Patent ID: 6359734
Filing Date: 2002-03-19
Classification: B42D,G06K

Abstract:
A surface pattern comprising:N visually recognizable patterns of surface portions having optically diffractive, microscopically fine relief structures, plane mirror faces or having light absorbing or scattering structures, the optical performance of which is determined by a reflection layer on the structures; at least one independent surface element sharing the N patterns and located within the N patterns; surface parts subdividing said surface element in such a way that a predetermined structured arrangement of the surface parts within said at least one independent surface element which is independent of the N patterns, said arrangement of the surface parts is not recognizable to the naked eye, and wherein each of the surface parts contains one of at least two different sub-structures that is a microscopically fine diffraction structure, a structure having light absorbing or scattering properties, or is a plane mirror; and a plastic laminate in which the optically diffractive, microscopically fine relief structures, the plane mirror faces or the light absorbing or scattering structures of the N patterns and of said surface parts are embedded, the optical performance of which is determined by a reflection layer on the structures and the mirror faces, wherein in each said at least one independent surface element, the microscopically fine diffraction structures of the surface parts have at least one spatial frequency fB, and the optically diffractive, microscopically fine-relief structures of the N patterns have spatial frequencies fR, and kÂ·fBâ‰ mÂ·fR wherein k is the diffraction order of light diffracted by the surface parts to be detected in a reading machine and m is the order of diffraction of light diffracted by the N patterns.