DEVELOPING DEVICE AND COLOR IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an image of satisfactory image density by a developing device which is constituted so that a toner carrier may be moved upward from beneath in a developing area that faces an image carrier. SOLUTION: As for the developing device, the toner carrier 21 is moved upward from beneath in the developing area that faces the image carrier, and toner (t) is supplied by a blade member for a toner feeding member to a toner supply member. In this case, a distance between the toner supply member and an upper wall surface 20b is controlled to be >=3 mm at a position where an angle α formed by a tangent L1 of the toner supply member and a horizontal line agrees with the repose angle of the toner, and provided that B1 denotes volume (cm3) of a space part E1 of maximum image area width sectioned by the tangent L1, the upper wall surface, the toner supply member and the toner carrier, X denotes circumferential speed (cm/min) of the image carrier, (a) denotes the toner consumption (g/cm) of the solid image of the maximum image area width, (h) denotes the rotating speed (rpm) of the toner feeding member, (n) denotes the number of the blade members (pieces), H denotes the toner quantity (g) supplied by one blade member, and ρ denotes toner specific gravity, (a) X