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. 10, 2021
Filed:
Jan. 11, 2019
Tianma Japan, Ltd., Kanagawa, JP;
Daisuke Sugimoto, Kawasaki, JP;
Hiroshi Haga, Kawasaki, JP;
Wuhan Tianma Micro-Electronics Co., Ltd., Wuhan, CN;
Tianma Japan, Ltd., Kanagawa, JP;
Abstract
A capacitance detection circuit includes an excitation signal source configured to supply an AC driving voltage to drive the detection electrode, a high-pass filter configured to cause a current signal input from the detecting electrode to be output after being attenuated in a prescribed frequency region that is lower than a frequency of the excitation signal source, and a current signal measurement circuit connected between the high-pass filter and the excitation signal source. The current signal measurement circuit is configured to measure a current signal from the high-pass filter. The high-pass filter includes a first passive circuit element connected in series between the detection electrode and the current signal measurement circuit, and a second passive circuit element connected in series between the excitation signal source and a node between the detection electrode and the first passive circuit element.