DEVELOPING APPARATUS AND IMAGE FORMING APPARATUS EQUIPPED WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a developing apparatus capable of preventing carrier from sticking on a photoreceptor, then, stably securing high image quality, and also, capable of preventing scratches on the photoreceptor, and also, preventing toner-scraping on the surface of the photoreceptor.

SOLUTION: Regarding the developing apparatus 1 for developing an electrostatic latent image carried on the surface of the photoreceptor by using two-component developer containing the toner and the carrier, the height (h) of a magnetic brush 11 coming in contact with the photoreceptor on the uppermost stream side in the photoreceptor rotating direction in a developing area, a developer quantity M per unit area on the photoreceptor to be supplied to the developing area, the bulk density ρ of the developer 2, the diameter DR of a developing roller 4, a distance D between the developing roller and the photoreceptor 12 at the closest position, and the contact length W of the magnetic brush of the developer carried by the developing roller with the photoreceptor in the developing area in the rotating direction of the developing roller are set so as to satisfy relation expressed by the following expressions; (DR/2+h)2>(DR/2+D)2+(W/2)2and D×ρ×100≥M≥10.

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