| 摘要 |
PURPOSE: To obtain a high forger prevention effect by recording information by successively laminating a metallic thin film layer, an infrared-ray absorption layer and a transparent protective layer on a medium base material and melting the metallic thin film layer. CONSTITUTION: A magnetic card MC is composed by successively laminating a metallic thin film layer 2, an infrared-ray absorption layer 3, a hiding layer 4, a transparent protective layer 5 and a magnetic recording part 6 on the one surface of medium base material 1. On the metallic thin film layer 2, a data recording pattern 7 and a clock recording pattern 8 for synchronization are formed by the irradiation with a thermal beam such as laser beam, etc., in accordance with a prescribed information pattern. In this case, laser beam is collected on the infrared-ray absorption layer 3 from the side of the transparent layer 5 for the wavelength of the laser of the magnetic card MC. As a result, a recording is performed because the laser beam projected on this infrared-ray absorption layer 3 is absorbed in the infrared ray absorption exothermic agent contained in the infrared-ray absorption layer 3, light energy is converted into heat energy and the metallic thin film layer 2 is melt due to this heat. |
