Fast-Access Optical Drive

A slim-line linear motor is presented for fast access in optical drives. By applying a three-phase commuting linear motor in combination with a split-optical head, an average seek time of 11 ms is realised for a 120-mm optical disc. The rotational latency is reduced by spinning the disc at 100 Hz, resulting in a total average access time of 25 ms. Two-stage radial tracking is applied, along with a one-dimensional lens actuator to attain high mechanical bandwidths. In addition, a novel scheme for counting tracks during high-speed access is proposed.