Chrominance signal demodulation circuit
US6690430B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 1999 |
| Grant date | Feb 10, 2004 |
| Priority date | — |
| Expiry date | Mar 25, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A chrominance signal demodulation circuit capable of precisely processing a chrominance signal demodulation even when a phase of an inputted chrominance signal is abruptly changed due to a tape track skew error. A first and second color difference signals in an R-Y axis and B-Y axis directions are obtained by multiplying a color burst signal of the inputted chrominance signal and color subcarrier signals generated by a color subcarrier generator. A demodulation phase detector 17 generates a phase error signal to compensate a phase difference between the phases of the color burst signal and the color subcarrier signal based on the first and second color difference signals obtained. The color subcarrier generator 12 generates color subcarrier signals compensated responsive to the phase error signal. Thereby, a chrominance information portion following to the color burst signal in the inputted chrominance signal is successively processed with a chrominance signal demodulation with a correct phase. After that, the color burst signal of the first and second color difference signals are replaced with predetermined standard color burst signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.