EP3007903B1 - Security structure having a diffractive optical element - Google Patents

Security structure having a diffractive optical element Download PDF

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Publication number
EP3007903B1
EP3007903B1 EP14733373.6A EP14733373A EP3007903B1 EP 3007903 B1 EP3007903 B1 EP 3007903B1 EP 14733373 A EP14733373 A EP 14733373A EP 3007903 B1 EP3007903 B1 EP 3007903B1
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EP
European Patent Office
Prior art keywords
diffractive optical
opaque
optical element
region
security
Prior art date
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EP14733373.6A
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German (de)
French (fr)
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EP3007903A1 (en
Inventor
Pierre Sarrazin
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Oberthur Fiduciaire SAS
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Oberthur Fiduciaire SAS
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30—Identification or security features, e.g. for preventing forgery
    • B42D25/346—Perforations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30—Identification or security features, e.g. for preventing forgery
    • B42D25/328—Diffraction gratings; Holograms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30—Identification or security features, e.g. for preventing forgery
    • B42D25/355—Security threads
    • B42D2033/22—
    • B42D2035/36—
    • B42D2035/50—

Definitions

  • the present invention relates to security structures and secure articles, in particular documents, comprising such structures.
  • DOEs diffractive optical elements
  • These elements can be produced with a view to being illuminated by monochromatic or polychromatic light, in order to generate the interference pattern by diffraction and transmission through the element to a viewing plane.
  • this display plane can be virtual and located between the element and the light source or be materialized by an actual surface located behind the element with respect to the source.
  • Australian patent application AT 2013 100 172 describes a security document comprising a multitude of openings produced by laser ablation generating a diffractive optical element and a reflective layer having on its surface series of grooves and a layer of liquid crystal.
  • Australian patent application AU 2011101567 describes the use and visualization of diffractive optical elements sensitive to at least three different wavelengths on security documents.
  • the diffractive optical elements are recorded with three different lengths and the interference pattern is reproduced by lighting at the appropriate wavelengths.
  • the invention aims to meet all or part of these needs.
  • non-opaque microzone designates an area which is sufficiently permeable to light to allow the visualization of the interference pattern by virtue of the light passing through this area, having a cross section of surface less than or equal to 1,000,000 ⁇ m 2 , better less or equal to 200,000 ⁇ m 2 , even better between 10 ⁇ m 2 and 200,000 ⁇ m 2 , even better between 5,000 ⁇ m 2 and 200,000 ⁇ m 2 .
  • the non-opaque microzone has a cross section sufficient to observe the DOE in transmitted light and sufficiently reduced so as not to be substantially visible in reflection.
  • a non-opaque microzone is thus of limited extent, being delimited by an opaque periphery.
  • the non-opaque microzone can be translucent, in particular diffusing part of the light passing through it or transparent, not diffusing the light passing through it.
  • the non-opaque microzone is transparent.
  • a non-opaque microzone has the advantage of being easily detectable only under certain observation conditions, and is therefore not easily visible to the naked eye if these observation conditions are not observed.
  • the use of a non-opaque microzone makes it easier to conceal the diffractive optical element and makes counterfeiting more difficult to carry out.
  • the non-opaque microzone can be of circular or non-circular cross-section, in particular polygonal, in particular regular or non-regular polygonal, or oblong, in particular elliptical.
  • the non-opaque microzone can be produced in a layer of fibrous or non-fibrous material which extends all around the non-opaque microzone.
  • the non-opaque microzone can be a microperforation of a layer of a substantially opaque material filled at least partially, preferably entirely, with a transparent material comprising in particular a protective adhesive material.
  • the transparent material by penetrating into the microperforation, makes it possible to join the layer of substantially opaque material and the layer carrying the diffractive optical element.
  • the fact that the microperforation is at least partially filled makes it possible to protect it from the external environment, in particular from dirt.
  • the or each non-opaque microzone can be defined by an absence of material within a layer of a substantially opaque material, in particular be defined by a microperforation through this opaque material when the latter is, for example, a fibrous substrate, or be defined by demetallization when the opaque material is metallic.
  • microperforations these are preferably carried out using a laser.
  • the microperforations are carried out using micro-needles or by water jet.
  • the axis of this microperforation is preferably oriented substantially normally on the surface of the layer through which the microperforation is carried out.
  • the axis can, as a variant, form an angle with the normal to the surface of the layer which is crossed by the microperforation.
  • the non-opaque microzone can be, when defined by a microperforation, of constant cross section or not over the thickness of the layer crossed by the microperforation.
  • the non-opaque microzone can also be delimited by an impression of an opaque ink, in particular an impression of a transparent plastic film, for example the same film as that on which the diffractive optical element is produced.
  • the same layer of the structure according to the invention may have a plurality of non-opaque microzones, each overlapping at least partially on the same diffractive optical element.
  • the non-opaque microzone (s) can each form a pattern which is found in at least part of the interference pattern generated by the diffractive optical element.
  • the non-opaque microzone has a contour which is found in the interference pattern, for example the same geometric shape.
  • non-opaque microzones can together define a pattern which is found in at least part of the interference pattern, for example the image of the same character, place, monument or object, or the same text, for example the value d '' a banknote or the name of a bank.
  • the pattern facilitates authentication by the observer by comparing said pattern to the interference pattern. This arrangement increases the security of the document because the counterfeiting requires the reproduction of the pattern both in the microzones and in the interference pattern of the security structure.
  • the thickness of the layer through which the microperforation passes can be between 10 and 1,000,000 ⁇ m.
  • the number of non-opaque microzones is preferably between 1 and 1500 non-opaque microzones per cm 2 , preferably between 10 and 500 per cm 2 , more preferably between 10 and 300 per cm 2 .
  • the diffractive optical element which generates the interference pattern in a viewing plane distant from the diffractive optical element is preferably of digital type. Its manufacture is then based, as described in WO 2008/031170 , on a matrixing carried out according to complex data which are reconstructed in the display plane to form a two-dimensional interference pattern.
  • the diffractive optical element when illuminated by a collimated light source, it generates an interference pattern producing an image in this viewing plane, which is visible on a surface positioned in this plane, or visible in transmission from this plan.
  • the mathematical transformation between the element and the visualization plane can be compared to a fast Fourier transform (FFT).
  • FFT fast Fourier transform
  • complex data comprising phase and amplitude information, must be physically encoded in the microstructure of the element.
  • the relief to be given to the microstructure can be calculated by carrying out the inverse FFT transform of the desired pattern in the display plane.
  • Diffractive optical elements are sometimes referred to as computer generated holograms, and differ from other types of holograms such as rainbow, Fresnel or volume reflection holograms.
  • the diffractive optical element is an embossed structure.
  • the interference pattern generated by the diffractive optical element is found at least in part, better in total, on the security structure, or on the article, in particular the document incorporating it, in particular in the form of a print and / or a security element, in particular a watermark, and / or a pattern generated by microperforations or a metallization or demetallization.
  • microperforations one of these can define the non-opaque microzone.
  • the diffractive optical element generates the image of a character and a watermark reproducing the same character is present on a fibrous substrate on which a microperforation is carried out defining the non-opaque microzone.
  • the non-opaque microzone can also belong to a security element which reproduces all or part of the interference pattern.
  • the non-opaque microzone is formed by demetallization of a metallic security thread and the image of a character produced by the interference pattern is found on the wire, being formed by demetallization thereon, with or without superposition with the diffractive optical element.
  • the diffractive optical element is smaller, in particular in all directions of its plane, than the non-opaque microzone.
  • the diffractive optical element may be larger in at least one direction of its plane than the non-opaque microzone.
  • the diffractive optical element is preferably formed on a thermoplastic film, preferably transparent, having a thickness less than or equal to 50 ⁇ m, in particular by embossing the latter.
  • This thermoplastic film can be laminated at least partially with the layer carrying the non-opaque microzone or through which the non-opaque microzone is produced.
  • the thermoplastic film comprising the diffractive optical element is fixed to the layer carrying the non-opaque microzone by an adhesive structure, preferably also protective, comprising an adhesive material.
  • the adhesive structure can be introduced in the liquid state between the thermoplastic film and the layer carrying the non-opaque microzone by means of at least one microperforation, in particular forming at least one non-opaque microzone.
  • thermoplastic film makes it possible to form the diffractive optical element independently of the rest of the secure article, and therefore to facilitate its manufacture.
  • thermoplastic film can be laminated or glued with a security element, in particular a security wire or foil, having at least one transparent zone, in particular the non-opaque microzone, overlapping at least partially with the diffractive optical element.
  • This security element may have a security pattern, in particular in the form of printing, microperforations or metallization or demetallization. As indicated above, this pattern can correspond at least partially to the interference pattern produced by the diffractive optical element.
  • the diffractive optical element can be recorded on the thermoplastic film by a process known as “roll to roll”.
  • the diffractive optical element can be viewed under polychromatic or monochromatic light.
  • the diffractive optical element can be associated with an optical, interference, iridescent or absorbent filter, placed on the path of the light reaching or leaving the optical element. diffractive.
  • This filter can belong to the security structure or to the article and thus constitute an additional security element as such.
  • the security structure may be in the form of an element which is integrated into a fibrous substrate during the manufacture thereof or which is attached to its surface.
  • the security structure can be in the form of a patch, security wire, foil or film.
  • the security structure may be exposed to the external environment on its two opposite faces or be exposed on only one of them or be covered on its two faces by one or more layers which are not completely opaque, for example a film protective or varnish.
  • the security structure can be in one piece at the time of its integration into or on the rest of the article, in particular of the document, or be composed of several sub-elements which are assembled via the rest of the article, in particular of the document, for example being reported on different faces of a substrate of the document. These sub-elements may or may not come into contact with each other.
  • a first sub-element can carry the diffractive optical element and second sub-element can carry the associated non-opaque microzone, and the two can be separated by at least one layer of substrate from the document or be assembled directly one with the other.
  • the security structure comprises a protective adhesive structure or an adhesive structure associated with a protective structure disposed between the first sub-element carrying the diffractive optical element, in particular the diffractive optical element and the second sub-element carrying the microzone not opaque.
  • protective adhesive structure or protective structure means a layer or a plurality of layers intended to protect mechanically and / or optically, the diffractive optical element in particular when the diffractive optical element is an embossed structure.
  • the protective adhesive structure preferably comprises a layer of a mixture of an HRI (high refractive index) material and an adhesive material which is placed on the diffractive optical element.
  • HRI high refractive index
  • the first sub-element comprises a layer of an HRI material, preferably deposited by vacuum spraying on the diffractive optical element, on which is preferably arranged a layer of an adhesive material, the layer of adhesive material being preferably disposed between the layer of HRI material and the second sub-element carrying the non-opaque microzone.
  • the superimposition of the layer of HRI material and the layer of adhesive material forms the protective adhesive structure.
  • the adhesive layer makes it possible to mechanically protect the diffractive optical element
  • the HRI material protects the diffractive optical element from attenuation or cancellation of its optical effect which could result from the presence of the adhesive material.
  • the protective structure associated with the adhesive structure comprises a mixture of a HRI (high refractive index) material and a binder, which is disposed on the diffractive optical element, the adhesive structure preferably being disposed on the protective structure, in particular between the second sub-element carrying the non-opaque microzone and the protective structure.
  • HRI high refractive index
  • the first sub-element comprises a layer of HRI material arranged, in particular deposited by vacuum spraying, on the diffractive optical structure, on which is arranged a layer comprising a binder, the superposition of the layer of HRI material and the layer comprising a binder forming the protective structure associated with the adhesive structure.
  • the adhesive structure is preferably arranged on the protective structure, in particular between the protective structure and the second sub-element carrying the non-opaque microzone.
  • the binder is secured for example by the presence of a specific marker or of a luminescent compound.
  • the layer of HRI material makes it possible to optically protect the diffractive optical element and the binder layer makes it possible to mechanically protect the diffractive optical element.
  • the HRI material makes it possible to protect the diffractive optical element from attenuation or cancellation of its optical effect which could result from the presence of the adhesive material and / or the layer comprising a binder.
  • an HRI material is meant a material having a high refractive index, preferably greater than or equal to 1.7.
  • the HRI material is chosen from zinc sulfide (ZnS), zinc oxide (ZnO), zirconium oxide (ZrO 2 ), titanium dioxide (TiO 2 ), carbon (C), indium oxide (In 2 O 3 ), indium tin oxide (ITO), tantalum pentoxide (Ta 2 O 5 ), cerium oxide (CeO 2 ), itrium oxide (Y 2 O 3 ), europium oxide (Eu 2 O 3 ), ferrous oxides, hafnium nitride (HfN), hafnium carbon (HfC), hafnium oxide (HfO 2 ), l lanthanum oxide (La 2 O 3 ), magnesium oxide (MgO), neodymium oxide (Nd 2 O3), praseodymium oxide (Pr 6 O 11 ), samarium oxide (Sm 2 O 3
  • the protective adhesive structure or the adhesive structure associated with a protective structure can be introduced via one or more microperforations of the second sub-element, in particular at least one microperforation defining a non-opaque microzone.
  • the protective adhesive structure or the adhesive structure associated with a protective structure may partially, preferably completely, fill the microperforation (s).
  • the diffractive optical element is arranged on a first side of the first sub-element, the second side of the sub-element having no diffractive optical element and the adhesive structure being disposed between the second sub-element and the second side of the first sub-element.
  • the adhesive structure is therefore not in contact with the diffractive optical element.
  • the security structure may include a plurality of said diffractive optical elements, each generating an interference pattern in a viewing plane distant from the diffractive optical element.
  • These diffractive optical elements can generate different or identical interference patterns, complementing each other or not.
  • the protective adhesive structure or the protective structure is applied to all the diffractive optical elements.
  • the security structure may include a plurality of non-opaque microzones, each at least partially superimposed on at least one respective diffractive optical element.
  • a plurality of non-opaque microzones is superimposed on the same diffractive optical element.
  • the non-opaque microzone (s) can visually define a pattern which is found at least partially in the interference pattern generated by at least one diffractive optical element.
  • several non-opaque microzones are arranged in an arrangement which reproduces one or more alphanumeric characters, and the interference pattern produces an image of these same alphanumeric characters in the display plane.
  • the pattern facilitates authentication by comparing the pattern to the interference pattern. This arrangement further increases the difficulty for the potential counterfeiter who should reproduce the pattern both in the microzones and in the interference pattern of the security structure.
  • the security structure may comprise at least one absorbent or interference filter, in particular a colored filter, at least partially superimposed on the non-opaque microzone.
  • the security structure may comprise at least two non-opaque microzones each formed by an axis microperforation forming an angle with the normal with the surface of the security structure, the angles being different. At least two diffractive optical elements may each overlap at least partially to a respective non-opaque microzone. This arrangement makes it possible, by orienting the light beam differently, to be able to visualize one or the other of the interference patterns produced and to be able to create, for example, an animation by alternately observing the two interference patterns.
  • the subject of the invention is also an article, according to claim 13, in particular a secure document comprising a security structure according to the invention.
  • the secure document may comprise a substrate, in particular a fibrous substrate, having at least one window, the window being at least partially superimposed both on the diffractive optical element and on the non-opaque microzone.
  • the security structure can be attached to or integrated into this substrate.
  • the secure article may have at least a second non-opaque microzone, at least partially superimposed both on the diffractive optical element and on the first non-opaque microzone.
  • the or each non-opaque microzone can be defined by absence of material, in particular by microperforation.
  • the microperforations can each be carried out in a fibrous jet. The observation is made through the two non-opaque microzones.
  • the secure article may include a substrate, in particular a fibrous substrate, comprising a microperforation defining the non-opaque microzone, and the diffractive optical element may be present on a security element attached to or integrated into said substrate.
  • the security structure consists of the security element and the substrate.
  • the secure article may include a security element having at least one non-opaque microzone superimposed on the diffractive optical element.
  • the latter can be formed on a thermoplastic film, which is assembled, for example by lamination, with the security element, when the latter is already in place or not on the document.
  • the secure item can be a passport, an identity card, an access card, a driver's license, an interactive playing or collecting card, a means of payment, in particular a payment card, a bank note. , a tax stamp, a sticker, a voucher or a coupon, a transport, loyalty, service or subscription card, a token or a casino plate.
  • the secure article preferably has at least one security element or pattern which is identical or at least partially similar to the interference pattern.
  • the two patterns can be identical except for a transformation, in particular to a homothety, have the same form, present the same information in particular in alphanumeric characters, the typography being able to be different.
  • the two reasons include, for example, the same written information, in particular on civil status, the currency of a denomination, the name of a place, a date, or the same visual information, in particular a photograph or a drawing.
  • the light is preferably collimated.
