Disk recording medium including data pre-formatted-data-recorded header having first and second identical address numbers radially displaced from each other on opposite sides of groove or land track center line, and disk drive unit for use with the recording medium

Abstract

A disk recording medium has reliability of address reading which is maintained equivalently to the conventional disk recording medium by recording a first address and a second address that are identical in a header area. By arranging the first and second addresses to be reversely displaced from the center line of a groove track or a land track to the radial direction of the medium, the distance between the first and second addresses when they are adjacent is increased, which eliminates the influence of crosstalk. This avoids redundancy of the header area and enables high-density recording to the disk recording medium.