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. 14, 2012
Filed:
Mar. 19, 2009
Masahiro Kanai, Suwa, JP;
Asami Kobayashi, Fujimi-machi, JP;
Naoki Yoshida, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A synchronous detection circuit includes: an offset compensation circuit which generates an offset compensation voltage to compensate an offset voltage superposed on a direct current voltage signal; and a temperature compensation circuit which generates a temperature compensation voltage to compensate variation of a direct current reference voltage that depends on a temperature in a signal path of a sensing circuit. In the circuit, the synchronous detection circuit synchronously detects an alternating current signal, the offset compensation voltage and the temperature compensation voltage are respectively superposed on the alternating current signal which is input into the synchronous detection circuit, and the synchronous detection circuit synchronously detects the alternating current signal on which the offset compensation voltage and the temperature compensation voltage have been superposed.