| 摘要 |
PURPOSE:To increase possible repetition times of recording and erasing by providing a 1st and a 2nd protective layer, each having higher melting point than a recording layer, and providing a reflecting layer which reflects light coming from the recording layer to the recording layer again. CONSTITUTION:The medium consists of the recording layer 3, first and second protective layers 2, 4 provided on and under the recording layer, respectively, each having higher melting point than the recording layer 3, and the reflecting layer 5 formed on the second protective layer 4 to reflect light which has trans mitted through the recording layer 3 to the recording layer 3 again. The record ing layer 3 has such properties that it becomes in the first solid state by raising the temp. of the layer with light irradiation to cause absorption of energy, melting and then rapidly cooling, and that it becomes in the second solid state by heating the first solid state and gradually cooling. Moreover, the recording layer features that its reflectance in the first solid state differs from that in the second solid state. The temp. of the recording layer 3 is maintained almost same (within 20K variation) for any film thickness. Thereby, repeatable cycles of recording and erasing of this medium can be significantly improved. |
