Thin protective overcoat layer for optical video disc
US4300143A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1979 |
| Grant date | Nov 10, 1981 |
| Priority date | — |
| Expiry date | Oct 22, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/162
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording medium comprises a light reflecting material which is coated with a light absorbing layer and overcoated with a thin, amorphous, coherent layer of an optically transparent and chemically and thermally stable material such as silicon dioxide. During recording, portions of the light absorbing layer are ablated by a modulated focussed light beam, thereby exposing portions of the reflecting layer while leaving the overcoat layer intact. Information is recorded in the form of a reflective-antireflective pattern. Dust particles and other surface contaminants can be wiped or washed off the recording medium without damage to the light absorbing layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.