| 摘要 |
<p>PURPOSE:To exactly discriminate that the magnetic card is dubbed one when this card is dubbed by contact magnetic transfer by a discriminating method which detects the reproduced output at the longitudinal end of the magnetic card, then subject the card to DC magnetization so as to invert the magnetization direction of its upper less coercive magnetic layer, detects the reproduced output mentioned above and compares the reproduced outputs before and after the inversion. CONSTITUTION:This magnetic card is constituted by successively laminating a lower magnetic layer and the upper magnetic layer from a nonmagnetic base side. The coercive force of the upper magnetic layer is smaller than the coercive force of the lower magnetic layer and the magnetization directions of the upper magnetic layer and the lower magnetic layer are the same. In addition, the range of the coercive force of the lower magnetic layer is in a 1000 to 40000e range.</p> |
