Patent ID: 8805247

Claim:
An image forming apparatus, comprising: a plurality of developer image forming portions for forming developer images in, a plurality of colors; a plurality of primary transfer members for transferring the developer images to an intermediate transfer member; a secondary transfer member for transferring the developer images to a recording medium; a medium transportation unit for transporting the recording medium to a secondary transfer position where the secondary transfer member transfers the developer images to the recording medium; a first contact cleaning member for cleaning the intermediate transfer member, said first contact cleaning member being arranged to contact with the intermediate transfer member on a downstream side of the secondary transfer member in a transportation direction of the recording medium; a second contact cleaning member, for cleaning the secondary transfer member; a voltage control unit for applying a transfer voltage to the primary transfer members and the secondary transfer member; a print number counting unit for counting a first print number of the recording media to be printed and a second print number of the recording media to be printed in an edgeless printing operation in which the developer image is formed in an area greater than the recording media; and a control unit for controlling the developer image portions, the primary transfer members, the secondary transfer member and the medium transportation unit, said control unit being arranged to perform a developer discarding operation, wherein, in the developer discarding operation, the developer image forming portions form a first discard developer image and a second discard developer image at different positions not to overlap with each other, the first and second discard developer images are transferred to the intermediate transfer member, the first contact cleaning member removes the first discard developer image without transferring the first discard developer image to the secondary transfer member, the second discard developer image is transferred to the secondary transfer member, the second contact cleaning member removes the second discard developer image, the voltage control unit is configured to apply a first transfer voltage to the secondary transfer member when the first discard developer image passes through the secondary transfer member, the voltage control unit is configured to apply a second transfer voltage different from the first transfer voltage to the secondary transfer member when the second discard developer image passes through the secondary transfer member, and said control unit is arranged to control the voltage control unit so that an amount of developer of the discard developer images that is transferred to the secondary transfer member is greater than that of developer of the discard developer images that is not transferred to the secondary transfer member according to a ratio of the second print number relative to the first print number.