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. 29, 1998
Filed:
Apr. 08, 1996
Kiyohiro Nozaki, Nara, JP;
Takao Tagawa, Kashihara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A coordinate input device includes (1) a pen switch sensing circuit for providing a power supply to a pen switch in a position sensing pen, and for sensing that the pen switch is turned on and off and (2) a pen switch control circuit for controlling a timing of the power supply. The power supply is provided to the pen switch only when coordinate sensing operations are not affected. The power supply is stopped in order to avoid a voltage change happening to the pen switch when the coordinate sensing operation is affected. Therefore, the pen switch is neither turned on nor turned off during a coordinate sensing period. Consequently, it is possible to avoid a wrong sensing of a coordinate indicated with the position sensing pen.