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1. (WO1998049655) APPLICATION AND METHOD FOR CHECKING DOCUMENTS WITH EFFECTIVE OPTICAL DIFFRACTION SECURITY LAYER

Pub. No.:    WO/1998/049655    International Application No.:    PCT/DE1998/001182
Publication Date: Fri Nov 06 00:59:59 CET 1998 International Filing Date: Sat Apr 25 01:59:59 CEST 1998
IPC: G07D 7/06
G07D 7/00
G07D 7/026
Applicants: WHD ELEKTRONISCHE PRÜFTECHNIK GMBH
PUTTKAMMER, Frank
Inventors: PUTTKAMMER, Frank
Title: APPLICATION AND METHOD FOR CHECKING DOCUMENTS WITH EFFECTIVE OPTICAL DIFFRACTION SECURITY LAYER
Abstract:
The invention relates to an application and a method for checking documents. Hitherto, documents with optical diffraction security layers, specially holograms, were checked by costly optical monitoring technology. The entire monitoring process was so time-consuming that the monitoring process could not be applied to fast operating processing machines. Rapid monitoring (as an authentication characteristic) constitutes a further security step in evaluating effective optical diffraction security layers. The effective optical diffraction layer has a discontinuous metallizing layer and/or partially metal layers and/or areas of metal layers on various planes. Several methods of measurement exist to detect electrical conductivity. In practice, the contactless capacitive method of measurement has proven to be more practical.