Compatible optical pickup for high-density recording/reproduction
US6563780B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2001 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Oct 5, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup compatible with optical discs having different formats. A first light source emits a first light beam suitable for a first format optical disc. An objective lens is optimized for a wavelength of the first light source. Light reflected from the first optical disc provides a reproduction signal. A second light source emits a second light beam suitable for a second format optical disc. A light splitter splits the second light beam and the objective lens focuses the split beams onto the second disc as a main light spot and a sub-light spot. Lights reflected from the main light spot and the sub-light spot are independently detected and then processed to correct for chromatic aberration caused by a difference in the wavelengths of the first and second light beams and/or spherical aberration caused by thickness difference between the first and second format optical discs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.