정밀근접구동과 조동기능이 결합된 일체형 광디스크 액츄에이터

Abstract

In optical disc system, a tracking system consists of a coarse actuator and a fine tracking actuator. This, 2-stage actuator, requires many devices in order to obtain large stroke and precisional displacement. Moreover, the moving parts become heavy because of the complicated configuration. In this paper, one dimensional new tracking actuator which combines fine tracking actuator with coarse actuator is designed and constructed. The system design is carried out as followings: Firstly, the Voice Coil Motor is used as a basic drive mechanism. The permeance method is used to analyze and to design VCM for large driving force. And it is proved experimentally by gauss meter instrument that magnetic flux density which is solved by permeance method analytically is right value. Secondly, the focus spring is designed with relation to the stability and characteristic of system. Thirdly, since friction is the dominant error source, the friction identification is carried out. After the actuator is constructed based on above design method, PD control is applied. It results in below ±0.1μm error resolution.