Patent ID: 6469979
Filing Date: 2002-10-22
Classification: G11B

Abstract:
A disk, comprising:a data area divided into sectors, each sector has a header comprising an address, each header has a first header and a second header which are recorded to deviate from a center of the track in opposite directions, and the first header and the second header have address areas in which address signals of the sectors are recorded and synchronous signal areas in which synchronous signals for detecting the address signals recorded in the address areas are recorded; wherein a first magnitude of the synchronous clock signal detected from the first header is Ivfo1 and a second magnitude of the synchronous clock signal detected from the second header is Ivfo3, the disk comprises pits corresponding to the synchronous signals of the first and second headers so that a ratio of the first magnitude Ivfo1 to the second magnitude Ivfo3 has a predetermined restricted value.