Security document having a security element embedded therein with visually and machine-testable marks

US5176405A · kind A · utility

Assignee

• GAO Gesellschaft für Automation und organisation mbH · DE

Inventors

• Wittich Kaule · Grafing, DE
• Michael Bohm · Heimstetten, DE

Key dates

• Filing date: Mar 7, 1991
• Grant date: Jan 5, 1993
• Expiry date: Mar 7, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S283/901
• WIPO field: Control
• WIPO sector: Instruments

Abstract

In a security document having an embedded security element in the form of a transparent thread with electrically conductive material in at least two layers, at least one layer is transparent or partly transparent at least in certain areas. The partly transparent layer interacts with marks located on the thread in such a way that the marks are largely concealed in incident light but are recognizable visually in transmitted light.