| 摘要 |
<p>PURPOSE:To detect a coordinate with high accuracy by providing a means for measuring a panel resistance and an analog switch resistance, in an electrostatic capacity type touch panel, and correcting an error of the coordinate from a result of measurement. CONSTITUTION:A current is made to flow to a panel 22 through an analog switch 27a from a constant-current source 38. Thereafter, the potential of the left upper end (coordinates 0, 0) and the right lower end (coordinates 1, 1) is measured by an A/D converter 37. By supplying this result of measurement to a control device 30 by an 8-bit signal, an analog switch resistance r0 (=r0'+r0'') and a panel resistance R can be known. Next, the control device 30 executes a correcting operation for eliminating an error of the coordinates, based on the resistance (r) and R. In such a way, the coordinate can be detected with high accuracy without depending on the analog switch resistance and the panel resistance.</p> |
