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.

Date of Patent:
Oct. 27, 2020

Filed:

Jun. 14, 2019
Applicant:

Alps Alpine Co., Ltd., Tokyo, JP;

Inventors:

Kiyoshi Sasai, Miyagi, JP;

Tatsumi Fujiyoshi, Miyagi, JP;

Shinichi Sagawai, Miyagi, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F 3/044 (2006.01); G06F 3/041 (2006.01); G01V 3/08 (2006.01); H03F 3/45 (2006.01); H03K 17/955 (2006.01); G01R 27/26 (2006.01);
U.S. Cl.
CPC ...
G06F 3/0418 (2013.01); G01R 27/26 (2013.01); G01V 3/08 (2013.01); G06F 3/041 (2013.01); G06F 3/044 (2013.01); H03F 3/45475 (2013.01); H03K 17/955 (2013.01); G06F 2203/04107 (2013.01); H03F 2200/129 (2013.01); H03F 2203/45116 (2013.01); H03F 2203/45526 (2013.01);
Abstract

A capacitance detection device includes a first voltage output circuit configured to output a first alternating current voltage supplied to a shield electrode provided proximate to a detection electrode, a second voltage output circuit configured to output a second alternating current voltage whose frequency and phase are the same as that of the first alternating current voltage and whose amplitude is less than that of the first alternating current voltage, and a current output circuit configured to output a driving current Is to the detection electrode so that the difference between the voltage of the detection electrode and the second alternating current voltage becomes smaller, and output a detection signal corresponding to the driving current. The second voltage output circuit outputs a second alternating current voltage whose amplitude is adjusted so that the driving current in the absence of the object proximate to the detection electrode.


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