Identification card with a visible authenticity feature and a method of manufacturing said card
First Claim
1. An identification card containing a plurality of synthetic layers in which information is provided by means of a laser beam, said information being visible in the form of changes in the optical properties of the synthetic material due to irreversible changes in the material caused by the laser beam, characterized in thatat least a first and a second layer have transparent areas which overlap,the first layer and the second layer have the property of changing visibly when exposed to the laser beam, this change being caused only as of certain intensity values and the particular intensity value required herefor being lower for the first layer than for the second layer,a first piece of information is provided in the first layer,a second piece of information is provided in the second layer, which is identical or is part of the first piece of information and is provided simultaneously with the first piece of information so that the second peice of information is present substantially congruent to the first piece of information in the recording direction, and in that the information in the first and second layers is provided by the beam in such a way as to be visible, either overlapping or singly, depending on the viewing angle, its appearance varying in accordance with the viewing angle.
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Accused Products
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.
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Citations
17 Claims
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1. An identification card containing a plurality of synthetic layers in which information is provided by means of a laser beam, said information being visible in the form of changes in the optical properties of the synthetic material due to irreversible changes in the material caused by the laser beam, characterized in that
at least a first and a second layer have transparent areas which overlap, the first layer and the second layer have the property of changing visibly when exposed to the laser beam, this change being caused only as of certain intensity values and the particular intensity value required herefor being lower for the first layer than for the second layer, a first piece of information is provided in the first layer, a second piece of information is provided in the second layer, which is identical or is part of the first piece of information and is provided simultaneously with the first piece of information so that the second peice of information is present substantially congruent to the first piece of information in the recording direction, and in that the information in the first and second layers is provided by the beam in such a way as to be visible, either overlapping or singly, depending on the viewing angle, its appearance varying in accordance with the viewing angle.
Specification