Optical pickup, optical information recording apparatus and optical information recording and reproducing apparatus using the optical pickup
US7990830B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 27, 2008 |
| Grant date | Aug 2, 2011 |
| Priority date | — |
| Expiry date | Oct 19, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1378
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In holographic recording, it is important to form stably an interference fringe between a reference beam and a signal beam in a holographic storage medium. To suppress factors degrading stability of the interference fringe, such as fluctuation of atmospheric air, position displacement of optical components and the like during propagation of the reference and signal beams, an optical pickup and an optical information recording/reproducing apparatus adopt an optical system structure providing a higher proportion of optical components shared by the reference and signal beams optical path than conventional optical system structure. To increase the proportion of shared optical components, the signal beam and the reference beam pass through the PBS prism as parallel beams and a concave lens is placed on a reference beam path just before the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.