Multilayer data carrier and methods for writing on a multilayer data carrier

US5298922A · kind A · utility

Assignee

• GAO Gesellschaft f. Automation v. Organ. MBH · DE

Inventors

• Hansjurgen Merkle · Munich, DE
• Joseph Lass · Munich, DE
• Alexander Hierweger · Rottach-Egern, DE
• Wolfgang Killar · Hersbruck, DE
• Erwin Lob · Munich, DE

Key dates

• Filing date: Dec 4, 1989
• Grant date: Mar 29, 1994
• Expiry date: Dec 4, 2009

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B42D2035/30
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A multilayer identity card exhibits an outer color layer of a first color and an inner color layer of a second color to allow for identity cards and the like to be written on in several colors. While the outer color layer absorbs virtually no laser beam light used for writing, the second, inner color layers absorbs the laser light. This causes the material of the second color layer to be thermally broken down during the writing operation, i.e. vaporized, sublimated, exposed to a chemical or physical reaction, so that the formation of pressure and resulting eruption blasts the first layer into particles. This makes the second color layer visible. Instead of the second color layer one can also provide a transparent layer of varnish having suitable properties in order to expose a multicolor security print, for example, below this transparent layer of varnish.