Luminance signal forming circuit for color tv camera which combines luminance signal derived from primary color signals with luminance signal derived from complementary color signals
US4805011A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 1987 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | Sep 23, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/88
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A luminance signal is formed from a first luminance signal produced by mixing a plurality of complementary color signals obtained from a television camera having complementary color filters and from a second luminance signal produced by mixing at a predetermined ratio a plurality of primary color signals that are derived from the plurality of complementary color signals, the first and second luminance signals are then mixed so that the composite output signal forms the desired luminance signal. The first luminance signal is level adjusted based upon the color temperature detection signal derived from a color temperature detector and a second luminance signal is balanced in level based upon this color temperature detection signal. The second luminance signal is derived by mixing the three primary color signals at a predetermined ratio. This ratio is variable and can be controlled in response to an automatic gain control signal derived from an automatic gain control circuit that receives the output of the television camera.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.