| 摘要 |
PURPOSE:To lower flicker of a fluorescent lamp when a CCD element is used by correcting magnitude of video signals adjusting gain of a gain controlling circuit automatically according to magnitude of video signals of each field. CONSTITUTION:Video signals applied to an input terminal 1 are applied to a gain control circuit 11, and at the same time, sent to a switching circuit 4. There, signals of one field are portioned to three signal lines 13, 14, 15. Signal lines 13-15 are sent to LPF 5-7 having the same characteristic, and three equalized signals are outputted to output lines 16-18, and switched successively by a switch 8 and applied to a divider 10. At the same time, they are equalized by an equalizing circuit 9. Input from the switch 8 is divided by output of the equalizing circuit 9 in the divider 10, and output signals of the divider 10 are supplied to the gain control circuit 11 as gain control signals.
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