Method of manufacture of a data processing card provided with signs and data processing card provided with signs obtained by laser radiation

US5234624A · kind A · utility

Inventors

• Eric J. Bauer · Neuchâtel, CH
• Hermann Stockburger · Bayreuth, DE

Key dates

• Filing date: Aug 19, 1991
• Grant date: Aug 10, 1993
• Expiry date: Aug 19, 2011

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B42D2035/08
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

Method of producing a data processing care by thermo-moulding a mixture of pulverulent polycarbonate with lamp-black at a proportion of 8 ppm of lamp-black with respect to the basic thermo-hardenable material. The inner face of the wall of the mould which gives rise to the front face of the card has a checkered pattern, the distance between the recesses, respectively the protrusions, of the checkered pattern being a multiple of the wave length of the laser ray used for applying on the card the contrasted signs. A laser tube piloted by a piloting unit including a program containing the indications which are to appear on the card, is used for directing a laser radiation onto the card. The infrared rays are absorbed by the lamp-black contained in the mass of the material of the card which is heated, thereby producing a change of color resulting in appearance of signs such as a signature and a photograph on the front face of the card.