| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming system for stabilizing the transfer efficiency of all the color toner images in an image forming device equipped with plural color developing devices and transferring the toner image to an intermediate transfer medium. SOLUTION: The image forming device is provided with a latent image carrier 21, plural developing devices 23Y, 23M, 23C and 23K, a primary transfer part R1 transferring the toner image successively developed with different color toner to the intermediate transfer medium 41, a primary transfer bias applying power source 126 for applying bias at the primary transfer part, and a secondary transfer part R2 transferring all the color toner images superposed and transferred on the intermediate transfer medium to recording paper, and uses a constant-voltage power source as the primary transfer bias applying power source. In the device, the developing device is selected in order that primary transfer efficiency is not good from the plural developing devices 23Y, 23M, 23C and 23K, and the corresponding color toner image is developed on the surface of the latent image carrier 21. |
