High density optical information recording medium using high refractive index layer
US5878022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1997 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Sep 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/25716
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed are an optical information recording medium for recording, reproducing and erasing information by emitting laser light with a wavelength in vacuum of .lambda., which has: a transparent substrate through which the laser light can be transmitted; a high refractive-index layer which is formed on the transparent substrate; a guide groove for tracking which is formed on the high refractive-index layer; and a recording layer which is formed on the guide groove for tracking; wherein a width W of the guide groove for tracking and a refractive index n.sub.a of the high refractive-index layer are so set that the following relation: W>.lambda./(2xn.sub.a) is obtained, and an optical information recording medium for reproducing information by emitting laser light with a wavelength in vacuum of .lambda., which has: a transparent substrate through which the laser light can be transmitted; a high refractive-index layer which is formed on the transparent substrate; a concave-convex pit which is formed on the high refractive-index layer; and a reflection layer which is formed on the concave-convex pit; wherein a width W.sub.p of the concave-convex pit and a refractive index n.sub.a of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.