| 摘要 |
PROBLEM TO BE SOLVED: To automatically prevent a viewer from viewing a video image that may cause a photosensitivity reaction. SOLUTION: A color demodulation circuit 13 applies color demodulation to an input composite video signal a1 and gives an R-Y signal to a flicker detection circuit 15. An LPF 16 of the flicker detection circuit 15 applies a low-frequency bandpass filtering to the R-Y signal from the color demodulation circuit 13 and outputs a low frequency R-Y signal c1 to a tuning amplifier 17. The tuning amplifier 17 applies tuning amplification with respect to frequency components of 3-24 Hz to the received low frequency R-Y signal c1 to generate a photo stimulus flicker component signal d1 and gives it to a level detection circuit 18. The level detection circuit 18 detects the level of the photo stimulating flicker component signal d1 and outputs the result of detection, that is, a detection signal e1. A gain control amplifier 14 applies gain control to the input composite video signal a1 on the basis of the detection signal e1. |
