Magneto-optic recording medium
US4412264A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1980 |
| Grant date | Oct 25, 1983 |
| Priority date | — |
| Expiry date | Oct 17, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C13/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is a magneto-optic recording medium to which magnetic Kerr effect is applied and characterized by the tracking guide on an even surface free from disorder of linear polarization. Since the tracking guide may be any type if it has a different reflection characteristic from that of the memory area viewing from magneto-optic standpoint, the tracking guide can be produced by a thermal treatment for changing the magnetic property of a part of a thin film with its magnetization easy axis in the direction perpendicular to the film surface. As no difference exists between the memory area and the guide area other than their magnetic properties, they are on the same plane and have no unevenness between their surfaces. Where, the guide area is assumed to have such magnetic property as the magnetization easy axis is parallel to the film surface, or it is perpendicular to the film surface but has no rectangular hysterisis. Such change of magnetic property can be obtained easily by an irradiation of laser beam to an amorphous alloy thin film with perpendicular magnetization easy axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.