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. 31, 2000
Filed:
Sep. 03, 1997
Yoshihiro Yamada, Ayama-gun, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A coordinate input device, which detects a signal outputted from a coordinate input pen on the surface of a tablet and converts it into coordinate data, is provided with: a phase-control circuit for shifting the phase of an ac signal from the device main body and for outputting the resulting signal to the coordinate input pen; a Sense Amp circuit for amplifying the ac signal with its phase changed that was outputted from the coordinate input pen and has been detected on the tablet surface; a phase-difference detection circuit for detecting the phase difference between the signal amplified by the Sense Amp circuit and the ac signal from the device main body; and a color conversion circuit for outputting, together with coordinate data, a specific piece of color information that corresponds to the phase difference that has been detected by the phase-difference detection circuit from pieces of color information that have been preliminarily stored in association with phase differences.