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:
Aug. 09, 1988
Filed:
Jul. 28, 1986
Shinji Masuda, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A charge detecting circuit includes a plurality of photodiodes, and a first multiplexer having a plurality of inputs connected to the photodiodes, respectively and operative to selectively connect one of its inputs to its output. Further, there are provided dummy capacitors of the same number as that of the photodiodes, each of the dummy capacitors having substantially the same capacitance as one corresponding photodiode, and a second multiplexer having a plurality of inputs connected to the dummy capacitors respectively, and operative to connect one of its inputs to its output. A differential amplifier is connected at its first input to the output of the first multiplexer and at its a second input to the output of the second multiplexer, so as to generate a photodetection signal.