| 摘要 |
<p>A system comprises a magnetic recording medium, a writing device, and a reading device. The magnetic recording medium has a heat-treated part (5) obtained by magnetizing a magnetic layer (2) and whose surface is covered with an opaque coating layer (3) not changeable by heating. The writing device is provided with a means for forming heat-treated marks (6) having a magnetic characteristic changed by heating in the heat-treated part (5) in a predetermined pattern. The reading device reads magnetically the information written on the magnetic recording medium by the writing device. By such a configuration, the information recorded on the medium is not easily altered, and the medium is not easily forged. Also, since the pattern of the heat-treated marks (6) can be read out by a magnetic means, there is no necessity for adding a sensing means and the cost of configuring the system can be reduced.</p> |
