Patent · US Expired

Method for verifying the state of a device used to examine sheet items

US6472670B1 · kind B1 · utility

5Cited by

4References

8Claims

0Family size

Assignee

GIESECKE & DEVRIENT GMBH · DE

Inventors

Achim Philipp · Munich, DE
Heinz Hornung · Gilching, DE

Key dates

Filing date	Nov 3, 2000
Grant date	Oct 29, 2002
Priority date	—
Expiry date	Nov 3, 2020

Classification

Technology area (CPC G)Physics
CPC primaryG07D7/12
WIPO fieldControl
WIPO sectorInstruments

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.