Optical disk.

摘要

A high density optical disk having data tracks and pre-grooves disposed in a track pitch not higher than 1.2 mu m provides groove signals to a disk drive having a two-divided optical detector for tracking control. The groove signal characteristics of the optical disk is such that an envelope cross-track signal, an envelope cross-track minimum signal and an envelope push-pull signal are not less than 0.10, not less than 0.12 and between 0.10 and 0.70, respectively, when normalized by a virtual mirror surface. The optical disk may be any of a magneto-optical (MO) disk, a ROM disk and a partial ROM disk and can provide any type of disk drives with sufficient groove signals for tracking control in both a magneto-optical area and a ROM area.