Magneto-optical recording device capable of reducing thermal interference between recording pits
US5602806A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Jun 28, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10595
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light intensity, direct overwrite, magneto-optical system generates signals such that, during the formation of a recording mark on an optical disk, a laser is driven a) at a pedestal power level, then b) at a quench power level for a first quench period t.sub.1, the quench power level being less than the pedestal power level, then c) at a write power level for a write period t.sub.2 whereby the reference bit becomes oriented in the writing direction, the write power level being greater than the pedestal power level, then d) at the quench power level for a second quench period t.sub.3, and then e) at the pedestal power level until the formation of another recording mark begins. The system is provided with a controller to determine optimal lengths of the quench periods t.sub.1 and t.sub.3, thereby reducing thermal interference between closely spaced recording marks. From sample recording marks, recorded with different quench periods t.sub.1 and t.sub.3, the controller calculates a "quality" value, such as bit error rate, jitter or figure of merit, then determines from the quality value the quench periods t.sub.1 and t.sub.3 which will produce the highest quality recording marks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.