Magneto-optical recording media having an auxiliary magnetic layer
US6424601B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 16, 1998 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Nov 16, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10593
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magneto-optical recording medium 11 has, in order from the laser irradiation side, a second auxiliary magnetic film 4, first auxiliary magnetic film 5, and magneto-optical recording film 6. First and second auxiliary magnetic films 4 and 5 change from in-plane magnetization to perpendicular magnetization when their respective critical temperatures TCR1 and TCR2 are exceeded. The Curie temperatures TC0, TC1 and TC2 of the magneto-optical recording film and the first and the second auxiliary magnetic films 4, 5 and their critical temperatures TCR1 and TCR2 satisfy the relationship: room temperature<TCR2<TCR1<TC0, TC1,TC2. The first auxiliary magnetic layer has a film thickness greater than the thickness of the magnetic wall. In response to irradiation by the reproducing light beam, recording magnetic domain 22 of magneto-optical recording film 6 is transferred, with size reduction, to first auxiliary magnetic film 5 and is then transferred, with magnification, to second auxiliary magnetic film 4. This is ideal for reproduction of a high-density recording medium since an amplified reproduction signal is obtained from magnified magnetic domains 23.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.