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:
Dec. 01, 2009
Filed:
Oct. 06, 2005
Shinichi Ito, Hyogo, JP;
Shinichi Ito, Hyogo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A touch key detects that an object touches the touch key. The touch key includes an electrode arranged to be touched with the object, an oscillator for outputting a high-frequency voltage and applies the high-frequency voltage to the electrode, a rectifier for rectifying and smoothing the high-frequency voltage output from the oscillator as to output a direct-current (DC) voltage, a reference voltage generator for generating a reference voltage, a subtracter for subtracting the reference voltage from the DC voltage output from the rectifier, a judging unit for detecting a voltage difference between the voltage output from the subtracter before and after changing and for determining that the object touches the electrode when the voltage difference exceeds a predetermined value. This touch key detects that an object touches the electrode with high sensitivity, and enhances the reliability of the judging unit.