| 摘要 |
PROBLEM TO BE SOLVED: To eliminate relative positional deviation of optical heads that conduct plural divided recordings and to stably conduct recording and reproducing operations by registering a total sum of defective sectors detected in the defect inspection of each recording region as defective sector control information of each recording surface and not registering a defective sector, slipping it and successively registering a next sector. SOLUTION: An inspection of the entire surface of a disk is beforehand conducted during a formating or a disk delivery. When the data of a recording and a reproducing do not agree with each other, it is discriminated that a defect exists in a sector and a defective sector number is written into a control region of the disk. The disk control information, that contains the defective sector information recorded in every recording surface, is read before a user recording and defective sector tnformation of every recording surface is summed. A defect information control circuit 9 replaces the summed up defective sectors with the defective sector information of two recording surfaces, the total sum of defective sectors is set to the defective sector of respective recording surfaces, slipped and reproduced. |
