Optical recording disk, and recording/reading apparatus using same
US5422874A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Sep 9, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/261
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a magneto-optical recording medium, in which are provided at least a reading layer and a writing layer on a substrate. A track guide groove is formed in the medium so as to include in-groove portions and on-land portions. Pits are formed on a portion along the track longitudinally adjacent where an in-groove portion and where no guide groove exists. Pits are also formed in an on-land portion between the in-groove portions of the track guide groove. Only a portion where a temperature has been raised by optical beam irradiation is read, while a domain of a writing layer is copied on the writing layer, whereby a writing/reading operation can be effected with narrower track pitches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.