Abstract: Information is provided in a multilayer identification card by means of a laser beam. This information is recorded by irreversibly changing (blackening) transparent synthetic material. Synthetic materials which blacken at different intensity values are used for the individual card layers. By controlling the laser beam intensity, information can thus be recorded only in one layer or else simultaneously in several layers. If the layer arrangement, layer materials and recording parameters (intensity, writing width, etc.) are selected appropriately, images can be produced which change their appearance when the viewing angle is changed. The various visual effects which can thereby be otained serve to distinguish the authenticity of the identification card.

Abstract: A multilayer identification card in which information in the form of patterns, letters, numbers and/or pictures is inscribed by means of a laser recorder in a laser transformable layer of the identification card which is made of plastic and is transparent in the visible spectral range.The material of this laser transformable layer is adapted to the laser recorder in such a way that it absorbs the laser energy strongly enough in the wavelength of the laser beam transformations such as discoloration, microbubble formation, etc., take place locally in the material, rendering the applied information very clearly visible and immune to falsification in the otherwise transparent layer. This layer which bears the information can either be designed as a transparent identification card cover layer or be covered by another plastic layer which is transparent both visually and for the laser recorder.