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:
Oct. 29, 2002
Filed:
Nov. 03, 2000
Applicant:
Inventors:
Achim Philipp, Kolbermoor, DE;
Heinz Hornung, Gilching, DE;
Assignee:
Giesecke & Devrient GmbH, Munich, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G07D 7/12 ;
U.S. Cl.
CPC ...
G07D 7/12 ;
Abstract
The invention relates to a method for checking the state of an apparatus for testing sheet material having at least one illumination device, transparent measuring window and detector. For ascertaining the soiling of a measuring window according to the invention the latter is irradiated with UV light by an illumination device, the UV light transmitted through the measuring window being filtered by a UV filter such that only a small fraction passes the filter and reaches a detector. Said fraction of UV light transmitted through the filter is detected and evaluated for determining the degree of soiling of the measuring window.