Method of controlling focus of optical disk recording and reproducing device
US7512042B2 · kind B2 · utility
1Cited by
2References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 14, 2005 |
| Grant date | Mar 31, 2009 |
| Priority date | — |
| Expiry date | Mar 22, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an optical disk recording and reproducing device which uses an optical disk having at least a first recording layer and a second recording layer, a thickness of a spacer section between the first recording layer and the second recording layer is measured, an amount of defocus with respect to the second recording layer is set based on the measured spacer thickness, and a focus servo operation is performed for focusing the laser light irradiated from an optical pickup device on the second recording layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.