Optical pickup
US6449095B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2000 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Sep 19, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup is disclosed which includes a first light source for emitting a first beam of light with a first wavelength; a second light source for emitting a second beam of light with a second wavelength, longer than the first wavelength; a condenser lens for condensing the first and second beam of light onto an information recording surface of a recording medium; and a diffractive optical element arranged in an optical path from the first and second light source to the condenser lens. The condenser lens condenses, for the first beam of light, a refracted beam of the first diffraction order of the first beam of light by means of the diffractive optical element as an information read beam or an information write beam. For the second beam of light, the condenser lens condenses a refracted beam of the second diffraction order, lower than the first diffraction order, of the second beam of light by means of the diffractive optical element as an information read beam or an information write beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.