Patent ID: 7145723
Filing Date: 2006-12-05
Classification: B42D

Abstract:
1. A security element with a pattern comprising surface portions and in the form of a laminate for authentication of a document, which includes at least a transparent protective layer, a transparent lacquer layer and an adhesive layer, wherein the lacquer layer is arranged between the protective layer and the adhesive layer and the refractive index abruptly changes at the interface between the adhesive layer and the lacquer layer and the surface portions of the pattern are composed of background surfaces and pattern elements, wherein in the region of the background surfaces the lacquer layer is smooth and flat in form and in the region of the pattern elements relief structures with a predetermined, optically effective structure depth are formed into the lacquer layer, the background surfaces are flat mirror surfaces for light incident into the laminate, and the relief structures are cross gratings formed from base gratings with periods and the periods are shorter than a predetermined limit wavelength at the short-wave end in the spectrum of visible light so that the pattern elements absorb and scatter the incident light, wherein in each relief structure the ratio of the absorbed and the scattered light is predeterminedly dependent on the optically effective structure depth prevailing in the relief structure.