Optical pickup device, optical disc device and focus adjusting method
US8427923B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2010 |
| Grant date | Apr 23, 2013 |
| Priority date | — |
| Expiry date | Jun 21, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2537
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup device includes an astigmatism element which imparts astigmatism to laser light reflected on a disc, a spectral element which changes propagating directions of four light fluxes obtained by dividing a light flux of the laser light reflected on the disc to disperse the four light fluxes from each other, and a photodetector having a sensor group which receives the four light fluxes. The optical pickup device is further provided with a memory which holds a correction value for suppressing a DC component in a tracking error signal resulting from a positional displacement of the spectral element. The tracking error signal is corrected by the correction value to thereby suppress the DC component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.