Optical pickup apparatus
US7664005B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 2007 |
| Grant date | Feb 16, 2010 |
| Priority date | — |
| Expiry date | Aug 1, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The adverse influence of reflected light from adjacent layers as stray light on a control signal or data signal is reduced when tracking a multilayered optical disc using differential push-pull method. The reflected light from the optical disc including stray light from an adjacent layer is once condensed with a condenser lens having little aberration and is then reflected by a reflecting mirror having a partial reflecting region. The resultant reflected light, which has the influence of stray light reduced, passes through a polarization beam splitter and becomes incident on a four-quadrant detector (for main beam) and a split detector (for sub beam) via a condenser lens having astigmatic aberration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.