摘要 |
<p>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.</p> |
申请人 |
GAO GESELLSCHAFT FUER AUTOMATION UND ORGANISATION MBH |
发明人 |
LASS, JOSEPH, DIPL.-PHYS. DR.;MERKLE, HANSJUERGEN, CHEM-.ING.;BECKER, WOLFGANG, DIPL.-PHYS.;HERGET, WERNER, DIPL.-ING.;LOB, ERWIN, DIPL.-ING. |