| 摘要 |
PURPOSE: A device for processing index signals is provided to timely generate logic pulses necessary for driving a beam index cathode ray tube with a simple configuration, so as to minimize index errors. CONSTITUTION: A start set pulse generator(102) is composed of the second flip-flop for inputting an output of an ADC to a clock terminal and inputting a horizontal synchronous signal to a clear terminal, and comprises many logic elements, to sense a starting point of the horizontal synchronous signal to output a start set signal. A frequency divider(101) includes the first flip-flops for inputting an output signal of a PLL and inputting a horizontal synchronous signal to a clear terminal as well as inputting the start set signal, and divides frequencies for R, G, B from an index signal. A blank pulse generator(104) includes a counter for inputting the horizontal synchronous signal and the output of the ADC, to make blank sections up to a point where an output pulse of the ADC becomes a predetermined frequency from a moment when the start set signal is generated, and makes a blank section up to a section of the horizontal synchronous signal. A run-in pulse generator(103) includes the third flip-flop for inputting an output of the blank pulse generator(104) to a clock terminal and inputting the horizontal synchronous signal to a clear terminal. The run-in pulse generator(103) includes a logic element for inputting an output of the start set pulse generator(102), to output a run-in pulse.
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