EP3148818A1

EP3148818A1 - Use of an optical security component for customising a security document and production of such a component

Info

Publication number: EP3148818A1
Application number: EP15729358.0A
Authority: EP
Inventors: Hugues Souparis; Jean SAUVAGE-VINCENT
Original assignee: Surys SA
Current assignee: Surys SA
Priority date: 2014-05-30
Filing date: 2015-05-28
Publication date: 2017-04-05
Anticipated expiration: 2035-05-28
Also published as: WO2015181289A1; FR3021583A1; EP3148818B1; FR3021583B1

Abstract

According to one aspect, the disclosure concerns the use of an optical security component (100, 200, 300, 500, 600) for customising a security document according to customisation data, the component being intended to be authenticated according to an observation face (F_obs), in a given spectral observation band, the component comprising: an opaque metal layer (104), structured to form a diffusing optical structure (20) in the spectral observation band, and customisable by laser ablation; and a layer or a set of layers forming an optically active structure (30), said layer or set of layers being arranged on the side of the structured metal layer opposite the observation face.

Description

USE OF AN OPTICAL SECURITY COMPONENT FOR CUSTOMIZATION OF A SECURITY DOCUMENT AND MANUFACTURING

OF SUCH A COMPONENT

FIELD OF DISCLOSURE The present disclosure relates to the field of security marking. More particularly, it relates to an optical security component for the production of a personalized security document, for example an identification document, which may comprise a paper support or a plastic or composite support such as a material card. polymer or a slip intended to fit into a passport. The authentication is intended to be done in reflection, for example with the naked eye.

STATE OF THE ART

Identity and travel documents such as national identity cards, driving licenses, passports, visas and registration certificates are basic means of control for a country. The solutions implemented to prevent counterfeiting and modification of official documents must guarantee not only the authenticity of identity documents and travel documents, but also the protection of personal data such as name, date of birth and Photo. Security must be both simple to verify but also difficult to imitate.

Many technologies implemented for securing the means of payment and official documents are based on variable optical effects easily authenticated to the naked eye, such as holograms. The applicant has thus developed an innovative technology based on the production of volume holograms whose image is individually personalized with the portrait of the document holder, for example. This volume hologram is produced by a direct method of recording the Bragg planes in a photopolymer material (see for example EP2238516B1). This technology allows the holographic recording of the personal data of the document holder at the heart of the security lamina, which offers a very high level of security by combining personalization and visual elements.

For the security of the personal data of the identity documents, laser ablation technology is also known, in particular in documents based on polycarbonate or polyvinyl chloride having reactive carbon atoms. laser. The published patents US 5331443, EP 0868314 and US 5808758 thus describe methods for personalizing security documents intended to be authenticated in reflection, in which the laser ablation is carried out in a thin metal layer, which allows a lower cost marking. energy, high speed and without risk of parasitic heating of the components of the layers. More specifically, in the published patent US 5331443, a metal layer is deposited on a diffractive optical structure for forming a hologram in reflection; the selective ablation of the metal layer according to patterns determined according to the personal data of the wearer makes it possible to render the component transparent and to eliminate the variable optical effect resulting from the formation of the hologram in the only places where the metal layer is ablated . In this case, it is therefore the background and not the personalization data that has a variable optical effect. The published patent EP 0868314 describes a component having two diffractive structures arranged one above the other, the diffractive structure on the side of the observation face being able to be personalized by laser ablation, leaving the ablated sites visible with the diffractive structure. lower. However, such a document lacks visibility due to the superposition of two layers simultaneously having varying optical effects. The published patent US 5808758 describes an identity card having a metal layer able to be ablated and below, a diffusing layer, so that the personalization data resulting from the ablation of the metal layer appear glossy on a black background to some observation angles.

