| 摘要 |
PROBLEM TO BE SOLVED: To provide a color image forming device capable of easily forming a monochrome image concurrently with a color image excellent in gradation with thin and thick toner. SOLUTION: This image forming device is a tandem type color image forming device where the pairs of processing units 100Y to 100K for forming respective thin and thick toner images in yellow(Y), magenta(M), cyan(C) and black(K) are arranged in series on a transfer belt 14a. In the case of forming the color image, the respective thin and thick toner images formed by the respective processing units 100 are successively superposed on the belt 14a so as to form the color toner image, and in the case of forming the monochrome image, the carrying upstream side of the belt 14a is turned and retreated with a backup roller 30 as a fulcrum so as to form the image only by the processing unit 100K for black(K). |
