| 摘要 |
PURPOSE:To detect a detecting signal efficiently with high sensitivity by setting a driving piezoelectric element and a detecting piezoelectric element separately at the same side face of a prismatic vibrator. CONSTITUTION:A pair of driving piezoelectric elements 12a as well as a pair of detecting piezoelectric elements 12b are set at two side faces of a vibrator 11 of a triangular prism, and a feedback piezoelectric element 12c is set at the remaining side face of the vibrator 11. Upon receipt of a signal of the feedback element 12c, a driving signal from an oscillation circuit 13 is divided to two by a variable resistor 15 and sent to the driving elements 12a and 12a, whereby the vibrator 11 is self-oscillated. Signals of the detecting elements 12b and 12b are differentially amplified at a differential amplifier 14 thereby to obtain a detecting signal of high sensitivity. |