Another example of implementation of securing personal data by laser ablation is described in the publication of the patent application FR 2975945. In this application, it is presented a plastic or composite identification card formed of a set of layers or "sheets" of which a sheet, for example a metal sheet, can undergo laser ablation in order to personalize the card. According to a variant, the card also comprises an optically variable diffractive device formed in or on the sheet to be ablated. The combination of the securing of personal data by laser ablation with the arrangement of an optically variable diffractive device makes it possible to reinforce the security of the identification card. However, again, the variable optical effect is not carried by the personalization data. In the case where the optically variable diffractive device is formed in the layer to be ablated, the image carried by the optically variable diffractive device is locally destroyed during the ablation.

The present disclosure proposes an optical security component in which it is the personalization data itself that carries the variable optical effect without the visibility being attenuated or the optical effect degraded. Such a component makes it possible, with respect to the techniques described in the prior art, to increase the security of the documents in which it is arranged by facilitating authentication while making reproduction much more difficult.

SUMMARY OF DISCLOSURE

According to a first aspect, one or more embodiments relate to an optical security component for manufacturing a personalized security document, the component being intended to be authenticated according to an observation face, in a given observation spectral band. the component comprising:

an opaque metal layer, structured to form a diffusing optical structure in the spectral observation band, and customized by laser ablation, for example according to personalization data;

a layer or set of layers forming an optically active structure, said layer or set of layers being arranged on the side of the structured metallic layer opposite to the observation face.

The spectral band of observation can be the visible one (typically between 380 nm and 780 nm), which allows an observation with the naked eye of the component.

In the present disclosure, a layer is said to be transparent in the observation spectral band, or more simply "transparent" if it passes at least 80% of an incident incident light flux at normal incidence. A layer is said to be opaque in the spectral band of observation, or more simply "opaque" if it leaves less than 20% of an incident light flux.

In the present disclosure, the term "optically active structure" is used to refer to any structure making it possible to form a variable optical effect, for example any variable color effect, either as a function of the illumination conditions or as a function of the observation conditions, for example as a function of the angle of observation in azimuth or tilt. The optically active structure may itself be opaque, transparent or semi-transparent.

This original arrangement of a security component makes it possible, by laser ablation of the structured metal layer, to generate personalization information, for example a photo or identification data, in the form of highly contrasting optically variable elements. Indeed, credentials appear on a neutral and stable background depending on the observation conditions, this background resulting from the diffusing optical structure formed by the structured metal layer. The neutral and stable background merges with the appearance of the support on which the component is arranged. This may for example be a diffusing white background or "dull white" in the case of a paper medium. An identification document bearing such a component has a very high level of security on the one hand because the identification data can be authenticated to the naked eye in a simple and reproducible manner, and secondly because it is difficult to reproduce. Such a document is also resistant to forgery since the ablated portion can not be reintegrated to the card.

The structures having a variable optical effect for the implementation of a security component according to the present disclosure are for example listed in the book "Optical Document Security" 2 ^nd edition, Rudolph L. van Renesse editor (1998), figure 15.1 (p.350).

The variable optical effects may result, for example, and without limitation, interference or diffraction phenomena, possibly coupled to mode dielectric resonance phenomena or surface plasmon resonance.

According to one or more embodiments, the layer or set of layers can be adapted for the formation of an optically variable diffractive device (or "DOVID") according to the English expression "Diffractive Optically Variable Image Device" ") With a variable color effect depending on the viewing angle. A DOVID type device generally comprises a layer structured to form a diffraction grating coated with a reflective layer, for example a high index dielectric layer or a metal layer.

According to one or more embodiments, the diffractive device is a structure that has a color effect at order 1.

According to one or more embodiments, the layer or set of layers may be adapted for the formation of an interference device.

According to one or more embodiments, the interference device is a Bragg hologram type structure having a color effect visible at the Bragg angle; it comprises for example a photopolymer layer in which is recorded a phase hologram.

According to one or more embodiments, the structure comprises a layer formed of a liquid crystal material. For example, the opaque metal layer may be carried by a structured transparent layer, arranged on the side of the observation face. This layer "support" of the structure can be tinted to match the color of the support of the document to which the component is intended.

According to one or more embodiments, the security optical component is adapted to the formation of a sticker for securing a document or a product. The optical security component comprises for example on the face opposite to the observation face an adhesive layer for transferring the component to the document or the product to be secured. According to one or more embodiments, the optical security component further comprises, on the side of the observation face, a carrier film to be detached after transfer of the component on the document.

