The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 2010
Filed:
Sep. 22, 2008
Jürgen Schützmann, Pfaffenhofen, DE;
Hendrik Derks, Geretsried, DE;
Jürgen Schützmann, Pfaffenhofen, DE;
Hendrik Derks, Geretsried, DE;
Giesecke & Devrient GmbH, Munich, DE;
Abstract
The invention relates to a method and an apparatus for recognizing forged documents of value, wherein the documents of value are illuminated with clocked excitation light of a light source. Within the bright phase of the excitation light a first luminescence intensity is detected, within the dark phase a second luminescence intensity. Because of the afterglow of the light pulses there is a residual fluorescence, which distorts the luminescence intensity in the dark phase. By linking the second luminescence intensity with the first luminescence intensity, e.g. by subtracting a scaled first luminescence intensity, a corrected second luminescence intensity is determined, which substantially corresponds to the phosphorescence signal of the document of value.