Optical element and optical pickup device
US7986604B2 · kind B2 · utility
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11Claims
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Key dates
| Filing date | Dec 6, 2007 |
| Grant date | Jul 26, 2011 |
| Priority date | — |
| Expiry date | Nov 21, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An objective lens causes birefringence, which causes wave aberration in outgoing light from the objective lens. A coated objective lens has a dielectric multilayer film that can reduce astigmatism component of the wave aberration to 5 mλ rms or smaller when 10 mλ rms or larger astigmatism component of wave aberration is generated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.