ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS

摘要

An electrophotographic image forming device is provided to carry out printing of mono images by one-component type developing method for realizing high speed printing and color images by two-component type developing method for resolving color registration problems. An electrophotographic image forming device includes a first developing unit(110K) for forming black and white images by two-component type developing method, and having a photosensitive medium for forming latent images by a first exposure unit. A plurality of second developing units(110C,110M,110Y) forms color images by one-component type developing method and respectively has photosensitive media forming latent images by second exposure units. A first intermediate transfer unit(1401) faces the first developing unit. A second intermediate transfer unit(1402) faces the second developing units. A control part outputs control signals for independently controlling the above unit. The photosensitive media of the first developing unit has a diameter larger than those of the second ones by integral times.