According to one or more embodiments, the security optical component is suitable for forming a card-type plastic document, comprising one or more structural layers, the structured metal layer forming the diffusing optical structure and the layer or the set of layers forming the optically active structure being carried by at least one of said structural layers. The security optical component comprises, for example, a transparency window at which the structured metallic layer forming the diffusing optical structure and the layer or set of layers forming the optically active structure are arranged. The transparency window is not necessarily traversing.

According to a second aspect, the present disclosure relates to the use of a security optical component for the personalization of a document or security product according to personalization data, the component being intended to be authenticated according to an observation face ( Fobs), in a given spectral observation band, the component comprising:

an opaque metal layer, structured to form a diffusing optical structure in the spectral observation band, and customizable by laser ablation; and

According to one or more embodiments, the use of a security optical component may refer to one or more embodiments of the component indicated below.

According to a third aspect, the present disclosure relates to a personalized security document or product comprising:

a personalized security optical component intended to be authenticated according to an observation face, in a given observation spectral band, the personalized security optical component comprising:

an opaque metal layer, structured to form a diffusing optical structure in the spectral observation band, and customized by laser ablation, for example according to personalization data; and

According to a fourth aspect, the present disclosure relates to methods of manufacturing security optical components according to the first aspect or for use according to the second aspect.

According to one or more embodiments, the manufacturing method is adapted to the manufacture of a sticker for securing a document or a product intended to be authenticated in a given spectral observation band, and comprises:

the formation on a film carrying an opaque metallic layer, structured to form a diffusing optical structure in the spectral observation band, and customizable by laser ablation, for example according to personalization data; and

depositing a layer or a set of layers to form an optically active structure.

According to one or more embodiments, the manufacturing method is adapted to the manufacture of a card or a customizable plastic sheet, the card or the sheet being formed from a stack of structural layers, the method comprising :

the formation of a first intermediate component comprising: the formation on a film carrying an opaque metallic layer structured to form a diffusing optical structure in the spectral observation band, and customizable by laser ablation, by example according to personalization data; and transferring the diffusing optical structure to a structure layer of the card or sheet, and removing the carrier film;

forming a second intermediate component comprising: forming on a carrier film a layer or set of layers to form an optically active structure; and transferring the optically active structure to a structural layer of the card or sheet and removing the carrier film.

BRIEF DESCRIPTION OF THE FIGURES

Other characteristics and advantages of the disclosure will become apparent on reading the description which follows, illustrated by the following figures:

Figure 1, a partial sectional view of an optical security component according to one or more embodiments of the present disclosure, applied to the production of a sticker;

Figures 2 and 3 are partial cross-sectional views of exemplary security components according to one or more embodiments of the present disclosure applied to making a plastic or composite card;

FIGS. 4A and 4B, partial views of intermediate components obtained at various stages of manufacture of a card or plastic sheet type security optical component, according to an example;

FIGS. 5A and 5B, views respectively in section and from above illustrating an example of an optical security component before personalization;

FIGS. 6A and 6B, views respectively in section and from above illustrating a security optical component after personalization, according to an example;

FIGS. 7A to 7B, cross-sectional views and top views respectively illustrating a security optical component after personalization, according to another example.

DETAILED DESCRIPTION

The figures are shown for purposes of illustration and are not representative of the scales or forms of the actual components.

Figures 1, 2 and 3 show, in partial sectional views, embodiments of an optical security component according to the present disclosure. Figure 1 shows a partial sectional view of a customizable vignette by laser ablation to be arranged on a document to secure, for example a self-adhesive label or hot transferable component. Figures 2 and 3 show partial sectional views of a customizable map by laser ablation, for example a plastic or composite identification card or a plastic passport page.

