Optical pickup apparatus
US7796488B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2008 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | Mar 17, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup apparatus aiming at reduction of adverse effect on a tracking control signal and a data signal by preventing the reflected light from the adjacent layers of a multilayer disc changing to a stray light. In this optical pickup apparatus, the reflected light from the optical disc including the stray light from the adjacent layer is once focused with a focusing lens and is then reflected with the reflection plate. A flat attenuation element is provided between the lens and the reflection plate parallel to the optical axis with inclusion of the optical axis under the condition separated from the reflection plate. The reflection plate reflects the reflected light from the relevant layer and the attenuation element shields the reflected light from the adjacent layer. The light returning to the focusing lens includes less influence of the stray light. This light is detected with a detector to become a control signal and a data signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.