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:
Oct. 20, 2009
Filed:
Jul. 15, 2005
Hiroki Morimura, Tokyo, JP;
Mamoru Nakanishi, Tokyo, JP;
Satoshi Shigematsu, Tokyo, JP;
Takahiro Hatano, Tokyo, JP;
Yukio Okazaki, Tokyo, JP;
Katsuyuki Machida, Tokyo, JP;
Hiroki Morimura, Tokyo, JP;
Mamoru Nakanishi, Tokyo, JP;
Satoshi Shigematsu, Tokyo, JP;
Takahiro Hatano, Tokyo, JP;
Yukio Okazaki, Tokyo, JP;
Katsuyuki Machida, Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A sensor cell includes a sensor electrode () formed on a substrate (), a signal output unit () which outputs a signal corresponding to a capacitance (Cf) formed between the sensor electrode and the surface of a finger (), a high-sensitivity electrode () formed on the substrate so as to be insulated and isolated from the sensor electrode, and a potential controller () which controls the potential of the finger surface via a capacitance (Cc) formed between the high-sensitivity electrode and the finger surface by controlling the potential of the high-sensitivity electrode. In this arrangement, when the resistance of the finger is high, the potential of the finger surface can be controlled so as not to fluctuate with the potential change of the sensor electrode. This makes it possible to increase the sensitivity of detection of the capacitance formed between the sensor electrode and the finger surface, so ridges and valleys of the finger surface can be clearly discriminated by outputs from a plurality of sensor cells.