DEVICE FOR SEPARATION OF COLOR AND BRIGHTNESS SIGNALS IN SECAM DECODER Russian patent published in 1994 - IPC

FIELD: television equipment. SUBSTANCE: device has low-pass filter 1, seven delay units 2, 4, 6, 10, 11, 14, 22, adder 3, two subtraction units 5, 7, unit 8 for determination of resting frequency of color sub-carrier, generator 8 for integral signal of resting frequency of color sub-carrier, five multipliers 12, 13, 16, 21, 24, low-pass filters 15, 23, which passing band can be adjusted, two generators 17, 25 for generation of integral envelope of frequency-modulated signal, two detectors 18, 26 for detection of complex envelope of frequency-modulated signal, two signal differentiating circuits 19, 27, two control signal generators 20, 28. Device provides shift of high-frequency constituent of integral video signal to base frequency along with use of different methods for control of passing bands of tracing filters in brightness and color channels. In addition device has frequency feedback. This results in possibility to set optimal dependencies of passing frequencies when size of frequency jumps in feedback circuits changes. EFFECT: increased quality of separation of brightness and color signals. 1 dwg