Patent ID: 7144617
Filing Date: 2006-12-05
Classification: B42D,G03G,Y10T

Abstract:
1. A security element comprising a reflective, optically variable surface pattern which is embedded in a layer composite of plastic material and which is visually recognizable from predetermined observation directions, formed from a mosaic of optically active surface elements, wherein the mosaic surfaces comprise at least one surface portion and a background surface which are arranged substantially adjacent and are occupied with microscopically fine, light-diffractive relief structures having substantially parallel grating vectors, wherein a first spatial frequency of the relief structure of the background surface and a second spatial frequency of the relief structure of the at least one surface portion have different values which are selected from predetermined spatial frequency ranges such that for white light illumination beams which are obliquely incident onto a plane of the layer composite, the at least one surface portion and the background surface deflect monochromatic light beams of different wavelengths parallel to a normal to the plane, wherein a difference between the first spatial frequency and the second spatial frequency is in a range of between 5 lines/mm and 40 lines/mm, wherein the background surface surrounds the at least one surface portion to form an item of information which is visually recognizable with the naked eye viewing the security element by a color contrast but which is not visually recognizable to the naked eye viewing a color copy of the security element, the adjacent background surface and the at least one surface portion both being reproduced in the same color in the color copy.