| 摘要 |
<p>PURPOSE:To prevent surely dishonest alteration and illegal use of a used magnetic card. CONSTITUTION:A magnetic recording layer 1 made of mixed material which contains at least binder, low Curie point magnetic recording material and heat foaming material is provided on a card substrate 2 made of polymer material to form a magnetic card. In the normal usage of the magnetic card, magnetic information is recorded and reproduced on and from the magnetic recording layer 1. After usage,the magnetic recording layer 1 is subjected to a heat treatment locally to make the heat foaming material in that local part foam and expand and a deformed magnetic recording layer 1' is formed. At that time, the magnetic characteristics in the magnetic recording layer 1 are substantially deteriorated by the existence of the deformed magnetic recording layer 1' and the magnetic information recorded on the deformed magnetic recording layer 1' vanishes. As a result, the recording and reproducing of magnetic information on and from the used magnetic card and the dishonest alteration and illegal use of the used magnetic card can be extremely difficult.</p> |
