| 摘要 |
<p>An ultrasonic touch system including a substrate and at least an ultrasonic transducing system on one end surface (Z1) of the substrate. The ultrasonic transducing system comprises at least an interdigital transducer (P) and at least an interdigital transducer (Q) corresponding to the interdigital transducer (P). An electric signal having a frequency approximately corresponding to the interdigital periodicity of the interdigital transducer (P) is applied to the interdigital transducer (P), causing the acoustic wave on the end surface (Z1) with a high efficiency, the acoustic wave having a wavelength approximately equal to the interdigital periodicity of the interdigital transducer (P). At this time, an electric signal having a frequency approximately corresponding to the wavelength of the acoustic wave generated on the end surface (Z1) is detected at the interdigital transducer (Q). When touching with a finger or other things on a part of the propagation medium of the acoustic wave on the end surface (Z1), the electric signal detected at the interdigital transducer (Q) is decreased. A touch on the substrate by a finger or other things is accordingly detected with a high sensitivity and a quick response time under operation with low power consumption and low voltage.</p> |
