High Speed Write Once Optical Memory using 130 mm Disk for Computer Use

Abstract

Fast data retrieval of the optical disk memory can be attributed to fast head accessing along with stable tracking and focusing servos and high speed decoding of error correcting code. To realize fast head access, an access control technique, with accurate position and speed information obtained from the disk surface and state observer, has been developed. A digitized servo circuit achieved a stable pull on the destination track after seek motion. By the above technique, less than 70 msec of the average access time was attained in a “full-height” sized optical disk drive. To realize high speed decoding, an error detection and correction processor with applied Eucl-idian algorithm has been developed. This paper describes the details of technology used to achieve the fast data retrieval.