| 摘要 |
<p>PURPOSE:To delete the coordinates of wrong input points by counting backward the information corresponding to the vibration transmission time from the calculated coordinate value and checking the obtained information. CONSTITUTION:A coordinate input device consists of a vibration transmitting plate 8 which transmits the vibrations as elastic waves, the vibration sensors 6 containing the piezoelectric elements which detect the elastic waves, etc. The detection signals received from the sensors 6 are amplified by a preamplifying circuits 9-11 and supplied to the waveform detecting circuits 12-14 respectively. The circuits 12-14 detect the arrival timing of a prescribed waveform component through the waveform processing of each detection signal and latch the clocking information of a clocking counter 14 via latch circuits 15-17. This clocking information (the arriving time information between an input point and each sensor 6) is supplied to a controller via a microcomputer, etc., for calculation of the input coordinates. Then the comparison is carried out between the measured vibration transmission distance and the vibration transmission distance counted backward from the coordinate value. Thus the presence or absence of a significant difference is checked between both distances for decision and deletion of a wrong detection point.</p> |
