The development of digital servo algorithms for optical disc players

A kick algorithm for tracking control and an automatic gain adjustment algorithm have been developed for optical disc players. The kick algorithm showed precise accessibility, which will lead to fewer access trials. As a consequence, faster access can be expected. Experimental results on the automatic gain adjustment system showed that the gain error at gain-crossover frequency was within ±1 dB, and the adjusting time was 0.2 second on the average. This system has the possibility of optimal adjustment for each disc. These functions can easily be implemented in the digital servo system by the use of LSIs