OPTICAL DISK HAVING VARIABLE MARGIN AREA RATIO AND METHOD FOR VARIABLY SETTING MARGIN AREA RATIO ON OPTICAL DISK

摘要

PROBLEM TO BE SOLVED: To minimize a ratio of fault occurrence and to reduce a defect disk by variably setting margin area ratios arranged in respective zones answering to nonuniformity in a recording characteristic of an optical disk. ;SOLUTION: Many margin areas are provided on the inner peripheral part and the outer peripheral part of the disk, and less margin areas are provided on the relatively stable central part. For instance, the whole is divided to 23 pieces of zones, and the margin area ratios are set so that the zone 0 becomes 10.73%, the zone 1 10.75%, the zones 2 and 3 8.06%, the zones 4, 5 5.37% the zones 6, 7 2.68%, the zones 8-12 2.69%, the zones 13-15 2.68%, the zones 16, 17 2.69%, the zones 18, 19 5.37%, the zone 20 8.06%, the one 21 8.05%, the zone 22 10.74% and the zone 23 becomes 10.73%. Although the whole mean is 5.37%, and is set to the same as the disk with existing fixed ratio, it is changeable according to progress of a manufacturing process without being limited to this.;COPYRIGHT: (C)1999,JPO