Optical information recording medium
US5745475A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1997 |
| Grant date | Apr 28, 1998 |
| Priority date | — |
| Expiry date | Jun 27, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24085
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information recording medium includes: a substrate including a groove having a concave shape and a land having a convex shape adjacent to the groove; and a recording layer on the substrate, wherein the recording layer consists of a material which changes between a first state and a second state whose optical property is different from that of the first state, a first portion of the optical information recording medium including a portion in the first state of the recording layer having a first reflectance, and a second portion of the optical information recording medium including a region in the second state of the recording layer having a second reflectance which is different from the first reflectance, whereby information is recorded onto the groove and the land, and wherein a ratio of the first reflectance to the second reflectance, a phase of reflected light from the first portion and a phase of reflected light from the second portion are set such that at least one of an amplitude and a carrier to noise ratio (CNR) of a signal obtained by reproducing information from the groove is approximately identical to that from the land.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.