Aberration correction element and optical pickup adopting the same
US6853614B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2001 |
| Grant date | Feb 8, 2005 |
| Priority date | — |
| Expiry date | Sep 9, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup includes an aberration correction element to correct chromatic aberration caused by variation of power from a light source when changing between operating modes in a recording medium. The aberration correction includes a first retardation member, which includes a stepped convex pattern with a plurality of steps at one side, and a second retardation member combined with the first retardation member. The second retardation member includes a stepped concave pattern with a plurality of steps at one side facing the first retardation member, the stepped concave pattern corresponding to the stepped convex pattern. The first and the second retardation members include different refractive indices for a light beam, which allows the first and the second retardation members to selectively create a phase difference of an incident light beam according to a polarization of the incident light beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.