Optical pickup device
US8009527B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2007 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | Nov 9, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The optical pickup device according to the present invention includes: a light source which emits a first light at a first wavelength, a second light at a second wavelength and a third light at a third wavelength; an optical path combining unit which combines vectors of the first, second and third light emitted by the light source, and matches optical axes of the first light and the third light; a light collection unit which condenses the light from the optical path combining unit into the optical information storage medium; a diffraction element which diffracts reflected light from the optical information storage medium; a first photo detector, a second photo detector and a third photo detector which receives the diffracted light from the first diffraction element; and a prevention unit formed between the first diffraction element and the first photo detector, the second photo detector and the third photo detector, and which prevents irradiation of + first-order diffracted light diffracted by the first diffraction element into the first photo detector, the second photo detector, and the third photo detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.