Optical pick-up device with convergent light diffraction for recording/reading information on optical recording medium
US6845077B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2003 |
| Grant date | Jan 18, 2005 |
| Priority date | — |
| Expiry date | May 16, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1381
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pick-up device for recording/reading an optical recording medium is provided, which can efficiently utilize light emitted from the laser light source. The optical pick-up device includes a light source, an optical system, a quarter-wave plate, a diffraction component, and a photodetector unit. The photodetector unit may further include a transmitting portion for transmitting the light beam emitted from the light source, and may be disposed opposite the light source in a vicinity of the light source so that light emitted from the light source is transmitted through the transmitting portion. The transmitting portion may be an aperture provided in the photodetector unit. Alternatively, the optical pick-up device may further include an optical path separator for separating the diffracted returning light beam from the light beam that passes from the light source to the diffraction component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.