Magneto-optical recording medium having a plurality of magnetic layers
US6061307A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1996 |
| Grant date | May 9, 2000 |
| Priority date | — |
| Expiry date | Nov 8, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10595
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
On a surface of a transparent substrate 1 having a preformat pattern 2 formed thereon are laminated a first recording layer 4 in which a recording state exists in one different magnetic field region of an applied external magnetic field and a second recording layer 6 in which two recording states exist in magnetic field regions different from that for the first recording layer. As required, dielectric layers 3, 5 and 7, a reflecting layer 8 and a protection layer 9 can be laminated. The 4-valued recording of information becomes possible by assigning information signals "1", "0", "3" and "2" to H.sub.0, H.sub.1, H.sub.2 and H.sub.3, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.