Optical pickup device and optical disc apparatus using same
US8270281B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2010 |
| Grant date | Sep 18, 2012 |
| Priority date | — |
| Expiry date | Nov 30, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/13925
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
According to the present invention, of all beams of light reflected from the optical disc, only light in a peripheral region excluding a push-pull region is used to generate a DPD signal. In this method of signal generation that optimizes internal light-receiving surface interconnections in a photodetector, the lens error signal required for the generation of a tracking error signal in the DPP scheme is amplified at a lower amplification factor. In addition, the light reflected from the multilayered optical disc will be divided into a plurality of regions and the divided beam of light will be focused at different positions on the photodetector. When the beam is focused upon a desired layer, stray light from recording layers other than those to be subjected to information reproduction will not enter the photodetector light-receiving surfaces used for servo signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.