Optical pickup apparatus
US6661765B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2000 |
| Grant date | Dec 9, 2003 |
| Priority date | — |
| Expiry date | Feb 20, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0683
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A laser beam emitted from a laser source provided at a silicon substrate passes through a hologram element formed of a translucent flat plate and a grating, thereby being subjected to NA conversion executed by an NA converting lens, passing through a polarizing film of a polarization beam splitter, and converging onto a magneto-optical disk via a collimator lens and an objective. A part of back-reflection from the magneto-optical disk, which is reflected by a polarizing film of the polarization beam splitter, is reflected by a reflection surface of the splitter, then branched into two polarized light beams by a Wollaston prism, and guided to one light receiving element group. On the other hand, another part of the back-reflection, which passes through the polarization beam splitter, is branched into two beams by the hologram element and guided to the other light receiving element groups.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.