Optical disk apparatus and optical disk having a hard address mark area
US5568459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1996 |
| Grant date | Oct 22, 1996 |
| Priority date | — |
| Expiry date | Jan 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0938
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk apparatus having rewritable optical disk with a spiral groove which is used as an information recording track. The track has two hard address mark areas formed once every rotation of the track around the center of the disk. The hard address mark areas are arranged in a single virtual straight line passing through the center of the disk to avoid crosstalk between recorded data and the hard address mark area. The track also has a periodic radial wobble groove containing frequency information at a specified period. A servo control circuit controls rotation of the disk at a constant linear velocity (CLV) in response to frequency information from the wobble groove. The hard address mark area and the wobble groove are pre-formed when pressing the disk. Sectors of equal length, where picture and sound information is recorded, are formed by recording a soft address mark signal produced in response to the hard address mark. The apparatus minimizes adverse effects due to crosstalk between reproduced data and the hard address mark. Therefore, high packing density recording of information can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.