Phase-change optical disks and processes for preparing the same
US5641606A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 1995 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Sep 5, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a phase-change type optical disk comprising a transparent substrate; a recording layer arranged on the transparent substrate wherein a phase-change occurs between crystalline state and amorphous state according to laser power irradiation; and protective layers arranged on and directly under the recording layer; the composition of the recording layer being represented by the general formula (Sb.sub.a Te.sub.b Ge.sub.c).sub.100-d .cndot.S.sub.d, wherein 5.ltoreq.a.ltoreq.60, 35.ltoreq.b.ltoreq.65, 5.ltoreq.c.ltoreq.65, a+b+c=100 and 0<d.ltoreq.40, and/or one or both of the protective layers comprising a mixture of Zn.sub.(1-x) S.sub.x wherein 0.50<x and one or more oxides, nitrides, fluorides, carbides and sulfides of metals or semimetals (proviso provided that sulfides are excluded when the metal is Zinc). The optical disk of the present invention is improved in a cyclability, i.e., number of overwrite cycles and error correctable cycles, and reduces deterioration of recording marks due to long term reading.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.