Optical pickup using a single light spot to generate tracking error signal and reproduction signal
US6580670B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2001 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | Aug 18, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1381
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup including a light detection element to divide light reflected from an optical recording medium into first through fourth light beam portions in a radial direction of the optical recording medium. From detection signals from the light detection element, a reproduction signal detection portion detects an information signal, and a tracking error signal detection portion detects a tracking error signal. The light source emits light that is focused as a single light spot on a main track of the optical recording medium. The tracking error signal detection portion gain controls and sums push-pull signals from the detection signals to detect, during a recording operation, a tracking error signal with reduced push-pull offset without erasing existing signals on adjacent tracks. The reproduction signal detection portion sums and gain controls the detection signals to detect an information signal containing reduced crosstalk from adjacent tracks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.