Patent ID: 7298997
Filing Date: 2007-11-20
Classification: G03G

Abstract:
1. A color image forming apparatus for forming a color toner image on a transfer material, comprising: (a) a plurality of photoreceptors on each of which a toner image having a color different from each other is formed; (b) an intermediate transfer body onto which the toner image formed on each of the photoreceptors is primary transferred successively; (c) a primary transferring unit for primary transferring the toner image; (d) a secondary transferring unit for secondary transferring the color toner image which has been formed by superimposing each of the toner images on the intermediate transfer body, onto a transfer material; (e) a pre-charger provided downstream of the primary transferring units with respect to a moving direction of the intermediate transfer body and upstream of the secondary transferring unit for applying an electric charge having the same polarity as that of an electric potential of a toner onto the color toner image prior to the secondary transferring on a surface of the intermediate transfer body; and (f) an electric potential adjusting device provided downstream of the pre-charger with respect to the moving direction of the intermediate transfer body and upstream of the secondary transferring unit for applying an electric charge having a polarity opposite to an electric potential of the toner onto the color toner image on the surface of the intermediate transfer body, and for applying a bias voltage having the same polarity as that of the electric potential of the toner onto a control grid.