Magneto-optical recording medium having multiple magnetic layers and reproducing method thereof
US6504797B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2000 |
| Grant date | Jan 7, 2003 |
| Priority date | — |
| Expiry date | Jan 25, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10586
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magneto-optical recording medium includes a first magnetic layer and a second magnetic layer. The first magnetic layer is an in-plane magnetized film at room temperature, but changes to a perpendicular magnetized film at a predetermined temperature higher than room temperature, and is thin enough to allow a light beam to pass through it. The second magnetic layer has perpendicular magnetic anisotropy and is arranged to allow magnetic coupling to the first magnetic layer when a light beam for reproduction comes from the first magnetic layer side. The rotation of the polarization plane of a light beam which is reflected off the first magnetic layer and the rotation of the polarization plane of the light beam which passed through the first magnetic layer and reflected off the second magnetic layer compensate each other, thereby canceling each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.