Security document with security features in the form of luminescing substances

US4442170A · kind A · utility

Assignee

• GAO Gesellschaft für Automation und organisation mbH · DE

Inventors

• Wittich Kaule · Grafing, DE
• Gerhard Schwenk · Puchheim, DE
• Gerhard Stenzel · Germering, DE

Key dates

• Filing date: Oct 23, 1981
• Grant date: Apr 10, 1984
• Expiry date: Oct 23, 2001

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31634
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

Security paper with narrow band luminescing authenticity characteristics which can only be excited in substantially the same wavelength region in which it also emits. With these authenticity characteristics therefore the authenticity signal is overlapped or covered by the test signal of several orders of magnitude stronger. The authenticity of the security papers cannot accordingly be tested with the normal processes or devices for determining of luminescence. The test devices used take advantage of the decay behavior of the luminescence emission for detection. The authenticity characteristics can be added to the paper material, the printing ink used, further mottling fibres or security threads.