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
  • B42D25/324—Reliefs
• • 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
  • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
  • B42D25/29—Securities; Bank notes
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
  • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
  • G07D7/003—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using security elements
• • B42D2035/20—

Definitions

• Optical structure in particular for a security document and / or of value
• the present invention relates to an optical structure, in particular for a security document and / or value.
• US Pat. No. 5,301,981 describes a ribbon comprising, on a first face, microreliefs forming a lenticular network.
• the ribbon has, on a second face opposite to the first, a succession of parallel black strips arranged so that, when the ribbon is observed in a direction perpendicular to its plane, the light beams are directed by the microreliefs on the strips. black.
• This gives a black image forming a screen to hide information on a document on which the ribbon is affixed.
• the international application WO 02/03104 discloses an optical structure capable of creating a first image, for example a holographic image, in reflection and a second image in transmission.
• WO 03/055692 discloses a document on which is applied a prismatic relief structure which is totally reflective at a certain angle of observation so as to mask information on the document, and transparent from another angle. in order to make this information visible.
• the invention aims to provide an optical structure, particularly for a security document and / or value, to create new optical effects in particular to enhance the security of the document against a possible attempt to counterfeit.
• an optical structure in particular for a security and / or value document, comprising: first and second opposite outer faces, - at least one first interface comprising a first network of microreliefs and arranged so that, when it passes through this first interface in the direction of the first outer face to the second outer face, one passes from one first medium having a first refractive index to a second medium having a second refractive index greater than the first, at least a second interface having a second microrelief array and arranged so that, when passing through this second interface in the direction of the first outer face to the second outer face, passing from a third medium having a third refractive index to a fourth medium having a fourth index of refraction less than the third, each interface having at least one portion shifted relative to at the other interface when the structure is observed in a direction substantially perpendicular to at least one of the outer faces.
• the interfaces may for example generate optical effects, possibly variable depending on the angle of observation, which are different from one interface to another.
• the invention thus makes it possible to create, in visible and / or infrared and / or ultraviolet light, new visual effects in order, for example, to improve the aesthetics of a document and / or the security thereof against an attempt to infringement.
• the interfaces may, if necessary, be entirely offset relative to each other, that is to say without overlapping portions.
• this pattern may have a different visual appearance of the visual appearance of an area surrounding it.
• the pattern may comprise for example an alphanumeric character, a symbol, a logo or a drawing.
• At least one of the microrelief arrays is superimposed at least partially, in particular exactly, on a substantially smooth zone, devoid of microrelief, of one of the outer faces.
• At least one of the interfaces may be formed for example on one of the outer faces of the structure.
• At least one of the first and fourth media may be formed by the ambient air.
• the second and third media may be formed for example by the same material and have the same refractive index, especially a material having a refractive index greater than 1, especially 1.5, for example 2.
• the second and third media may be formed by different materials and / or having different refractive indices.
• the first medium may be formed for example by a first material on which the first micro-relief array is made and the second medium by a second deposited material, in particular by vacuum deposition, on the first material.
• the second material may partially or wholly cover the first material and form, if desired, at least one pattern.
• the second material may form, if necessary, an outer protection of the optical structure and have a refractive index, for example greater than 1.8.
• the second material can be obtained for example by vaporization, for example zinc sulphide having a refractive index of about 2.3.
• the difference between the second refractive index and the first refractive index is greater than 0.1, more preferably 0.15, preferably 0.2 or 0.3 or 0.4. Preferably, this difference is between 0.4 and 0.6.
• the difference between the third refractive index and the fourth refractive index is greater than 0.1, more preferably 0.15, preferably 0.2 or 0.3 or 0.4. Preferably, this difference is between 0.4 and 0.6.
• At least one of the interfaces is arranged so that, for at least a first range of observation angles, a portion of the structure at the right of this interface appears substantially transparent when the structure is observed from one of the first and second outer laces, especially in visible light and / or infrared and / or ultraviolet.
• At least one of the interfaces may be arranged so that, for at least a second range of observation angles, a portion of the structure at the right of this interface appears substantially reflective when the structure is observed from a face outside, especially in visible light and / or infrared and / or ultraviolet.
• At least one of the interfaces is arranged in such a way that, for a first range of observation angles, a portion of the structure at the right of this interface appears substantially transparent when the structure is observed from an outside face. predetermined and, for a second range of viewing angles, this portion of the structure appears substantially reflective when the structure is observed from said outer face.
• the interface or interfaces when the interface or interfaces have a contour defining a pattern, it may appear, in visible light, with a reflective or transparent appearance depending on the viewing angle of the structure.
