Binary encoding method for data read from optical record and device therefor
US4819222A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 21, 1986 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | Apr 21, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1419
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention relates to a binary encoding method for reading the data from an optical record comprising steps of photo-electrically reading the optically recorded data which are encoded into binary codes with an FM encoding method and of comparing thus obtained video signals with a threshold to encode the same into binary codes and the device therefor. This invention is featured by the structure that the mark rate of binary encoded signals are detected to obtain the deviation thereof from a preset mark rate and the reading sensitivity of a reading means is adjusted based on said deviation in a manner to make the mark rate of the binary encoded signals identical to the preset mark rate. This invention is further characterized by the structure that video signals are binary encoded by plural groups of binary encoding means on the basis of different thresholds and the binary encoded signals of the group having the optimal mark rate are selected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.