  • the diffractive optical element when the diffractive optical element is lit, the light passes through the non-opaque microzone before meeting the diffractive optical element and generating an interference pattern.
  • the light source can be polychromatic, the display plane being virtual and positioned between the light source and the security structure.
  • the polychromatic light can be white light.
  • the interference pattern is observed through the non-opaque microzone which serves as a viewfinder.
  • the method may include the step of disposing at least one filter, for example a colored or interference filter, between the light beam and the security structure, or between the viewing plane and the observer.
  • at least one filter for example a colored or interference filter
  • the presence of the filter makes it possible to select a single wavelength and to more easily see a hidden or hardly visible element without the filter, in particular in the case of a complex multiton pattern consisting of a superposition of simple patterns of different colors.
  • the light source can be monochromatic, being in particular coherent and / or collimated light, the display plane being real and positioned after the security structure with respect to the light source.
  • the verification of the presence of an interference pattern can be done using a device equipped with a camera, in particular a portable telephone with focusing arranged in the viewing plane.
  • a device other than the eye makes it possible to avoid any danger for the eye related to a high light intensity, in particular in the case of the use of a laser.
  • the method may include the step of comparing an interference pattern generated by the diffractive optical element with a pattern present on the article, in particular defined by a watermark, a printing, a metallization or a demetallization or microperforations, or in a form that is not directly understandable, for example stored on an RFID chip or on a server which can be accessed through a link on the document.
  • the method may include the step of verifying that the data of the interference pattern correspond to data carried elsewhere by the document.
  • the latter can be arranged to automatically analyze the observed image and for example compare it with reference information, or decrypt it to extract information to compare with reference information, to verify the authenticity of the article, especially the document.
  • the electronic device can be arranged to analyze the interference pattern observed and access a database making it possible to verify the authenticity of the article, in particular of the document.
  • the article in particular the document, can carry information which allows access via a remote server to reference data which makes it possible to verify that the image observed comes from an authentic diffractive optical element.
  • This information can be stored in an RFID chip present on the document and read by the device used to observe the interference pattern, for example using NFC technology.
  • the secure article 10 shown in Figures 1 and 2 for example a document such as a banknote, comprises a security structure 2 according to the invention, comprising a diffractive optical element 40 overlapping at least partially with a non-opaque microzone 30.
  • the article 10 comprises a substrate 11, in particular made of paper, provided with a window 15 which visually gives access to the diffractive optical element 40.
  • the non-opaque microzone 30 is formed by a microperforation of axis X carried out through a substrate 18, in particular of paper, of the document 10, assembled with the substrate 11.
  • the diffractive optical element is produced on a film 43 of transparent plastic, which is assembled with a security element 20 having a non-opaque zone 23 at least partially superimposed on the diffractive optical element 40 and on the microperforation 30.
  • the thermoplastic film 43 can be made of polyethylene terephthalate (PET).
  • the diffractive optical element 40 generates an interference pattern in a distant viewing plane.
  • the at least partial alignment of the different openings and transparent zones defines a non-opaque zone A which goes on either side of the secure document 1.
  • the interference pattern of the safety structure 2 is displayed by lighting the non-opaque microzone 30 by a light source 60, in a plane 62 distant from the diffractive optical element 40.
  • the safety structure 2 is preferably arranged so that its plane is oriented orthogonally to the incident light coming from the light source 60 and that the non-opaque microzone 30 is preferably positioned on the side of the light source 60.
  • the non-opaque microzone 30 makes it possible in particular to target the diffractive optical element 40 with the incident beam.
  • the light source 60 is preferably collimated.
  • the light source 60 can be a monochromatic light source, in particular a laser.
  • the display plane 62 is then real and is positioned downstream of the security structure 2 with respect to the light source 60.
  • the interference pattern 66 can be displayed using a portable device, in particular of a portable telephone set in photo or video mode and positioned in the viewing plane 62. The interference pattern 66 is viewed through the non-opaque microzone 30.
  • the light source 60 can be a polychromatic source.
  • the display plane 62 is then virtual and positioned upstream of the security structure 2 with respect to the light source 60.
  • the interference pattern 66 is displayed by observing the light source 60 through the non-microzone opaque 30.
  • the authentication of the security structure 2 may require the use of a filter 68 positioned upstream or downstream of the security structure 2. This filter can make it possible to filter the wavelengths visible to the eye.
  • the authentication of the security structure 2 can be done by comparison of the interference pattern 66 generated by the diffractive optical element 40 with one or more additional pieces of information present on the security structure 2 or the article 10 associated for example with a comparison pattern defined by a watermark, printing, metallization or demetallization or microperforations.
  • the non-opaque microzone 30, being in particular a demetallization or a microperforation, can constitute, at least partially, the reason for comparison.
  • the invention is not limited to a particular secure article, and this may be other than a valuable document, in particular an identity document or a card.
  • Substrates 11 and 18 of the example of Figures 1 and 2 may thus be non-fibrous.
  • the diffractive optical element 40 can be formed on a thermoplastic film 43 according to one of the methods described above.
  • the thickness e of the diffractive optical element 40 is preferably less than or equal to 50 ⁇ m, better still less than or equal to 25 ⁇ m.
  • the diffractive optical element 40 can be, as illustrated on the figure 2 , of larger section than that of the non-opaque microzone 30.
  • the non-opaque microzone 30 preferably has a section S of less than 1,000,000 ⁇ m 2 , better less than or equal to 200,000 ⁇ m 2 , even better between 10 ⁇ m 2 and 200,000 ⁇ m 2 , even better between 5,000 ⁇ m 2 and 200,000 ⁇ m 2 .
  • the non-opaque microzone 30, when it is produced in the form of microperforation, can be arranged in various ways.
  • the non-opaque microzone 30 may have a variable cross section, in particular narrowing in the direction of the diffractive optical element 40.
  • a non-opaque microzone 30 formed by a microperforation whose axis X forms a non-zero angle ⁇ with the normal to the surface of the safety structure 2.
  • the angle ⁇ can be between -45 ° and 45 °.
  • the safety structure 2 can comprise at least two non-opaque micro-zones 30 1 and 30 2 opening onto the same surface S 12 , each non-opaque micro-zone 30 1 and 30 2 being able to be superimposed on a respective diffractive optical element 40 1 or 40 2 .
  • This configuration allows, by varying the viewing angle, to choose the diffractive optical element that one wishes to view. An animation can be observed if necessary by alternating the visualization of the two interference patterns.
  • the non-opaque microzone 30 can be produced other than in the form of a microperforation through an opaque layer.
  • the non-opaque microzone 30 can be filled with a transparent, colorless or non-opaque material.
  • the non-opaque microzone 30 can be delimited by a print 35.
  • the layer 38 on which the print is made can be a transparent film which carries, on the face opposite to the print, the diffractive optical element 40.
  • the non-opaque microzone 30 can be formed by demetallization of a metal layer 37, as illustrated in the figure 19 .
  • the security structure 2 may include an optical filter placed on the path of the light gaining or leaving the diffractive optical element.
  • a security structure 2 comprising an optical filter 80, absorbent or interference, in particular colored, superimposed on the non-opaque micro-zone 30.
  • the filter 80 can be positioned upstream or downstream from the diffractive optical element 40.
  • the filter 80 makes it possible to select one or more wavelengths of light when viewing the interference pattern.
  • the filter allows you to personalize the interference pattern by allowing the choice of display color.
  • the security structure 2 can comprise a plurality of diffractive optical elements 40 1 , ..., 40 i and respective non-opaque micro-zones 30 1 , ..., 30 i with respective axes X 1 , ..., X i , each non-opaque microzone 30 1 ; ...; 30 i superimposed on a diffractive optical element 40 1 ; ...; 40 i corresponding.
  • the security structure 2 can comprise a security element 20 comprising one or more non-opaque zones 23, each non-opaque zone overlapping at least partially with at least one diffractive optical element 40 1 , ..., 40 i .
  • a non-opaque zone 23 can be superimposed with at least two diffractive optical elements 40 1 , ..., 40 i .
  • the security structure 2 comprises a plurality of colored filters 60 1 , ..., 60 i , in particular of different colors, each superimposed on at least one respective diffractive optical element 40 1 , ..., 40 i .
  • the security structure 2 may include a security element 20 which is at least partially superimposed on the diffractive optical element 40 and on the non-opaque microzone 30. More particularly, as illustrated, this security element 20 may be visible at through the window 15 and come between the substrate 11 and the film 43 carrying the diffractive optical element 40.
  • the security element 20 is preferably at least partially opaque, for example being metallized.
  • the non-opaque zone 23 can be formed by demetallization or perforation.
  • the element 20 can provide visible security through the window 15, for example in the form of a pattern 50 situated outside of the non-opaque zone 23, this pattern 50 being for example formed by printing or demetallization, as illustrated in FIG. figure 1 .
  • the pattern 50 is for example made up of alphanumeric characters, as illustrated in the figure 1 . It can be a text providing information on the name of the bank, the country and / or the value of the denomination.
  • the pattern 50 can be produced in accordance with the teaching of application WO 2006/066927, in the form of halftone dots restoring an image in transmitted light, one of the demetallizations or perforations of the pattern 50 which can constitute the non-opaque microzone 30.
  • the pattern 50 is preferably found in part or totally in the interference pattern 66 generated by the diffractive optical element 40.
  • the pattern 50 representing the value of the cut is found in the interference pattern which also represents the value of the cut, the typography being able to be identical or different.
  • a security element 20 comprising a metallized layer
  • metallized layer as usable metals, mention may be made of aluminum, copper, gold, iron, silver, chromium , nickel, zinc, cadmium, bismuth and their alloys and oxides.
  • the security element 20 may be in the form of a patch, a wire or a security foil.
  • the security element 20 is a security wire
  • its width may be relatively small, preferably less than or equal to 10 mm.
  • the window 15 can be made by cutting and have an outline of any shape, for example circular, elliptical or polygonal, as illustrated in the figure 1 , in particular in the shape of a regular polygon or not.
  • Window 15 can be unique on the document or the latter can include several. In this case, the windows 15 can be arranged on the same side of the document or on opposite sides.
  • the window 15 can be formed by modifying for example the accumulation of fibers on the forming fabric and the non-opaque microzone 30 can be formed in particular using micro-needles or by water jet, preferably by laser ablation. .
  • the jets 11, 18 are for example fibrous jets assembled in the wet phase.
  • the two jets 11, 18 each have a thickness / of for example between 10 and 1000 ⁇ m, better still between 50 and 700 ⁇ m.
  • the two jets 11, 18 can comprise natural and / or synthetic fibers.
  • the substrates 11 and 18 can also be non-fibrous.
  • the document 10 may have a multilayer structure comprising at least one fibrous layer and one layer of thermoplastic material.
  • the diffractive optical element 40 is laminated with the security element 20 before being incorporated into the secure document 1.
  • the diffractive optical element 40 is fixed to the security element 20 by gluing, hot or cold.
  • the adhesive used is for example a transparent adhesive of the polymer adhesive type such as NOLAX.
  • the assembly consisting of the security element 20 and the diffractive optical element 40 can be incorporated between the two jets 11, 18, the security element 20 being positioned on the side of the window 15, as illustrated in the figure 2 .
  • article 10 may include various additional security elements, first level, second or third level.
  • additional security elements some are detectable by eye, in daylight or in artificial light, without the use of a particular device.
  • These security elements comprise for example colored fibers or boards, printed or metallized wires totally or partially. These security elements are said to be first level.
  • UV ultraviolet
  • IR infrared
  • Additional security elements require a more sophisticated detection device for their detection.
  • These security elements are for example capable of generating a specific signal when they are subjected, simultaneously or not, to one or more sources of external excitation. Automatic signal detection allows the document to be authenticated, if necessary.
  • These security elements include, for example, tracers in the form of active materials, particles or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation. These security elements are said to be third level.
  • At least one of these security elements can define information found in the interference pattern generated by the diffractive optical element 40.
  • the diffractive optical element 40 and the layer 18 defining the non-opaque microzone 30 may be in contact with one another, as is the case in particular in the example of the figure 2 .
  • the diffractive optical element 40 and the layer 18 defining the non-opaque microzone 30 can be separated by one or more intermediate layers.
  • the film 43 carrying the diffractive optical element 40 can be positioned adjacent to the substrate 11 comprising the window 15, and the security element 20 can be interposed between the film 43 and the non-opaque microzone 30.
  • the diffractive optical element 40 in particular the side of the film 43 carrying the latter, and the layer 18 are separated by a protective adhesive structure 45 preferably comprising a layer of a mixture of an adhesive material and an HRI material.
  • the protective adhesive structure 45 makes it possible to secure the film 43 carrying the diffractive optical element 40 and the layer 18.
  • the presence of the HRI material makes it possible to prevent attenuation or cancellation of the optical effects of the diffractive optical element which could be caused by the superimposition of adhesive material with the diffractive optical element 40.
  • the diffractive optical element 40 can, as a variant, carry a layer of an HRI material 47, in particular deposited on the diffractive optical element 40 by vaporization under vacuum, itself carrying a layer of an adhesive material.
  • the layer 47 makes it possible to protect the diffractive optical element 40 against attenuation or cancellation of its optical effect due to the presence of the adhesive structure.
  • the mechanical protection of the latter is obtained by the layer of adhesive material 46.
  • the diffractive optical element 40 in particular the side of the film 43 carrying the latter, and the layer 18 are separated by an adhesive structure 46 comprising an adhesive material and a protective structure 47 comprising an HRI material, the protective structure 47 being applied to the diffractive optical element 40, in particular on the side of the film 43 carrying the diffractive optical element 40 and the adhesive structure 46 being disposed between the protective structure 47 and the layer 18.
  • the protective structure 47 may include a binder, preferably secure.
  • the film 43 and the layer 18 are separated by an adhesive structure 46, the latter being located on the side of the film 43 not having the diffractive optical element 40.
  • a protective structure 47 comprising an HRI material may be present on the element diffractive optics 40, and in particular completely cover the latter. This protective structure 47 makes it possible in particular to mechanically protect the diffractive optical element 40 during assembly of the safety structure 2 with the article 10 while retaining the optical properties.
  • the film 43 and the layer 18 are separated by a protective structure 47 comprising a layer of HRI material 47a, a layer of a binder 47b and an adhesive structure 46 comprising an adhesive material.
  • the layer of HRI material 47a preferably covers at least partially the diffractive optical element 40 and the layer of binder 47b preferably covers the layer of HRI material 47a.
  • the binder is secure, in particular by one or more luminescent or absorbent substances under UV, visible and / or IR excitation.
  • the luminescent or absorbent substances are not diffusing and the binder layer 47b is transparent.
  • the luminescent or absorbent substances are preferably particles of nanometric sizes.
  • the layers 47a, 47b and 46 are transparent so as not to disturb the optical effect generated by the diffractive optical element.
  • the protective structure 47 can be deposited by printing on the diffractive optical element 40 as explained in the patent application FR 2961319 , that is to say that the hollows of the diffractive optical element 40 are filled with the HRI material
  • the protective structure 47 or the protective adhesive structure 45 may comprise nanoparticles of metal oxides, such as TiO2, having in particular a diameter between 1 and 100 nm, better between 5 and 25 nm and / or a transparent varnish and / or a crosslinkable organic binder and / or a pigment dispersant.
  • metal oxides such as TiO2
  • the thickness of the protective adhesive structure 45 is preferably between 1 and 10 microns, better still between 2 and 5 microns.
  • the adhesive structure 46 or the protective adhesive structure 45 is introduced by microperforations between the diffractive optical element 40, and / or the film 43 carrying it, and the layer 18.
  • layers 46 or 45 are introduced so as to fill the microperforations to protect them against the external environment, in particular dirt, as explained in the application DE 10 2011 004935 .
  • the security element 20 can be positioned in the window 15, the film 43 still extending between the two jets 11 and 18.
  • the diffractive optical element 40 can be produced in a film 43 which extends continuously around the diffractive optical element 40.
  • the film 43 which served to produce the diffractive optical element 40 does not extend to the beyond this, as illustrated in figure 5 .
  • the film 43 can be positioned in the window 15. It can be the same for the security element 20, when present.
  • the security structure 2 may include a diffractive optical element 40 and a security element 20 having a non-opaque microzone 30 overlapping at least partially with the diffractive optical element 40.
  • the first jet 11 may have a window 15 and the second jet 18 may have a non-opaque zone 32.
  • the window 15 and the non-opaque zone 32 may or may not have the same shape and size and overlap at least partially with the element diffractive optics 40 and the non-opaque microzone 30 so as to form a transparent transparent zone A on the secure document 1.
  • the security structure 2 can have substantially the same shape as the window 15 and position itself in the latter.
  • Secure document 1 shown in figure 9 , comprises two substrates 11, 18 constituted by first and second jets 11, 18 each provided with a microperforation 30, 16, preferably produced by laser ablation, and receive between them a diffractive optical element 40.
  • Secure document 1 shown in figure 11 , comprises a first substrate 11 forming the first jet, provided with a window 15, and a second substrate 18 forming the second jet, provided with a non-opaque microzone 30.
  • the window 15 and the microperforation 30 are superimposed so as to form in the secure document a transparent zone A which goes on either side of the secure document 1 in which is positions the diffractive optical element 40.
  • the diffractive optical element 40 can be positioned between the two jets 11, 18, the film 43 being directly in contact with the latter.
  • the optical security element 40 can be positioned between a substrate 18 and a security element 20, the substrate comprising the non-opaque microzone 30.
  • the security element 20 may include a pattern 50, here the letters AW, produced by a plurality of microperforations 19, one of these microperforations possibly constituting the non-opaque microzone 30, for example the tip of A.
  • the motif AW can be reproduced on the interference pattern generated by the diffractive optical element 40.
  • the non-opaque microzone 40 can be of various shapes, in particular circular, as illustrated in the figure 1 , or any other, for example triangular as illustrated on the figure 28A , or in the shape of a crescent, as illustrated on the figure 28B .

