DISC MEDIUM WITH LOCATION RESOLUTION IMPROVED LABEL SIDE, AND METHOD AND APPARATUS FOR READING PATTERNS FORMED ON THE DISC MEDIA

摘要

A disk medium for improving location resolution on a label surface, and a method and a device for reading patterns formed on the disk medium are provided to enhance the location resolution of the disk medium in case of light scribing, thus a desired picture of a user is more precisely and smoothly printed on a label surface on an outer circumferential side of a disk. A disk recording medium is equipped with a speed control feature zone on the inner circumference of a label surface. The feature zone has 2 divided bands on inner and outer circumferential sides, and periodic patterns formed on each divided band are distorted from periodic patterns of neighboring divided bands as pi/2 or pi in phase so as to generate the twice larger number of pulses than a single-shaped pattern while the disk medium is rotated one time.