Optical pickup driver having piezoelectric elements of different voltages at start and steady state

摘要

The present invention is directed to a drive device comprising an electromechanical transducer ( 25 ) attached to one end of a drive shaft ( 24 ) and adapted to be expanded and contracted in the axial direction of the drive shaft ( 24 ) in accordance with drive voltage to thereby allow the drive shaft ( 24 ) to undergo displacement in the axial direction thereof, and an optical pick-up ( 14 ) movably supported in the axial direction of the drive shaft ( 24 ) and moved along the drive shaft ( 24 ) as the result of the fact that the drive shaft ( 24 ) is caused to undergo displacement by the electromechanical transducer ( 25 ) to apply a drive voltage higher than that at the time of steady transfer to the electromechanical transducer ( 25 ) at the time of starting.