FIG. 1 represents a customizable security optical component 100 intended to be transferred to a document or a product in order to secure it. It comprises, according to one or more embodiments, a carrier film 101, for example a film of polymer material, for example a polyethylene terephthalate (PET) film of a few tens of micrometers, for example 10 to 100 μιη, for example between 20 and 40 μιη, as well as a detachment layer 102, for example of natural or synthetic wax. The detachment layer makes it possible to remove the polymer support film 101 after attachment of the security optical component to the product or document to be secured. This layer is optional and can be continuous or discontinuous. The optical security component 100 furthermore comprises a layer 103 made of transparent material in the structured observation spectral band, on which is deposited a thin metallic layer 104 opaque to form a diffusing optical structure 20 which appears as a neutral and stable background as will be described in more detail later. The metal layer is customizable by laser ablation (for example an Nd-YAG type laser); it is a layer for example of aluminum or other reflective material such as gold, silver, copper, chromium or an alloy of these materials 20 to 100 nm thick, preferably 30 to 60 nm. In the example of FIG. 1, the component 100 furthermore comprises a transition layer 105 (optional) as well as a set of layers 106, 107 forming an optically active structure 30, examples of which will be given in more detail by the following. The transition layer 105 provides cohesion between the structured metal layer 104 and the layer or set of layers forming the optically active structure. The transition layer 105 may be an adhesive resin or a primary adhesion layer. She is transparent. Then added a layer of adhesive 108, for example a re-activatable adhesive layer hot or permanent, for fixing the security component on the product or document. In the case of a permanent adhesive layer 108, a protective layer 109 (for example a silicone paper) can be deposited on the adhesive layer 108. In practice, the security optical component 100 can be manufactured by stacking the layers on the support film 101, then the component is fixed on a document / product to be secured by the adhesive layer 108. The support film 101 can then be detached, for example by means of the release layer 102 Apart from the reflective layer 104 which is opaque, all the layers are preferably transparent. However, the layer (s) 106-107 forming the optically active structure and / or the adhesive layer 108 may be stained to provide the personalization data with a particular background color.

In the example of Figure 1, the structured metal layer 104 is obtained by depositing a metal layer on a structured layer 103, said support layer of the structure. The support layer of the structure 103 comprises, for example, microstructures having a random distribution, both spatially and in its dimensions, in order to provide an observer, after coating with the opaque metal layer, with a neutral, stable background effect. color and gloss in all conditions of use. The support layer of the structure 103 may be slightly tinted to match the shade of the substrate on which the component is to be applied. The structured metal layer 104 is customizable by laser ablation. The ablation of the metal layer can be done before or after transfer of the security optical component to the document or product to be secured; the ablation is done according to the personalization data of the wearer, for example identification data and / or a photograph of the wearer, for example treated in gray levels. The optically active structure is only revealed at the ablated areas of the metal layer.

In the example of FIG. 1, the optically active structure is formed of a set of layers 106, 107 suitable for producing a device of the DOVID type, and for example of the DID type.

A device of the DID type is known and described, for example, in the published application FR 2509873. The device of the DID type comprises according to one or more embodiments a multilayer film with a layer of high refractive index encapsulated between two layers of low index of refraction, the high refractive index layer being structured to form a subwavelength network characterized by a grating vector, such that the multilayer film acts at zero order as a structured waveguide permitting exciting resonances of guided modes at different wavelengths depending on the polarization. In reflection, such a component behaves like a band pass filter, forming a colored mirror whose color varies with the direction observation. In other words, an observer observing a device of DID type will see a colored effect of a first color in a first orientation and a color effect in a second color according to a second orientation obtained by azimuthal rotation of the device. Each "first" and "second" color corresponds to a spectral band of interest between 380 nm and 780 nm, centered on a wavelength defined by the period and depth of the sub-wavelength network, the thickness of the high index layer and the index difference between the high index and low index layers. The desired central wavelengths may for example be around 500 nm and 630 nm, making it possible to generate respectively green and red colors in direct reflection. The period of the grating may be chosen according to the central wavelength of interest, and is between 100 and 600 nm, for example between 200 and 500 nm. The difference between the high index and the low index is for example greater than 0.5.

According to one or more embodiments, the optically active structure may be an interference type structure.

For example, it may be a stack of layers of different refractive indices, unstructured, to form an interference filter. Such a structure is described for example in the published application US2007241553.

For example, the structure is a so-called Bragg structure. In one example, the optically active structure comprises a layer in which is inscribed a phase grating to form a volume hologram; the layer is for example a photopolymer layer in which the hologram can be recorded. In this case, the optical effect is visible at the Bragg angle. Such a structure is described for example in the published application US8059320.

An optical security component of the type of FIG. 1 implementing a device of the DOVID type, and more precisely of the DID type, can be manufactured for example according to the following steps.

In a first step, the microstructures making it possible to form the diffusing optical structure are recorded by photolithography or electron beam lithography on a photosensitive support or "photoresist" according to the Anglo-Saxon expression. The recording of the diffusing structure will for example be made by optical copy of a naturally diffusing structure, or the recording of the speckle of a laser beam whose microscopic characteristics are naturally random and analogous. An electroplating step allows to postpone these optical structures in a resistant material for example nickel-based to make a matrix or "master" metal. Embossing is carried out from the matrix to transfer the diffusing structure on the layer 103 made of transparent material (FIG. 1), for example a stamping varnish of a few microns thick carried by the film 101 from 12 μιη to 50 μιη. of polymeric material, for example PET (polyethylene terephthalate), or by the detachment layer 102 when provided. The stamping can be done by hot pressing of the transparent material ("hot embossing") or by molding ("UV casting" or "UV Curing"). The refractive index of the layer formed by the stamping varnish is, for example, 1.5. Then comes the metallization of the entire surface of the layer thus embossed by means of a metal customizable by laser ablation, for example a metal selected from silver, aluminum, gold, chromium, copper or an alloy of these metals. The metallization is for example carried out by evaporation under vacuum or by "sputtering".

One or more transition layers (105-106) are for example deposited on the structured metal layer to ensure cohesion with the other part of the component which carries the optically variable structure. In the case of a device of the DID type, at least one of these layers (106 in FIG. 1) may be a stamping layer made of a dielectric material of refractive index n o, for example a low index layer. for example a stamping varnish a few microns thick.

For producing the active optical structure, an optical structure formed, for example, of the subwavelength grating (s) in the case of the DID is recorded by photolithography or electron beam lithography on a photosensitive medium (or "Photoresist" according to the Anglo-Saxon expression). Again, an electroplating step makes it possible to transfer the optical structure in a resistant material, for example based on nickel, to produce a new metal matrix or "master" comprising the optical structure. Then comes the stamping of the layer 106 by the new matrix, for example by molding and UV crosslinking ("UV casting"). Next is the deposition on the layer 106 thus embossed with the layer 107 of refractive index or not different from, for example by evaporation in vacuo. The layer 107 is, for example, a high-index layer, for example Zinc sulphide (ZnS) with a refractive index of 2.2, or titanium dioxide (TiO ₂ ) with a refractive index of 2.5. or in high-index optical polymer material and its thickness between 40 and 200 nm. This follows the application of the layer 108 of refractive index n ₂ different from ni, for example an adhesive layer of a few microns thick, then the application of a protective layer 109 (optional). In the case where the active optical structure 30 is formed of an interference filter, it will be possible for example on the transition layer 105 to deposit a set of layers of different refractive indices, unstructured, adapted to the performing the interference filter, then applying the adhesive layer 108.

In the case where the active optical structure 30 is formed of a structure of

Bragg, it may for example be deposited a layer of photosensitive material, either on a transition layer 105, or directly on the metallized layer 104 of the diffusing structure 20. A laser source can be used to make the optical copy a plate comprising the holographic grating and / or for recording directly in the photosensitive material a Bragg grating. The recording is fixed in the material by a flash of UV light capable of permitting the crosslinking of the photopolymer.

FIGS. 2 and 3 illustrate two examples of the component according to the present disclosure, adapted for the production of a customizable map by laser ablation, for example a plastic or composite identity card of the identity card type, driver's license, etc. . or a passport slip.

