{HEAD ~ The pattern} of illuminated pixels changes smoothly with {TAIL ~ time} to produce the required uniform high quality grey level 
{ HEAD ~ The pattern } of illuminated pixels changes smoothly with { TAIL ~ time } to produce the required uniform high quality grey level
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH