| 摘要 |
PURPOSE:To perform sync expansion and waveform shaping at the same circuit by adding a capacitance at the emitter end of an output terminal transistor in a sync expansion circuit connected to the input terminal of a quadratic differential type outline enhancement circuit. CONSTITUTION:An input compound video signal, before it is inputted to a quadratic differential type of outline enhancement circuit IC17, is inputted to a combination sync expansion and a waveform arrangement circuit 27. An input video signal is clamped with a transistor Q1, and a current is withdrawn only at a sync chip part with a differential amplifier consisting of transistors Q2 and Q3, and the sync expansion is performed. A resistor R and a capacitor C added on the emitter of an output transistor Q4 in the differential amplifier enhance the trailing edge of the sync chip part, and by adding the signal and the output signal of the IC17, the waveform of the sync chip part can be shaped.
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