Patent Number: 7,535,153

Title: Drive control method for a piezoelectric actuator, drive control apparatus for a piezoelectric actuator, and electronic device

Abstract: The piezoelectric actuator drive control device has a controller, and executes an initialization process including an optimum phase difference acquisition process P1 and a phase difference inversion detection process P4 at a predetermined frequency. As a result, the optimum phase difference is updated each time the optimum phase difference acquisition process P1 runs to account for wear or temperature change from continuous operation. Furthermore, even if the phase difference between the drive signal and detection signal inverts during a drive frequency sweep due to variation in the vibration characteristic of the piezoelectric actuator, the phase difference inversion frequency and clamping frequency are reset each time the phase difference inversion detection process P4 is executed, thus preventing phase difference feedback control errors. Appropriate drive control based on the optimum phase difference can therefore be provided because the suitability and stability of the optimum phase difference are assured.

Inventors: Urano; Osamu (Okaya, JP)

Assignee: Seiko Epson Corporation

International Classification: H01L 41/08 (20060101)

Expiration Date: 2021-05-19 0:00:00