Optical disk apparatus
US6934226B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2002 |
| Grant date | Aug 23, 2005 |
| Priority date | — |
| Expiry date | Feb 23, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The quantity of spherical aberration correction is predetermined for each recording plane of an optical disk on which focusing control is performed. Before operating the focusing control, the quantity of spherical aberration to be corrected by an aberration correcting system is set based on an output signal from an aberration correction quantity switching device that corresponds to the type of the optical disk and the recording plane to be subjected to the focusing control. This makes it possible to perform stable focusing control on each recording plane of a multi-layer optical disk with high density by using an objecting lens having a large NA after spherical aberration has been corrected properly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.