Magneto-optical recording medium, recording and playback method and apparatus for the same
US5473583A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1994 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Nov 23, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/182
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetooptical recording medium having a higher recording density, improved bit error rate and superior weather resistance and a recording and playback method for the same are provided. The magnetooptical recording medium has a first magnetooptical layer having a high Curie temperature a second perpendicularly magnetizable magnetooptical layer having a low Curie temperature and a third perpendicularly magnetizable magnetooptical layer having an intermediate Curie temperature set between the Curie temperatures of the first and second magnetooptical layers, laminated in this order on a substrate. The first, second and third magnetooptical layers are formed respectively of amorphous alloys containing GdFeCo, TbFeTi and TbFeCoTi as the main component thereof. The first, second and third magnetooptical layers are exchange-coupled at 10.degree. C. to 90.degree. C., and the first and third magnetooptical layers are not magnetostatically coupled in the external magnetic field for reading use at the temperature at which the magnetization of the second magnetooptical layer is diminished.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.