| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of contamination due to a color developer other than the monochrome color arising when an image to be formed is changed from a plurality of color images to a monochrome image even if a mechanism is not provided that causes a developer image formation unit of a non-use color among a plurality of developer image formation units to be separated from an image carrier.SOLUTION: A control unit is configured to, when an image to be formed is changed from a full color image to a monochrome image, control so as to cause timing starting a formation of the monochrome image to be more delayed by preset delay time than other cases. More specifically, the control unit is configured to, when the image to be formed is changed from the full color image to the monochrome image, control so as to cause the timing starting the formation of the monochrome image to be more delayed by the preset delay time than when the image to be formed is the full color image, the image to be formed is the monochrome image and a previously formed image is also the monochrome image.SELECTED DRAWING: Figure 7 |
