Importance

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Abstract

A laminated hard-to-counterfeit data carrier card with an opaque median plastic layer and transparent outer plastic layers has a plurality of groups of light conductors which extend through the median layer and represent encoded information which can be decoded by inserting the card into the slot of a decoding apparatus wherein a light source directs radiation against one side of the inserted card and a suitable circuit including rhotodiodes decodes the pattern of light rays which issue from the other side of the inserted card. The encoded information can represent sums of money, units of time, the serial number of the card, the identification number of the bearer and/or other data. Each group of light conductors can be destroyed or removed independently of the other groups, especially if each group denotes a unit of currency. The cross-sectional area of each light conductor is less than the square of the thickness of the card. The light conductors may constitute holes, light conducting filaments of glass or plastic, or light-conducting tubes. The light conductors form several parallel rows and the diameter of each light conductor is approximately 0.05 mm. The distance between neighboring light conductors in a group is approximately 0.3 mm.

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First Claim