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. 14, 1987
Filed:
Feb. 27, 1985
Kazuo Yoshikawa, Atsugi, JP;
Toru Asano, Kawasaki, JP;
Hisashi Yamaguchi, Atsugi, JP;
Hideaki Takizawa, Kawasaki, JP;
Shizuo Andoh, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A coordinate detecting apparatus for determining the coordinate data of a point on a plane by indicating the point with a touch of a fingertip or other load to the point. The apparatus comprises a transparent resistive film forming the plane (touch panel) and a buffer circuit operating as a voltage follower circuit having substantially infinate input impedance. The buffer amplifier is operatively connected between each selected pair of facing ends of a substantially rectangular region of the resistive film, and equalizes the potentials at the ends. The change of the impedance between one of the ends and the ground is detected in accordance with the touch of the fingertip to the touch panel and is used as an original coordinate data. Further modifications concerning the avoidance of degradation in the detection quality due to fluctuations of the impedance provided by the touch of a fingertip, for example, and the methods to perform 2-dimensional coordinate detection are described.