| 摘要 |
Wave motions such as ultrasonic waves and alternating electric field and the like are received, and are converted into mechanical vibration which is then imparted to a piezoelectric element to generate alternating electric signals. When the frequency of mechanical vibration is in agreement with the natural frequency of the piezoelectric element, a liquid crystal display element is driven by the alternating electric signals. Thus, a piezoelectric plate is vibrated by wave motion at its natural frequency, and an LCD is operated by its output, thereby to constitute a wave motion detector which operates without any power source. This is simple in construction, small, does not require a power supply, and can therefore be used in various fields of art. |
