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