Optical system of optical pick-up
US6900949B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2004 |
| Grant date | May 31, 2005 |
| Priority date | — |
| Expiry date | Jan 22, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical system of an optical pick-up for a plurality of types of optical discs with a corresponding plurality of light sources. A first coupling lens that is used at least for the first optical disc, and an objective lens that is used for the plurality of types of optical discs. A beam for the first optical disc emitted by the plurality of light sources passes through the first coupling lens and is incident on the objective lens as a diverging beam. The diverging beam being given spherical aberration by the coupling lens. When the objective lens shift occurs, a coma component relating to the spherical aberration of the diverging beam which is shifted with respect to the objective lens due to the shift of the objective lens is canceled by a coma generated by the objective lens and the cover layer of the first optical disc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.