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:
Jun. 28, 1994
Filed:
May. 14, 1992
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
The invention provides a coordinates input device capable of detecting coordinates with high accuracy by eliminating errors that could be contained in detected voltage depending on the condition of the pressure applied to a coordinates input section. When pressure is applied to a plane resistive sheet of the coordinates input section, the maximum voltage applied to the coordinates input section is detected by means of an A/D converter prior to the detection of the coordinates, and correction is made by a reference voltage regulating circuit so that a reference voltage becomes equal to the maximum voltage. Thereafter, the A/D converter converts the detected voltage to digital data on the basis of the corrected reference voltage, for calculation of the coordinates. Errors that could be contained in the detected voltage when detecting the coordinates can thus be eliminated.