DATA RECORDING DEVICE AND RECORDING METHOD DATA REPRODUCING DEVICE AND REPRODUCING METHOD

PROBLEM TO BE SOLVED: To increase operation speed of change processing performed when a defective sector is detected and to enable recording data without using capacity uselessly, when data is recorded in an optical disk. SOLUTION: When data is recorded in an optical disk, recorded data is divided into blocks corresponding to integral multiple of sectors of an optical disk, an error correction code is added for each block, data to which an error correction code is added is recorded making a fragment having the prescribed size corresponding to integral multiple of a block as a unit detecting whether a defect exists in a sector to be recorded or not. And when a defective sector is detected during recording data in a fragment, rerecording data to be recorded in the sector is performed in the succeeding sector in the fragment.