• the invention can, if necessary, allow, by varying the angle of observation, to see the pattern successively positive, with a reflective appearance and surrounded by a transparent zone and, in negative, with a transparent appearance surrounded by a reflective area.
• at least one of the microreliefs has substantially a triangular prism shape.
• the network of microreliefs may be arranged for example so as to restore a metallized appearance, especially reflecting, when the optical structure is observed in a predetermined range of angles.
• the microrelief array (s) may be similar to that present on the film marketed by 3M under the name Scotch TM Optical Lighting Film.
• At least one of the microreliefs comprises at least one curved, concave or convex surface, each curved surface being able to create a lens effect.
• the curved surface may for example be a half-cylindrical surface or spherical cap, in particular half-spherical, this list not being limiting.
• the microreliefs have a thickness greater than the wavelengths of visible light, possibly near-infrared or ultraviolet radiation.
• the microreliefs may have a thickness, for example, greater than 1 ⁇ m.
• the thickness of the microreliefs is preferably less than 10 mm, especially 1 mm. In an exemplary implementation of the invention, at least a portion of the microreliefs extends in a longitudinal direction, the microreliefs being substantially parallel to each other.
• the microreliefs respectively of the first and second networks may be identical or, alternatively, different, for example having different shapes and / or dimensions.
• the microreliefs of the first and second networks can be made on a common support, on the same face of this support or on two opposite faces thereof.
• the optical structure may comprise, for example, a support with at least one micro-relief array on one side, the microrelief network being partially covered with a coating layer having a refractive index higher than that of the support, so that the first interface is formed between the support and the ambient air and the second interface between the support and the coating layer, the first and second interfaces being in particular adjacent.
• the coating layer may comprise, for example, zinc sulphide.
• optical structure according to the invention can thus be made relatively easily because a single set of microreliefs can be used to form the two interfaces.
• the first and second microrelief networks can be made on separate supports.
• the structure may comprise, if desired, at least one electrically conductive material.
• the authentication and / or the identification of the structure can thus be based on a measurement of the electrical conductivity of the latter, in addition to its visual observation.
• the structure comprises at least one support on which at least a portion of the microreliefs is made, the support being in particular made of a substantially transparent polymer material, such as polyester or PMMA ( polymethylmethacrylate).
• a substantially transparent polymer material such as polyester or PMMA ( polymethylmethacrylate).
• the support may comprise an electrically conductive layer, for example based on a conductive polymer such as polythiophene or its derivatives or based on an indium tin oxide composite.
• the structure may be devoid of metal, in particular a metallized layer.
• the optical structure may have a strip shape with a width in particular between 1.5 mm and 100 mm, in particular between 2 mm and 45 mm.
• the structure may alternatively have a shape chosen from: a polygonal shape, for example rectangular or square, an oval shape, a circular shape, this list not being limiting.
• the structure may be arranged to be able to be transferred at least partially to a face of a document, the structure may comprise at least one layer of adhesive.
• the structure may comprise, in addition to the microrelief network, at least one authentication and / or identification element chosen from at least one of the following elements: an element for highlighting a falsification, in particular visible and or detectable by means of a specific detection device, an element with variable, interferential and / or diffractive, iridescent or liquid crystal optical effect, a magnetic coating, tracers detectable by X-ray fluorescence, biomarkers, a varnish or an ink, luminescent, fluorescent or phosphorescent tracers, photochromic, thermochromic, electroluminescent and / or piezochromic compounds and / or which change color in contact with one or more predetermined products.
• the structure may comprise, where appropriate, at least one fluorescent material under infrared and / or ultraviolet radiation, deposited for example in the form of a layer, in particular on one of the faces of the structure.
• the invention can thus make it possible to observe, in visible light, under infrared and / or ultraviolet radiation excitations, an underlying fluorescent layer, through the portion of the structure appearing transparent for the first range of observation angles. .
• the aforementioned portion of the structure being reflective, does not allow the observation of the fluorescence of the underlying layer.
• the invention further relates, in another of its aspects, independently or in combination with the foregoing, to an optical structure comprising at least one array of microreliefs arranged so that, for a first range of angles of observation, the portion of the structure covered by the network appears substantially reflective when viewed from a predetermined face and, for a second range of observation angles, this portion appears substantially transparent when the structure is observed from said face.
• the structure is arranged so that, when viewed at a predetermined angle and from a predetermined face, the structure has both at least one substantially transparent zone and at least one less a substantially reflective zone.
• the invention further relates, in another of its aspects, a sheet material comprising an optical structure as defined above.
• sheet material may denote in the description and the claims a fibrous sheet based on cellulosic and / or synthetic fibers, having a monolayer or multilayer structure, composite or not.
• a sheet material may for example have a relatively small thickness, especially less than or equal to 3 mm, for example equal to about 100 microns, and be flexible.
• the sheet material can be packaged in a reel, especially before being cut to the desired format.
• sheet material can also denote a flexible or rigid film with a monolithic or multilayer structure.
• the optical structure advantageously comprises at least one apparent portion on one side of the sheet material.
• the optical structure may be partially embedded in the mass of the sheet material, the latter including in particular at least one window leaving the optical structure unobstructed.
• the optical structure may extend from a first edge of the sheet material to a second edge opposite the first.
• the optical structure is disposed on one side of the sheet material, for example being glued to this face.
• the sheet material comprises at least one piece of information such as an alphanumeric character, a symbol, a logo or a drawing, the optical structure being arranged so as to be able to mask substantially the information element when this structure is observed in a first range of angles and has a reflective appearance.
• the sheet material may comprise at least one fibrous layer or, alternatively, a plastics material.
• at least one of the first and second outer faces of the optical structure may be in contact with the ambient air or the fibrous material of the sheet material.
• the invention further relates, in another of its aspects, a security document and / or value comprising a sheet material as defined above.
• the document may be one of the following: a bank note, an identity document, a passport sheet or cover, a visa, a coupon, a document of value other than a bank note, for example a check or a credit card, a label of protection and / or authentication, a label of traceability.
• a packaging device in particular a packaging, comprising a sheet material as defined above.
• the subject of the invention is also a method of authentication and / or identification of an article, in particular a document, comprising an optical structure as defined above, the method comprising the following steps :
• the process may comprise the following steps:
• FIGS. 1 and 2 represent, schematically and partially, an optical structure according to the invention, respectively observed at two different angles
• FIG. 3 schematically and partially illustrates an array of microreliefs of the optical structure of FIGS. 1 and 2
• FIG. 4 very schematically illustrates the path of light beams in the structure of FIG. 3;
• FIG. 1 and 2 represent, schematically and partially, an optical structure according to the invention, respectively observed at two different angles
• FIG. 3 schematically and partially illustrates an array of microreliefs of the optical structure of FIGS. 1 and 2
• FIG. 4 very schematically illustrates the path of light beams in the structure of FIG. 3
• FIG. 1 and 2 represent, schematically and partially, an optical structure according to the invention, respectively observed at two different angles
• FIG. 3 schematically and partially illustrates an array of microreliefs of the optical structure of FIGS. 1 and 2
• FIG. 4 very schematically illustrates the path of light beams in the structure of FIG. 3
• FIG. 1 and 2 represent, schematically
• FIG. 5 represents, schematically and partially, in section, the optical structure of Figure 1
• Figures 6 and 7 show, schematically and partially, two documents according to examples of the invention
• Figure 8 shows, schematically and partially, in perspective, a packaging according to to the invention
• Figures 9 to 16 show, schematically and partially, in section, different examples of optical structures according to the invention.
• FIGS. 1, 2 and 5 show an optical structure 1 according to an exemplary implementation of the invention, having first and second opposite outer faces 2 and 3.
• the optical structure 1 comprises on each of the faces 2 and 3 at least one microrelief network 5 extending over a portion 4 only of the corresponding face 2 or 3, as illustrated in FIG. 5.
• the structure 1 has a first interface 11, respectively a second interface 12, formed by the microrelief array or networks 5 of the first face 2, respectively the second face 3, as illustrated in FIG. 5.
• Each network 5 comprises in the example in question microreliefs 6 shown in FIG. 3, in the form of a triangular prism each having dimensions, in cross-section, greater than the wavelengths of the visible light, and possibly near-infrared radiation.
• These dimensions, in particular the thickness e of the microreliefs may for example be greater than 1 ⁇ m, especially 1.2 ⁇ m.
• the distance d between the vertices of two adjacent prisms may be between 100 microns and 900 microns, being for example close to 350 microns.
• the thickness e of a prism can be for example between 50 microns and 300 microns, for example being close to 170 microns.
• the maximum thickness E of the optical structure 1 may be between 100 ⁇ m and 900 ⁇ m, being for example close to 500 ⁇ m.
• the angle ⁇ between a local normal X to the optical structure 1 and a face of a microrelief 6 may be between 30 ° and 60 °, for example being close to 45 °.
• microreliefs 6 are advantageously chosen as a function of the refractive index of the material or materials used in the structure 1.
• the microreliefs 6 form parallel ridges in the example under consideration.
• the microrelief network 5 may for example be similar to that present on the film marketed by the American company 3M under the name Scotch TM Optical Lighting Film.
• the structure 1 is preferably flexible, for example being able to be foldable.
• the microreliefs 6 are made of a material 15 having a refractive index greater than that of air, this material may be for example a transparent polymer such as polyester or PMMA.
• the microreliefs 6 can be obtained for example by etching, mechanical or chemical. Alternatively, the microreliefs 6 can be obtained by printing an ink or by embossing.
• the angles a 0, a 1 and a 2 may for example be substantially equal to 0 °, 45 ° and 90 °, respectively.
• angles a 3 , su and a 5 may for example be substantially equal to 0 °, 45 ° and 90 °, respectively.
• the at least one microrelief network 5 may define, in positive or in negative, at least one pattern 10 formed for example by a text, a symbol, a logo and / or a drawing.
• the pattern 10 may appear substantially transparently surrounded by a substantially reflective zone, as illustrated in FIG.
• the pattern 10 may appear with a substantially reflective appearance surrounded by a substantially transparent area, as illustrated in Figure 2.
• the structure 1 may comprise, where appropriate, a succession of patterns 10 repeating regularly in one direction.
• the network of microreliefs 5 may be arranged to restore a reflective metal appearance depending on the viewing angle.
• the material on which the microrelief arrays 5 are formed may be based on a transparent polymer.
• Authentication and / or identification using the structure 1 can thus include, where appropriate, the following steps: measuring the electrical conductivity of the structure 1, - conclude as to the authenticity and / or the identity of structure 1 at least through this measure.
• the structure 1 may have a strip shape with a width in particular between 1.5 mm and 100 mm.
• FIG. 6 shows a security and / or value document 20 constituted by a bank note, this document comprising a sheet material 21 formed by a fibrous layer in which the optical structure 1 is partially embedded.
• the structure 1 extends from a first edge 23 of the sheet material 21 to a second edge 24 opposite to the first.
• the sheet material 21 may comprise one or more windows 22 leaving the optical structure 1 unobstructed.
• FIG. 7 shows an optical structure 1 having a shape, for example a substantially rectangular shape, this structure 1 being affixed to one face of the sheet material 21, without being embedded in the mass of this material 21 , for example being glued on with the aid of an adhesive layer, possibly under temperature and pressure.
• the optical structure 1 may be arranged to mask at least one information element 25 present on the sheet material 21 when the structure 1 appears with a reflective appearance.
• the information element 25 becomes visible through a portion 26 of the structure 1 when the latter is observed at an adequate viewing angle.
• the information element 25 may for example be printed on one side of the sheet material 21.
• Document 20 may alternatively be one of the following: an identity document, a passport sheet or cover, a visa, a coupon, a valuable document other than a banknote, for example a check or a credit card, a label of protection and / or authentication, a label of traceability.
• FIG. 8 shows a packaging device 30 such as a package, for example a box, with an optical structure 1 affixed to a face 31 of the box 30.
• the optical structure 1 may comprise, in addition to the one or more 5, at least one authentication and / or identification element chosen from at least one of the following elements: an element for highlighting a falsification, in particular visible and / or detectable by means of microreliefs 5; a specific detection device, an element with variable optical effect, interferential and / or diffractive, iridescent or liquid crystal, a magnetic coating, tracers detectable by X-ray fluorescence, biomarkers, a varnish or an ink, luminescent tracers fluorescent or phosphorescent, photochromic, thermochromic, electroluminescent and / or piezochromic compounds and / or which change color in contact with one or more predetermined products.
• the optical structure 1 may comprise a monolithic support 29 based on the material 15, on the faces 2 and 3 of which are formed the
• the optical structure 1 may comprise a monolithic support 30 such as a film, having a first completely smooth face 31 and, on a second face 32 opposite the first face 31, covered portions 4 by one or more networks 5 of microreliefs separated by zones 8 substantially smooth.
• a monolithic support 30 such as a film, having a first completely smooth face 31 and, on a second face 32 opposite the first face 31, covered portions 4 by one or more networks 5 of microreliefs separated by zones 8 substantially smooth.
• the structure 1 further comprises at least one element 33 of smaller area than the support 30 and fixed, for example by gluing, on the face 31 of the support 30, which element 33 comprises on one face an array of microreliefs 5 covering exactly a substantially smooth zone 8 of the face 32 of the support 30.
• the outer face 2 of the structure 1 is formed both by the face 31 of the support 30 and the microrelief network 5 of the element 33.
