Objective lens, optical pickup device, and optical recording/reproducing apparatus
US8345356B2 · kind B2 · utility
0Cited by
3References
10Claims
0Family size
Assignee
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Key dates
| Filing date | May 15, 2009 |
| Grant date | Jan 1, 2013 |
| Priority date | — |
| Expiry date | Feb 27, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1374
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An objective lens for converging light emitted from a light source onto an optical recording medium to record and reproduce information consists of a single lens that has at least one aspheric surface. The following conditional expressions (1) and (2) are satisfied:−0.90<R1/R2<−0.45 (1)0.70<d/f<1.40 (2)where R1 denotes a radius of curvature (mm) of a light source side surface near an optical axis,
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.