IMAGE FORMING APPARATUS

摘要

An image forming apparatus includes an image carrier, a transfer member, a power supply, and a control device that controls the power supply to output a DC-AC superimposed bias or a DC bias to transfer a toner image on the image carrier onto a recording medium. The control device controls the power supply to alternately output a first bias being a DC component the same in polarity as the DC bias and a second bias being a DC component opposite in polarity to the DC bias to clean the transfer member when image formation is not taking place. The first bias is output with two target output values including a first value and a second value lower than the first value. The second bias is output with one target output value. An output time of the second bias is longer than an output time of the first bias.

主权项

1. An image forming apparatus comprising:
an image carrier to carry a toner image; a transfer member to form a transfer nip between the image carrier and the transfer member; a power supply to output a superimposed bias having a direct-current component superimposed with an alternating-current component and a direct-current bias consisting of a direct-current component; and a control device that controls the power supply to output the superimposed bias or the direct-current bias to transfer the toner image on the image carrier onto a recording medium in the transfer nip, wherein the control device controls the power supply to alternately output a first bias corresponding to a direct-current component the same in polarity as the direct-current bias and a second bias corresponding to a direct-current component opposite in polarity to the direct-current bias to clean the transfer member when image formation is not taking place, wherein the first bias is output with a target output value set in two stages including a first stage and a second stage lower than the first stage, wherein the second bias is output with a target output value set in one stage, and wherein an output time of the second bias is longer than an output time of the first bias.