| 摘要 |
<p>PURPOSE:To reduce noise included in a received signal and sampling error and to improve the resolution of a detected position by providing a position detecting method for an ultrasonic system touch panel. CONSTITUTION:This touch panel input device consists of a panel 1 which can propagate a surface acoustic wave and attenuates the surface acoustic wave by a contacting body on the panel 1, a sending-out means 2 for the surface acoustic wave, a receiving means 3, transmitting and receiving circuit means 2 and 3 for the surface acoustic wave, an amplifying means 4, a detecting means 5, an A/D converting means 6, a storage means 8 which stores a value after A/D conversion, a comparing means 13 which detect the place of attenuation of the surface acoustic wave by a touch, and a sample point selecting means 12 and an arithmetic means 11 which determines the touch position according to the attenuation quantity of the received waveform.</p> |
