Video signal white level corrector
US4486781A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1982 |
| Grant date | Dec 4, 1984 |
| Priority date | — |
| Expiry date | Apr 19, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video signal white level corrector wherein a digital memory is used to store a correction signal which is applied to a signal multiplier to remove white level shading which results from optic and beam misalignment of a scanner. Video signals are applied to a multiplier 10, the output therefrom being the corrected video signal. The correction signal is stored for future use in a digital memory 14 after being compared to a reference voltage at comparator 20. In a first, or "store", mode, the output from the comparator 20 is coupled to an integrator 22, the output of which increases or decreases the gain of multiplier 10. In a second, or "operate", mode, the output from the digital memory is coupled to integrator 22 to also control the gain of multiplier 10.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.