Optical pickup including polarization holographic optical element and photodetector
US7369467B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2004 |
| Grant date | May 6, 2008 |
| Priority date | — |
| Expiry date | Jun 15, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0956
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is an optical pickup including a polarization holographic optical element (HOE) and a photodetector. The optical pickup includes a light source, an optical path changer, an objective lens, a polarization HOE, and a photodetector. The polarization HOE has a pattern designed to generate different astigmatisms in the left and right halves of the polarization HOE in a tangential direction and to divide plus and minus first-order beams in a radial direction. The photodetector includes a first light-receiving portion receiving a zero-order beam and second and third light-receiving portion that are disposed on either side of the first light-receiving portion in the tangential direction and respectively receive the plus and minus first-order beams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.