| 摘要 |
PURPOSE:To reduce the check time of the two sides of the medium, the readout of information and the initializing time and to attain high speed processing, by writing or reading in/from both front and rear sides of a medium where two recording layers are placed closely. CONSTITUTION:Reading and writing circuits 11, 12 are provided to heads 3 and 5 respectively. Since the write is performed with the two heads 3, 5 from both front and rear sides at the same time, the magnetic flux 14 from each head is generated from both the sides at the same time. Even if the flux at the front side reaches a magnetic layer 9 of the rear side, the flux at the rear side is dominant, and even if the flux 14 reaches the head 3 or the magnetic layer 7 at the front side and the erasure and write are duplicated, since the magnetic flux of the head 3 is dominant for the write, the effect from the head is cancelled for the write, allowing to perform the write, initialization, certification and readout for both the sides at the same time. |
