FIG. 1 represents an exploded perspective view of a first embodiment of a card-type security document; chip, incorporating a latent image security pattern according to the invention; FIG. 2 represents an exploded perspective view of a second embodiment of a security document of the smart card type, incorporating a security motif in the form of a latent image according to the invention; FIG. 3 represents an exploded perspective view of a third embodiment of a security document of the smart card type, incorporating a security motif in the form of a latent image according to the invention; FIG. 4 represents an exploded perspective view of a latent image obtained by printing or etching located under an OVI; FIG. 5 represents a photograph of the result of the lamination of an engraved pattern under a CLI or MLI;

detailed description

Referring to FIG. 1, there is shown a card 10 comprising a multilayer structure having two outer layers 1 which are made of transparent material, for example polycarbonate, two opaque or transparent intermediate layers 2 and which serve to receive the graphic personalization of the card 10, in the form of graphic prints, and a central layer 3.

When the card is a smart card, it comprises a microelectronic module 8 disposed in a cavity of one of the layers, as known per se.

When the smart card is a non-contact operating card, the central layer 3 carries an antenna 4, for example etched by removal of material in a thin metal layer disposed on the material of the central layer 3.

The upper layer 1 or 2 comprises a security pattern 6, of the OVI, OVD, PWM, CLI, or hologram type.

According to the invention, the central layer 3 comprises, opposite the security pattern 6 of the upper layer 1 or 2, a cutout 5 according to a certain specific pattern. It may be a logo, letter, number, or any recognizable pattern.

During the lamination of the layers of the card, the slight depression of a few tens of micrometers of the layer 3 due to the cutting 5 refers, attenuated, in the adjacent layers, namely in particular the layer 2 and the layer of transparent protection 1. As a result, the hollow due to the cut 5 is transferred by transfer to the security pattern 6, on which it causes an indelible marking.

In other words, the transfer of the blank 5 through the layers 1,2 creates a latent image or ghost image on the security pattern 6, and this latent image reproduces the shape of the blank 5.

So that the transfer of the pattern 5 of the layer 3 is done correctly on security pattern 6 of an adjacent layer 1,2, it is preferable that the layer 3 is made of a material with little or no fluency, or at least not as fl uid than the adjacent layers 1 or 2, so that the transfer of the depression of the cutout 5 to the security pattern 6 is done correctly.

As shown in FIG. 2, the cutout 5 in the layer 3 can be replaced by a 5 'relief image creating an irregularity which is transmitted during the lamination, in the form of a latent image, into the security pattern 6 of the layer 1. Given the weakness of the relief (a few micrometers), it is not represented in the figure. This relief image 5 'can in particular, in the case of a chip card provided with an antenna, be made in the same manner as the antenna, for example by etching a thin metal layer disposed on the layer 3 , the tracks of the antenna and the image 5 'then being in slight relief with respect to the surface of the central layer 3.

According to another variant shown in Figure 3, a pattern 5 "is printed for example on one of the intermediate layers 2 opposite the security pattern 6 located in this example in the lower transparent layer 1. Again, as this impression of the pattern 5 "creates a slight local relief on the layer 2, the image of this relief is transferred to the security pattern 6 during the lamination, in the form of a latent image superimposed on the pattern of security 6.

FIG. 4 shows a security element 6 'of MLI type disposed on the stack of layers 1,2 of a security document. One of the layers of the card stack includes metal tracks of an antenna, which form a pattern 5 '' specific in terms of thickness, arrangement, or appearance. Due to the lamination of the layers of the stack, the slight relief formed by the tracks of the pattern 5 '"will refer to the layer 2 and the upper layer 1, which will modify the appearance of the MLI 6', which will appear visually as the combination between the MLI 6 'and the 5' 'pattern In other words, the pattern 5' "prints or transfers a ghost image into the MLI 6 '."

Figure 5 shows a photograph of a concrete example of implementation of the invention. In superposition of the security element 6 "constituted by an OVI, a latent image 9 is observed formed by the trace of antenna tracks on the OVI 6".

According to the embodiments of the invention, the thickness of the relief pattern 5, 5 ', 5 ", 5'" (antenna or pattern of extra thickness, or pattern printed in relief or hollowed out on one of the layers of the 10) is between 10 and 30 micrometers in the case of an engraved or wound or printed antenna, and is between 25 and 50 microns in the case of a perforation 5 formed in the perforated central layer 3.

Advantages of the invention

In all the cases described, the raised or recessed element 5, 5 ', 5 ", 5"' is embedded in the layers of the card body and comes to mark the rolling of the security element 6, which which has the effect of creating a latent image on this security element, without altering the functionality thereof. Therefore, it would be useless to cut the card or the support to recover or replace this security element 6, it will remain marked by a custom imprint, visible and indelible.

It should be noted that to reproduce the latent image, it would be necessary to have two distinct elements, namely the relief element or specific recessed element 5, 5 ', 5 ", 5'", and the element of security, which substantially complicates any attempt at fraud.

Claims (8)

1 - Security document comprising a laminated multilayer structure (1,2) of which at least one layer (1,2) comprises a first security pattern (6; 6 '; 6 ") visible to the naked eye, characterized in that it comprises on a layer (3) intermediate distinct from that which carries said security pattern (6; 6 '; 6 ") and opposite thereof, a second pattern (5; 5'; 5"; 5 "") made slightly in relief or recessed with respect to the surface of said layer (3), so that the lamination of the layers (1,2,3) produces by transfer of said second pattern (5; 5'5 " 5m), the appearance on said first security pattern (6; 6'.6 ") of a latent and indelible security mark (9). 2 - Security document according to claim 1, characterized in that said intermediate layer (3) is dimensionally stable and without creep during lamination, this layer (3) being able to support said second pattern (5; 5,; 5 "; ') in relief or hollow. 3 - Security document according to claim 2, characterized in that said second security pattern (5; 5 '; 5 "; 5"') is constituted by an engraved, wound or printed antenna portion, in relief relative to said intermediate layer (3), and whose thickness is between 10 and 30 micrometers. 4 - Security document according to claim 2, characterized in that said second security pattern (5; 5,; 5 "; 5",) is constituted by a localized perforation of said intermediate layer (3), and whose depth is 25 and 50 micrometers. 5 - Security document according to any one of the preceding claims, characterized in that said first security pattern (6) is constituted by a hologram, an OVI, an OVD, a CLI or MLI. 6 - Security document according to any one of the preceding claims, characterized in that it is in the form of a smart card, contact or without contact. 7 - security document according to any one of claims 1 to 5, characterized in that it is in the form of an electronic data page or a Data Page without electronic. 8 - Process for producing a laminated multilayer security document according to any one of the preceding claims, comprising a step of arranging on at least one of the layers (1, 2, 3) of said document, a first element of security (6) hologram type, OVI, OVD, CLI or MLI, characterized in that it further comprises a step of modifying one of the layers (1,2,3) to laminate, to bring a second security element (5, 5 ', 5 ", 5"') made in relief or recessed, representing a recognizable pattern, said second security element being arranged facing said first security element (6) and capable of causing this, by transfer during the lamination of the various layers together, an indelible mark (9) phantom.