A magneto-optical recording system including a recording medium having a reversal preventive layer for preventing a magnetization reversal of a bias layer which is magnetostatically coupled to a recording layer
US5412627A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1993 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | May 14, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10586
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Light beams having two different power levels are radiated on a magneto-optical medium having a recording layer and a bias layer magnetostatically coupled to the recording layer, thereby recording and erasing information. Upon radiation of a high level beam, a beam irradiated portion of the recording layer is heated to reach a magnetization reversal temperature, and the direction of magnetization of the irradiated portion follows a direction of a leakage field generated by a magnetization distribution formed by heating of the bias layer. Upon radiation of a low level beam, a beam irradiated portion of the recording layer is heated to reach a magnetization reversal temperature to cause the bias layer to generate a leakage field having a magnitude smaller than that upon radiation of the high level beam. In this case, the direction of magnetization of the recording layer is opposite to that of the leakage field obtained upon radiation of the high level beam. The directions of magnetization of the bias layer are kept unchanged before and after the radiation of the high level beam and before and after the radiation of the low level beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.