Patent ID: 9550390
Date: 2017-01-24
CPC Classifications: B41M,B42D,G02B,G06K

Claim:
1. An optical security component intended to be checked in reflection by an acquisition device in a checking spectral band, comprising: a layer which is reflective in the checking spectral band, wherein the layer is deposited on a structured face of a material layer transparent in the checking spectral band and wherein the structured face exhibits a structured zone comprising: microstructures distributed spatially in a random manner over the whole of the structured zone with a spatial frequency distribution following a lorentzian curve so as to form an optical structure which under illumination in the checking spectral band forms an isotropic diffusing white, wherein the heights of the microstructures are distributed according to a random function, modulated over the zone by a modulation function so as to form, after illumination of the component at a given angle, a first image in grey levels identifiable by observation in direct reflection and a second image in grey levels identifiable by observation in indirect reflection, identical to the first image with the exception of a reversed contrast.