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:
Jul. 09, 1996
Filed:
Feb. 28, 1994
Takao Tagawa, Kashihara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
There is provided a display-integrated type tablet device which can achieve a high coordinate detection accuracy even when an electrode density of electrodes is greater than a electrode density of the other electrodes in a display panel. A segment electrode scanning clock signal for scanning segment electrodes having an electrode density three times as high as that of common electrodes has a frequency three times as high as a common electrode scanning clock signal. Shift data input to a segment electrode drive circuit has the same pulse width as that of the shift data input to a common electrode drive circuit. As a result, a scanning speed in an x-direction (shift speed of a segment electrode scanning signal) can be made approximately equal to a scanning speed in a y-direction (shift speed of a common electrode scanning signal). Furthermore, the width of the segment electrodes in an active state is made equal to the width of the common electrode. Thus a waveform of a voltage induced at a detection electrode of a detection pen in an x-coordinate detection period and a waveform of a voltage induced in a y-coordinate detection period are made approximately equal to each other to obtain a high coordinate detection accuracy.