An image forming apparatus of non-contact developing method using two-component
developer material which is capable of obtaining a clear image free from fogging,
ghost and toner contamination. The image forming apparatus has at least one developing
unit which includes a developing roll and a magnetic roll, the developing unit
develops an electrostatic latent image on a photosensitive body with a toner thin
layer formed on the surface of a developing roll wherein a toner thin layer forming
region on the developing roll is smaller than a magnetic brush forming region on
the magnetic roll. A high resistivity region is adjacent each end of the toner
thin layer forming region on the developing roll. A control device controls a developer
material replenishment and controls the biasing to the developing roll and magnetic roll.