In these examples, the component comprises a set of layers of thickness generally of between 50 and 400 μιη, merged together to form a document of nominal thickness of 750μιη for a card. The structural layers may be of plastic material, for example polycarbonate; among the set of layers, a thicker layer can form the heart of the document or "heart map" in the case of a map-type document, and the other layers of structure can be distributed symmetrically on both sides. another card's heart to form after the merger the card body.

Thus, in the example of FIG. 2, a customizable security optical component 200 comprises a set of structure layers 201 to 205, as described below. The component 200 further comprises on the side of the observation face of the card (recto) an opaque metal layer structured to form a diffusing optical structure 20 and customizable by laser ablation. The component 200 also comprises on the opposite side to the observation face (verso) a layer or set of layers adapted to the formation of an active optical structure 30. In this example, the diffusing optical structure 20 and structure active optics 30 are carried by two different layers of structure, 202, 204, the two layers being then merged with the others layers of structure, the central layer 203 forming the card core. According to one or more embodiments, all the structure layers are transparent in their entirety. According to one or more embodiments, only the layers 201 to 203 are transparent in their entirety. According to one or more embodiments, at least one of the structure layers 201 to 203 is opaque and has a transparency window on the other. whereof the diffusing optical structure 20 and the active optical structure 30 are arranged. In FIG. 2, the transparency window is indicated by dashed lines. The transparency window is for example obtained by only making a partial impression of the opacified structure layer. The transparency window may not cross the entire component, only the area between the observation face and the optically active structure to be transparent.

FIG. 3 represents another example of a customizable security optical component adapted to the manufacture of a plastic card or sheet. The customizable security optical component 300 comprises, as in the preceding example, a set of structure layers 201 to 205, and as before, an opaque metal layer structured to form the diffusing optical structure 20 and customizable by laser ablation and a layer or assembly However, in this example, the diffusing optical structure 20 and the active optical structure 30 are carried by a single structure layer 202. In one or more embodiments, the structures are carried by the card core 203. As previously, the diffusing optical structure 20 is arranged on the front side and the active optical structure 30 is arranged on the back side. The layer 203 is fused with the other layers of structure. Here again, at least one of the structure layers, for example the layer 202, may be opaque and have a transparency window at the location of which the diffusing optical structure 20 and the active optical structure 30 are arranged. layers beneath the optically active structure 30 is optional.

Whether in the example of FIG. 2 or in that of FIG. 3, the structured metallic layer forming the diffusing optical structure 20 can be ablated to reveal at the level of the ablated zones of the metal layer the Optically active structure 30. The ablation can be done according to the personalization data of the wearer, for example identification data and / or a photograph of the wearer.

Figures 4A and AB illustrate partial views of components intermediate 41, 42, obtained at different stages of manufacture of a customizable plastic security component card or plastic sheet, as shown in the examples of Figures 2 or 3, to obtain the diffusing optical structure 20 and active optical structure 30 respectively.

A step of producing an intermediate component 41 for manufacturing the diffusing optical structure 20 is shown in FIG. 4A. The intermediate component 41 may comprise, as in the embodiment of the vignette shown in 100 FIG. 1, a support film 401, for example a film made of a polymer material, for example a film of polyethylene terephthalate (PET) of a few tens of micrometers , for example 10 to 100 μιη preferably 20 to 40 μιη, and a detachment layer 402, for example natural wax or synthetic (optional). The intermediate component 41 also comprises a layer 403 made of transparent material in the structured observation spectral band, on which a thin opaque metal layer 404 is deposited, the set of two layers 403, 404 forming the diffusing optical structure 30 which appears as a neutral and stable background. The method of manufacturing the structured metal layer may be similar to that described in the embodiment of the vignette (Figure 1). The metal layer is customizable by laser ablation; is then added a layer of adhesive 408, for example a heat-reactive adhesive layer or for example crosslinkable adhesive. The adhesive layer 408 makes it possible to fix the intermediate component 41 on a structural layer. The detachment layer 402 can then be used to remove the polymer support film 401 after attachment of the intermediate component to the structural layer so that only the diffusing optical structure 20 remains.

