Distributed Digital Servo

Abstract

Optical disks manufactured by a continuous web process [1] are attractive from a cost point of view, in comparison with conventional injection molded disks, but require a more complex servo system implementation to deal with the more challenging characteristics of track distortions. A new servo system, Digital Distributed Servo (DDS), is proposed that deals effectively with these characteristics and of which the implementation has become attractive due to the strong progress over the last years in price/performance of DSP based integrated electronic systems. In addition DDS requires little disk overhead, has a long term potential for low cost drive implementation and has a natural growth path for disk capacity and drive performance.