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