A step of producing an intermediate component 42 for producing the diffusing optical structure 30 is shown in FIG. 4B. The intermediate component 42 may comprise, as before, a support film 401 and a release layer 402. On these layers is deposited (e) the set of layers adapted (e) to the formation of the optically active structure 30. The layer or set of layers for the formation of the optically active structure 30 may be one or the other of the layers or sets of layers described previously in the case of the example of FIG. 1 and the manufacturing method can be similar. Then, as before, an adhesive layer 408, for example a heat-reactive or crosslinkable adhesive layer, is added for fixing the security component to a structural layer. Thus, as in the case of the intermediate compound 41, the intermediate component 42 can be fixed on a structural layer and then the support film removed, for example by means of the release layer, so that there remains only the In one or more embodiments, the intermediate compounds 41, 42 are fixed on the front and back of the same structural layer (see example of FIG. 3). According to one or more embodiments, the intermediate compounds 41, 42 are fixed on two different layers of structure (see example of Figure 2).

Figures 5 to 7 illustrate, according to various examples, the optical effects obtained by means of an optical security component according to the present disclosure, before and after customization by laser ablation.

FIGS. 5A and 5B show a partial view in section and a view from above of a first customizable security optical component 500, before personalization by laser ablation. In this example, the component 500 is for example a plastic card or leaflet type component, as illustrated by means of FIGS. 2 and 3. However, the effects described would be similar with a vignette component, as illustrated for example by means of FIG. Figure 1, after transfer to a document or product to secure. In the example of FIG. 5, the customizable security optical component 500 comprises a set of layers including a metal layer structured to form a diffusing optical structure 20 as previously described and a layer or a set of adapted layer. (e) forming an optically active structure 30 as previously described. All other layers are not represented. The diffusing optical structure 20 and optically active structure 30 are arranged at a transparency window of the component. In this example, the layer or set of layers is for example adapted to the formation of a Bragg grating created in a photopolymer material. Before ablation, the optically active structure is not visible by an observer. Whatever the lighting or observation conditions, there is thus observed (see FIG. 5B) a neutral and stable background at the level of the diffusing optical structure 20 resulting from the structured metallic layer, which for example melts with the hue of the map or substrate of the document on which the component is embedded.

Figures 6A and 6B show the same component 500 after customization by laser ablation. As can be seen in FIG. 6A, the structured metal layer forming the diffusing optical structure 20 is discontinuous after ablation of the metal layer so that the optically active structure 30 is revealed at the ablated areas. Thus, an observer can appear (Figure 6B) with a very intense color effect, at the Bragg angle, personalization data recorded by means of laser ablation, and presented in this example in the form of a sun. The colored effect will be all the more important as the personalization data are visible on a stable neutral background obtained by the diffusing optical structure 20. Moreover, the colored effect will be variable, in particular by tilt rotation of the component, and therefore easily authenticatable and difficult to reproduce (that is to say difficult to imitate by technologies accessible to counterfeiters).

Figs. 7A through 7C show an embodiment of a customizable security optical component 700, wherein the optically active structure 30 is of the DID type. In these figures, the component is represented after laser ablation customization of the structured metal layer forming the diffusing optical structure 20. In this example, with respect to the effects illustrated in FIGS. 6B, an additional effect resulting from the presence of a optical structure of the DID type. The personalization data, again represented here in the form of a sun, present in this case a variable color effect by azimuthal rotation of the component (FIGS. 7B, 7C). According to one embodiment (not shown in FIGS. 7B, 7C) it is possible to provide for the optically active structure 30 at least a first element of type DID and a second element of type DID, the networks of the first and second elements being oriented in perpendicular directions, so that during an azimuthal rotation of the component, the colors of the two elements are reversed.

Although described through a number of exemplary embodiments, the optical security component, the use and the method of manufacturing said component comprise various variants, modifications and improvements which will be apparent to those skilled in the art. it being understood that these various variants, modifications and improvements are within the scope of the disclosure as defined by the following claims.

