Apparatus for correcting for shading defects in video signals induced by variations in the speed of scanning spots in a TV camera
US4823188A · kind A · utility
4Cited by
9References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1985 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Sep 3, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/15
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device for correcting shading in video signals which has conventionally occurred due to variations in speeds of the scanning spots. Speeds of the scanning spot are detected, and variations in these speeds are also detected. In addition, conventional-type digital correction values for correcting geometry and convergence errors are produced. Variations in speed are detected, and are digital-to-analog converted. A shading output correction signal indicative of a sweep speed variation is produced. This signal is added to the digital correction values to form a corrected correction value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.