Black and white level adjustment and normalization circuit for a color video printer
US4694355A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 16, 1985 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | Sep 16, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/81
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A color video printer for producing a color photographic copy from a color video signal. A self-processing color photographic element is exposed to a sequence of six color field images constituting a full frame of a color video image. The printer includes a monochrome cathode-ray-tube (CRT) and a rotatable color filter having red (R), green (G) and blue (B) filters which are sequentially moved into an optical path between the CRT and the self-processing photographic element positioned at an exposure station. A video signal circuit provides a color video signal to be copied. The color video signal includes luminance and chrominance signals which are demodulated to concurrent R, G, and B component signals. The luminance signal is amplified by a variable gain amplifier which reduces the level of the luminance signal in response to detection of the level of one of the color component signals exceeding a predetermined limit. A gate is selectively actuated to apply one of the color component signals to the CRT. Operator adjustable controls are provided for adjusting the black and white limits of the color component signal applied to the CRT.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.