Magneto-optical medium for reproducing information by the utilization of magnetic wall movement, and signal reproducing method
US5936915A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Sep 16, 2017 |
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 of which the magnetic wall moves and which contributes to reproduction, a third magnetic layer in which information is accumulated, and a second magnetic layer disposed between the first and third magnetic layers and having a lower Curie temperature than those of the first and third magnetic layers. The following is satisfied at the lowest temperature Ts whereat the exchange-coupling between the first and third magnetic layers is cut: EQU .vertline.k1*d.sigma.w1/dT.vertline.>2*Ms1*Hw1>.vertline.k2*d.sigma.w1/dT.v ertline. EQU .vertline.k1*d.sigma.w3/dT.vertline.<2*Ms3*Hw3 wherein T denotes temperature as represented by cgs unit system; .sigma.w1, Ms1 and Hw1 denote the magnetic wall energy density, saturation magnetization and magnetic wall coercivity, respectively, of the first magnetic layer as represented by cgs unit system; .sigma.rw3, Ms3, Hw3 denote the magnetic wall energy density, saturation magnetization and magnetic wall coercivity, respectively, of the third magnetic layer as represented by cgs unit system; and k1 and k2 denote, respectively, one and the other temperature gradient of the temperature profi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.