Optical pickup for recording/reproducing optical discs of multiple thicknesses
US6590851B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 2000 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | May 20, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/13727
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup including: first and second light sources for generating first and second laser beams having different wavelengths corresponding to first and second media having different thicknesses, respectively; an objective lens that has diverging and converging/focusing portions, to focus the first and second laser beams from the first and second light sources onto the first and second media, respectively; a photodetector to receive the first and second laser beams that are emitted from the first and second light sources and reflected, respectively, by the first and second media; and a collimating lens arranged on the optical path between the objective lens, and the first and second light sources. The optical pickup is compatible with both existing digital versatile disks (DVDs), and high-definition (HD)-DVDs, which need a blue light source near 405 nm and an objective lens that has a numerical aperture of 0.6 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.