Sampling arrangement for a television ghost signal cancellation system

Abstract

A ghost signal sampling arrangement is provided which includes a gate coupled to receive a ghost contaminated video signal. The gate passes a portion of the video signal including a main signal component available for use as a training signal and its corresponding ghost signal components. The gated signal portion is applied to a differentiator, which passes a first signal corresponding to the training signal, and subsequent signals corresponding to the ghost signal components when present. A clipping limiter is coupled to receive the signals produced by the differentiator, and produces a sampling signal corresponding to the first, training signal component, to the exclusion of the ghost signal components. A serial shift register is coupled to receive the sampling signal, which passes through the shift register and appears at sequential ones of its parallel outputs. A plurality of sampling circuits each have a control input coupled to respectively different outputs of the shift register, and a signal input coupled to the output of the differentiator. The sampling circuits sample the signal at the output of the differentiator in response to the application of a sampling signal at their respective inputs, thereby developing a time sequence of samples of the differentiator output signal. These samples may be applied to weighting function circuits for the development of weighting function signals for a ghost eliminator.