US 12,246,553 B2
Optical security components, manufacture of such components and secure documents equipped with such components
Nelson Gananathan, Aubervilliers (FR)
Assigned to SURYS, Bussy Saint Georges (FR)
Appl. No. 18/575,194
Filed by SURYS, Bussy Saint Georges (FR)
PCT Filed Jul. 11, 2022, PCT No. PCT/EP2022/069357
§ 371(c)(1), (2) Date Dec. 28, 2023,
PCT Pub. No. WO2023/281123, PCT Pub. Date Jan. 12, 2023.
Claims priority of application No. 2107518 (FR), filed on Jul. 9, 2021.
Prior Publication US 2024/0262123 A1, Aug. 8, 2024
Int. Cl. B42D 25/324 (2014.01); B42D 25/328 (2014.01); B42D 25/373 (2014.01); G02B 5/18 (2006.01)
CPC B42D 25/324 (2014.10) [B42D 25/328 (2014.10); G02B 5/1857 (2013.01); B42D 25/373 (2014.10)] 16 Claims
OG exemplary drawing
 
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.