# US 12,246,553 B2 · Optical security components, manufacture of such components and secure documents equipped with such components > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,246,553 B2 - Document ID: US12246553B2 - Status: Granted - Kind: B2 - Application number: 18/575,194 - Filed: 2022-07-11 - Published: 2024-08-08 - Granted: 2025-03-11 - Earliest claimed: 2021-07-09 - Assignees: Surys - Applicants: Surys - Inventors: Nelson Gananathan - Web page: https://patentgrep.com/patent/US12246553B2 ## CPC - B42D 25/324: Reliefs - B42D 25/328: Diffraction gratings; Holograms - G02B 5/1814: {structurally combined with one or more further optical elements, e.g. lenses, mirrors, prisms or other diffraction gratings (G02B5/189 takes precedence)} - G02B 5/1857: {using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams} - G02B 5/1861: {Reflection gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence)} - B42D 25/373: Metallic materials - 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 - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical security component may include a first layer, a diffractive structure etched on the first layer, a second reflective layer covering the diffractive structure. The diffractive structure includes a first pattern consisting of a set of facets arranged to form various subsets of facets, each subset of facets including a facet with symmetry of revolution arranged concentrically. In each group of the subsets of facets, the subsets of facets present, in point regions defined by identical polar coordinates, a local alteration of the surface, such as to produce a recognizable graphic object for a given tilt angle and azimuth angle. The polar coordinates vary from one group to another, so as to produce a dynamic visual effect observable in reflection by change of tilt and/or azimuth. ## Claims ### Claim 1 An optical security component configured for authentication in reflected light, from at least a first viewing face, the component comprising: a first layer made of dielectric material, transparent in visible light; at least a first diffractive structure etched on said first layer; and a second layer, covering said first diffractive structure at least partially, and having a spectral band of reflection in visible light; and wherein: said first diffractive structure comprises at least a first pattern consisting of a set of facets arranged to form a plurality of subsets of facets, each subset of facets comprising one or more facets with symmetry of revolution arranged concentrically, said facet(s) of each subset of facets each having a slope with an angular value comprised, in absolute value, between a non-zero minimum angular value and a maximum angular value strictly less than 90°, said facet(s) of each subset of facets each having a given maximum height, a maximum lateral dimension of each subset of facets being smaller than 300 μm; in each group of a plurality of groups of subsets of facets, said subsets of facets each present, in a point region defined by an angular sector with polar coordinates comprising an angular coordinate and a radial coordinate which are identical for all subsets of facets of the group, a local alteration of a surface of the point region of each subset of facets that produces a graphical object for a given tilt angle and azimuth angle; at least said angular coordinate varies from one group to another, in such a way as to produce, when the component is illuminated along a given lighting axis, a dynamic visual effect observable in reflected light by a change of azimuth, said dynamic visual effect comprising a movement and/or a deformation of said graphical object. ### Claim 2 (depends on 1) The optical security component as claimed in claim 1, wherein said local alteration of the surface comprises a zero local slope of the surface. ### Claim 3 (depends on 1) The optical security component as claimed in claim 1, wherein said local alteration of the surface comprises a local modulation of the first pattern by a second pattern forming a periodic grating, of predetermined period included between 150 nm and 500 nm, said grating being determined so as to produce, after deposition of the second layer, a resonant effect. ### Claim 4 (depends on 1) The optical security component as claimed in claim 1, wherein in at least a first region, said first pattern is modulated by a second pattern forming a periodic grating, of predetermined period included between 150 nm and 500 nm, said grating being determined so as to produce, after deposition of the second layer, a resonant effect. ### Claim 5 (depends on 4) The optical security component as claimed in claim 4, wherein said local alteration of the surface comprises a local modification of a property of said periodic grating. ### Claim 6 (depends on 1) The optical security component as claimed in claim 1, wherein said polar coordinates vary from one group to another, in such a way as to further produce, when the component is illuminated along a given lighting axis, a dynamic visual effect observable in in reflected light by a change of tilt. ### Claim 7 (depends on 1) The optical security component as claimed in claim 1, wherein the second layer comprises a metal material. ### Claim 8 (depends on 1) The optical security component as claimed in claim 1, wherein the dielectric material of the first layer has a first refractive index and the second layer comprises a dielectric material having a second refractive index such that a difference between the second refractive index and the first refractive index is greater than or equal to 0.3. ### Claim 9 (depends on 1) The optical security component as claimed in claim 1, wherein the angular value of the slope of each facet of the set of facets is comprised, in absolute value, between 1° and 45°. ### Claim 10 (depends on 1) The optical security component as claimed in claim 1, wherein the facets of the set of facets have an identical height. ### Claim 11 (depends on 1) The optical security component as claimed in claim 1, wherein each subset of facets comprises at least 5 facets with symmetry of revolution arranged concentrically. ### Claim 12 (depends on 1) A secure object comprising a substrate and an optical security component as claimed in claim 1, deposited on said substrate. ### Claim 13 (depends on 12) A method for authenticating a secure object as claimed in claim 12, comprising: viewing said optical security component along a viewing axis forming a given viewing angle with the lighting axis; a tilting and/or azimuthal movement of said secure object resulting in a dynamic visual effect comprising a movement and/or deformation of said graphical object. ### Claim 14 (depends on 12) A method for authenticating a secure object as claimed in claim 12 by means of an optical imaging device comprising an optical imaging axis, said authentication method comprising: forming an image of said optical security component, by means of the optical imaging device, said optical imaging axis forming a given viewing angle with the lighting axis; a tilting and/or azimuthal movement of said secure object or a tilting and/or azimuthal movement of said optical imaging axis resulting in a dynamic visual effect comprising a movement and/or deformation of said graphical object. ### Claim 15 (depends on 14) The authentication method as claimed in claim 14, wherein the lighting axis and the optical imaging axis are coincident. ### Claim 16 A method for manufacturing an optical security component intended to be viewed in reflected light from a viewing face, the method comprising: depositing, on a support film, a first layer made of dielectric material, transparent in visible light; forming, on said first layer, at least a first diffractive structure, depositing a second layer, covering said first diffractive structure at least partially, and having a spectral band of reflection in visible light, wherein: said first diffractive structure comprises at least a first pattern consisting of a set of facets arranged to form a plurality of subsets of facets, each subset of facets comprising one or more facets with symmetry of revolution arranged concentrically, said facet(s) of each subset of facets each having a slope with an angular value comprised, in absolute value, between a non-zero minimum angular value and a maximum angular value strictly less than 90°, said facet(s) of each subset of facets each having a given maximum height, a maximum lateral dimension of each subset of facets being smaller than 300 μm; in each group of a plurality of groups of subsets of facets, said subsets of facets each present, in a point region defined by an angular sector with polar coordinates comprising an angular coordinate and a radial coordinate which are identical for all subsets of facets of the group, a local alteration of a surface of the point region of each subset of facets that produces a graphical object for a given tilt angle and azimuth angle; at least said angular coordinate varies from one group to another, in such a way as to produce, when the component is illuminated along a given lighting axis, a dynamic visual effect observable in reflected light by a change of azimuth, said dynamic visual effect comprising a movement and/or a deformation of said graphical object.