{HEAD ~ a scanner} which detects a side of a sheet on which {TAIL ~ an image} is formed using a thermally decolorable coloring agent 
{ HEAD ~ a scanner } which detects a side of a sheet on which { TAIL ~ an image } is formed using a thermally decolorable coloring agent
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH