When the threshold level VREF·1 is set slightly lower than the level V1 of white, a video signal 36 is obtained in which red, blue and {HEAD ~ black} are in {TAIL ~ the L level state} 
When the threshold level VREF·1 is set slightly lower than the level V1 of white , a video signal 36 is obtained in which red , blue and { HEAD ~ black } are in { TAIL ~ the L level state }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL