Abstract
This research presents a novel design of the optical pickup head actuator for improving the performance deficiencies due to its heavy mass and large volume. Different from the pickup head of current optical disc drives, the coils and magnets are arranged along the axial direction for the purpose of space saving. The proposed prototype possesses the advantages, such as lighter, smaller, thinner, and less components. Furthermore, by integrating micro-electromechanical processes with electric circuits to produce much smaller actuators can meet the future trend of the optical storage technology because of their quasi-plane arrangement. This paper summarizes relative literatures and introduces working principles for the required performance of optical pickup head actuators. From conceptual design to prototype implementation, magnetic theories, such as equivalent magnetic circuit method, equivalent magnetic charge method, and equivalent current method are used to analyze the characteristics of the actuator. Finite element analysis software, ANSYS, is also applied to predict structural vibration. Finally, the dynamic characteristics of the actuator are tested by using a laser doppler vibrometer. In comparison with an existing optical pickup head, SPU3200, manufactured by Sankyo Seiki Mfg. Co., about one-third moving mass of the actuator is reduced. In addition, six and half times higher in stiffness, three and half times higher in open-loop bandwidth are achieved.