| 摘要 |
A security element which is stuck on to a substrate has a reflecting, optically variable surface pattern (11) which is embedded in a layer composite of plastic material and which is visually recognisable to the naked eye from predetermined observation directions. The surface pattern (11) is formed from a mosaic of surface elements (12; 13; 14) with optically active structures. At least in a part of the surface pattern (11) identical surface portions (15) with optically active relief structures are additionally arranged regularly in regions which are independent of the mosaic. The surface portions (15) involve a largest dimension of less than 0.2 mm and a length-to-width ratio of at least 3:1, wherein the center points (16) of the surface portions form a dot matrix with periods of more than 8 dots per mm and the longitudinal surface portions (15) in each region are oriented parallel to a preferred direction. The regions form an item of concealed, visually imperceptible information which appears as an artefact on a color copy of the security element and can be recognised by the naked eye. |
