| 摘要 |
PURPOSE:To obtain an optical recording medium in which a RAM part in which a user can record, reproduce and erase and a ROM part in which the user can only reproduce by utilizing the difference of a recording temperature. CONSTITUTION:A magneto-optic disk 2A has a RAM part 4a at the inside and a ROM part 6a at the outside. The part 4a has an SiN dielectric layer 10, a TbFeCo recording layer 12, an SiN dielectric layer 14, and an Al reflecting film 16 sequentially laminated on a polycarbonate board 8. The part 6a uses a TbCo recording layer 18, and the other structure is the same as the part 4a. The layer 12 of the RAM 14 has a Curie temperature of 190 deg.C, and the layer 18 of the ROM 6a has a Curie temperature of 300 deg.C higher than the temperature which can be raised in a magneto-optic disk apparatus used by a user. A trader can record a desired software on the ROM area with a low-cost exclusive unit, and the user does not erase the purchased software even if the erroneously operated. When a protect program is previously charged in the software, the illegal copy can be prevented. |
