Opto-magnetic recording medium with a garnet ferrite recording layer, and opto-magnetic information recording/reproducing device
US6759137B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 2000 |
| Grant date | Jul 6, 2004 |
| Priority date | — |
| Expiry date | Apr 21, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magneto-optical recording media. The magneto-optical recording medium of the present invention has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. The manufacturing method of the present invention comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer. In the magneto-optical recording and playback device to record and play back data of the present invention, the wavelength of light for recording data is different from that for reading data, which is preferable for a magneto-optical recording medium comprising a garnet ferrite layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.