Multi-focus objective lens, optical pickup apparatus and optical information recording reproducing apparatus
US7463570B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2005 |
| Grant date | Dec 9, 2008 |
| Priority date | — |
| Expiry date | May 19, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/13727
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multi-focal objective lens for use in an optical pickup apparatus for recording and/or reproducing information using a first light flux with a wavelength λ1 on a first and second optical discs, includes a first optical surface including a first diffractive structure. The multi-focal objective lens converges a diffracted light flux with one of the m-th diffraction order and the n-th diffraction order on an information recording surface of the first optical disc for recording and/or reproducing information of the first optical disc, and converges a diffracted light flux with another of the m-th diffraction order and the n-th diffraction order on an information recording surface of the second optical disc for recording and/or reproducing information of the second optical disc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.