Optical pickup device and optical disc device
US8427922B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2010 |
| Grant date | Apr 23, 2013 |
| Priority date | — |
| Expiry date | Feb 24, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup device is so configured as to change the propagating directions of light fluxes in four light flux areas defined in the periphery of an optical axis of laser light, out of the laser light reflected on a disc, to separate the four light fluxes one from the other. A signal light area where only signal light exists is defined on a detecting surface of a photodetector. Sensors for signal light is disposed at a position in the signal light area to be irradiated by the signal light, and a tracking error signal is generated based on a signal from the sensors. A direct-current component of the tracking error signal resulting from positional displacements of the sensors is cancelled by adjusting a gain of the signal from the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.