| 摘要 |
PURPOSE:To easily make the circuit an IC, by raising the noise resistance, characteristic, reducing the characteristic required for the peripheral circuit, and also removing a capacitor from the circuit. CONSTITUTION:When a composite synchronizing signal is provided to the input terminal 301, logical ''0'' is output by rise of an input signal to the output terminal 306 of the FF309, and the counter 303 is made a count state. The counter 303 counts a clock pulse provided to the counter terminal 308, and when the count number has attained to a fixed value, the C terminal output is made logical ''1''. The time requirEd for making this count number attain to the fixed value is decided in advance so as to become 0.5-1H. As soon as the C terminal output becomes logical ''1'', the terminal 306 becomes logical ''1'', and the counter 303 is reset. As a result, a coincidence pulse of rise of a horizontal synchronizing signal, and phase is obtained by the output terminal 305 of the FF309. According to such a constitution, even if a noise has entered when the potential of the terminal 307 is low, it is masked by the outputs of the FF309 and the counter 303, and it does not exercise influence on the output waveform. |
