| 摘要 |
PURPOSE:To flatten frequency characteristics by suppressing the acoustic radiation resistance of a high frequency range part while increasing a low frequency range part by transmitting the oscillation energy of a piezoelectric ceramics thin film to an acoustic emitter plate which has high rigidity and low density. CONSTITUTION:A piezoelectric thin film 1 made of a ceramics material is provided, and electrodes 2 and 3 are formed on both main surfaces of the thin film 1. A frame member 4 holds the circumferential edge of the thin film 1. The electrodes 2 and 3 are applied with electric signals. Further, an acoustic emitter (AE) plate 5 is arranged at the circumference of the frame member 4. Furthermore, corrugations 161, 162, and 163 are formed on at least either of the top and reverse surfaces of the AE plate 5. Namely, the corrugations 161, 162 and 163 are formed on the top and reverse surfaces of the AE plate 5 to increase compliance, thereby suppressing the propagation in an intermediate and a high frequency range. |