Description

La présente invention concerne les structures de sécurité et les articles, notamment documents, sécurisés comportant de telles structures.The present invention relates to security structures and secure articles, in particular documents, comprising such structures.

Arrière-planBackground

L'utilisation d'éléments optiques diffractifs (DOEs) en tant qu'éléments de sécurité pour produire un motif d'interférences à partir d'une source lumineuse est connue. Ces éléments peuvent être réalisés en vue d'être éclairés par une lumière monochromatique ou polychromatique, afin de générer le motif d'interférences par diffraction et transmission à travers l'élément vers un plan de visualisation. Selon les cas, ce plan de visualisation peut être virtuel et situé entre l'élément et la source lumineuse ou être matérialisé par une surface réelle située en arrière de l'élément par rapport à la source.The use of diffractive optical elements (DOEs) as security elements to produce an interference pattern from a light source is known. These elements can be produced with a view to being illuminated by monochromatic or polychromatic light, in order to generate the interference pattern by diffraction and transmission through the element to a viewing plane. Depending on the case, this display plane can be virtual and located between the element and the light source or be materialized by an actual surface located behind the element with respect to the source.

La demande internationale WO 01/00418 décrit un élément optique diffractif réalisé directement sur un document par ablation laser.International demand WO 01/00418 describes a diffractive optical element produced directly on a document by laser ablation.

La demande de brevet australien AU 2013100172 décrit un document de sécurité comportant une multitude d'ouvertures réalisée par ablation laser générant un élément optique diffractif et une couche réflective présentant à sa surface des séries de rainures et une couche de cristal liquide.Australian patent application AT 2013 100 172 describes a security document comprising a multitude of openings produced by laser ablation generating a diffractive optical element and a reflective layer having on its surface series of grooves and a layer of liquid crystal.

La demande internationale WO 99/37488 décrit des documents de sécurité à base de matière plastique dans lesquels l'élément optique diffractif est positionné sur ou dans une fenêtre transparente ou semi-transparente, de façon à être visualisé en utilisant une source lumineuse polychromatique collimatée grâce à la présence d'une autre fenêtre située, sur le même document, à distance de l'élément.International demand WO 99/37488 describes plastic-based security documents in which the diffractive optical element is positioned on or in a transparent or semi-transparent window, so as to be viewed using a polychromatic light source collimated by the presence of another window located, on the same document, at a distance from the element.

La demande internationale WO 2007/079549 décrit l'utilisation et la visualisation d'éléments optiques diffractifs sur des documents de sécurité. Les éléments sont réalisés de façon à enregistrer des données individuelles, notamment des données présentes par ailleurs sur le document, telles qu'un portrait ou un état civil dans le cas d'une pièce d'identité.International demand WO 2007/079549 describes the use and visualization of diffractive optical elements on security documents. The elements are made so as to record individual data, in particular data present elsewhere on the document, such as a portrait or a civil status in the case of an identity document.

La demande internationale WO 2008/031170 décrit la réalisation et l'utilisation de documents de sécurité comportant au moins un élément optique diffractif et une structure optique à lentilles ou un autre élément de sécurité ayant une structure en relief réalisée par embossage. Cette demande décrit également l'utilisation et la visualisation d'éléments optiques diffractifs binaires ou à plusieurs niveaux de phase.International demand WO 2008/031170 describes the production and use of security documents comprising at least one diffractive optical element and an optical lens structure or another security element having a relief structure produced by embossing. This application also describes the use and visualization of binary diffractive optical elements or at several phase levels.

La demande de brevet australien AU 2011101567 décrit l'utilisation et la visualisation d'éléments optiques diffractifs sensibles à au moins trois longueurs d'ondes différentes sur des documents de sécurité. Les éléments optiques diffractifs sont enregistrés avec trois longueurs différentes et le motif d'interférences est restitué par éclairage aux longueurs d'ondes adéquates.Australian patent application AU 2011101567 describes the use and visualization of diffractive optical elements sensitive to at least three different wavelengths on security documents. The diffractive optical elements are recorded with three different lengths and the interference pattern is reproduced by lighting at the appropriate wavelengths.

Il existe un besoin pour pouvoir utiliser des éléments optiques diffractifs avec différents types de substrats sans nécessiter au moment de la fabrication de l'élément la présence de la totalité du document.There is a need to be able to use diffractive optical elements with different types of substrates without requiring at the time of manufacture of the element the presence of the entire document.

Il existe également un besoin pour perfectionner encore les structures de sécurité et les articles sécurisés intégrant de telles structures, notamment afin de rendre plus difficile la contrefaçon.There is also a need to further improve security structures and secure articles incorporating such structures, in particular in order to make counterfeiting more difficult.

L'invention vise à répondre à tout ou partie de ces besoins.The invention aims to meet all or part of these needs.

Résumésummary

L'invention a pour objet, selon un premier de ses aspects, une structure de sécurité, selon la revendication 1, comportant:

  • au moins une microzone non opaque de section inférieure ou égale à 1000000 µm2,
  • au moins un élément optique diffractif générant au moins un motif d'interférences dans un plan de visualisation éloigné de l'élément optique diffractif, superposé au moins partiellement à la microzone non opaque.
The subject of the invention is, according to a first of its aspects, a security structure according to claim 1, comprising:
  • at least one non-opaque microzone of section less than or equal to 1,000,000 µm 2 ,
  • at least one diffractive optical element generating at least one interference pattern in a viewing plane distant from the diffractive optical element, at least partially superimposed on the non-opaque microzone.

Microzone non opaqueNon-opaque microzone

Par « microzone non opaque », on désigne une zone suffisamment perméable à la lumière pour permettre la visualisation du motif d'interférences grâce à la lumière traversant cette zone, présentant une section transversale de surface inférieure ou égale à 1000000 µm2, mieux inférieure ou égale à 200000 µm2, encore mieux comprise entre 10 µm2 et 200000 µm2, en encore mieux comprise entre 5000 µm2 et 200000 µm2. De préférence, la microzone non opaque présente une section transversale suffisante pour observer le DOE en lumière transmise et suffisament réduite pour ne pas être sensiblement visible en réflexion. Une microzone non opaque est ainsi d'étendue limitée, étant délimitée par un pourtour opaque. La microzone non opaque peut être translucide, notamment diffuser une partie de la lumière la traversant ou transparente, ne diffusant pas la lumière la traversant. De préférence, la microzone non opaque est transparente.The term “non-opaque microzone” designates an area which is sufficiently permeable to light to allow the visualization of the interference pattern by virtue of the light passing through this area, having a cross section of surface less than or equal to 1,000,000 μm 2 , better less or equal to 200,000 µm 2 , even better between 10 µm 2 and 200,000 µm 2 , even better between 5,000 µm 2 and 200,000 µm 2 . Preferably, the non-opaque microzone has a cross section sufficient to observe the DOE in transmitted light and sufficiently reduced so as not to be substantially visible in reflection. A non-opaque microzone is thus of limited extent, being delimited by an opaque periphery. The non-opaque microzone can be translucent, in particular diffusing part of the light passing through it or transparent, not diffusing the light passing through it. Preferably, the non-opaque microzone is transparent.

Par « un pourtour opaque », il faut comprendre de densité optique supérieure du pourtour ou égale à 1, mieux 1,5.By “an opaque periphery”, it is necessary to understand an optical density greater than the periphery or equal to 1, better 1.5.

Une microzone non opaque présente l'avantage de n'être facilement détectable que sous certaines conditions d'observation, et n'est ainsi pas aisément visible à l'œil nu si ces conditions d'observation ne sont pas respectées. Ainsi, l'utilisation d'une microzone non opaque permet de dissimuler plus facilement l'élément optique diffractif et rend la contrefaçon plus difficile à réaliser.A non-opaque microzone has the advantage of being easily detectable only under certain observation conditions, and is therefore not easily visible to the naked eye if these observation conditions are not observed. Thus, the use of a non-opaque microzone makes it easier to conceal the diffractive optical element and makes counterfeiting more difficult to carry out.

La microzone non opaque peut être de section circulaire ou non circulaire, notamment polygonale, en particulier polygonale régulière ou non régulière, ou oblongue, notamment elliptique.The non-opaque microzone can be of circular or non-circular cross-section, in particular polygonal, in particular regular or non-regular polygonal, or oblong, in particular elliptical.

La microzone non opaque peut être réalisée dans une couche d'un matériau fibreux ou non qui s'étend tout autour de la microzone non opaque.The non-opaque microzone can be produced in a layer of fibrous or non-fibrous material which extends all around the non-opaque microzone.

La microzone non opaque peut être une microperforation d'une couche d'un matériau sensiblement opaque rempli au moins partiellement, de préférence entièrement, par un matériau transparent comportant notamment un matériau adhésif protecteur. Le matériau transparent, en pénétrant dans la microperforation, permet de solidariser la couche de matériau sensiblement opaque et la couche portant l'élément optique diffractif. Le fait que la microperforation soit au moins partiellement remplie permet de la protéger de l'environnement extérieur, notamment des salissures.The non-opaque microzone can be a microperforation of a layer of a substantially opaque material filled at least partially, preferably entirely, with a transparent material comprising in particular a protective adhesive material. The transparent material, by penetrating into the microperforation, makes it possible to join the layer of substantially opaque material and the layer carrying the diffractive optical element. The fact that the microperforation is at least partially filled makes it possible to protect it from the external environment, in particular from dirt.

Par exemple, la ou chaque microzone non opaque peut être définie par une absence de matière au sein d'une couche d'un matériau sensiblement opaque, notamment être définie par une microperforation à travers ce matériau opaque lorsque celui-ci est, par exemple, un substrat fibreux, ou être définie par une démétallisation lorsque le matériau opaque est métallique.For example, the or each non-opaque microzone can be defined by an absence of material within a layer of a substantially opaque material, in particular be defined by a microperforation through this opaque material when the latter is, for example, a fibrous substrate, or be defined by demetallization when the opaque material is metallic.

En présence de microperforations, celles-ci sont, de préférence, réalisées à l'aide d'un laser. En variante, les microperforations sont réalisées à l'aide de micro-aiguilles ou par jet d'eau.In the presence of microperforations, these are preferably carried out using a laser. Alternatively, the microperforations are carried out using micro-needles or by water jet.

Lorsque la microzone non opaque est constituée par une microperforation, l'axe de cette microperforation est de préférence orienté sensiblement normalement à la surface de la couche à travers laquelle est réalisée la microperforation. L'axe peut, en variante, former un angle avec la normale à la surface de la couche qui est traversée par la microperforation.When the non-opaque microzone is constituted by a microperforation, the axis of this microperforation is preferably oriented substantially normally on the surface of the layer through which the microperforation is carried out. The axis can, as a variant, form an angle with the normal to the surface of the layer which is crossed by the microperforation.

La microzone non opaque peut être, lorsqu'elle est définie par une microperforation, de section transversale constante ou non sur l'épaisseur de la couche traversée par la microperforation.The non-opaque microzone can be, when defined by a microperforation, of constant cross section or not over the thickness of the layer crossed by the microperforation.

La microzone non opaque peut encore être délimitée par une impression d'une encre opaque, notamment une impression d'un film transparent en matière plastique, par exemple le même film que celui sur lequel est réalisé l'élément optique diffractif.The non-opaque microzone can also be delimited by an impression of an opaque ink, in particular an impression of a transparent plastic film, for example the same film as that on which the diffractive optical element is produced.

Une même couche de la structure selon l'invention peut présenter une pluralité de microzones non opaques se superposant chacune au moins partiellement au même élément optique diffractif.The same layer of the structure according to the invention may have a plurality of non-opaque microzones, each overlapping at least partially on the same diffractive optical element.

La ou les microzones non opaques peuvent former chacune un motif qui se retrouve dans au moins une partie du motif d'interférences généré par l'élément optique diffractif.The non-opaque microzone (s) can each form a pattern which is found in at least part of the interference pattern generated by the diffractive optical element.

Par exemple, la microzone non opaque présente un contour qui se retrouve dans le motif d'interférences, par exemple une même forme géométrique.For example, the non-opaque microzone has a contour which is found in the interference pattern, for example the same geometric shape.

Plusieurs microzones non opaques peuvent définir ensemble un motif qui se retrouve dans au moins une partie du motif d'interférences, par exemple l'image d'un même personnage, lieu, monument ou objet, ou un même texte, par exemple la valeur d'une coupure ou le nom d'une banque. Le motif facilite l'authentification par l'observateur par comparaison dudit motif au motif d'interférence. Cet agencement augmente la sécurité du document du fait que la contrefaçon nécessite la reproduction du motif à la fois dans les microzones et dans le motif d'interférence de la structure de sécurité.Several non-opaque microzones can together define a pattern which is found in at least part of the interference pattern, for example the image of the same character, place, monument or object, or the same text, for example the value d '' a banknote or the name of a bank. The pattern facilitates authentication by the observer by comparing said pattern to the interference pattern. This arrangement increases the security of the document because the counterfeiting requires the reproduction of the pattern both in the microzones and in the interference pattern of the security structure.

Dans le cas d'une microzone non opaque formée par une microperforation, l'épaisseur de la couche traversée par la microperforation peut être comprise entre 10 et 1000000 µm.In the case of a non-opaque microzone formed by a microperforation, the thickness of the layer through which the microperforation passes can be between 10 and 1,000,000 μm.

Le nombre de microzones non opaques est, de préférence, comprise entre 1 et 1500 microzones non opaques par cm2, de préférence entre 10 et 500 par cm2, encore de préférence entre 10 et 300 par cm2.The number of non-opaque microzones is preferably between 1 and 1500 non-opaque microzones per cm 2 , preferably between 10 and 500 per cm 2 , more preferably between 10 and 300 per cm 2 .

Elément optique diffractifDiffractive optical element

L'élément optique diffractif qui génère le motif d'interférences dans un plan de visualisation éloigné de l'élément optique diffractif est de préférence de type numérique. Sa fabrication se fonde alors, comme décrit dans WO 2008/031170 , sur un matriçage effectué en fonction de données complexes qui sont reconstruites dans le plan de visualisation pour former un motif d'interférences en deux dimensions. Ainsi, quand l'élément optique diffractif est éclairé par une source lumineuse collimatée, il génère un motif d'interférences produisant une image dans ce plan de visualisation, qui est visible sur une surface positionnée dans ce plan, ou visible en transmission à partir de ce plan.The diffractive optical element which generates the interference pattern in a viewing plane distant from the diffractive optical element is preferably of digital type. Its manufacture is then based, as described in WO 2008/031170 , on a matrixing carried out according to complex data which are reconstructed in the display plane to form a two-dimensional interference pattern. Thus, when the diffractive optical element is illuminated by a collimated light source, it generates an interference pattern producing an image in this viewing plane, which is visible on a surface positioned in this plane, or visible in transmission from this plan.

