Patent ID: 7440719

Claim:
A color image forming apparatus, comprising: an image carrier; an image forming unit which forms a toner image on the image carrier; a plurality of support members; an intermediate transfer belt which is extended and given a tension by the plurality of support members; a primary image transfer unit which transfers the toner image on the image carrier onto the intermediate transfer belt; a secondary image transfer unit which transfers the toner image on the intermediate transfer belt onto a transfer material; a scorotron discharger which is arranged on the upstream of the second image transfer unit, includes a discharge electrode and a grid electrode and discharges a charge on the toner image on the intermediate transfer belt; and an elastic body electrode which is arranged to be opposite to the scorotron discharger and to contact the back of the part of the intermediate transfer belt where the intermediate transfer belt is supported in a planar state; wherein at least one of the plurality of support members has a configuration for adding more tension in the vicinity of the center of the intermediate transfer belt than in the vicinity of the both ends.