Optical recording medium and its recording method
US6071587A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1998 |
| Grant date | Jun 6, 2000 |
| Priority date | — |
| Expiry date | Sep 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording medium of phase change type which exhibits an increased number of overwritable operations is provided. The optical recording medium comprises a substrate, and a first dielectric layer, a recording layer, a second dielectric layer, and a metal reflective layer disposed on the substrate in this order, and the first dielectric layer comprises a dielectric layer 1a on the side of the substrate and a dielectric layer 1b in contact with the recording layer. The dielectric layer 1a comprises ZnS--SiO.sub.2, and the dielectric layer 1b comprises Si.sub.3 N.sub.4 and/or Ge.sub.3 N.sub.4. The second dielectric layer may comprise a single layer of ZnS--SiO.sub.2, SiO.sub.2 or oxide of a rare earth metal. The second dielectric layer may also comprise a laminate of a dielectric layer 2a comprising ZnS--SiO.sub.2 on the side of the substrate and a dielectric layer 2b comprising SiO.sub.2 or oxide of a rare earth metal on the side of the reflective layer. The dielectric layer 1b has a thickness of 0.5 to 40 nm, and ratio of thickness of the dielectric layer 1b to the thickness of the first dielectric layer is up to 0.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.