Improvement of Dynamic Characteristics for Symmetric-Type Slim Optical Pickup Actuator by Changing Coil Shape

As rotational speed and track density of disk media in optical disk drives increases, an optical pickup actuator must have a high servo bandwidth for its focusing and tracking control to follow disk fluctuations. In this paper, we propose an efficient method to improve control bandwidth of actuators through changing the shape of cross section of coils without redesigning structural parts