| 摘要 |
PURPOSE:To considerably improve C/N by holding the variance of depth of tracking guide grooves within + or -10% of an average groove depth. CONSTITUTION:With respect to an optical disk which is used as a video disk, a compact disk, or a file memory disk for office and is expected as a memory disk for computer, tracking guide grooves and a recording layer are provided on a transparent substrate, and the variance of depth of tracking guide grooves is held within + or -10% of the average groove depth. It is convenient if the recording layer of the optical disk is a magneto-optical recording layer, and it is preferable that the magneto-optical recording layer is a vertical magnetized magnetic layer consisting of a rare earth transition metal alloy. Thus, a disk for information of good C/N is obtained. |
