APPARATUS FOR PRODUCING MASTER DISK FOR OPTICAL DISK, PRODUCTION OF MASTER DISK FOR OPTICAL DISK, DEVICE FOR FORMING OPTICAL DISK, METHOD FOR FORMING OPTICAL DISK, AND OPTICAL DISK REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To enable the sure reproducing of addresses both at the time of reproduction of grooves and at the time of reproduction of lands by forming the grooves of a prescribed width on a master disk and forming header parts by prescribed pits. ;SOLUTION: A stamper is formed by using a glass master disk and an optical disk (RAM) 51 on which data are to be recorded in the grooves and the lands for recording and reproducing, is formed by using the stamper. The head parts of each recording area of the RAM 51 are composed of the plural pits and are preformatted for the grooves. The edges in the tangent direction of the disk on one side exist on the same line as the one side edge of the grooves and the edge on the other one side exist in the positions of the center lines of the lands in the form protruding to the lands. The pits of the head parts are asymmetrical with the center lines of the grooves. The output signals of adders 26c, 26d are supplied to a land/groove discrimination circuit 40. The circuit 40 discriminates whether the reproducing beam corresponds to the lands or grooves or not by the respective added outputs.;COPYRIGHT: (C)1998,JPO