La transformation mathématique entre l'élément et le plan de visualisation peut s'apparenter à une transformée de Fourier rapide (FFT). Ainsi, les données complexes, comportant des informations de phase et d'amplitude, doivent être encodées physiquement dans la microstructure de l'élément. Le relief à donner à la microstructure peut se calculer en réalisant la transformée FFT inverse du motif désiré dans le plan de visualisation.The mathematical transformation between the element and the visualization plane can be compared to a fast Fourier transform (FFT). Thus, complex data, comprising phase and amplitude information, must be physically encoded in the microstructure of the element. The relief to be given to the microstructure can be calculated by carrying out the inverse FFT transform of the desired pattern in the display plane.

Les éléments optiques diffractifs sont parfois qualifiés d'hologrammes générés par ordinateur, et diffèrent des autres types d'hologrammes tels que les hologrammes arc-en-ciel, de Fresnel ou de réflexion volumique.Diffractive optical elements are sometimes referred to as computer generated holograms, and differ from other types of holograms such as rainbow, Fresnel or volume reflection holograms.

De préférence, l'élément optique diffractif est une structure embossée.Preferably, the diffractive optical element is an embossed structure.

De préférence, le motif d'interférences généré par l'élément optique diffractif se retrouve au moins en partie, mieux en totalité, sur la structure de sécurité, ou sur l'article, notamment le document l'incorporant, notamment sous forme d'une impression et/ou d'un élément de sécurité, notamment un filigrane, et/ou d'un motif généré par des microperforations ou une métallisation ou démétallisation. Dans le cas des microperforations, l'une de ces dernières peut définir la microzone non opaque.Preferably, the interference pattern generated by the diffractive optical element is found at least in part, better in total, on the security structure, or on the article, in particular the document incorporating it, in particular in the form of a print and / or a security element, in particular a watermark, and / or a pattern generated by microperforations or a metallization or demetallization. In the case of microperforations, one of these can define the non-opaque microzone.

Par exemple, l'élément optique diffractif génère l'image d'un personnage et un filigrane reproduisant le même personnage est présent sur un substrat fibreux sur lequel est réalisée une microperforation définissant la microzone non opaque.For example, the diffractive optical element generates the image of a character and a watermark reproducing the same character is present on a fibrous substrate on which a microperforation is carried out defining the non-opaque microzone.

La microzone non opaque peut aussi appartenir à un élément de sécurité qui reproduit tout ou partie du motif d'interférences. Par exemple, la microzone non opaque est formée par démétallisation d'un fil de sécurité métallisé et l'image d'un personnage produite par le motif d'interférences se retrouve sur le fil, étant formée par démétallisation sur celui-ci, avec ou sans superposition avec l'élément optique diffractif.The non-opaque microzone can also belong to a security element which reproduces all or part of the interference pattern. For example, the non-opaque microzone is formed by demetallization of a metallic security thread and the image of a character produced by the interference pattern is found on the wire, being formed by demetallization thereon, with or without superposition with the diffractive optical element.

De préférence, l'élément optique diffractif est plus petit, notamment dans toutes les directions de son plan, que la microzone non opaque. En variante, l'élément optique diffractif peut être plus grand dans au moins une direction de son plan que la microzone non opaque.Preferably, the diffractive optical element is smaller, in particular in all directions of its plane, than the non-opaque microzone. Alternatively, the diffractive optical element may be larger in at least one direction of its plane than the non-opaque microzone.

L'élément optique diffractif est de préférence formé sur un film thermoplastique, de préférence transparent, ayant une épaisseur inférieure ou égale à 50 µm, notamment par embossage de ce dernier. Ce film thermoplastique peut être laminé au moins partiellement avec la couche portant la microzone non opaque ou à travers laquelle est réalisée la microzone non opaque. En variante, le film thermoplastique comportant l'élément optique diffractif est fixé à la couche portant la microzone non opaque par une structure adhésive, de préférence protectrice également, comportant un matériau adhésif. Comme décrit précédemment, la structure adhésive peut être introduite à l'état liquide entre le film thermoplastique et la couche portant la microzone non opaque par l'intermédiaire d'au moins une microperforation notamment formant au moins une microzone non opaque.The diffractive optical element is preferably formed on a thermoplastic film, preferably transparent, having a thickness less than or equal to 50 μm, in particular by embossing the latter. This thermoplastic film can be laminated at least partially with the layer carrying the non-opaque microzone or through which the non-opaque microzone is produced. As a variant, the thermoplastic film comprising the diffractive optical element is fixed to the layer carrying the non-opaque microzone by an adhesive structure, preferably also protective, comprising an adhesive material. As described above, the adhesive structure can be introduced in the liquid state between the thermoplastic film and the layer carrying the non-opaque microzone by means of at least one microperforation, in particular forming at least one non-opaque microzone.

La présence du film thermoplastique permet de former l'élément optique diffractif indépendamment du reste de l'article sécurisé, donc de faciliter sa fabrication.The presence of the thermoplastic film makes it possible to form the diffractive optical element independently of the rest of the secure article, and therefore to facilitate its manufacture.

Le film thermoplastique peut être laminé ou collé avec un élément de sécurité, notamment un fil ou foil de sécurité, présentant au moins une zone transparente, notamment la microzone non opaque, se superposant au moins partiellement avec l'élément optique diffractif. Cet élément de sécurité peut présenter un motif de sécurisation, notamment sous forme d'impression, de microperforations ou d'une métallisation ou démétallisation. Comme indiqué ci-dessus, ce motif peut correspondre au moins partiellement au motif d'interférences produit par l'élément optique diffractif.The thermoplastic film can be laminated or glued with a security element, in particular a security wire or foil, having at least one transparent zone, in particular the non-opaque microzone, overlapping at least partially with the diffractive optical element. This security element may have a security pattern, in particular in the form of printing, microperforations or metallization or demetallization. As indicated above, this pattern can correspond at least partially to the interference pattern produced by the diffractive optical element.

L'élément optique diffractif peut être enregistré sur le film thermoplastique par un procédé dit de rouleau à rouleau (« roll to roll »).The diffractive optical element can be recorded on the thermoplastic film by a process known as “roll to roll”.

L'élément optique diffractif peut être visualisé sous lumière polychromatique ou monochromatique.The diffractive optical element can be viewed under polychromatic or monochromatic light.

L'élément optique diffractif peut être associé à un filtre optique, interférentiel, irisé ou absorbant, placé sur le trajet de la lumière atteignant ou quittant l'élément optique diffractif. Ce filtre peut appartenir à la structure de sécurité ou à l'article et constituer ainsi un élément de sécurité supplémentaire en tant que tel.The diffractive optical element can be associated with an optical, interference, iridescent or absorbent filter, placed on the path of the light reaching or leaving the optical element. diffractive. This filter can belong to the security structure or to the article and thus constitute an additional security element as such.

Structure de sécuritéSecurity structure

La structure de sécurité peut se présenter sous la forme d'un élément qui est intégré dans un substrat fibreux lors de la fabrication de celui-ci ou qui est rapporté à sa surface.The security structure may be in the form of an element which is integrated into a fibrous substrate during the manufacture thereof or which is attached to its surface.

La structure de sécurité peut se présenter sous la forme de patch, de fil de sécurité, de foil ou de film.The security structure can be in the form of a patch, security wire, foil or film.

La structure de sécurité peut être exposée à l'environnement extérieur sur ses deux faces opposées ou l'être sur seulement l'une d'entre elles ou être recouverte sur ses deux faces par une ou plusieurs couches non complètement opaques, par exemple un film de protection ou un vernis.The security structure may be exposed to the external environment on its two opposite faces or be exposed on only one of them or be covered on its two faces by one or more layers which are not completely opaque, for example a film protective or varnish.

La structure de sécurité peut être d'une seule pièce au moment de son intégration dans ou sur le reste de l'article, notamment du document, ou être composée de plusieurs sous-éléments qui sont assemblés par l'intermédiaire du reste de l'article, notamment du document, par exemple étant rapportés sur des faces différentes d'un substrat du document. Ces sous-éléments peuvent venir en contact ou non les uns avec les autres. Par exemple, un premier sous-élément peut porter l'élément optique diffractif et deuxième sous-élément peut porter la microzone non opaque associée, et les deux peuvent être séparés par au moins une couche de substrat du document ou être assemblés directement l'un avec l'autre.The security structure can be in one piece at the time of its integration into or on the rest of the article, in particular of the document, or be composed of several sub-elements which are assembled via the rest of the article, in particular of the document, for example being reported on different faces of a substrate of the document. These sub-elements may or may not come into contact with each other. For example, a first sub-element can carry the diffractive optical element and second sub-element can carry the associated non-opaque microzone, and the two can be separated by at least one layer of substrate from the document or be assembled directly one with the other.

De préférence, la structure de sécurité comporte une structure adhésive protectrice ou une structure adhésive associée à une structure protectrice disposée entre le premier sous-élément portant l'élément optique diffractif, notamment l'élément optique diffractif et le deuxième sous-élément portant la microzone non opaque.Preferably, the security structure comprises a protective adhesive structure or an adhesive structure associated with a protective structure disposed between the first sub-element carrying the diffractive optical element, in particular the diffractive optical element and the second sub-element carrying the microzone not opaque.

On entend par « structure adhésive protectrice ou structure protectrice », une couche ou une pluralité de couches destinée à protéger mécaniquement et/ou optiquement, l'élément optique diffractif notamment lorsque l'élément optique diffractif est une structure embossée.The term "protective adhesive structure or protective structure" means a layer or a plurality of layers intended to protect mechanically and / or optically, the diffractive optical element in particular when the diffractive optical element is an embossed structure.

La structure adhésive protectrice comporte, de préférence, une couche d'un mélange d'un matériau HRI (high refractive index) et d'un matériau adhésif qui est disposé sur l'élément optique diffractif.The protective adhesive structure preferably comprises a layer of a mixture of an HRI (high refractive index) material and an adhesive material which is placed on the diffractive optical element.

En variante, le premier sous-élément comporte une couche d'un matériau HRI, de préférence déposée par vaporisation sous vide sur l'élément optique diffractif, sur laquelle est, de préférence, disposée une couche d'un matériau adhésif, la couche de matériau adhésif étant, de préférence, disposée entre la couche d'un matériau HRI et le deuxième sous-élément portant la microzone non opaque. La superposition de la couche de matériau HRI et de la couche de matériau adhésif forme la structure adhésive protectrice. La couche adhésive permet de protéger mécaniquement l'élément optique diffractifAs a variant, the first sub-element comprises a layer of an HRI material, preferably deposited by vacuum spraying on the diffractive optical element, on which is preferably arranged a layer of an adhesive material, the layer of adhesive material being preferably disposed between the layer of HRI material and the second sub-element carrying the non-opaque microzone. The superimposition of the layer of HRI material and the layer of adhesive material forms the protective adhesive structure. The adhesive layer makes it possible to mechanically protect the diffractive optical element

Le matériau HRI permet de protéger l'élément optique diffractif d'une atténuation ou d'une annulation de son effet optique qui pourrait résulter de la présence du matériau adhésif.The HRI material protects the diffractive optical element from attenuation or cancellation of its optical effect which could result from the presence of the adhesive material.

En variante encore, la structure protectrice associée à la structure adhésive comporte un mélange d'un matériau HRI (high refractive index) et d'un liant, qui est disposé sur l'élément optique diffractif, la structure adhésive étant, de préférence, disposée sur la structure protectrice, notamment entre le deuxième sous-élément portant la microzone non opaque et la structure protectrice.In another variant, the protective structure associated with the adhesive structure comprises a mixture of a HRI (high refractive index) material and a binder, which is disposed on the diffractive optical element, the adhesive structure preferably being disposed on the protective structure, in particular between the second sub-element carrying the non-opaque microzone and the protective structure.

En variante encore, le premier sous-élément comporte une couche d'un matériau HRI disposée, notamment déposée par vaporisation sous vide, sur la structure optique diffractive, sur laquelle est disposée une couche comportant un liant, la superposition de la couche de matériau HRI et de la couche comportant un liant formant la structure protectrice associée à la structure adhésive. La structure adhésive est, de préférence, disposé sur la structure protectrice, notamment entre la structure protectrice et le deuxième sous-élément portant la microzone non opaque.In another variant, the first sub-element comprises a layer of HRI material arranged, in particular deposited by vacuum spraying, on the diffractive optical structure, on which is arranged a layer comprising a binder, the superposition of the layer of HRI material and the layer comprising a binder forming the protective structure associated with the adhesive structure. The adhesive structure is preferably arranged on the protective structure, in particular between the protective structure and the second sub-element carrying the non-opaque microzone.

De préférence, le liant est sécurisé par exemple par la présence d'un marqueur spécifique ou d'un composé luminescent. La couche de matériau HRI permet de protéger optiquement l'élément optique diffractif et la couche de liant permet de protéger mécaniquement l'élément optique diffractif.Preferably, the binder is secured for example by the presence of a specific marker or of a luminescent compound. The layer of HRI material makes it possible to optically protect the diffractive optical element and the binder layer makes it possible to mechanically protect the diffractive optical element.

Le matériau HRI permet de protéger l'élément optique diffractif d'une atténuation ou d'une annulation de son effet optique qui pourrait résulter de la présence du matériau adhésif et/ou de la couche comportant un liant.The HRI material makes it possible to protect the diffractive optical element from attenuation or cancellation of its optical effect which could result from the presence of the adhesive material and / or the layer comprising a binder.

Par « un matériau HRI », on comprend un matériau ayant un indice de réfraction élevée, de préférence supérieur ou égal à 1,7. De préférence, la matériau HRI est choisi parmi le sulfure de zinc (ZnS), l'oxyde de zinc (ZnO), l'oxyde de zirconium (ZrO2), le dioxyde de titane (TiO2), le carbone (C), l'oxyde d'indium (In2O3), l'oxyde d'indium-étain (ITO), le pentoxyde de tantale (Ta2O5), l'oxyde de cerium (CeO2), l'oxyde d'itrium (Y2O3), l'oxyde d'europium (Eu2O3), les oxydes ferreux, le nitrure d'hafnium (HfN), le carbone d'hafnium (HfC), l'oxyde d'hafnium (HfO2), l'oxyde de lanthane (La2O3), l'oxyde de magnésium (MgO), l'oxyde de neodyme (Nd2O3), l'oxyde de praseodyme (Pr6O11), l'oxyde de samarium (Sm2O3), le trioxyde d'antimoine (Sb2O3), le carbone de silicium (SiC), le nitrure de silicium (SizNu), le monoxyde de silicium (SiO), le trioxyde de sélénium (Se2O3), l'oxyde d'étain (SnO2), le trioxyde de tungstène (WO3), leurs combinaisons et similaires.By "an HRI material" is meant a material having a high refractive index, preferably greater than or equal to 1.7. Preferably, the HRI material is chosen from zinc sulfide (ZnS), zinc oxide (ZnO), zirconium oxide (ZrO 2 ), titanium dioxide (TiO 2 ), carbon (C), indium oxide (In 2 O 3 ), indium tin oxide (ITO), tantalum pentoxide (Ta 2 O 5 ), cerium oxide (CeO 2 ), itrium oxide (Y 2 O 3 ), europium oxide (Eu 2 O 3 ), ferrous oxides, hafnium nitride (HfN), hafnium carbon (HfC), hafnium oxide (HfO 2 ), l lanthanum oxide (La 2 O 3 ), magnesium oxide (MgO), neodymium oxide (Nd 2 O3), praseodymium oxide (Pr 6 O 11 ), samarium oxide (Sm 2 O 3 ), antimony trioxide (Sb 2 O 3 ), silicon carbon (SiC), silicon nitride (SizNu), silicon monoxide (SiO), selenium trioxide (Se 2 O 3) ), tin oxide (SnO 2 ), tungsten trioxide (WO 3 ), combinations thereof and the like.

