| 摘要 |
PURPOSE:To reduce operating noises from a piezoelectric element by a simple constitution by charging or discharging the piezoelectric element through a resistor having a specific electric resistance prescribed based on the electrostatic capacity of the piezoelectric element. CONSTITUTION:A piezoelectric element driving circuit 37 is constituted of a high voltage generation circuit 41 and four switching circuits of 42 FL, 42 FR, 42 RL and 42 RR provided corresponding to piezo-actuators of 19 FL, 19 FR, 19 RL and 19 RR. Each switching circuit has the same constitution, for example, the switching circuit 42 FL includes a charging circuit 61 which applies voltage to the piezo-actuator 19 FL from a high voltage terminal of the high voltage generation circuit 41 and a discharging circuit 62 which discharges voltage applied to the piezo-actuator 19 FL to a low voltage terminal of the high voltage generation circuit 41, and these circuits 61 and 62 provide the charging resistance 64 and the discharging resistance 67 having a specific relation with the electrostatic capacity of the piezo-actuator 19 FL. |
