A signal generator generates {HEAD ~ a plurality} of {TAIL ~ grey level signals} which are inputted into a one bit per pixel raster scan video display device  
A signal generator generates { HEAD ~ a plurality } of { TAIL ~ grey level signals } which are inputted into a one bit per pixel raster scan video display device
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH