摘要 |
<p>. A beam index color television receiver having a beam index color cathode ray tube including a screen with an image area at which a plurality of groups of .color phosphor elements and index elements are arranged and a run-in area at which the index elements are arranged, an index signal sensing circuit detecting index signals from the index elements and generating index pulses, a phase-locked loop circuit including a phase comparator supplied with the output of index signal sensing circuit, a controlled oscillator controlled by the output of the phase comparator, and a divider dividing a frequency of the output of the oscillator and supplying a divided output to the phase comparator, a gate signal generating-circuit supplied with the output of the controlled oscillator and generating a plurality of gate signals, a gate circuit sequentially selecting predetermined primary color signals from three primary color signals in response to the gate signals and supplying selected primary color signals to the cathode ray tube, a circuit supplying a first pulse having a predetermined level to the cathode ray tube for activating the index elements of the run-in area. In this case, there are provided a mode set circuit supplying a mode set pulse to the gate signal generating circuit for controlling a phase of the plurality of gate signals in response to the index pulses, and an initializing pulse generating circuit for initializing an operating condition of the divider in the phase-locked loop at starting portion of the scanning period.</p> |