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. 30, 2005
Filed:
Jul. 03, 2002
Masaki Yoshioka, Kanagawa, JP;
Motoyasu Yano, Kanagawa, JP;
Keiichi Shinozaki, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
A capacitance sensor used as a fingerprint sensor is provided which includes, in addition to a sensor array () in which sensor cells () each with a sense electrode are disposed in the form of an array, a canceling dummy block () having, disposed in an area having no relation with any object under detection, one column of dummy cells () corresponding to each row in the sensor array () and each having a dummy electrode nearly identical in parasitic capacitance to the sense electrode of the sensor cell (). Also, a differentiation output unit () is provided to differentiate between a sensed voltage Vsig sensed at the sensor array () by sensing circuit () and sensed voltage Vdmy sensed at the canceling dummy block (), thereby eliminating the influence of a variation in parasitic capacitance Cp, caused by a production tolerance.