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