Patent ID: 7675218
Filing Date: 2010-03-09
Classification: G04C,H01L,H02N

Abstract:
1. A piezoelectric actuator drive apparatus for driving a piezoelectric actuator having a vibrating body that vibrates due to application of a drive signal having a prescribed drive frequency to a piezoelectric element, said piezoelectric actuator driving a driven member, said piezoelectric actuator drive apparatus comprising: driving means for supplying said drive signal to the piezoelectric element of said vibrating body; vibration state detection signal outputting means for outputting a vibration state detection signal that indicates vibration state of said vibrating body; phase correcting means for correcting a phase of said vibration state detection signal to corrected phase, on the basis of voltage of said vibration state detection signal; phase difference detection means for detecting phase difference between said phase of drive signal and said corrected phase; comparison means for comparing said phase difference with a target phase difference which is a target to optimize said vibration state at which the vibrating body is efficiently driven; and control means for controlling said phase difference to approach said target phase difference by changing said drive frequency.