Constant luminance tint reference
US4228457A · kind A · utility
0Cited by
1References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 11, 1979 |
| Grant date | Oct 14, 1980 |
| Priority date | — |
| Expiry date | Jul 11, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/643
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a VIR-responsive Tint Control system a dematrixing circuit for synthesizing, from the individual chrominance demodulator outputs, a ZERO-COLOR reference signal. The VIR chrominance interval signal and the ZERO-COLOR reference signals are used as input to a feedback loop that also includes the receiver's chrominance subcarrier oscillator. By comparing the VIR chrominance interval signal to the synthesized ZERO-COLOR reference subcarrier oscillator phase errors are corrected by virtue of a single sampling of the VIR signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.