| 摘要 |
PURPOSE:To realize the maximum utilization of a recording area and to shorten an access time, by writing an alternate sector at the time of generating an error on a recording sector immediately behind a sector on which the said information is written. CONSTITUTION:When the error is generated in the information written previously, the generation of the error is detected 35, and an error flag is inserted 36 in the sector in which the said error is generated, and an alternate flag is inserted in the sector following the said sector. Next, a data signal (t) to be written on the sector in which the error is generated is written on the sector in which the alternate flag is inserted previously. Next, by scanning those sectors by a laser beam again, the error flag is read out by a detection circuit 31 and the alternate flag by a detection circuit 32, and furthermore, the presence/absence of the information written on the alternate sector is detected by a detection circuit 35.
|
