Optical disc apparatus and method of reproducing a wobble signal
US7266074B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2002 |
| Grant date | Sep 4, 2007 |
| Priority date | — |
| Expiry date | Aug 1, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2562
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc apparatus and a wobble signal detection method in which a light beam projected onto an optical disc and reflected by the optical disc is divided into at least four light regions in the direction corresponding to the radial direction of the optical disc to detect the light regions, and a wobble signal is detected by performing a subtraction on first and second difference signals, the first difference signal obtained by performing a subtraction on detection signals for the inner light regions of the divided and/or detected light beam and the second difference signal obtained by performing a subtraction on detection signals for the outer light regions of the divided and/or detected light beam. Accordingly, when a wobble signal is reproduced from an optical disc manufactured by a wobble modulation manner, a wobble signal is prevented from being degraded due to the interference (cross talk) from the wobbles of adjacent tracks, even though the track pitch of the optical disc is reduced to improve the recording density.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.