| 摘要 |
PURPOSE:To reduce data errors and to improve reliability of peeling strength by providing groups of fine pits smaller than a pit in a prepit area all over the surface of the data area of the recording film. CONSTITUTION:A track on the disk is divided into a servo area having prepits and a data area. The servo area consists of two pits 1, 2 staggered for the track, mirror part 3, one pit 4 on the center of the track, and other pits. The pits 1, 2 are used for tracking servo, the mirror part 3 is for focusing, and the pit 4 is for extraction of reproducing clock signal. Each pit in the data area is elliptic, 0.1mum long in the tangential direction of the track and 0.5mum long in the radial direction of the disk. By providing groups of these protective pits, an effect of absorbing increase of pressure in the medium on recording is obtained, and movement of the recording film is suppressed. |
