Apparatus for reading an optically coded disc-shaped record carrier
US4536864A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 28, 1983 |
| Grant date | Aug 20, 1985 |
| Priority date | — |
| Expiry date | Apr 28, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2545
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to an apparatus for reading a disc-shaped record carrier with a spiral information track in which an optically readable digitally coded information signal is recorded with a spatial bit frequency which is independent of the radius of the track turn. The scanning speed of the information track is selected to be a factor n higher than the scanning speed normally employed of the reproduction for the recorded information. By means of a memory device, information blocks being read and comprising a fixed number of data bits are time-expanded to restore the customary time relationship. A control unit determines the read-in cycles of the memory device for the storage of the information blocks being read and, via the radial positioning system for the read spot, it determines the scanning pattern of the record carrier so that the ultimately recorded information blocks are reproduced in the same sequence and at the desired rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.