Process for the manufacture of non-replicable holograms possessing authenticity features and a reading device to check authenticity

US5943144A · kind A · utility

Assignee

• BUNDESDRUCKEREI GMBH · DE

Inventors

• Gunther Dausmann · Erding, DE
• Klaus Gnadig · Munich, DE
• Zishao Yang · Erding, DE

Key dates

• Filing date: Sep 25, 1996
• Grant date: Aug 24, 1999
• Expiry date: Sep 25, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G03H1/0011
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A process for the manufacture of non-replicable holograms possessing authenticity features which are copies of a master hologram. To form a master hologram, a hologram is taken of a randomly structured optical element, for example of a ground glass screen or a diffusor. The resulting hologram forms an authenticity feature, with an optical system which leads to a hologram with a pattern of lines that are parallel to one another.