| 摘要 |
PURPOSE:To produce a magnetic card which is not affected by external magnetic fields by forming a superconductor film on a magnetic material. CONSTITUTION:The magnetic material 2 is fixed by using a method such as coating. The superconductor film 3 is formed atop said material by coating or sputtering, dipping, etc., of a superconductor together with a thermoplastic resin after kneading. The infiltration of magnetic fluxes from the outside to the magnetic material 2 is prohibited by the complete diamagnetism of the superconductor film at ordinary temp. Since the superconductor film 3 exists in the magnetic field in the direction where the magnetic fluxes from the resin plate 1 side negative the external magnetic fields, the external magnetic fields hardly act on the magnetic material 2. The temp. of the superconductor film 3 is increased to the superconduction transition temp. or above by previously heating the magnetic head of a contact type, then reproduction is executed at the time of information reproduction. |
