Optical magnetic disk with separate regions provided on it
US5247495A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1991 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | Feb 20, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10528
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magneto-optical disc according to the present invention has separate regions located between mutually adjacent recording tracks. In the separate regions, magneto-optical signals are impossible to record or smaller than the recording tracks. Therefore, it is possible to maintain a low erasing power that is constant even when conditions such as off-tracking, defocusing and changes of operating temperature occur. The present invention provides a magneto-optical disc, further, which in a light modulating system restricts the recording domain so as to improve the number of times the disc can be rewritten, providing a magneto-optical disk that is highly compatible with different drives. Further, the magneto-optical disk according to the present invention is provided such that a residual signal is not caused if recording power during overwriting is lower than the previous recording power in a magnetic modulating system, further improving compatibility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.