DEVELOPING DEVICE

PURPOSE:To improve the developing agent exchanging performance of a developing device by successively arranging N and S magnetic poles on the inner peripheral section of a magnetic roll and, at the same time, forming a strong repulsive magnetic field only at the part facing a developing agent stirring member. CONSTITUTION:N and S magnetic poles N1-N3 and S1-S4 are successively arranged on the inner peripheral section of a magnetic roller 11 and, at the same time, fixed magnets S2 and S2 having strong magnetic force, preferably 400-800 gauss at the surface of a developing sleeve 12, of the same polarity are adjacently provided in the peripheral direction at the part facing a developing agent stirring member 13 to form a strong repulsive magnetic field. The developing agent carried by the sleeve 12 is separated from the surface of the sleeve 12 by repulsion after developmenet and mixed for recirculation with the developing agent mixed and stirred by the stirring roller 13 for recirculation in addition to a new developing agent efficiently supplied to the sleeve 12 by the roller 13. Therefore, copied pictures which are free from unevenness in density and declines in density can be obtained.