Apparatus and record carrier for optical disc memory with correction pattern and master disc cutting apparatus
US4949331A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1986 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Jun 17, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10582
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A record carrier having a disc-shaped substrate and a recording layer for optically writing information therein is disclosed which includes a guide groove extended in the rotational direction of the record carrier so that a plurality of revolutions of the guide groove are spaced apart from each other in radial directions of the record carrier, and a pit pattern provided between adjacent guide grooves, at positions arranged at intervals in the above rotational direction, for detecting the deviation of a light spot from the center line between adjacent guide grooves. The recording/reproducing operation for this record carrier is performed in such a manner that the first tracking error signal is detected from diffracted light from the guide groove, the second tracking error signal is detected from the pit pattern, and information is recorded in and reproduced from a land formed between adjacent guide grooves in a state that a tracking operation is performed using the first and second tracking error signals. The second tracking error signal detected from the pit pattern is not affected by the tilting of the record carrier and the movement of the light spot. When a tracking signal obtai…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.