A color identification circuit for use on a television receiver. (Machine-translation by Google Translate, not legally binding)

摘要

A color identification circuit for use in a color television receiver for a color television pal signal that contains a color synchronizing signal with two quadrature components, the first of which maintains the same line-to-line phase and the second of which alternates its phase by 180º from line to line, said identification circuit comprising a synchronous demodulator device for the synchronous demodulation of at least the color synchronizing signal in a phase that is alternated from line to line symmetrically in relation to the invariable phase of the first quadrature component of the color synchronizing signal by means of a sequential line distribution device, while the line sequential distribution device may be in a correct or incorrect distribution state and, by means of a correction signal derived from a color synchronizing signal demodulates synchronously in the aforementioned synchronous modulator device, the incorrect distribution state may be changing to the correct distribution state, characterized in that said circuit comprises means for obtaining the synchronous demodulation of the color synchronizing signal in such a phase as in the distribution state of the sequential line distribution device, the amplitude of the correction signal derived from the synchronized color signal synchronously demodulated is substantially at a maximum. (Machine-translation by Google Translate, not legally binding)