Rewritable optical disk comprises recording area divided into groups by annular boundaries with spare area with sectors to be allocated in place of defective sections

摘要

The disk recording area is divided into groups by annular boundaries, each group has a spare area with sectors to be allocated in place of defective sections. The number of sectors per track differ from one group to another. - DETAILED DESCRIPTION - Several radially innermost and outermost tracks of a zone are guard areas not used for recording or reproducing data. A control data area, holding information to control recording/reproduction, is provided at the radially innermost read-only area. In the rewritable areas inside the radially innermost zone and outside the radially outermost zone are defect management areas (DMAs) that hold information needed to control replacement of defective sectors. Two DMAs are on the radially inward side and two on the radially outward side. - The control data contains information on the number, sizes and start positions of the DMAs. The start position of the control data area is always at the same position regardless of the disk recording capacity. The sizes of spare areas are specified at initialization of the optical disk by the disk processing apparatus. The sizes or first addresses of the spare areas are recorded in the defect management areas. The position of the spare area used in place of a defective sector and the defective sector position are managed by a defect list in a DMA.