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