Optically modulated overwritable recording device
US5475666A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 1993 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Mar 3, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10506
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A recording device for recording information upon optically modulated overwritable magneto-optical recording medium including four magnetic layers first records DC "1" and then a test signal at high and low recording laser power levels upon a test track of the recording medium. The high and low recording laser power levels are successively modified to scan a two-dimensional region of the high and low recording laser power levels, and the optimal high and low recording laser power levels are determined on the basis of the reproduction signal levels corresponding to respective combination of high and low recording laser power levers. The reproduction signal levels are represented upon the .alpha.-K plane which is divided into six characteristic regions, The optimal combination of high and low recording laser power levels is determined as a representative point within the region of correct reproduction with a predetermined allowance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.