| 摘要 |
<p>PURPOSE:To read/write information from/in a card like recording medium in capable of alteration by using materials which are modified from ferromagnetic materials to nonmagnetic materials by heating and materials which are modified from nonmagnetic materials to ferromagnetic materials with mechanical deformation. CONSTITUTION:Stripes of information recording parts made of a ferromagnetic martensitic austenitic stainless steel and an information recording part 4 made of a nonmagnetic austenitic steel are formed on a supporting body 5. Main information is recorded on the strip 2, and timing information is recorded on the stripe 3. The information recording part 4 is mechanically deformed in plural positions to form ferromagnetic parts 6, and positions and the number of them are controlled to the record information, and the information is read from them. The intensity of irradiation of a laser beam is controlled to form ternary information consisting of ferromagnetic part '2', halfway modified part '1', and overall modified part '0', and timing information is recorded on the information recording part by another laser beam at the time of issuing a medium 1. Main information is recorded on the information recording part 3 simultaneously with the recording of timing information. Magnetic modification cannot be discriminated from the external to keep the medium safe, and the device to accurately write/read the information is obtained.</p> |
