| 摘要 |
PURPOSE:To contrive to decrease the number of heads by erasing in parallel recording areas of the inside and the outside of a disk by two heads at the time of recording, changing the head after the erasion and recording a signal in parallel. CONSTITUTION:Recording track erasion processings of recording areas 32, 34 of the inside and the outside of a magneto-optical disk 1 are executed in parallel. As for the area 32, since a downward external magnetic field by a permanent magnet 20 in a permanent magnet group 15B is utilized, the processing is executed by radiating a laser beam from a head 30. On the other hand, as for the outside recording area 34, since a downward external magnetic field by a permanent magnet 18 of a permanent magnet group 15A is made uniform in the magnetization direction, the processing is executed by radiating a laser beam from a head 26. When the erasing operation is ended, recording is executed by executing a tracking control so that the head 26 brings an erasing track of the area 32 to tracking control and the head 30 traces an erasing track of the area 34. The reproducing operation is executed by tracing a laser beam simultaneously to recording tracks of the area 32 and the area 34 by the head 26 and the head 30, respectively. |