• the microreliefs 5 may, for example, initially be present on the entire face 32 of the support 30 and some of these microreliefs are subjected to a treatment to be eliminated, for example by etching or by mechanical action, in order to create the substantially smooth zones 8.
• the optical structure 1 is formed of a plurality of elements 33 arranged on either side of an intermediate support 35 formed for example by a transparent film, so that an array of microreliefs 5 of an element 33 on one side of the support 35 is arranged in line with a zone 36 without element 33 on the other side of the support.
• the elements 33 may be arranged on the same side of the support 35 formed for example by a transparent adhesive film. At least one of the elements 33 may come for example from the cutting of a monolithic support 30 with microreliefs, at least one of the elements 33 being returned and returned to the space left by the cut.
• the optical structure 1 comprises two supports 30 with microreliefs, fixed on two opposite faces of an intermediate support 35.
• the optical structure 1 is covered on each of its two opposite faces 2 and 3 of a layer of a coating 37 such as a transparent varnish.
• the assembly 39 thus formed has substantially smooth outer faces.
• the layers 37 on the faces 2 and 3 may have identical refractive indices or not.
• FIG. 14 shows an optical structure 40 comprising a support 41 made of a transparent polymer material, optionally associated with an electrically conductive polymer, and having opposite faces 42 and 43.
• the face 42 of the support 41 is entirely covered by a microrelief network 5.
• the face 43 is completely smooth, devoid of microreliefs.
• the optical structure 40 further comprises a coating layer 45 covering the microrelief network 5, on a portion of the face 42.
• the coating layer 45 may be deposited for example by vacuum deposition, in particular by vaporization, of a material having a refractive index greater than that of the material of the support 41.
• the coating layer 45 contains for example zinc sulphide having a refractive index of about 2.3, the support 41 being made for example based on a polymer having a refractive index of about 1.5.
• the structure 40 thus has two interfaces formed by the microreliefs 5. One of the interfaces separates the material 15 from the ambient air, and the other of the interfaces separates the material 15 from the material of the coating layer 45, which allows to produce different optical effects depending on the angle of view.
• the coating layer 45 may have a thickness greater than the thickness of the microrelief network 5, as illustrated in FIG. 14. As a variant, the coating layer 45 may have a maximum thickness substantially equal to the thickness of the microrelief networks. 5, as illustrated in FIG.
• layer 45 may form a pattern.
• the microreliefs may have a shape other than a prismatic shape.
• FIG. 16 illustrates an optical structure 50 having, on each of the opposite faces 51 and 52, at least one microrelief network 53, each microrelief having substantially a half-cylinder shape.
• Each microrelief network 53 extends opposite a substantially smooth portion 54 of the opposite face.
• the microreliefs 53 form lenses producing different optical effects depending on whether the light beam first passes through the microrelief network 53 or the substantially smooth zone 54, as can be seen from the paths of the light beams F and G in FIG. 16.
• the characteristics of the various embodiments described can be combined with each other within the variants that are not illustrated.

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• General Physics & Mathematics (AREA)
• Business, Economics & Management (AREA)
• Finance (AREA)
• Engineering & Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Physics & Mathematics (AREA)
• Accounting & Taxation (AREA)
• Credit Cards Or The Like (AREA)
• Laminated Bodies (AREA)
• Inspection Of Paper Currency And Valuable Securities (AREA)
• Facsimile Heads (AREA)
• Optical Filters (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Photoreceptors In Electrophotography (AREA)
• Diaphragms For Electromechanical Transducers (AREA)

Applications Claiming Priority (2)

Publications (3)

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• 2005
  • 2005-11-16 FR FR0553480A patent/FR2893424B1/fr active Active
• 2006
  • 2006-11-16 CA CA002629926A patent/CA2629926A1/fr not_active Abandoned
  • 2006-11-16 DE DE602006005395T patent/DE602006005395D1/de active Active
  • 2006-11-16 BR BRPI0618742-0A patent/BRPI0618742A2/pt not_active IP Right Cessation
  • 2006-11-16 US US12/085,033 patent/US8439402B2/en not_active Expired - Fee Related
  • 2006-11-16 WO PCT/FR2006/051186 patent/WO2007057613A1/fr active Application Filing
  • 2006-11-16 ES ES06831348.5T patent/ES2322874T5/es active Active
  • 2006-11-16 EP EP06831348.5A patent/EP1951528B2/de active Active
  • 2006-11-16 AT AT06831348T patent/ATE423687T1/de not_active IP Right Cessation

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