Method and apparatus for recording and reproducing signal on and from optical information recording medium
US7729218B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 2006 |
| Grant date | Jun 1, 2010 |
| Priority date | — |
| Expiry date | Oct 24, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00557
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Test signals are recorded on a prescribed area in an optical disc. The prescribed area is scanned by a laser beam while the power of the laser beam is changed among different DC erasing values. The different DC erasing values are assigned to the recorded test signals, respectively. The recorded test signals are reproduced from the prescribed area to obtain reproduced signals. Parameter values of the respective reproduced signals are detected. The detected parameter values correspond to the different DC erasing values, respectively. Among the detected parameter values, a detected parameter value is decided which matches a target. One corresponding to the decided parameter value is selected from the different DC erasing values. A prescribed coefficient and the selected DC erasing value are multiplied to calculate an optimum level of an erasing power of the laser beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.