La structure adhésive protectrice ou la structure adhésive associée à une structure protectrice peut être introduite via une ou plusieurs microperforations du deuxième sous-élément, notamment au moins une microperforation définissant une microzone non opaque. La structure adhésive protectrice ou la structure adhésive associée à une structure protectrice peut remplir partiellement, de préférence totalement, la ou les microperforations.The protective adhesive structure or the adhesive structure associated with a protective structure can be introduced via one or more microperforations of the second sub-element, in particular at least one microperforation defining a non-opaque microzone. The protective adhesive structure or the adhesive structure associated with a protective structure may partially, preferably completely, fill the microperforation (s).

En variante, l'élément optique diffractif est disposé d'un premier côté du premier sous-élément, le deuxième côté du sous-élément ne présentant pas d'élément optique diffractif et la structure adhésive étant disposée entre le deuxième sous-élément et le deuxième côté du premier sous-élément. La structure adhésive n'est donc pas en contact avec l'élément optique diffractif.As a variant, the diffractive optical element is arranged on a first side of the first sub-element, the second side of the sub-element having no diffractive optical element and the adhesive structure being disposed between the second sub-element and the second side of the first sub-element. The adhesive structure is therefore not in contact with the diffractive optical element.

La structure de sécurité peut comporter une pluralité desdits éléments optiques diffractifs, générant chacun un motif d'interférences dans un plan de visualisation éloigné de l'élément optique diffractif.The security structure may include a plurality of said diffractive optical elements, each generating an interference pattern in a viewing plane distant from the diffractive optical element.

Ces éléments optiques diffractifs peuvent générer des motifs d'interférences différents ou identiques, se complétant ou non.These diffractive optical elements can generate different or identical interference patterns, complementing each other or not.

De préférence, la structure adhésive protectrice ou la structure protectrice est appliquée sur tous les éléments optiques diffractifs.Preferably, the protective adhesive structure or the protective structure is applied to all the diffractive optical elements.

La structure de sécurité peut comporter une pluralité de microzones non opaques se superposant chacune au moins partiellement à au moins un élément optique diffractif respectif.The security structure may include a plurality of non-opaque microzones, each at least partially superimposed on at least one respective diffractive optical element.

De préférence, une pluralité de microzones non opaques se superpose à un même élément optique diffractif.Preferably, a plurality of non-opaque microzones is superimposed on the same diffractive optical element.

La ou les microzones non opaques peuvent définir visuellement un motif qui se retrouve au moins partiellement dans le motif d'interférences généré par au moins un élément optique diffractif. Par exemple, plusieurs microzones non opaques sont disposées selon un agencement qui reproduit un ou plusieurs caractères alphanumériques, et le motif d'interférences produit une image de ces mêmes caractères alphanumériques dans le plan de visualisation. Le motif facilite l'authentification par comparaison du motif au motif de l'interférence. Cet agencement augmente encore la difficulté pour le contrefacteur potentiel qui devrait reproduire le motif à la fois dans les microzones et dans le motif d'interférence de la structure de sécurité.The non-opaque microzone (s) can visually define a pattern which is found at least partially in the interference pattern generated by at least one diffractive optical element. For example, several non-opaque microzones are arranged in an arrangement which reproduces one or more alphanumeric characters, and the interference pattern produces an image of these same alphanumeric characters in the display plane. The pattern facilitates authentication by comparing the pattern to the interference pattern. This arrangement further increases the difficulty for the potential counterfeiter who should reproduce the pattern both in the microzones and in the interference pattern of the security structure.

La structure de sécurité peut comporter au moins un filtre absorbant ou interférentiel, notamment un filtre coloré, se superposant au moins partiellement à la microzone non opaque.The security structure may comprise at least one absorbent or interference filter, in particular a colored filter, at least partially superimposed on the non-opaque microzone.

La structure de sécurité peut comporter au moins deux microzones non opaques formées chacune par une microperforation d'axe formant un angle avec la normale avec la surface de la structure de sécurité, les angles étant différents. Au moins deux éléments optiques diffractifs peuvent se superposer chacun au moins partiellement à une microzone non opaque respective. Cette disposition permet, en orientant différemment le faisceau de lumière, de pouvoir visualiser l'un ou l'autre des motifs d'interférences produits et de pouvoir créer par exemple une animation en observant alternativement les deux motifs d'interférences.The security structure may comprise at least two non-opaque microzones each formed by an axis microperforation forming an angle with the normal with the surface of the security structure, the angles being different. At least two diffractive optical elements may each overlap at least partially to a respective non-opaque microzone. This arrangement makes it possible, by orienting the light beam differently, to be able to visualize one or the other of the interference patterns produced and to be able to create, for example, an animation by alternately observing the two interference patterns.

Article, notamment document, sécuriséArticle, including document, secure

L'invention a également pour objet un article, selon la revendication 13, notamment document, sécurisé comportant une structure de sécurité selon l'invention.The subject of the invention is also an article, according to claim 13, in particular a secure document comprising a security structure according to the invention.

Le document sécurisé peut comporter un substrat, notamment fibreux présentant au moins une fenêtre, la fenêtre étant au moins partiellement superposée à la fois à l'élément optique diffractif et à la microzone non opaque. La structure de sécurité peut être rapportée sur ce substrat ou intégrée à celui-ci.The secure document may comprise a substrate, in particular a fibrous substrate, having at least one window, the window being at least partially superimposed both on the diffractive optical element and on the non-opaque microzone. The security structure can be attached to or integrated into this substrate.

L'article sécurisé peut présenter au moins une deuxième microzone non opaque, au moins partiellement superposée à la fois à l'élément optique diffractif et à la première microzone non opaque. La ou chaque microzone non opaque peut être définie par absence de matière, notamment par une microperforation. Les microperforations peuvent être réalisées chacune dans un jet fibreux. L'observation se fait à travers les deux microzones non opaques.The secure article may have at least a second non-opaque microzone, at least partially superimposed both on the diffractive optical element and on the first non-opaque microzone. The or each non-opaque microzone can be defined by absence of material, in particular by microperforation. The microperforations can each be carried out in a fibrous jet. The observation is made through the two non-opaque microzones.

L'article sécurisé peut comporter un substrat, notamment fibreux, comportant une microperforation définissant la microzone non opaque, et l'élément optique diffractif peut être présent sur un élément de sécurité rapporté sur ledit substrat ou intégré à celui-ci. Dans ce cas, la structure de sécurité est constituée de l'élément de sécurité et du substrat.The secure article may include a substrate, in particular a fibrous substrate, comprising a microperforation defining the non-opaque microzone, and the diffractive optical element may be present on a security element attached to or integrated into said substrate. In this case, the security structure consists of the security element and the substrate.

L'article sécurisé peut comporter un élément de sécurité présentant au moins une microzone non opaque se superposant à l'élément optique diffractif. Ce dernier peut être formé sur un film thermoplastique, qui est assemblé, par exemple par lamination, avec l'élément de sécurité, alors que celui-ci est déjà en place ou non sur le document.The secure article may include a security element having at least one non-opaque microzone superimposed on the diffractive optical element. The latter can be formed on a thermoplastic film, which is assembled, for example by lamination, with the security element, when the latter is already in place or not on the document.

L'article sécurisé peut être un passeport, une carte d'identité, une carte d'accès, un permis de conduire, une carte à jouer ou à collectionner interactive, un moyen de paiement, notamment une carte de paiement, un billet de banque, un timbre fiscal, une vignette, un bon d'achat ou un coupon, une carte de transport, de fidélité, de prestation ou d'abonnement, un jeton ou une plaque de casino.The secure item can be a passport, an identity card, an access card, a driver's license, an interactive playing or collecting card, a means of payment, in particular a payment card, a bank note. , a tax stamp, a sticker, a voucher or a coupon, a transport, loyalty, service or subscription card, a token or a casino plate.

L'article sécurisé présente de préférence au moins un élément de sécurité ou motif identique ou similaire au moins partiellement au motif d'interférences.The secure article preferably has at least one security element or pattern which is identical or at least partially similar to the interference pattern.

Par « similaire », on comprend que les deux motifs peuvent être identiques à une transformation près, notamment à une homothétie près, avoir la même forme, présenter la même information notamment en caractères alphanumériques, la typographie pouvant être différente. Les deux motifs comportent, par exemple, les mêmes informations écrites, notamment sur l'état civil, la devise d'une coupure, le nom d'un lieu, une date, ou les mêmes informations visuelles, notamment une photographie ou un dessin.By "similar", it is understood that the two patterns can be identical except for a transformation, in particular to a homothety, have the same form, present the same information in particular in alphanumeric characters, the typography being able to be different. The two reasons include, for example, the same written information, in particular on civil status, the currency of a denomination, the name of a place, a date, or the same visual information, in particular a photograph or a drawing.

Procédé d'authentificationAuthentication process

L'invention a encore pour objet un procédé d'authentification, selon la revendication 14, d'une structure de sécurité ou d'un article, notamment document, sécurisé selon l'invention, comportant les étapes consistant à :

  • éclairer l'élément optique diffractif avec une source de lumière,
  • vérifier, notamment au travers de la microzone non opaque, la présence d'un motif d'interférence dans un plan de visualisation éloigné de l'élément optique diffractif.
The subject of the invention is also a method of authentication, according to claim 14, of a security structure or of an article, in particular document, secured according to the invention, comprising the steps consisting in:
  • illuminating the diffractive optical element with a light source,
  • verify, in particular through the non-opaque microzone, the presence of an interference pattern in a viewing plane distant from the diffractive optical element.

La lumière est de préférence collimatée.The light is preferably collimated.

De préférence, lors de l'éclairage de l'élément optique diffractif, la lumière traverse la microzone non opaque avant de rencontrer l'élément optique diffractif et de générer un motif d'interférence.Preferably, when the diffractive optical element is lit, the light passes through the non-opaque microzone before meeting the diffractive optical element and generating an interference pattern.

La source de lumière peut être polychromatique, le plan de visualisation étant virtuel et positionné entre la source de lumière et la structure de sécurité. La lumière polychromatique peut être une lumière blanche. Le motif d'interférences est observé au travers de la microzone non opaque qui sert de viseur.The light source can be polychromatic, the display plane being virtual and positioned between the light source and the security structure. The polychromatic light can be white light. The interference pattern is observed through the non-opaque microzone which serves as a viewfinder.

Le procédé peut comporter l'étape consistant à disposer au moins un filtre, par exemple coloré ou interférentiel, entre le faisceau de lumière et la structure de sécurité, ou entre le plan de visualisation et l'observateur.The method may include the step of disposing at least one filter, for example a colored or interference filter, between the light beam and the security structure, or between the viewing plane and the observer.

La présence du filtre permet de sélectionner une seule longueur d'onde et de voir plus facilement un élément caché ou difficilement visible sans le filtre, notamment dans le cas d'un motif complexe multiton constitué d'une superposition de motifs simples de couleurs différentes.The presence of the filter makes it possible to select a single wavelength and to more easily see a hidden or hardly visible element without the filter, in particular in the case of a complex multiton pattern consisting of a superposition of simple patterns of different colors.

En variante, la source de lumière peut être monochromatique, étant notamment une lumière cohérente et/ou collimatée, le plan de visualisation étant réel et positionné après la structure de sécurité par rapport à la source de lumière.As a variant, the light source can be monochromatic, being in particular coherent and / or collimated light, the display plane being real and positioned after the security structure with respect to the light source.

La vérification de la présence d'un motif d'interférence peut se faire à l'aide d'un appareil équipé d'une caméra, notamment d'un téléphone portable avec mise au point disposé dans le plan de visualisation. L'utilisation d'un appareil autre que l'œil permet d'éviter tout danger pour l'œil lié à une intensité lumineuse élevée, notamment dans le cas de l'utilisation d'un laser.The verification of the presence of an interference pattern can be done using a device equipped with a camera, in particular a portable telephone with focusing arranged in the viewing plane. The use of a device other than the eye makes it possible to avoid any danger for the eye related to a high light intensity, in particular in the case of the use of a laser.

Le procédé peut comporter l'étape consistant à comparer un motif d'interférence généré par l'élément optique diffractif à un motif présent sur l'article, notamment définie par un filigrane, une impression, une métallisation ou une démétallisation ou des microperforations, ou sous une forme non directement appréhendable, par exemple enregistrée sur une puce RFID ou sur un serveur auquel il peut être accédé grâce à un lien présent sur le document.The method may include the step of comparing an interference pattern generated by the diffractive optical element with a pattern present on the article, in particular defined by a watermark, a printing, a metallization or a demetallization or microperforations, or in a form that is not directly understandable, for example stored on an RFID chip or on a server which can be accessed through a link on the document.

Le procédé peut comporter l'étape consistant à vérifier que les données du motif d'interférences correspondent bien à des données portées par ailleurs par le document.The method may include the step of verifying that the data of the interference pattern correspond to data carried elsewhere by the document.

Dans le cas de l'observation du motif d'interférences généré par l'élément optique diffractif par un appareil électronique, ce dernier peut être agencé pour analyser automatiquement l'image observée et par exemple la comparer à une information de référence, ou la décrypter pour en extraire une information à comparer à une information de référence, afin de vérifier l'authenticité de l'article, notamment du document.In the case of the observation of the interference pattern generated by the diffractive optical element by an electronic device, the latter can be arranged to automatically analyze the observed image and for example compare it with reference information, or decrypt it to extract information to compare with reference information, to verify the authenticity of the article, especially the document.

L'appareil électronique peut être agencé pour analyser le motif d'interférence observé et accéder à une base de données permettant de vérifier l'authenticité de l'article, notamment du document.The electronic device can be arranged to analyze the interference pattern observed and access a database making it possible to verify the authenticity of the article, in particular of the document.

L'article, notamment le document, peut être porteur d'une information qui permet d'accéder via un serveur distant à des données de référence qui permettent de vérifier que l'image observée provient d'un élément optique diffractif authentique.The article, in particular the document, can carry information which allows access via a remote server to reference data which makes it possible to verify that the image observed comes from an authentic diffractive optical element.

Cette information peut être stockée dans une puce RFID présente sur le document et lue par l'appareil utilisé pour observer le motif d'interférences, par exemple grâce à la technologie NFC.This information can be stored in an RFID chip present on the document and read by the device used to observe the interference pattern, for example using NFC technology.

L'invention pourra être mieux comprise à la lecture de la description détaillée qui va suivre, d'exemples non limitatifs de mise en œuvre de celle-ci, et à l'examen du dessin annexé, sur lequel :

  • la figure 1 représente de façon schématique un exemple de document sécurisé selon l'invention,
  • la figure 2 est une section selon II-II de la figure 1,
  • les figures 3 à 6 sont des vues analogues à la figure 2, de variantes de réalisation de l'exemple de la figure 1,
  • la figure 7 représente de façon schématique un autre exemple de document sécurisé selon l'invention,
  • la figure 8 est une section selon VIII-VIII de la figure 7,
  • la figure 9 représente de façon schématique un autre exemple de document sécurisé selon l'invention,
  • la figure 10 est une section selon X-X de la figure 8,
  • la figure 11 représente de façon schématique un autre exemple de document sécurisé selon l'invention,
  • la figure 12 est une section selon XII-XII de la figure 10,
  • la figure 13 est une vue analogue à celle de la figure 12,
  • les figures 14 à 20 représentent d'autres exemples de structures de sécurité selon l'invention,
  • les figures 21 et 22 représentent, en section, des variantes de structures de sécurité selon l'invention,
  • les figures 23 à 26 sont des vues analogues à la figure 2, de variantes de réalisation de l'exemple de la figure 1,
  • la figure 27 représente un autre élément de sécurité selon l'invention,
  • les figures 28A et 28B représentent des variantes de la microzone non opaque, et
  • les figures 29 et 30 illustrent, de façon schématique, la visualisation du motif d'interférences.
The invention will be better understood on reading the detailed description which follows, of nonlimiting examples of implementation thereof, and on examining the appended drawing, in which:
  • the figure 1 schematically represents an example of a secure document according to the invention,
  • the figure 2 is a section according to II-II of the figure 1 ,
  • the figures 3 to 6 are views analogous to the figure 2 , alternative embodiments of the example of the figure 1 ,
  • the figure 7 schematically represents another example of a secure document according to the invention,
  • the figure 8 is a section according to VIII-VIII of the figure 7 ,
  • the figure 9 schematically represents another example of a secure document according to the invention,
  • the figure 10 is a section along XX of the figure 8 ,
  • the figure 11 schematically represents another example of a secure document according to the invention,
  • the figure 12 is a section according to XII-XII of the figure 10 ,
  • the figure 13 is a view similar to that of the figure 12 ,
  • the figures 14 to 20 represent other examples of security structures according to the invention,
  • the Figures 21 and 22 represent, in section, variants of safety structures according to the invention,
  • the figures 23 to 26 are views analogous to the figure 2 , alternative embodiments of the example of the figure 1 ,
  • the figure 27 represents another security element according to the invention,
  • the Figures 28A and 28B represent variants of the non-opaque microzone, and
  • the Figures 29 and 30 schematically illustrate the visualization of the interference pattern.

