{HEAD ~ Apparatus} is provided for comparing {TAIL ~ the difference} in the signals between the superimposed document and for analyzing the difference to provide a signal related to the copy quality 
is provided for comparing
{ HEAD ~ Apparatus } is provided for comparing { TAIL ~ the difference } in the signals between the superimposed document and for analyzing the difference to provide a signal related to the copy quality
HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH