Optical pickup having a polarization beam splitter
US7450477B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2004 |
| Grant date | Nov 11, 2008 |
| Priority date | — |
| Expiry date | Aug 2, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1395
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup which can remove birefringence due to the non-uniformity of an optical recording medium by using a polarization beam splitter. The optical pickup includes a light source emitting a laser beam, a beam splitter reflecting part of incident light and straight transmitting the remaining light to change a proceeding path of the incident light, an objective lens focusing the incident light passed through the beam splitter to form a light spot on an optical recording medium, a polarization beam splitter arranged on an optical path between the beam splitter and the objective lens for transmitting light having one polarization and reflecting light having a different polarization. The optical pickup further includes a first photodetector for receiving the light having one polarization which is reflected from the optical recording medium and is transmitted by the polarization beam splitter and passes through the beam splitter, and a second photodetector for receiving the light having a different polarization reflected from the optical recording medium that is reflected by the polarization beam splitter. An information signal and error signals are then determined from a signal…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.