| 摘要 |
<p>PURPOSE:To provide the ultrasonic touch panel for sensing a fact that a person's finger, an object or a spot of a laser light comes into contact with the plate surface of a substrate, and specifying its contact position by providing an ultrasonic transmitting/receiving means on the plate surface of the substrate. CONSTITUTION:When a linear chirp signal is inputted from interdigital electrodes TX and TY, an electric signal of a frequency varied roughly in accordance with electrode periodic length of the interdigit electrodes TX and TY is converted to an elastic surface wave and propagated along a piezoelectric substrate 1, and an elastic surface wave of wavelength being roughly equal to electrode periodic length of interdigital electrodes RX and RY is converted to a delay electric signal, and outputted from the interdigital electrodes RX and RY. When a propagation path of the elastic surface wave on the piezoelectric substrate 1 is brought into contact by substance which is softer than the piezoelectric substrate 1 and is apt to absorb an ultrasonic wave, the elastic surface wave corresponding to the contact position is attenuated, and in accordance therewith, the delay electric signal is also attenuate. The contact position can be detected from frequency of the delay electric signal attenuated in such a way.</p> |
