| 摘要 |
<p>PURPOSE:To prevent generation of unnecessary vibration caused by inertial reaction force, to make a supporting structure body light, and to prevent a drop of efficiency of a transmitter and receiver, and deterioration of its directivity, by fixing an absorbing vibrator to the supporting body which support the transmitter and receiver. CONSTITUTION:A supporting bobbin 3 is fixed to a substrate 4 through a transmitting and receiving vibrator 2 and a similar absorbing vibrator 5. To this bobbin 3 and the transmitting and receiving vibrator 2, a transmitting and receiving circuit 8 is connected, and to the absorbing vibrator 5, an absorbing vibrator controlling circuit 9 is connected, and by the circuit 9, the absorbing vibrator 5 is controlled. One terminal of this absorbing vibrator 5 is grounded through a detecting element having a low resistance value in the circuit 9, the other terminal is connected to an output terminal of an amplifier 6, and between a non-inversion terminal and an inversion terminal of said amplifier 6, voltage across the terminals of the detecting element 7 is applied. In this way, unnecessary vibration generated in the substrate by the absorbing vibrator 5 is absorbed, and a drop of efficiency of a transmitter and receiver, and deterioration of its directivity are prevented.</p> |
