To provide a developing device that reduces the degree of deterioration of carrier without increasing the amount of discharged developer.
A supply screw 26 for supplying developer to a developing roller 24 and an agitating screw 25 disposed parallel to the supply screw 26 are provided with spiral vanes 29 and 30, respectively, which convey developer in opposite directions and reverse a conveyance direction at least in one area. Circulation holes 31, 32, and 33 for permitting developer passage are formed in a partition 28 at both ends of each of the spiral vanes 29 and 30 and at a position opposite the position where the conveyance direction reverses. Accordingly, a plurality of circulation paths R1 and R2 where the developer circulates between the adjacent circulate holes 31, 32, and 33 are formed.
MAEDA OSAMU
Mitsuo Tanaka
Atsushi Maeda