METHOD FOR IMPROVED FOCUSING CONTROL IN AN OPTICAL MEMORY SYSTEM

摘要

A preformatted optical recording disk for use in an optical data storage system in which a laser beam of predetermined frequency is focused on the disk. The disk comprises a substrate having reflective, dielectric and absorbing layers deposited in a manner so as to establish an anti-reflection condition for an incident laser beam. The disk is preformatted by recording optical holes in the absorbing layer so as to form one or more tracks wherein each track includes a plurality of headers positioned at predetermined locations along the track. Each header comprises a plurality of optical holes constructed and arranged so as to constitute predetermined embedded timing, track following and focusing data on the disk for use by an optical data storage system.