A coordinate detecting apparatus.

摘要

The coordinate detecting apparatus allows a person to input the coordinate of a point (4) on a plane by indicating the point with a touch of a fingertip (16) to the point. The apparatus comprises a transparent resistive film (1) constituting the plane (touch panel) and a buffer circuit (15) operating as a voltage follower circuit having substantially infinite input impedance. The buffer amplifier is operatively connected between each selected pair of facing ends (2,3) of the substantially rectangular region of the resistive film, and equalizes the potentials at the ends. A change of impedance between one of the ends and ground (17) is detected in accordance with the touch of the fingertip to the touch panel and used as original coordinate data. Further modifications concern the avoidance of degradation in the detection quality due to fluctuations of the impedance (Co) provided by the touch of a fingertip, for example, and methods to perform 2-dimensional coordinate detection.