Sur les figures, schématiques, les proportions relatives réelles des différents éléments constitutifs n'ont pas été nécessairement respectées, dans un souci de clarté du dessin. Certaines couches peuvent avoir été représentées de façon monolithique dans un souci de simplification, alors qu'elles peuvent être constituées de plusieurs sous-couches en réalité. De plus, certaines couches peuvent être assemblées par l'utilisation de couches adhésives disposées entre elles, qui ne sont pas toujours représentées sur les figures. Enfin, en présence de zones opaques et non opaques juxtaposées, on n'a représenté que schématiquement cette présence avec deux zones seulement disposées côte-à-côte, étant entendu que dans la réalité ces différentes zones seront le plus souvent plus de deux, avec des agencements pouvant être complexes, pour définir un texte ou une image tramée par exemple. L'élément optique diffractif a été représenté de façon très simple et schématique sur les figures. Les reliefs de surface éventuels causés par un éventuel embossage ne sont notamment pas représentés, cela n'exclu en rien leur présence éventuel.In the diagrammatic figures, the actual relative proportions of the various constituent elements have not necessarily been respected, for the sake of clarity of the drawing. Certain layers may have been represented monolithically for the sake of simplification, while they may in fact be made up of several sublayers. In addition, certain layers can be assembled by the use of adhesive layers arranged between them, which are not always shown in the figures. Finally, in the presence of opaque and non-opaque zones juxtaposed, this presence has only been represented schematically with two zones only arranged side by side, it being understood that in reality these different zones will most often be more than two, with arrangements can be complex, to define a text or a raster image for example. The diffractive optical element has been shown very simply and schematically in the figures. The possible surface reliefs caused by a possible embossing are in particular not shown, this in no way excludes their possible presence.

L'article sécurisé 10 représenté aux figures 1 et 2, par exemple un document tel qu'un billet de banque, comporte une structure de sécurité 2 selon l'invention, comportant un élément optique diffractif 40 se superposant au moins partiellement à une microzone non opaque 30.The secure article 10 shown in Figures 1 and 2 , for example a document such as a banknote, comprises a security structure 2 according to the invention, comprising a diffractive optical element 40 overlapping at least partially with a non-opaque microzone 30.

L'article 10 comporte un substrat 11, notamment en papier, pourvu d'une fenêtre 15 qui donne visuellement accès à l'élément optique diffractif 40.The article 10 comprises a substrate 11, in particular made of paper, provided with a window 15 which visually gives access to the diffractive optical element 40.

Dans l'exemple considéré, la microzone non opaque 30 est formée par une microperforation d'axe X réalisée à travers un substrat 18, notamment en papier, du document 10, assemblé avec le substrat 11.In the example considered, the non-opaque microzone 30 is formed by a microperforation of axis X carried out through a substrate 18, in particular of paper, of the document 10, assembled with the substrate 11.

L'élément optique diffractif est réalisé sur un film 43 en matière plastique transparente, qui est assemblé avec un élément de sécurité 20 présentant une zone non opaque 23 superposée au moins partiellement à l'élément optique diffractif 40 et à la microperforation 30.The diffractive optical element is produced on a film 43 of transparent plastic, which is assembled with a security element 20 having a non-opaque zone 23 at least partially superimposed on the diffractive optical element 40 and on the microperforation 30.

Le film thermoplastique 43 peut être en polyéthylène téréphtalate (PET).The thermoplastic film 43 can be made of polyethylene terephthalate (PET).

L'élément optique diffractif 40 génère un motif d'interférences dans un plan de visualisation éloigné.The diffractive optical element 40 generates an interference pattern in a distant viewing plane.

L'alignement au moins partiel des différentes ouvertures et zones transparentes définit une zone non opaque A qui va de part et d'autre du document sécurisé 1.The at least partial alignment of the different openings and transparent zones defines a non-opaque zone A which goes on either side of the secure document 1.

On va décrire en se référant aux figures 29 et 30 des exemples de procédés de visualisation de la structure de sécurité 2 selon l'invention.We will describe with reference to Figures 29 and 30 examples of display methods of the security structure 2 according to the invention.

La visualisation du motif d'interférences de la structure de sécurité 2 se fait par éclairage de la microzone non opaque 30 par une source de lumière 60, dans un plan 62 éloigné de l'élément optique diffractif 40.The interference pattern of the safety structure 2 is displayed by lighting the non-opaque microzone 30 by a light source 60, in a plane 62 distant from the diffractive optical element 40.

La structure de sécurité 2 est, de préférence, disposée de manière à ce que son plan soit orienté orthogonalement à la lumière incidente provenant de la source de lumière 60 et que la microzone non opaque 30 soit de préférence positionnée du côté de la source de lumière 60.The safety structure 2 is preferably arranged so that its plane is oriented orthogonally to the incident light coming from the light source 60 and that the non-opaque microzone 30 is preferably positioned on the side of the light source 60.

La microzone non opaque 30 permet notamment de viser avec le faisceau incident l'élément optique diffractif 40.The non-opaque microzone 30 makes it possible in particular to target the diffractive optical element 40 with the incident beam.

La source de lumière 60 est, de préférence, collimatée.The light source 60 is preferably collimated.

Comme illustré sur la figure 29, la source de lumière 60 peut être une source de lumière monochromatique, notamment un laser. Le plan de visualisation 62 est alors réel et est positionné en aval de la structure de sécurité 2 par rapport à la source de lumière 60. La visualisation du motif d'interférences 66 peut se faire à l'aide d'un appareil portable, notamment d'un téléphone portable réglé en mode photo ou vidéo et positionné dans le plan de visualisation 62. Le motif d'interférence 66 est visualisé au travers de la microzone non opaque 30.As illustrated in the figure 29 , the light source 60 can be a monochromatic light source, in particular a laser. The display plane 62 is then real and is positioned downstream of the security structure 2 with respect to the light source 60. The interference pattern 66 can be displayed using a portable device, in particular of a portable telephone set in photo or video mode and positioned in the viewing plane 62. The interference pattern 66 is viewed through the non-opaque microzone 30.

Comme illustré sur la figure 30, la source de lumière 60 peut être une source polychromatique. Le plan de visualisation 62 est alors virtuel et positionné en amont de la structure de sécurité 2 par rapport à la source de lumière 60. La visualisation du motif d'interférence 66 se fait en observant la source de lumière 60 au travers de la microzone non opaque 30.As illustrated in the figure 30 , the light source 60 can be a polychromatic source. The display plane 62 is then virtual and positioned upstream of the security structure 2 with respect to the light source 60. The interference pattern 66 is displayed by observing the light source 60 through the non-microzone opaque 30.

L'authentification de la structure de sécurité 2 peut nécessiter l'utilisation d'un filtre 68 positionné en amont ou aval de la structure de sécurité 2. Ce filtre peut permettre de filtrer les longueurs d'onde visibles à l'œil.The authentication of the security structure 2 may require the use of a filter 68 positioned upstream or downstream of the security structure 2. This filter can make it possible to filter the wavelengths visible to the eye.

L'authentification de la structure de sécurité 2 peut se faire par comparaison du motif d'interférences 66 généré par l'élément optique diffractif 40 avec une ou plusieurs informations additionnelles présentes sur la structure de sécurité 2 ou l'article 10 associé par exemple à un motif de comparaison défini par un filigrane, une impression, une métallisation ou une démétallisation ou des microperforations. La microzone non opaque 30, étant notamment une démétallisation ou une microperforation, peut constituer, au moins partiellement, le motif de comparaison.The authentication of the security structure 2 can be done by comparison of the interference pattern 66 generated by the diffractive optical element 40 with one or more additional pieces of information present on the security structure 2 or the article 10 associated for example with a comparison pattern defined by a watermark, printing, metallization or demetallization or microperforations. The non-opaque microzone 30, being in particular a demetallization or a microperforation, can constitute, at least partially, the reason for comparison.

L'invention n'est pas limitée à un article sécurisé en particulier, et celui-ci peut être autre qu'un document de valeur, notamment un document d'identité ou une carte. Les substrats 11 et 18 de l'exemple des figures 1 et 2 peuvent ainsi être non fibreux.The invention is not limited to a particular secure article, and this may be other than a valuable document, in particular an identity document or a card. Substrates 11 and 18 of the example of Figures 1 and 2 may thus be non-fibrous.

L'élément optique diffractif 40 peut être formé sur un film thermoplastique 43 selon l'une des méthodes décrites précédemment. L'épaisseur e de l'élément optique diffractif 40 est, de préférence, inférieure ou égale à 50 µm, mieux inférieure ou égale à 25 µm.The diffractive optical element 40 can be formed on a thermoplastic film 43 according to one of the methods described above. The thickness e of the diffractive optical element 40 is preferably less than or equal to 50 μm, better still less than or equal to 25 μm.

L'élément optique diffractif 40 peut être, comme illustré sur la figure 2, de section plus grande que celle de la microzone non opaque 30.The diffractive optical element 40 can be, as illustrated on the figure 2 , of larger section than that of the non-opaque microzone 30.

La microzone non opaque 30 a, de préférence, une section S inférieure à 1000000 µm2, mieux inférieure ou égale à 200000 µm2, encore mieux comprise entre 10 µm2 et 200000 µm2, encore mieux comprise entre 5000 µm2 et 200000 µm2.The non-opaque microzone 30 preferably has a section S of less than 1,000,000 µm 2 , better less than or equal to 200,000 µm 2 , even better between 10 µm 2 and 200,000 µm 2 , even better between 5,000 µm 2 and 200,000 µm 2 .

La microzone non opaque 30, lorsqu'elle est réalisée sous forme de microperforation, peut être agencée de diverses manières.The non-opaque microzone 30, when it is produced in the form of microperforation, can be arranged in various ways.

Comme illustré sur la figure 14, la microzone non opaque 30 peut avoir une section variable, notamment se rétrécissant en direction de l'élément optique diffractif 40.As illustrated in the figure 14 , the non-opaque microzone 30 may have a variable cross section, in particular narrowing in the direction of the diffractive optical element 40.

On a représenté sur la figure 15 une microzone non opaque 30 formée par une microperforation dont l'axe X forme un angle α non nul avec la normale à la surface de la structure de sécurité 2. L'angle α peut être compris entre -45° et 45°.We have represented on the figure 15 a non-opaque microzone 30 formed by a microperforation whose axis X forms a non-zero angle α with the normal to the surface of the safety structure 2. The angle α can be between -45 ° and 45 °.

Comme illustré sur la figure 16, la structure de sécurité 2 peut comporter au moins deux microzones non opaques 301 et 302 débouchant sur la même surface S12, chaque microzone non opaque 301 et 302 pouvant se superposer à un élément optique diffractif 401 ou 402 respectif. Cette configuration permet, en faisant varier l'angle de visualisation, de choisir l'élément optique diffractif que l'on souhaite visualiser. Une animation peut le cas échéant s'observer en alternant la visualisation des deux motifs d'interférences.As illustrated in the figure 16 , the safety structure 2 can comprise at least two non-opaque micro-zones 30 1 and 30 2 opening onto the same surface S 12 , each non-opaque micro-zone 30 1 and 30 2 being able to be superimposed on a respective diffractive optical element 40 1 or 40 2 . This configuration allows, by varying the viewing angle, to choose the diffractive optical element that one wishes to view. An animation can be observed if necessary by alternating the visualization of the two interference patterns.

La microzone non opaque 30 peut être réalisée autrement que sous forme d'une microperforation à travers une couche opaque.The non-opaque microzone 30 can be produced other than in the form of a microperforation through an opaque layer.

Comme illustré sur la figure 17, la microzone non opaque 30 peut être remplie d'un matériau non opaque transparent, incolore ou non.As illustrated in the figure 17 , the non-opaque microzone 30 can be filled with a transparent, colorless or non-opaque material.

Comme illustré sur la figure 18, la microzone non opaque 30 peut être délimitée par une impression 35. La couche 38 sur laquelle est réalisée l'impression peut être un film transparent qui porte, sur la face opposée à l'impression, l'élément optique diffractif 40.As illustrated in the figure 18 , the non-opaque microzone 30 can be delimited by a print 35. The layer 38 on which the print is made can be a transparent film which carries, on the face opposite to the print, the diffractive optical element 40.

En variante, la microzone non opaque 30 peut être formée par une démétallisation d'une couche métallique 37, comme illustré sur la figure 19.As a variant, the non-opaque microzone 30 can be formed by demetallization of a metal layer 37, as illustrated in the figure 19 .

La structure de sécurité 2 peut comporter un filtre optique placé sur le trajet de la lumière gagnant ou quittant l'élément optique diffractif.The security structure 2 may include an optical filter placed on the path of the light gaining or leaving the diffractive optical element.

On a représenté sur la figure 20 une structure de sécurité 2 comportant un filtre optique 80, absorbant ou interférentiel, notamment coloré, se superposant à la microzone non opaque 30.We have represented on the figure 20 a security structure 2 comprising an optical filter 80, absorbent or interference, in particular colored, superimposed on the non-opaque micro-zone 30.

Le filtre 80 peut être positionné en amont ou en aval de l'élément optique diffractif 40. Le filtre 80 permet de sélectionner une ou plusieurs longueurs d'onde de la lumière lors de la visualisation du motif d'interférences. Le filtre permet d'obtenir une personnalisation du motif d'interférence en permettant le choix de la couleur de visualisation.The filter 80 can be positioned upstream or downstream from the diffractive optical element 40. The filter 80 makes it possible to select one or more wavelengths of light when viewing the interference pattern. The filter allows you to personalize the interference pattern by allowing the choice of display color.

Comme illustré sur la figure 21, la structure de sécurité 2 peut comporter une pluralité d'éléments optiques diffractifs 401, ..., 40i et des microzones non opaques respectives 301,..., 30i d'axes respectifs X1,..., Xi, chaque microzone non opaque 301 ; ... ; 30i se superposant à un élément optique diffractif 401 ; ... ; 40i correspondant.As illustrated in the figure 21 , the security structure 2 can comprise a plurality of diffractive optical elements 40 1 , ..., 40 i and respective non-opaque micro-zones 30 1 , ..., 30 i with respective axes X 1 , ..., X i , each non-opaque microzone 30 1 ; ...; 30 i superimposed on a diffractive optical element 40 1 ; ...; 40 i corresponding.

La structure de sécurité 2 peut comporter un élément de sécurité 20 comportant une ou plusieurs zones non opaques 23, chaque zone non opaque se superposant au moins partiellement avec au moins un élément optique diffractif 401, ..., 40i. Une zone non opaque 23 peut se superposer avec au moins deux éléments optiques diffractifs 401, ..., 40i.The security structure 2 can comprise a security element 20 comprising one or more non-opaque zones 23, each non-opaque zone overlapping at least partially with at least one diffractive optical element 40 1 , ..., 40 i . A non-opaque zone 23 can be superimposed with at least two diffractive optical elements 40 1 , ..., 40 i .

Dans la variante représentée à la figure 23, la structure de sécurité 2 comporte une pluralité de filtres colorés 601,..., 60i, notamment de couleurs différentes, se superposant chacun à au moins un élément optique diffractif respectif 401, ..., 40i.In the variant shown in figure 23 , the security structure 2 comprises a plurality of colored filters 60 1 , ..., 60 i , in particular of different colors, each superimposed on at least one respective diffractive optical element 40 1 , ..., 40 i .

