Optical disc and optical disc driving apparatus
US5933410A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 26, 1997 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | Jun 26, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc using a single-spiral land and groove track format enabling accurate tracking offset correction and reliable detection of the transition point between a land track and a groove track, and a driving apparatus therefor. Four physical address areas PID1, PID2, PID3, and PID4 are recorded to a header area such that PID1 and PID2 are offset one-half track pitch toward the outside circumference of the disc from the groove track center, and PID3 and PID4 are offset one-half track pitch toward the inside circumference of the disc from the groove track center, and the physical address areas PID1-PID4 can be detected by means of a difference signal in the radial direction. The single frequency pattern area VFO at the beginning of each PID is lengthened by PID1 and PID3, thereby enabling tracking offset correction using a sum signal, and detection of the land-groove transition point using a difference signal obtained from the PID offset.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.