Comb filter employing a charge transfer device with plural mutually

Abstract

A comb filter comprising a charge transfer device (CTD) structure for separating frequency interleaved luminance and chrominance components of a composite color television signal directly within the CTD structure. The CTD structure has first and second pairs of input sections of substantially identical geometry, one input section of the second pair being preceded by a signal inverter. Signal charge as applied to the first and second input pairs are delayed such that signal charge from the first input pair exhibits a 1H delay relative to signal charge from the second input pair, when the signal charge from the respective input pairs are combined with each other. A first charge summing well combines mutually in-phase signal charge at multiples of the line scanning frequency from the first and second inputs to provide a combed luminance signal charge component, while a second well combines mutually inverted or out-of-phase signal charge at these frequencies from the first and second inputs to provide a combed chrominance signal charge component.