Optical record carrier and scanning device
US6667949B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2000 |
| Grant date | Dec 23, 2003 |
| Priority date | — |
| Expiry date | Mar 19, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0013
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical record carrier is described comprising a track for carrying data encoded in optical marks. A parameter of the track has a periodic variation for generating a varying signal when scanning the track, for example a variation of the center of a pre-groove usually called wobble. The track further comprises reference elements, e.g. headers, interrupting the periodic variation. The phase of the periodic variation after the reference elements is indicative of a property of the record carrier for controlling the scanning of the record carrier in dependence of said property. In particular the phase may indicate whether or not the bottom of the pre-groove is closer to the scanning beam entry side of the disc. Further a scanning device is described comprising a detector for detecting said phase based on the varying signal. The device adapts its scanning control means to the indicated property.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.