Claims

1. Use of an optical security component (100, 200, 300, 500, 600) for customizing a document or security product according to personalization data, the component being intended to be authenticated according to a face of observation (F ₀ b _s ), in a given spectral observation band, the component comprising: an opaque metal layer (104), structured to form a diffusing optical structure (20) in the spectral observation band, and customizable by laser ablation; and a layer or set of layers forming an optically active structure (30), said layer or set of layers being arranged on the side of the structured metal layer opposite to the viewing face.

2. Use of a security optical component according to claim 1, the opaque metal layer (104) being carried by a structured transparent dielectric layer (103), arranged on the side of the observation face.

3. Use of an optical security component according to claim 2, the transparent dielectric layer (103) being tinted to match the color of the support of the document or product to which the component is intended.

The use of an optical safety component according to any one of the preceding claims, the component further comprising, between the structured metal layer (104) and the one or more layers forming the optically active structure, at least one transparent transition layer (105) in the spectral observation band.

5. Use of a security optical component according to any one of the preceding claims, wherein the layer or set of layers forms an optically variable diffractive device (DOVID).

6. Use of an optical security component according to claim 5, the optically variable diffractive device being a device of the DID type, and comprising a first structured layer of dielectric material of given refractive index encapsulated between two layers of dielectric material of different refractive indices from that of the first layer.

7. Use of an optical security component according to any one of claims 1 to 4, the layer or set of layers forming a Bragg hologram.

8. Use of an optical security component according to any one of the preceding claims, the component being adapted to the formation of a sticker for securing a document or a product, comprising on the opposite side to the observation face an adhesive layer (108) for transferring the component to the document or the product to be secured.

9. Use of a security optical component according to claim 8, the component further comprising, on the side of the observation face, a carrier film (101) intended to be detached after transfer of the component to the document.

Use of an optical security component according to any one of claims 1 to 7, the component being adapted for forming a card-type plastic document, further comprising one or more structural layers (201- 205), the structured metal layer forming the diffusing optical structure (20) and the layer or set of layers forming the optically active structure (30) being carried by at least one of said structural layers.

The use of an optical security component according to claim 10, the component comprising a transparency window at which the structured metallic layer forming the diffusing optical structure (20) and the layer or the structure are arranged. set of layers forming the optically active structure (30).

12. Optical security component (100, 200, 300, 500, 600) for manufacturing a personalized security document or product, the component being intended to be authenticated according to an observation face (F _0bs ), in a given spectral observation band, the component comprising: an opaque metal layer (104), structured to form a diffusing optical structure (20) in the spectral observation band, and customized by laser ablation according to personalization data; and a layer or set of layers forming an optically active structure (30), said layer or set of layers being arranged on the side of the structured metal layer opposite to the viewing face.

13. Document or personalized security product comprising:

a personalized security optical component (100, 200, 300, 500, 600) intended to be authenticated according to an observation face (Fobs), in a given observation spectral band, the personalized security optical component (100, 200, 300, 500, 600) comprising: an opaque metal layer (104), structured to form a diffusing optical structure (20) in the spectral observation band, and customized by laser ablation according to personalization data; and a layer or set of layers forming an optically active structure (30), said layer or set of layers being arranged on the side of the structured metal layer opposite to the viewing face.

14. A method of manufacturing a security optical component (100, 200, 300, 500, 600) for use according to any one of claims 1 to 11, adapted to the manufacture of a sticker (100) for securing a document, the method comprising:

the formation on a carrier film (101) of the opaque metal layer (104;

depositing a layer or a set of layers to form an optically active structure (30).

15. A method of manufacturing a security optical component (100, 200, 300, 500, 600) for use according to any one of claims 1 to 11, adapted to the manufacture of a card (200, 300 ) or a customizable plastic sheet, the card (200, 300) or the sheet being formed from a stack of structural layers (201-205), the method comprising:

forming a first intermediate component (41) comprising: forming on a carrier film (401) the structured opaque metal layer (404); and transferring the diffusing optical structure (20) to a structure layer of the board (200, 300) or sheet, and removing the carrier film (401); forming a second intermediate component (42) comprising: forming on a carrier film (401) the layer or set of layers to form an optically active structure (30); and transferring the optically active structure (30) to a structure layer of the card (200, 300) or sheet and removing the carrier film (401).