Image forming apparatus

摘要

The image forming apparatus, which includes a plurality of photosensitive drums, charging devices that contact and charge respective photosensitive drums, developing devices that attach toner including a metal particle, which is a polishing particle, and develop latent images, and cleaning devices that remove remaining toner from surfaces of the photosensitive drums and allows toner images of each color formed on the photosensitive drums to be sequentially superposed on an intermediate transfer belt to form a color image, has a primary transfer bias control unit that switches polarity of primary transfer bias, except for a time of image formation on the photosensitive drums, to polarity equal to or opposite to electrostatic charge of toner in response to an average printing rate of each color of a predetermined number of immediately previous papers.

主权项

1. An image forming apparatus, comprising
a plurality of photoreceptors; charging devices that contact and charge respective photoreceptors; developing devices that attach toner including a metal particle, which is a polishing particle, and develop latent images; and cleaning devices that remove remaining toner from surfaces of the photoreceptors, wherein toner images of each color are formed on the photoreceptors to be sequentially superposed on an intermediate transfer belt to form a color image, the image forming apparatus further comprising a primary transfer bias control unit that switches polarity of primary transfer bias, except for a time of image formation on the photoreceptors, to polarity equal to or opposite to electrostatic charge of toner in response to an average printing rate of each color of a predetermined number of immediately previous papers.