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:
Jan. 20, 2004
Filed:
Nov. 12, 1999
Motoyasu Yano, Kanagawa, JP;
Masashi Takeda, Kanagawa, JP;
Takeshi Koyama, Tokyo, JP;
Keiichi Shinozaki, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
When a current charge method is used as a method of detecting capacitance, there poses a problem in which S/N is deteriorated by a dispersion in element characteristics of a cell to be detected and when a voltage charge method is used, since parasitic capacitances of column sense lines are very large and accordingly, there is needed some devise for sampling electric charge charged to the capacitance. There are arranged unit cells having detection electrodes and cell selecting switches connected between the detection electrodes and column sense lines in an array shape, electric charge is charged from detecting circuits to the detection electrodes under constant charge voltage, and thereafter, the column sense lines are imaginarily grounded to thereby detect the capacitances formed between the detection electrodes and the surface of the finger in accordance with recesses and projections of a fingerprint via the column sense lines.