| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic amplitude correction circuit for a video input signal that utilizes a circuit with a simple configuration to automatically correct the amplitude of a video signal outputted from a video image photographing device and can output the video signal with a prescribed amplitude to an image display device. SOLUTION: The automatic amplitude correction circuit for a video input signal consists of a series connection of a capacitor, a clamp circuit and a gain control amplifier connected between a video signal input terminal and a video signal output terminal in this order from the video signal input terminal, of an analog/digital converter that receives a reference level signal outputted from the clamp circuit and converts the signal into a DC, and of a comparator circuit that compares a reference level of the video signal received as a DC signal from the analog/digital converter with a specified reference level to generate an amplitude correction signal and to give it to the gain control amplifier.
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