PROBLEM TO BE SOLVED: To provide a driving method and a driving device of a capacitance type transducer which can reduce dispersion in a transmission sound pressure generated in characteristic dispersion of the capacitance type transducer used in an ultrasonic conversion element or the like.SOLUTION: A driving method of a capacitance type transducer 1 includes a plurality of elements 3 each having a cell 2 with a structure in which a vibration membrane 11 including one electrode 10 of a pair of electrodes formed with a gap 8 therebetween is supported so as to vibrate. In a mode in which at least a partial element group of the plurality of elements 3 receives an acoustic wave, a voltage smaller than the minimum pull-in voltage among pull-in voltages of each element in the element group is applied to the element group as a reception bias voltage. In a mode in which the element group transmits the acoustic wave, a voltage smaller than the reception bias voltage is applied to the element group as a transmission bias voltage.COPYRIGHT: (C)2015,JPO&INPIT【課題】超音波変換素子などに用いられる静電容量型トランスデューサの特性ばらつきで生じる送信音圧のばらつきを低減させられる静電容量型トランスデューサの駆動方法、駆動装置などを提供する。【解決手段】間隙8を隔てて形成された一対の電極のうちの一方の電極10を含む振動膜11が振動可能に支持された構造のセル2を有する素子3を複数個備えた静電容量型トランスデューサ1の駆動方法である。複数の素子3のうち少なくとも一部の素子群が音響波を受信するモードでは、前記素子群内の各素子のプルイン電圧のうちの最小のプルイン電圧より小さい電圧を受信バイアス電圧として前記素子群に印加する。前記素子群が音響波を送信するモードでは、前記素子群に前記受信バイアス電圧より小さい電圧を送信バイアス電圧として印加する。【選択図】図1
