Optical information reproducing method, optical information reproducing device, and optical information recording medium
US7933179B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2008 |
| Grant date | Apr 26, 2011 |
| Priority date | — |
| Expiry date | Jul 14, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a super-resolution optical disk for the purpose of achieving an increase in the density of recording data by reproducing a recording mark smaller than optical resolution, the optimum reproduction power needs to be determined since the quality of a super-resolution reproduced signal strongly depends on the reproduction laser power. However, since the track error signal required for tracking servo also depends on the reproduction power, there is a need for a method for determining the reproduction power taking into account both the stabilization of tracking servo and a quality improvement of the reproduction signal. The reproduction power is changed under conditions with focusing servo applied but without application of tracking servo. Thereby, a cross track signal is detected to identify a reproduction power region that leads to quality improvement of both a reproduction signal and a track error signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.