| 摘要 |
PROBLEM TO BE SOLVED: To attain both subjects to prevent the life of an image forming unit from being uselessly shortened and to prevent the reduction of the productivity, even though both subjects are antithetical, as for a tandem type image forming device. SOLUTION: As for the image forming device, the image is formed under a color printing mode using plural image carriers, or a monochromatic printing mode using one image carrier. In this case, the device is provided with an inputting means for inputting whether a life priority mode is selected, or a productivity priority mode is selected, a detecting means for detecting whether an image to be formed is a color image or a monochromatic black image, and an image forming means (S35), as for the image forming means, in the case the life priority mode is selected (S33: No), the image is formed under the color printing mode when the image to be formed is a color one (S34→S36) and the image is formed under the monochromatic printing mode when the image to be formed is the monochromatic black one (S34→S35), and in the case the productivity priority mode is selected (S31: Yes), the image is formed under the color printing mode (S35). |
