Method and device for correcting the phase of a half-line-frequency clock in a PAL or SECAM colour television receiver

Abstract

Abstract The present invention relates to a circuit adapted to a system for decoding PAL or SECAM colour television chrominance signals in order to furnish a square-wave signal with frequency equal to half the line frequency and whose 0s and 1s correspond in a specified manner to the nature of the information contained in respective successive lines. This circuit comprises a switch (10) directing the sampled and demodulated burst signal towards one or other of the outputs A or B. An Exclusive OR gate (20) furnishes, as a function of the result of the comparison of the values appearing on the channels A and B, a signal FL/2 at half the line frequency, corresponding to the output of a flip-flop (15) or to the reverse of this output. <IMAGE>

Inventors

• 👤 Patrick Douziech
• 👤 Michel Imbert

Bibliographic Details