Development of the Actuator for Super Compact Optical Pickup

The authors report development of an actuator for use in thin optical pickups for compact disk players. To achieve smooth, reliable operation when stood upright as well as when laid flat, a sliding actuator design was chosen over a spring-supported mechanism. The design was based on analyses of the transfer characteristics, proper frequency of vibration of the bobbin and other factors. Basic performance of the actuator are described, including sensitivity, field characteristics and smoothness of operation, and measures taken to improve the sliding action of shaft and sleeve are explained. The optical pickup is thin (13.2 mm), highly reliable, and operates satisfactorily whether laid flat or stood upright.