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