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:
Mar. 06, 1990
Filed:
Apr. 07, 1989
Applicant:
Inventor:
Richard A Melcher, Croydon, PA (US);
Assignee:
Brandt, Inc., Bensalem, PA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250205 ;
Abstract
Apparatus for examining documents moved along a path between a light source normally energized at a first level and a photodetector, in which a first potential proportional to the long term average value of the photodetector output with no document between the light source and the photodetector and a second potential proportional to the instantaneous value of the photodetector output are compared to energize the light source at a higher level by shorting part of the resistance in the normal energizing circuit when the second potential falls below a predetermined percentage of the first potential.