Beam rotation actuator based on dove prism in the optical storage media

Abstract

A beam rotation actuator, which can be utilized to improve the data transfer rate for optical disk systems, has been developed. The newly developed beam rotation actuator with high-resolution and fast response was assembled for micro positioning of an optical storage media. The beam rotation actuator is utilized to put multi-beam spots on more than one track on an optical disk simultaneously in addition to tracing multi-beam spots on tracks in a radial direction. Multi-beam spots turn on an optical axis by rotating dove prism in the optical path at the end of a cantilever arm. The beam rotation actuator is made of bimorph peizoelectric material. The dove prism is responsible for both high-resolution movement as well as multi-beam spot rotation. The dynamic equation of the beam rotation actuator is derived theoretically. The actuator is designed on the grounds of an analytical equation. It is shown that the beam rotation actuator has a natural frequency of 54 Hz or more, and the actuator has high-resolution. The application performance of the beam rotation actuator is verified as the feedback control is applied. (C) 2000 Published by Elsevier Science Ltd.