Objective lens, optical element, optical pick-up apparatus and optical information recording and/or reproducing apparatus equipped therewith
US7872959B2 · kind B2 · utility
3Cited by
5References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2008 |
| Grant date | Jan 18, 2011 |
| Priority date | — |
| Expiry date | Jul 13, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/13727
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A hybrid objective lens has a refractive lens and a diffractive optical element constructed by plural coaxial ring-shaped zones on at least one optical surface thereof. When n1, n2 and n3 each is a diffraction order of a diffracted ray having a maximum light amount among diffracted rays of each of first, second and third light flux having wavelength λ1, λ2 and λ3 when respective light flux comes to be incident into the diffractive structure respectively, the following formulas are satisfied:|n1|>|n2|, and |n1|>|n3|, and
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.