Patent ID: 7447455

Claim:
A color image forming apparatus capable of performing a mono color printing mode for forming an image using a developer of one color, comprising: a plurality of photoconductors; a charger for charging each of the photoconductors; a development unit for forming a developer image on each of the photoconductors; a transfer unit including an image transfer member for receiving the developer image from each of the photoconductors and a transfer voltage supply member for supplying a transfer bias voltage to the image transfer member; a first cleaning unit for cleaning each of the photoconductors; and a control unit for controlling the photoconductors, charger, development unit and transfer unit in a mono color printing mode to form a developer image on an image area of a selected one of the plurality of photoconductors, to transfer the formed developer image to a non-image area of the image transfer member, and to divide the transferred developer image into portions and reverse-transfer the divided portions of the transferred developer image from the image transfer member to remaining photoconductors.