Device and process for checking sheet articles such as bank notes or securities

US6061121A · kind A · utility

Assignee

• GIESECKE & DEVRIENT GMBH · DE

Inventors

• Norbert Holl · Germering, DE
• Florian Holzner · Weßling, DE
• Heinz Hornung · Gilching, DE
• Bernd Wunderer · Birkenfeld, DE

Key dates

• Filing date: Nov 10, 1997
• Grant date: May 9, 2000
• Expiry date: Nov 10, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G07D7/121
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus for testing sheet material includes an illumination device which illuminates the sheet material continually and in the total spectral region to be tested, and a receiving device having at least two linear parallel CCD arrays. A filter transmitting a certain spectral region is mounted on each CCD array. The individual filters are selected so that at least one transmits in the visible spectral region and one in the invisible spectral region. For detection of the light diffusely reflected or transmitted by the sheet material, the individual CCD arrays produce electric signals from the received light which are then processed in an evaluation device and compared with reference data for testing the sheet material.