Holographic optical pickup device, optical information recording and reproducing device, and method of reproducing optical information, having angular variable element arrangements for changing a light angle
US8937855B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2013 |
| Grant date | Jan 20, 2015 |
| Priority date | — |
| Expiry date | Jun 19, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00772
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A holographic optical pickup device includes an optical axis split element for splitting a reference beam into two light beams in different propagation directions having polarized states substantially orthogonal to each other, angular variable elements for changing incident angle of the reference beam for irradiating an optical information recording medium, an image sensor for detecting a diffracted beam generated from a recorded region upon irradiation of the optical information recording medium with the reference beam to form a reproduction signal, and photodetectors for detecting the diffracted beam generated from the recorded region upon irradiation of the optical information recording medium with the reference beam. An angular error signal is generated for controlling the angular variable element using signals detected by the photodetectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.