| 摘要 |
PURPOSE:To obtain a member for optical information recording, reproducing, and erasing having excellent performance by forming two-layer dielectric layer between a disk substrate and recording thin film, and providing dielectric layers having larger thermal conductivity on both sides of the recording thin film. CONSTITUTION:There are successively formed a first dielectric layer 2, second thin dielectric layer 4, recording thin film 3, third dielectric layer 5, and reflecting layer 6 to constitute the member for information recording and erasing by thermally changing the state of the thin film with irradiation of laser light 9. The second thin dielectric layer 4 and third dielectric layer 5 are made of the same material, different from the material of the first dielectric layer 2. The thermal conductivity of the second and third dielectric layers 4, 5 are made larger than that of the first dielectric layer 2. By this method, dielectric layers of larger thermal conductivity are provided on both sides of the recording thin film, and thereby, cooling rate on recording and erasing can be decreased. Moreover, thermal shock caused by repetition of recording and erasing can be decreased, which improves cycle characteristics of the medium. |
