Optical recording media objective lens and optical pickup device using it
US7298687B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 2004 |
| Grant date | Nov 20, 2007 |
| Priority date | — |
| Expiry date | Sep 26, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording media objective lens is disclosed for converging either of two working lights of a first wavelength or a second wavelength. The working light of the first wavelength is converged at a first numerical aperture onto the first optical recording medium and the working light of the second wavelength is converged at a second numerical aperture onto the second optical recording medium. An aperture adjusting zonal part is included on at least one of the objective lens surfaces for apparently eliminating light at the periphery of a light flux having a wavelength λ1 while maintaining light at the periphery of a light flux having a wavelength λ2, where λ1 is one of the first and second wavelengths and λ2 is the other wavelength. The aperture adjusting zonal part is formed so as to satisfy two conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.