Protective layer for optical information recording medium
US4847132A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Oct 15, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/259
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A protective layer which is applied to rewritable optical information recording medium comprising a substrate and a photosensitive thin film. When exposed to optical energy, the thin layer is capable of undergoing a reversible phase change by which an optical reflectivity is changed between two states. The protective layer is inhibiting the thermal damages of the substrate during light irradiation and also controlling thermal and optical boundary conditions. The protective layer is made of the mixture of mutually solid insoluble materials. The typical choice of the mixture of small crystalline grains of ZnS and noncrystalline SiO.sub.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.