Correction of rapid periodic timing errors in the production of

Abstract

Timing errors are detected by phase comparison of the color carrier at the line scanning frequency repetition rate and the errors so successively determined for one oblique track on the tape are loaded into an intermediate register. While a second magnetic head of the reproducer performs the same operation on the next track, the errors stored in the intermediate register are subtracted from their average value produced by an integrator and loaded into a final storage register, of which there is one for each track of a line packet, but only after being combined, in a noise-scrubbing process, with an error value previously stored in a corresponding location in that register so as to provide a suitable moving average. During the next period in which the intermediate storage register is loaded with the errors relating to another track, all of the main storage registers are read, providing as many pulses as there are tracks in a packet for recurrent correction of timing errors within the period of one television line.