Solid immersion mirror type objective lens and optical pickup device adopting the same
US6801492B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2001 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Apr 3, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/13725
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A solid immersion mirror (SIM) type objective lens and an optical pickup employing the same. The objective lens has a first curved surface which condenses incident light and a second curved surface surrounding the first curved surface which diverges incident light. A second transmission surface disposed to face the first transmission surface has an area which transmits incident light and a first reflection surface surrounding the second transmission surface which reflects incident light. A second reflection surface which surrounds the second curved reflects incident light. The objective lens realizes an NA of 0.7 or more with a single lens; has a working distance enabling far field recording/reproducing; has a smaller blocking area than that of the conventional SIM; and generates a smaller amount of side lobe. Where the objective lens is adopted in an optical pickup device, generation of jitter during reproduction or cross erasure during recording is minimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.