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. 28, 2012
Filed:
Oct. 18, 2007
Kiyoshi Tateishi, Hannou, JP;
Yuji Tawaragi, Tokyo, JP;
Kiyoshi Tateishi, Hannou, JP;
Yuji Tawaragi, Tokyo, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
A capaciatance detector is provided, which outputs an electric signal dependent on the capacitance present on an object to be measured. The capaciatance detector includes a measurement terminal to be disposed in contact with or in proximity to the object being measured; an impedance conversion circuit connected to the measurement terminal to form a resonant circuit; a reference phase oscillator for supplying a reference phase signal at a constant frequency to the resonant circuit; phase comparison means for outputting, as a capacitance detected signal, a phase difference signal indicative of the phase difference between a resonant signal, which is extracted from the resonant circuit in response to the reference phase signal being applied to the resonant circuit, and the reference phase signal; and resonance frequency regulation means for regulating the resonance frequency of the resonant circuit based on the phase difference signal.