| 摘要 |
<p>PURPOSE:To improve the accuracy of an A/D converter circuit without providing the partitioning electrodes to both X and Y axis resistance plates. CONSTITUTION:The external resistances are inserted at both ends of each of X and Y axis electrodes respectively, and the tap terminals A, B and C are provided at the middle of each external resistance for partition of the outputs of those resistance plates. Then both ends of each resistance and the terminals A-C are connected to an A/D converter circuit via the changeover switches 63 and 64 which are switched to each other for each section in accordance with the detected position data. In regard of the position information on an X axis resistance plate, this plate is switched toward an X contact and a prescribed point is pressed with a pen. Then the position data on each of divided sections of the resistance plate are compared with the data divided equally into 256 pieces, for example, by the A/D converter circuit. If no detected data is included in a prescribed section, the overflow output emerges to switch successively the switches 63 and 64 for each section. Then the position data are outputted when they are included in a set range. In the same way, the position information on a Y axis resistance plate is detected after this plate is switched toward a Y contact.</p> |
