| 摘要 |
<p>PURPOSE:To double increase recording capacity without improving recording density and to prevent recording information from being altered by alternatively laminating plural magnetic recording layers, whose coercive force is different, and plural magnetic transferring layers, whose coercive force is smaller than that of any magnetic recording layer, on a magnetic card substrate. CONSTITUTION:First and second magnetic recording layers 10 and 11, whose coercive force is different, and first-third magnetic transferring layers 7, 8 and 9, whose coercive force is smaller than that of the respective recording layers 10 and 11, are alternatively laminated on a substrate 6 of a multi-layer magnetic card 5 and the coercive force of the recording layer 10 is made larger than that of the recording layer 11. When the information are recorded and reproduced on the card 5, at first, information A are recorded on the recording layer 10 by a ring-shaped magnetic head and next, the recording current of the head is adjusted. Then, information B are recorded on the recording layer 11 without erasing the information recorded on the recording layer 10. Next, an alternative current magnetic field is generated in the head and passed through under the head. Then, the information A and B, which are recorded on the recording layers 10 and 11, are transferred to the transferring layers 7, 8 and 9.</p> |
