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:
May. 26, 1992
Filed:
Oct. 29, 1990
Applicant:
Inventor:
Terrence C Schmidt, Wellesley, Ontario, CA;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2502082 ; 2502 / ;
Abstract
An ambient light rejecting quad photodiode sensor having compensation diodes connected with reverse polarity to respective quadrant photodiodes within the sensor, the compensation diodes being located outside of the area of illumination. By direct connection of compensation diodes in reverse polarity to each quadrant of the quad photodiodes, a large boost in signal to noise ratio is achieved for eliminating the effects of ambient room light as well as sensor dark current.