Optical head having two vertical cavity surface emitting lasers with different wavelengths
US5986998A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 23, 1997 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Oct 23, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/4087
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup which can be employed for different formats of a disk recording medium is disclosed. The optical pickup device includes a light source including first and second vertical cavity surface emitting lasers closely disposed to each other for emitting light having different wavelengths and different radiation angles, an objective lens for focusing the light emitted from the light source on a recording surface of a recording medium, a photodetector for detecting information signals and error signals by receiving the light reflected from the recording medium, a polarized beam splitter disposed on an optical path between the light source and the objective lens to redirect a proceeding path of incident light, and a wavelength plate disposed on the optical path between the objective lens and the polarized beam splitter to convert a polarization component of incident light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.