Patent ID: 9465330
Filing Date: 2016-10-11
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: a photoreceptor; a developing unit that forms a toner image on the photoreceptor; an intermediate transfer member that rotates in only one direction and has a surface onto which the toner image formed on the photoreceptor is primarily transferred; a primary transfer roller that primarily transfers the toner image formed on the photoreceptor onto the intermediate transfer member with application of a bias; a first bias applicator that applies a bias to the primary transfer roller; a secondary transfer roller that secondarily transfers the toner image primarily transferred on the intermediate transfer member onto a recording medium with application of a bias; a second bias applicator that applies a bias to the secondary transfer roller; a pre-brush that is placed downstream of the secondary transfer roller along a rotational direction of the intermediate transfer member, and abuts against the surface of the intermediate transfer member; a pre-brush bias applicator that applies a bias to the pre-brush; a cleaning blade that is placed downstream of the pre-brush along the rotational direction of the intermediate transfer member, and abuts against the surface of the intermediate transfer member to remove toner remaining on the intermediate transfer member; a first control unit that, when the toner passes through a position where the secondary transfer roller is placed, controls the second bias applicator to apply to the secondary transfer roller a bias of the opposite polarity to that of a charge of the toner to remove the toner, which is primarily transferred onto the intermediate transfer member, from the intermediate transfer member; and a second control unit that, after the operation of the first control unit, controls the second bias applicator to apply to the secondary transfer roller a bias of the same polarity as that of the charged toner and then controls the pre-brush bias applicator to apply to the pre-brush a bias of the opposite polarity to that of the toner.