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. 03, 1998
Filed:
Sep. 22, 1995
Applicant:
Inventors:
Hsin-Fu Tseng, Los Altos, CA (US);
Weng-Lyang Wang, Saratoga, CA (US);
Assignee:
ScanVision, San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ; H04N / ;
U.S. Cl.
CPC ...
348243 ; 345245 ;
Abstract
A contact image sensing system that eliminates the use of npn phototransistors. The device comprises a plurality of sensing elements, a like number of dummy sensing elements, control and drive clocks, a digital scanning shift register, and a differential amplifier. The device operates by sequentially reading the voltage output of the sensors, then comparing that output with the output of the dummy sensors so that any noise or offset in the signal can be cancelled by a differential amplifier.