Patent ID: 7259799

Claim:
An AGC (automatic gain control) detector device for television receivers displaying video pictures consisting of a plurality of horizontal lines to be built up successively, comprising means for inputting a CVBS (color video blanking sync) signal which includes horizontal sync pulses having a front porch region and a back porch region and occurring once a horizontal line during a horizontal sync period when generating a current video picture, and further includes vertical sync pulses occurring during a vertical sync period before the generation of a new video picture and including serration pulses which occur during a serration pulse region being part of the vertical sync period, means for generating gating pulses having a period which is equal to the line period of the horizontal sync pulses, and means for adjusting said gating pulses such that they occur at the back porch region (ΔT 1 ) relative to the horizontal sync pulses, characterized by means for shifting the occurrence of said gating pulses during the serration pulse region of the vertical sync period so that the gating pulses occur earlier by a time interval corresponding to the time distance (ΔT 1 +ΔT 2 ) between a front porch region and the next back porch region or later by a time interval corresponding to the time distance (ΔT 3 −ΔT 1 ) between a back porch region and the next front porch region.