Objective optical element, optical pick-up apparatus, and optical information recording reproducing apparatus
US6856471B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2003 |
| Grant date | Feb 15, 2005 |
| Priority date | — |
| Expiry date | Jul 19, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An objective optical element for use in an optical pickup apparatus, includes an objective lens to converge the light flux emitted from the first and second light sources; and an optical functional surface including a common region and an exclusive region. When a first optical information medium is used, a sine condition unsatisfied-amount whose value is maximum exists on the common region. The following formula is satisfied:0.5≦COMA2/COMA1≦1.0where COMA1 is a coma aberration (λ1 rms) when a light flux goes slantingly to be incident with a view angle of 1° onto the objective optical element when the first optical information medium is used, and COMA2 is a coma aberration (λ2 rms) when a light flux goes slantingly to be incident with a view angle of 1° onto the objective optical element when the second optical information medium is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.