On voit sur la figure 2 notamment que la structure de sécurité 2 peut comporter un élément de sécurité 20 qui se superpose au moins partiellement à l'élément optique diffractif 40 et à la microzone non opaque 30. Plus particulièrement, comme illustré, cet élément de sécurité 20 peut être visible à travers la fenêtre 15 et s'interposer entre le substrat 11 et le film 43 porteur de l'élément optique diffractif 40.We see on the figure 2 in particular that the security structure 2 may include a security element 20 which is at least partially superimposed on the diffractive optical element 40 and on the non-opaque microzone 30. More particularly, as illustrated, this security element 20 may be visible at through the window 15 and come between the substrate 11 and the film 43 carrying the diffractive optical element 40.

L'élément de sécurité 20 est, de préférence, au moins partiellement opaque, étant par exemple métallisé.The security element 20 is preferably at least partially opaque, for example being metallized.

La zone non opaque 23 peut être formée par démétallisation ou perforation.The non-opaque zone 23 can be formed by demetallization or perforation.

L'élément 20 peut apporter une sécurité visible à travers la fenêtre 15, par exemple sous la forme d'un motif 50 situé hors de la zone non opaque 23, ce motif 50 étant par exemple formé par impression ou démétallisation, comme illustré à la figure 1.The element 20 can provide visible security through the window 15, for example in the form of a pattern 50 situated outside of the non-opaque zone 23, this pattern 50 being for example formed by printing or demetallization, as illustrated in FIG. figure 1 .

Le motif 50 est par exemple constitué de caractères alphanumériques, comme illustré sur la figure 1. Il peut s'agir d'un texte renseignant sur le nom de la banque, du pays et/ou sur la valeur de la coupure.The pattern 50 is for example made up of alphanumeric characters, as illustrated in the figure 1 . It can be a text providing information on the name of the bank, the country and / or the value of the denomination.

Le motif 50 peut être réalisé conformément à l'enseignement de la demande WO 2006/066927, sous forme de points de trame restituant une image en lumière transmise, une des démétallisations ou perforations du motif 50 pouvant constituer la microzone non opaque 30.The pattern 50 can be produced in accordance with the teaching of application WO 2006/066927, in the form of halftone dots restoring an image in transmitted light, one of the demetallizations or perforations of the pattern 50 which can constitute the non-opaque microzone 30.

Le motif 50 se retrouve, de préférence, en partie ou totalement dans le motif d'interférence 66 généré par l'élément optique diffractif 40. Par exemple, sur la figure 1, le motif 50 représentant la valeur de la coupure se retrouve dans le motif d'interférence qui représente également la valeur de la coupure, la typographie pouvant être identique ou différente.The pattern 50 is preferably found in part or totally in the interference pattern 66 generated by the diffractive optical element 40. For example, on the figure 1 , the pattern 50 representing the value of the cut is found in the interference pattern which also represents the value of the cut, the typography being able to be identical or different.

D'une façon générale, dans le cas d'un élément de sécurité 20 comportant une couche métallisée, en tant que métaux utilisables, on peut citer l'aluminium, le cuivre, l'or, le fer, l'argent, le chrome, le nickel, le zinc, le cadmium, le bismuth et leurs alliages et oxydes.Generally, in the case of a security element 20 comprising a metallized layer, as usable metals, mention may be made of aluminum, copper, gold, iron, silver, chromium , nickel, zinc, cadmium, bismuth and their alloys and oxides.

L'élément de sécurité 20 peut se présenter sous la forme d'un patch, d'un fil ou d'un foil de sécurité.The security element 20 may be in the form of a patch, a wire or a security foil.

Dans le cas ou l'élément de sécurité 20 est un fil de sécurité, sa largeur peut être relativement faible, de préférence inférieure ou égale à 10 mm.In the case where the security element 20 is a security wire, its width may be relatively small, preferably less than or equal to 10 mm.

La fenêtre 15 peut être réalisée par découpe et avoir un contour de toute forme, par exemple circulaire, elliptique ou polygonal, comme illustré sur la figure 1, notamment en forme de polygone régulier ou non.The window 15 can be made by cutting and have an outline of any shape, for example circular, elliptical or polygonal, as illustrated in the figure 1 , in particular in the shape of a regular polygon or not.

La fenêtre 15 peut être unique sur le document ou ce dernier peut en comporter plusieurs. Dans ce cas, les fenêtres 15 peuvent être disposées sur une même face du document ou sur des faces opposées.Window 15 can be unique on the document or the latter can include several. In this case, the windows 15 can be arranged on the same side of the document or on opposite sides.

La fenêtre 15 peut être formée en modifiant par exemple l'accumulation des fibres sur la toile de formation et la microzone non opaque 30 peut être formée notamment à l'aide de micro-aiguilles ou par jet d'eau, de préférence par ablation laser. Les jets 11, 18 sont par exemple des jets fibreux assemblés en phase humide.The window 15 can be formed by modifying for example the accumulation of fibers on the forming fabric and the non-opaque microzone 30 can be formed in particular using micro-needles or by water jet, preferably by laser ablation. . The jets 11, 18 are for example fibrous jets assembled in the wet phase.

Les deux jets 11, 18 présentent chacun une épaisseur / comprise par exemple entre 10 et 1000 µm, mieux entre 50 et 700 µm.The two jets 11, 18 each have a thickness / of for example between 10 and 1000 μm, better still between 50 and 700 μm.

Les deux jets 11, 18 peuvent comporter des fibres naturelles et/ou synthétiques.The two jets 11, 18 can comprise natural and / or synthetic fibers.

Les substrats 11 et 18 peuvent encore être non fibreux.The substrates 11 and 18 can also be non-fibrous.

Plus généralement, le document 10 peut présenter une structure multicouche comportant au moins une couche fibreuse et une couche de matière thermoplastique.More generally, the document 10 may have a multilayer structure comprising at least one fibrous layer and one layer of thermoplastic material.

De préférence, l'élément optique diffractif 40 est laminé avec l'élément de sécurité 20 avant d'être incorporé dans le document sécurisé 1.Preferably, the diffractive optical element 40 is laminated with the security element 20 before being incorporated into the secure document 1.

En variante, l'élément optique diffractif 40 est fixé à l'élément de sécurité 20 par collage, à chaud ou à froid. L'adhésif utilisé est par exemple un adhésif transparent de type adhésif polymère tel que NOLAX.Alternatively, the diffractive optical element 40 is fixed to the security element 20 by gluing, hot or cold. The adhesive used is for example a transparent adhesive of the polymer adhesive type such as NOLAX.

L'ensemble composé de l'élément de sécurité 20 et de l'élément optique diffractif 40 peut être incorporé entre les deux jets 11, 18, l'élément de sécurité 20 se positionnant du côté de la fenêtre 15, comme illustré sur la figure 2.The assembly consisting of the security element 20 and the diffractive optical element 40 can be incorporated between the two jets 11, 18, the security element 20 being positioned on the side of the window 15, as illustrated in the figure 2 .

D'une façon générale, l'article 10 peut comporter divers éléments de sécurité annexes, de premier niveau, deuxième ou troisième niveau. Parmi les éléments de sécurité supplémentaires, certains sont détectables à l'œil, en lumière du jour ou en lumière artificielle, sans utilisation d'un appareil particulier. Ces éléments de sécurité comportent par exemple des fibres ou planchettes colorées, des fils imprimés ou métallisés totalement ou partiellement. Ces éléments de sécurité sont dits de premier niveau.In general, article 10 may include various additional security elements, first level, second or third level. Among the additional security elements, some are detectable by eye, in daylight or in artificial light, without the use of a particular device. These security elements comprise for example colored fibers or boards, printed or metallized wires totally or partially. These security elements are said to be first level.

D'autre type d'éléments de sécurité supplémentaires sont détectables seulement à l'aide d'un appareil relativement simple, tel qu'une lampe émettant dans l'ultraviolet (UV) ou l'infrarouge (IR). Ces éléments de sécurité comportent par exemple des fibres, des planchettes, des bandes, des fils ou des particules. Ces éléments de sécurité peuvent être visibles à l'œil nu ou non, étant par exemple luminescents sous un éclairage d'une lampe de Wood émettant dans une longueur d'onde de 365 nm. Ces éléments de sécurité sont dits de deuxième niveau.Other types of additional security features are only detectable using a relatively simple device, such as an ultraviolet (UV) or infrared (IR) emitting lamp. These security elements comprise for example fibers, boards, strips, threads or particles. These security elements may or may not be visible to the naked eye, being for example luminescent under the illumination of a Wood lamp emitting in a wavelength of 365 nm. These security elements are said to be second level.

D'autres types d'éléments de sécurité supplémentaires nécessitent pour leur détection un appareil de détection plus sophistiqué. Ces éléments de sécurité sont par exemple capables de générer un signal spécifique lorsqu'ils sont soumis, de manière simultanée ou non, à une ou plusieurs sources d'excitation extérieure. La détection automatique du signal permet d'authentifier, le cas échéant, le document. Ces éléments de sécurité comportent par exemple des traceurs se présentant sous la forme de matières actives, de particules ou de fibres, capables de générer un signal spécifique lorsque ces traceurs sont soumis à une excitation optronique, électrique, magnétique ou électromagnétique. Ces éléments de sécurité sont dits de troisième niveau.Other types of additional security elements require a more sophisticated detection device for their detection. These security elements are for example capable of generating a specific signal when they are subjected, simultaneously or not, to one or more sources of external excitation. Automatic signal detection allows the document to be authenticated, if necessary. These security elements include, for example, tracers in the form of active materials, particles or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation. These security elements are said to be third level.

Au moins l'un de ces éléments de sécurité peut définir une information se retrouvant dans le motif d'interférences généré par l'élément optique diffractif 40.At least one of these security elements can define information found in the interference pattern generated by the diffractive optical element 40.

L'élément optique diffractif 40 et la couche 18 définissant la microzone non opaque 30 peuvent être au contact l'un de l'autre, comme c'est le cas notamment dans l'exemple de la figure 2.The diffractive optical element 40 and the layer 18 defining the non-opaque microzone 30 may be in contact with one another, as is the case in particular in the example of the figure 2 .

En variante, l'élément optique diffractif 40 et la couche 18 définissant la microzone non opaque 30 peuvent être séparés par une ou plusieurs couches intermédiaires.Alternatively, the diffractive optical element 40 and the layer 18 defining the non-opaque microzone 30 can be separated by one or more intermediate layers.

Par exemple, comme illustré sur la figure 3, le film 43 portant l'élément optique diffractif 40 peut se positionner de façon adjacente au substrat 11 comportant la fenêtre 15, et l'élément de sécurité 20 peut s'interposer entre le film 43 et la microzone non opaque 30.For example, as illustrated in the figure 3 , the film 43 carrying the diffractive optical element 40 can be positioned adjacent to the substrate 11 comprising the window 15, and the security element 20 can be interposed between the film 43 and the non-opaque microzone 30.

De préférence et comme illustré sur la figure 23, l'élément optique diffractif 40, notamment le côté du film 43 portant ce dernier, et la couche 18 sont séparés par une structure adhésive protectrice 45 comportant préférentiellement une couche d'un mélange d'un matériau adhésif et d'un matériau HRI. La structure adhésive protectrice 45 permet de solidariser le film 43 portant l'élément optique diffractif 40 et la couche 18. La présence du matériau HRI permet d'empêcher l'atténuation ou l'annulation des effets optiques de l'élément optique diffractif qui pourrait être causé par la superposition de du matériau adhésif avec l'élément optique diffractif 40.Preferably and as illustrated on the figure 23 , the diffractive optical element 40, in particular the side of the film 43 carrying the latter, and the layer 18 are separated by a protective adhesive structure 45 preferably comprising a layer of a mixture of an adhesive material and an HRI material. The protective adhesive structure 45 makes it possible to secure the film 43 carrying the diffractive optical element 40 and the layer 18. The presence of the HRI material makes it possible to prevent attenuation or cancellation of the optical effects of the diffractive optical element which could be caused by the superimposition of adhesive material with the diffractive optical element 40.

L'élément optique diffractif 40 peut, en variante, porter une couche d'un matériau HRI 47, notamment déposée sur l'élément optique diffractif 40 par vaporisation sous vide, portant elle-même une couche d'un matériau adhésif. Dans ce cas, la couche 47 permet de protéger l'élément optique diffractif 40 contre une atténuation ou une annulation de son effet optique dû à la présence de la structure adhésive. La protection mécanique de ce dernier est obtenue par la couche de matériau adhésif 46.The diffractive optical element 40 can, as a variant, carry a layer of an HRI material 47, in particular deposited on the diffractive optical element 40 by vaporization under vacuum, itself carrying a layer of an adhesive material. In this case, the layer 47 makes it possible to protect the diffractive optical element 40 against attenuation or cancellation of its optical effect due to the presence of the adhesive structure. The mechanical protection of the latter is obtained by the layer of adhesive material 46.

En variante, comme illustré sur la figure 24, l'élément optique diffractif 40, notamment le côté du film 43 portant ce dernier, et la couche 18 sont séparés par une structure adhésive 46 comportant un matériau adhésif et une structure protectrice 47 comportant un matériau HRI, la structure protectrice 47 étant appliquée sur l'élément optique diffractif 40, notamment sur le côté du film 43 portant l'élément optique diffractif 40 et la structure adhésive 46 étant disposée entre la structure protectrice 47 et la couche 18.Alternatively, as illustrated in the figure 24 , the diffractive optical element 40, in particular the side of the film 43 carrying the latter, and the layer 18 are separated by an adhesive structure 46 comprising an adhesive material and a protective structure 47 comprising an HRI material, the protective structure 47 being applied to the diffractive optical element 40, in particular on the side of the film 43 carrying the diffractive optical element 40 and the adhesive structure 46 being disposed between the protective structure 47 and the layer 18.

La structure protectrice 47 peut comporter un liant, de préférence sécurisé.The protective structure 47 may include a binder, preferably secure.

Dans la variante illustrée sur la figure 25, le film 43 et la couche 18 sont séparés par une structure adhésive 46, cette dernière étant située du côté du film 43 ne présentant pas l'élément optique diffractif 40. Une structure protectrice 47 comportant un matériau HRI peut être présente sur l'élément optique diffractif 40, et notamment recouvrir en totalité ce dernier. Cette structure protectrice 47 permet notamment de protéger mécaniquement l'élément optique diffractif 40 lors de l'assemblage de la structure de sécurité 2 avec l'article 10 tout en conservant les propriétés optiques.In the variant illustrated on the figure 25 , the film 43 and the layer 18 are separated by an adhesive structure 46, the latter being located on the side of the film 43 not having the diffractive optical element 40. A protective structure 47 comprising an HRI material may be present on the element diffractive optics 40, and in particular completely cover the latter. This protective structure 47 makes it possible in particular to mechanically protect the diffractive optical element 40 during assembly of the safety structure 2 with the article 10 while retaining the optical properties.

Dans la variante illustrée sur la figure 26, le film 43 et la couche 18 sont séparés par une structure protectrice 47 comportant une couche d'un matériau HRI 47a, une couche d'un liant 47b et une structure adhésive 46 comportant un matériau adhésif. La couche de matériau HRI 47a recouvre, de préférence, au moins partiellement l'élément optique diffractif 40 et la couche de liant 47b recouvre, de préférence, la couche de matériau HRI 47a.In the variant illustrated on the figure 26 , the film 43 and the layer 18 are separated by a protective structure 47 comprising a layer of HRI material 47a, a layer of a binder 47b and an adhesive structure 46 comprising an adhesive material. The layer of HRI material 47a preferably covers at least partially the diffractive optical element 40 and the layer of binder 47b preferably covers the layer of HRI material 47a.

De préférence, le liant est sécurisé, notamment par une ou plusieurs substances luminescentes ou absorbantes sous excitation UV, visible et/ou IR. De préférence, les substances luminescentes ou absorbantes ne sont pas diffusantes et la couche de liant 47b est transparente. Les substances luminescentes ou absorbantes sont, de préférence, des particules de tailles nanométriques.Preferably, the binder is secure, in particular by one or more luminescent or absorbent substances under UV, visible and / or IR excitation. Preferably, the luminescent or absorbent substances are not diffusing and the binder layer 47b is transparent. The luminescent or absorbent substances are preferably particles of nanometric sizes.

De préférence, les couches 47a, 47b et 46 sont transparentes pour ne pas perturber l'effet optique généré par l'élément optique diffractif.Preferably, the layers 47a, 47b and 46 are transparent so as not to disturb the optical effect generated by the diffractive optical element.

