binary data producing circuit means for converting {HEAD ~ said multi gradation image data} into {TAIL ~ binary image data}; and 
into
binary data producing circuit means for converting { HEAD ~ said multi gradation image data } into { TAIL ~ binary image data } ; and
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH