Process for optically storing information using materials having a single phase in both the crystalline state and the amorphous state
US4787077A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1987 |
| Grant date | Nov 22, 1988 |
| Priority date | — |
| Expiry date | Aug 28, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical storage system has an information containing film of a material which has a crystallization temperature between 100.degree. C. and 400.degree. C. and can be switched between the amorphous and the crystalline states. Both the amorphous and crystalline states are substantially a single phase where the stoichiometric ratio of the material remains unchanged. Spots on the film is heated with a circular laser beam with a controlled pulse duration and intensity to melt the material in the spots. The spots are quenched at one rate to produce the amorphous state, and in a second revolution of the disk, at a different rate to produce the crystalline state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.