| 摘要 |
PURPOSE:To prevent the copying variance by securing the coincidence between the center of a master medium and that of a slave medium with use of a means which prescribes the outer circumferences of those media. CONSTITUTION:A floppy disk 2 serving as a slave medium is put on a disk- shaped master medium having the same diameter as the disk 2. The hub holes 3a and 3b of the disk 2 are fitted at a center spindle 1c and a driving spindle 1d provided at a recess part 1b of a tray 1. Thus the disk 2 is put on the tray 1 and a disk-shaped master medium 100 is put on the disk 2. These disk media 9 and 10 fixed with pressure to the tray 1 via press-contact rings 4 and 5. Then the transfer magnetic fields are applied to both media 9 and 10 via magnetic field coils 6 and 7. Thus the magnetic information on both media 9 and 10 are simultaneously transferred magnetically on both sides of the disk 2. In this case both master media 9 and 10 are pressed repetitively to each other and therefore the thickness of each of both media 9 and 10 is increased compared with that of the disk 2. In such a way, the center variance is prevented among those disk 2 and both media 9 and 10 respectively.
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