The image forming apparatus 17, wherein {TAIL ~ a fine powder} of Mohs scale of {HEAD ~ hardness} being not less than 6.0 is added to the developer from outside 
The image forming apparatus 17 , wherein { TAIL ~ a fine powder } of Mohs scale of { HEAD ~ hardness } being not less than 6.0 is added to the developer from outside
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH