PROBLEM TO BE SOLVED: To easily detect position deviation at an origin position of an ultrasonic wave probe during stop of vibration.SOLUTION: An origin position deviation detection system of an ultrasonic wave probe of the invention is configured to detect an output of a reference position detection sensor, then divide a change range of the output voltage of the reference position detection sensor by two voltages V1, V2, then set range setting so as to satisfy following conditions: Z1 is less than the voltage V1 Z2 is equal to or higher than the voltage V1 and equal to or lower than the voltage V2 Z3 is higher than the voltage V2 to a power source voltage Vcc. If the sensor output voltage is in the range of the Z2, a piezoelectric element group is at a reference position, if the sensor output voltage is in the range of Z1, a rotation angle θ of an optic rotary disk is deviated to a minus direction to the reference position, and if the sensor output voltage is in the range of Z3, the rotation angle θ is deviated to a plus direction where the rotation angle θ is plus to the reference position.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2017,JPO&INPIT【課題】超音波探触子の搖動停止時の原点位置での位置ずれの検出を容易にする。【解決手段】本発明の超音波探触子の原点位置ずれ検出システムでは、前記基準位置検出センサの出力を検出して、前記基準位置検出センサの出力電圧の変化範囲を2個の電圧V1と電圧V2で分割し、それらの範囲設定を以下のようにし、 Z1:電圧V1未満 Z2:電圧V1以上~電圧V2以下 Z3:電圧V2より大~電源電圧Vcc 前記センサ出力電圧が前記Z2の範囲にあれば、前記圧電素子群は基準位置にあり、また、前記センサ出力電圧が前記Z1の範囲にあれば、基準位置に対して前記光学回転円板の回転角θがマイナスとなる方向にずれており、さらに、前記センサ出力電圧がZ3の範囲にあれば、基準位置に対して前記回転角θがプラスとなる方向にずれていると判定する。【選択図】図3
