| 摘要 |
PURPOSE:To make the final value of the displacement of a piezoelectric element caused by applying a voltage always constant independent of the temperature by providing a voltage control means which outputs a control signal to a switch element so that a driving voltage to be applied to the piezoelectric element becomes a predetermined voltage that is determined in dependence on the temperature detected by a temperature sensor. CONSTITUTION:In a driving circuit for a piezoelectric element having a switch element 3 which charges a piezoelectric element 2 by a d.c. power supply 1 in response to a control signal S1, provided are a temperature sensor 7 for detecting the temperature of the piezoelectric element 2, and a voltage control means 10 for outputting the control signal S1 to the switch element 3 so that a driving voltage E2 to be applied to the piezoelectric element 2 becomes a predetermined voltage which is determined depending on the temperature detected by the temperature sensor 7. Since the displacement amount in the operational aspect of the piezoelectric element 2 is controlled in this way so that the final position of the actuator becomes constant independent of the temperature, the printing pressure of a dot printer becomes constant independently of the temperature, whereby the operational instability of the actuator depending on the temperature characteristics of the residual strain of the piezoelectric element 2 is improved.
|
