| 摘要 |
<p>PURPOSE:To prevent the accuracy of a resistance value of a conductive thin film having a common electrode from being requested too high by inputting the potential of the common electrode outputted from the potential of a contact point of the conductive thin film to a high input impedance detector. CONSTITUTION:The position coordinate input device is provided with a common electrode 11a provided on the peripheral edge part on one conductive thin film 11, two pairs of parallel electrodes 12a - 12d provided on edge parts on all sides on the other conductive thin film 12, and a high input impedance detector 17 for detecting and outputting the potential of the common electrode 11a. When a voltage of an electrode 14 is applied between electrodes 12c - 12d, and an arbitrary point P on the conductive thin film 11 is pressed down, the potential of the contact point P of the thin films 11, 12 is outputted through the electrode 11a, an amplifier 17 and an A/D converter 18. Also, since the input impedance of the amplifier 17 is set extremely high, even if a resistance R2 is fluctuated, no influence is exerted on an output of the amplifier 17. In such a way, as for one piece in the conductive thin films 11, 12, it becomes unnecessary to take high the accuracy of a resistance value.</p> |