Le dépôt de la structure protectrice 47 peut se faire par impression sur l'élément optique diffractif 40 comme expliqué dans la demande de brevet FR 2961319 , c'est-à-dire que les creux de l'élément optique diffractif 40 sont comblés avec le matériau HRIThe protective structure 47 can be deposited by printing on the diffractive optical element 40 as explained in the patent application FR 2961319 , that is to say that the hollows of the diffractive optical element 40 are filled with the HRI material

La structure protectrice 47 ou la structure adhésive protectrice 45 peuvent comporter des nanoparticules d'oxydes de métal, tel que TiO2, ayant notamment un diamètre compris entre 1 et 100 nm, mieux entre 5 et 25 nm et/ou un vernis transparent et/ou un liant organique réticulable et/ou un dispersant pigmentaire.The protective structure 47 or the protective adhesive structure 45 may comprise nanoparticles of metal oxides, such as TiO2, having in particular a diameter between 1 and 100 nm, better between 5 and 25 nm and / or a transparent varnish and / or a crosslinkable organic binder and / or a pigment dispersant.

L'épaisseur de la structure adhésive protectrice 45 est, de préférence, comprise entre 1 et 10 microns, mieux entre 2 et 5 microns.The thickness of the protective adhesive structure 45 is preferably between 1 and 10 microns, better still between 2 and 5 microns.

De préférence, la structure adhésive 46 ou la structure adhésive protectrice 45 est introduite par les microperforations entre l'élément optique diffractif 40, et/ou le film 43 le portant, et la couche 18. De préférence, comme illustré sur les figures 23 et 24, les couches 46 ou 45 sont introduites de sorte à remplir les microperforations pour les protéger contre l'environnement extérieur, notamment les salissures, comme expliqué dans la demande DE 10 2011 004935 .Preferably, the adhesive structure 46 or the protective adhesive structure 45 is introduced by microperforations between the diffractive optical element 40, and / or the film 43 carrying it, and the layer 18. Preferably, as illustrated in the figures 23 and 24 , layers 46 or 45 are introduced so as to fill the microperforations to protect them against the external environment, in particular dirt, as explained in the application DE 10 2011 004935 .

Comme illustré sur la figure 4, l'élément de sécurité 20 peut se positionner dans la fenêtre 15, le film 43 s'étendant toujours entre les deux jets 11 et 18.As illustrated in the figure 4 , the security element 20 can be positioned in the window 15, the film 43 still extending between the two jets 11 and 18.

L'élément optique diffractif 40 peut être réalisé dans un film 43 qui s'étend continûment autour de l'élément optique diffractif 40. En variante, le film 43 qui a servi à réaliser l'élément optique diffractif 40 ne s'étend pas au-delà de celui-ci, comme illustré à la figure 5.The diffractive optical element 40 can be produced in a film 43 which extends continuously around the diffractive optical element 40. As a variant, the film 43 which served to produce the diffractive optical element 40 does not extend to the beyond this, as illustrated in figure 5 .

Comme illustré sur la figure 6, le film 43 peut se positionner dans la fenêtre 15. Il peut en être de même de l'élément de sécurité 20, lorsque présent.As illustrated in the figure 6 , the film 43 can be positioned in the window 15. It can be the same for the security element 20, when present.

Comme illustré sur les figures 7 et 8, la structure de sécurité 2 peut comporter un élément optique diffractif 40 et un élément de sécurité 20 présentant une microzone non opaque 30 se superposant au moins partiellement à l'élément optique diffractif 40.As illustrated on Figures 7 and 8 , the security structure 2 may include a diffractive optical element 40 and a security element 20 having a non-opaque microzone 30 overlapping at least partially with the diffractive optical element 40.

Le premier jet 11 peut présenter une fenêtre 15 et le deuxième jet 18 peut présenter une zone non opaque 32. La fenêtre 15 et la zone non opaque 32 peuvent avoir ou non les mêmes forme et taille et se superposent au moins partiellement avec l'élément optique diffractif 40 et la microzone non opaque 30 de manière à former une zone A transparente traversante sur le document sécurisé 1. La structure de sécurité 2 peut avoir sensiblement la même forme que la fenêtre 15 et se positionner dans cette dernière.The first jet 11 may have a window 15 and the second jet 18 may have a non-opaque zone 32. The window 15 and the non-opaque zone 32 may or may not have the same shape and size and overlap at least partially with the element diffractive optics 40 and the non-opaque microzone 30 so as to form a transparent transparent zone A on the secure document 1. The security structure 2 can have substantially the same shape as the window 15 and position itself in the latter.

Le document sécurisé 1, représenté à la figure 9, comporte deux substrats 11, 18 constitués par des premier et deuxième jets 11, 18 munis chacun d'une microperforation 30, 16, réalisée de préférence par ablation laser, et reçoivent entre eux un élément optique diffractif 40. L'élément optique diffractif 40 et les deux microperforations 30, 16 se superposent.Secure document 1, shown in figure 9 , comprises two substrates 11, 18 constituted by first and second jets 11, 18 each provided with a microperforation 30, 16, preferably produced by laser ablation, and receive between them a diffractive optical element 40. The diffractive optical element 40 and the two microperforations 30, 16 overlap.

Le document sécurisé 1, représenté à la figure 11, comporte un premier substrat 11 formant le premier jet, muni d'une fenêtre 15, et un deuxième substrat 18 formant le deuxième jet, muni d'une microzone non opaque 30. La fenêtre 15 et la microperforation 30 se superposent de manière à former dans le document sécurisé une zone A transparente qui va de par et d'autre du document sécurisé 1 dans laquelle se positionne l'élément optique diffractif 40.Secure document 1, shown in figure 11 , comprises a first substrate 11 forming the first jet, provided with a window 15, and a second substrate 18 forming the second jet, provided with a non-opaque microzone 30. The window 15 and the microperforation 30 are superimposed so as to form in the secure document a transparent zone A which goes on either side of the secure document 1 in which is positions the diffractive optical element 40.

Comme illustré sur la figure 12, en particulier lorsque l'élément optique diffractif 40 est porté par un film thermoplastique 43, l'élément optique diffractif 40 peut se positionner entre les deux jets 11, 18, le film 43 étant directement au contact de ceux-ci.As illustrated in the figure 12 , in particular when the diffractive optical element 40 is carried by a thermoplastic film 43, the diffractive optical element 40 can be positioned between the two jets 11, 18, the film 43 being directly in contact with the latter.

Comme illustré sur la figure 13, l'élément de sécurité optique 40 peut se positionner entre un substrat 18 et un élément de sécurité 20, le substrat comportant la microzone non opaque 30.As illustrated in the figure 13 , the optical security element 40 can be positioned between a substrate 18 and a security element 20, the substrate comprising the non-opaque microzone 30.

Comme illustré sur la figure 27, l'élément de sécurité 20 peut comporter un motif 50, ici les lettres AW, réalisé par une pluralité de microperforations 19, l'une de ces microperforations pouvant constituer la microzone non opaque 30, par exemple la pointe du A. Le motif AW peut être reproduit sur le motif d'interférences généré par l'élément optique diffractif 40.As illustrated in the figure 27 , the security element 20 may include a pattern 50, here the letters AW, produced by a plurality of microperforations 19, one of these microperforations possibly constituting the non-opaque microzone 30, for example the tip of A. The motif AW can be reproduced on the interference pattern generated by the diffractive optical element 40.

La microzone non opaque 40 peut être de diverses formes, notamment circulaire, comme illustré sur la figure 1, ou tout autre, par exemple triangulaire comme illustré sur la figure 28A, ou en forme de croissant, comme illustré sur la figure 28B.The non-opaque microzone 40 can be of various shapes, in particular circular, as illustrated in the figure 1 , or any other, for example triangular as illustrated on the figure 28A , or in the shape of a crescent, as illustrated on the figure 28B .

L'invention n'est pas limitée aux exemples illustrés.The invention is not limited to the examples illustrated.

Les particularités des exemples illustrés peuvent se combiner au sein de variantes non illustrées.The particularities of the illustrated examples can be combined within variants not illustrated.

L'expression « comportant un » est synonyme de « comportant au moins un », sauf lorsque le contraire est spécifié.The expression “comprising a” is synonymous with “comprising at least one”, except when the contrary is specified.

Claims (14)

  1. A security structure (2) comprising:
    - at least one non-opaque micro-region (30),
    - at least one diffractive optical element (40) of the digital type generating at least one interference pattern (66) in an image-forming plane (62) at a distance from the diffractive optical element (40), superposed, at least partially, onto the non-opaque micro-region (30), characterized in that the non-opaque micro-region (30) has a cross section that is less than or equal to 1000000 µm2.
  2. The structure as claimed in claim 1, the non-opaque micro-region (30) being defined by the absence of material within a layer (18 ; 20) of a substantially opaque material.
  3. The structure as claimed in either of claims 1 and 2, the non-opaque micro-region (30) being defined by a micro-perforation or a de-metallization, and/orbeing bounded by printing with an opaque ink.
  4. The structure as claimed in any one of the preceding claims, the non-opaque micro-region (30) having a cross section less than or equal to 200000 µm2, or better in the range between 10 µm2 and 200000 µm2, or even better in the range between 5000 µm2 and 200000 µm2.
  5. The structure as claimed in any one of the preceding claims, the interference pattern (66) generated by the diffractive optical element (40) being found, at least in part, or better in its entirety, on the security structure (2), or on the article (10) incorporating it, notably in the form of a printed feature, of a watermark, of a pattern generated by micro-perforations, one of which defines notably said non-opaque micro-region (30), or a metallization or de-metallization.
  6. The structure as claimed in any one of the preceding claims, the non-opaque micro-region (30) forming a pattern being found on at least a part of the interference pattern (66), preferably identical or similar to the latter.
  7. The structure as claimed in any one of the preceding claims, comprising a protective adhesive structure (45), disposed between the diffractive optical element (40) and a sub-element carrying the non-opaque micro-region (30), the protective adhesive structure (45) comprising notably a mixture of an adhesive material and of an HRI material, or the protective adhesive structure (45) being formed notably of a layer of an HRI material, preferably deposited by vacuum evaporation on the diffractive optical element, and of a layer of an adhesive material.
  8. The structure as claimed in claim 7, the protective adhesive structure (45) filling, at least partially, or better completely, at least one micro-perforation.
  9. The structure as claimed in any one of claims 1 to 6, comprising an adhesive structure (46) associated with a protective structure (47), disposed between the diffractive optical element (40) and a sub-element carrying the non-opaque micro-region (30), the protective structure (47) comprising preferably a mixture of an HRI material and of a binder and being applied to the diffractive optical element (40), or the adhesive structure (46) being notably disposed between a sub-element carrying the non-opaque micro-region (30) and the protective structure (47), or the protective structure (47) being preferably formed from the superposition of a layer of an HRI material (47a) and of a layer comprising a binder (47b), the layer comprising a binder (47b) being disposed on the layer of HRI material (47a), the adhesive structure filling preferably, at least partially, or better completely, at least one micro-perforation.
  10. The structure as claimed in any one of the preceding claims, the diffractive optical element (40) being formed on a thermoplastic film (43), preferably transparent, having a thickness less than or equal to 50 µm, the thermoplastic film (43) being preferably laminated with a layer (20) at least partially opaque defining said non-opaque micro-region (30), the thermoplastic film (43) being preferably laminated with a security element (20), notably a security thread or foil, having at least one transparent region (23) being superposed, at least partially, with the diffractive optical element (40) and a security element notably in the form of a printed feature, of a watermark, of a pattern generated by micro-perforations or a metallization or de-metallization.
  11. The structure as claimed in any one of the preceding claims, comprising a plurality of said diffractive optical elements (40) and a plurality of non-opaque micro-regions (30), each notably being superposed, at least partially, onto at least one respective diffractive optical element (40).
  12. The structure as claimed in any one of the preceding claims, comprising at least one optical filter (80), notably a colored filter, being superposed, at least partially, with the non-opaque micro-region (30).
  13. A secure article (10) comprising a security structure (2) as claimed in any one of claims 1 to 12, the article comprising
    - a substrate (11), notably fibrous, having at least one window (15), this window (15) being, at least partially, superposed both onto the diffractive optical element (40) and onto the first non-opaque micro-region (30) or
    - a substrate (11) having at least a second non-opaque micro-region (16), the second non-opaque micro-region (16) being, at least partially, superposed both onto the diffractive optical element (40) and onto the non-opaque micro-region (30).
  14. A method of authentication of a security structure as claimed in any one of claims 1 to 12, comprising the steps consisting in:
    - illuminating the diffractive optical element with a light source (60),
    - verifying, notably through the non-opaque micro-region, the presence of an interference pattern (66) in an image-forming plane (62) at a distance from the diffractive optical element (40), for example by means of a device equipped with a camera, notably a mobile telephone.
EP14733373.6A 2013-06-10 2014-06-10 Security structure having a diffractive optical element Active EP3007903B1 (en)

Applications Claiming Priority (2)

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FR1355344A FR3006795B1 (en) 2013-06-10 2013-06-10 SAFETY STRUCTURE WITH DIFFRACTIVE OPTICAL ELEMENT
PCT/IB2014/062097 WO2014199296A1 (en) 2013-06-10 2014-06-10 Security structure having a diffractive optical element

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Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102015010334A1 (en) * 2015-08-07 2017-02-09 Giesecke & Devrient Gmbh security element
GB2542783B (en) 2015-09-29 2018-02-07 De La Rue Int Ltd Security print media and method of manufacture thereof
KR102563400B1 (en) * 2015-10-02 2023-08-03 도판 인사츠 가부시키가이샤 anti-counterfeit structure
US10479128B2 (en) * 2017-10-27 2019-11-19 Assa Abloy Ab Security feature
FR3080324B1 (en) * 2018-04-23 2022-04-01 Oberthur Fiduciaire Sas SECURE SHEET
FR3085974B1 (en) 2018-09-14 2020-12-18 Oberthur Fiduciaire Sas METHOD OF MANUFACTURING A MATERIAL IN SHEET, MACHINE, SHEET MATERIAL AND CORRESPONDING SECURITY DOCUMENT

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2451732A1 (en) * 1974-10-31 1976-05-06 Unitec Gmbh & Co Kg IDENTITY CARRIER AND READING DEVICE FOR IT
DE69918529T2 (en) 1998-01-21 2005-08-18 Securency Pty. Ltd., Craigieburn METHOD FOR VERIFYING THE AUTHENTICITY OF SECURITIES AND IDENTIFICATIONS AND DOCUMENTS FOR THE APPLICATION OF THIS METHOD
AUPQ125999A0 (en) 1999-06-28 1999-07-22 Securency Pty Ltd Method of producing a diffractive structure in security documents
SI1805042T1 (en) * 2004-08-27 2011-05-31 Kxo Ag Security document with a volume hologram forming a partial motif
PL1674286T3 (en) 2004-12-23 2011-07-29 Arjowiggins Security Security element having a digitised mark and security support or document comprising same
US20100195174A1 (en) 2006-01-16 2010-08-05 Securency International Pty. Ltd. Data Storage in a Diffractive Optical Element
DE112007002178T5 (en) * 2006-09-15 2009-07-30 Securency International Pty Ltd., Craigieburn Radiation curable embossed ink security devices for security documents
CH698233B1 (en) * 2006-10-12 2011-02-28 Australia Reserve Bank Security document with micro prisms.
MTP4301B (en) 2010-03-25 2011-10-26 Securency Int Pty Ltd High refractive index coatings and their use in the protection of surface relief structures
DE102010015302A1 (en) * 2010-04-14 2011-10-20 Bundesdruckerei Gmbh Self-activating optical security element
DE102011004935A1 (en) 2011-03-01 2012-09-06 Bundesdruckerei Gmbh Composite body and method of making a composite having an internal security feature
AU2011101567B4 (en) 2011-11-30 2012-08-09 Innovia Security Pty Ltd Diffractive device
AU2013100172B4 (en) 2013-02-19 2013-08-22 Ccl Secure Pty Ltd Security device with covert images

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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AU2014279723B2 (en) 2018-04-26
WO2014199296A1 (en) 2014-12-18
JP2016530118A (en) 2016-09-29
EP3007903A1 (en) 2016-04-20
FR3006795B1 (en) 2016-12-09
AU2014279723A1 (en) 2015-12-24
FR3006795A1 (en) 2014-12-12

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