| 摘要 |
PURPOSE:To prevent the decrease in the data processing efficiency of an optical disk whose data write reliability is not sufficient by using properly a normal recording area and an alternate area wherein data is recorded as a substitute for a defective block in a recording area succeeding to the normal recording area. CONSTITUTION:A lateral axis is a time base and shows the appearance of indexes I1 and I2 detected periodically according to the rotation of the disk. Further, the timing signal S1 of switching between writing operation W and reading operation R, timing signal S2 of switching between buffer memories M1 and M2, and timing signal S3 of switching for jumping a head from a track being accessed to its adjacent outside track are used to perform the data writing operation and reading and checking operation repeatedly on the optical disk. The writing operation starts at a track TN to write data from the buffer memory M1 in respective data blocks in the normal area during a period t0, and when the index I2 is detected, jump to an outside track is made with the timing signal S3 to perform switching to the reading operation. |
