{TAIL ~ A correction signal} is applied to the modulator to maintain substantially uniform exposure across the output medium notwithstanding variations in the velocity of {HEAD ~ the beam} 
{ TAIL ~ A correction signal } is applied to the modulator to maintain substantially uniform exposure across the output medium notwithstanding variations in the velocity of { HEAD ~ the beam }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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 HEAD