| 摘要 |
PURPOSE: A device for separating synchronizing signals of a video processing system is provided to allow an AGC(Automatic Gain Control) unit to perform gain control of synchronizing signals for inputted video signals, and to buffer video signals without changing the size for outputting, so as to stably process signals. CONSTITUTION: A buffer(210) receives clamped video signals for buffering, and outputs a buffered result. An AGC(Automatic Gain Control) unit(220) receives the clamped video signals, and responds to a predetermined gain control signal(CON) to automatically control the size of the clamped video signals. An LPF(Low Pass Filter)(230) filters low band components of the gain-controlled signals to eliminate color signal components and an RF(Radio Frequency) noise, and outputs an eliminated result. A comparator(250) receives the filtered signals to be compared with a predetermined reference level(REF), and outputs a compared result as separated synchronizing signals, then generates a selection signal(SEL) corresponding to the compared result. A synchronizing level measurer(260) receives the synchronizing signals from the comparator(250) to measure a level, and outputs the level-measured result as the gain control signal(CON). And a multiplexer(240) respectively applies the output signals of the buffer(210) and output signals of the AGC unit(220) as the first and the second input, and selectively outputs the first and second inputs to a video output terminal(VOUT) in response to the selection signal(SEL).
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