Optical pickup with improved collimating lens for use with long and short wavelength laser beams
US7120109B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2000 |
| Grant date | Oct 10, 2006 |
| Priority date | — |
| Expiry date | Oct 6, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/13922
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup capable of effectively reducing chromatic aberration that includes a collimating lens, which includes a diverging lens with diverging power and a focusing lens with focusing power, arranged on the optical path between a light source and an objective lens, wherein assuming that the total focal length of the collimating lens is f and the focal length of the diverging lens is fn, the collimating lens satisfies the relationship −1.5>f/fn. The optical pickup is compatible with both existing digital versatile disks (DVDs), and high-definition (HD)-DVDs, which will not yet standardized, need a blue light source near 405 nm and an objective lens having an numerical aperture of 0.6 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.