| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily and reliably bring a piezoelectric actuator out of abnormal state, such as operation failure state or inoperative state. <P>SOLUTION: Using a driving speed determination unit 14, it is determined whether or not the traveling speed of a slider portion 22 of a piezoelectric actuator relative to its rod portion 21 is lower than a predetermined speed. When it is determined by the driving speed determination unit 14 that the traveling speed is lower than the predetermined speed, a frequency equal or close to the resonance frequency (f3) of the piezoelectric actuator is set as the driving frequency for the piezoelectric actuator on a driving frequency setting unit 12. The piezoelectric actuator is driven by a drive unit based on the frequency equal or close to the resonance frequency, set on the driving frequency setting unit 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
