Circuit for converting a colour television time division multiplex

Abstract

A color television Y/U/V luminance-chrominance multiplex signal with signals which may or may not be compressed in time comprises for a television line the associated luminance information Y and half the chrominance information U or V. As a result the circuit should supply the chrominance information directly (U, V) and repeatedly (U', V') during a subsequent television line. To avoid the use of an accurate, expensive delay device having a line period delay, the circuit includes an input shift register (A) of the series-in, parallel-out type, which is coupled through an on-off switch circuit (B1, B2) to parallel inputs of two shift registers (C1, C2) of the parallel-in, series-out type. During a line blanking period (THB) writing is effected from the input shift register in the output shift registers and during two subsequent line scan periods (THS1, THS2) reading is effected consecutively therefrom. Reading may be effected in opposite phase if a repetition is to be effected after exactly one line period.