摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device capable of obtaining a color image having satisfactory density of respective colors by controlling a transfer current so that each color transfer efficiency and a retransfer ratio of the subsequent color in an image forming part may be balanced. SOLUTION: As for the transfer current Ia for applying the maximum transfer efficiency and the transfer current Ib for applying both of a high transfer efficiency and a low retransfer ratio, the relation of Ia>=Ib is established. In Fig. 2, Ia is about 17.5 μA, Ib is about 11.5 μA. Then, at a 1st station free from the generation of the retransfer, the transfer current is controlled to be Ia = about 17.5 μA so as to attain the maximum transfer efficiency, and at the 2nd and subsequent stations for generating the retransfer, the transfer current is controlled to be Ib = about 11.5 μA so as to obtain the high transfer efficiency and the low retransfer ratio. The transfer current is obtained by controlling a primary transfer bias of a constant voltage as follows, Vy=300 V at the 1st station, and Vm=Vc=Vk=170 V at the 2nd to 4th stations. |