Patent ID: 8532531

Claim:
An image forming apparatus, comprising: an image bearing member configured to bear a toner image; a rotatable, endless intermediate transfer member; a primary transfer member configured to primarily transfer the toner image from the image bearing member to the intermediate transfer member at a primary transfer portion; a secondary transfer member configured to secondarily transfer the toner image from the intermediate transfer member to a transfer material at a secondary transfer portion; and a charging unit disposed upstream of the primary transfer portion and downstream of the secondary transfer portion in the rotating direction of the intermediate transfer member and configured to charge residual toner on the intermediate transfer member, wherein the charging unit includes a brush member in which a plurality of conductive fibers including an electric insulating portion and an electric conductive portion are bundled, part of the outer circumferential surface of the conductive fibers serves as the conductive portion, and the other part serves as the insulating portion, and wherein the conductive portion of some of the conductive fibers opposes a surface of the intermediate transfer member, and not the conductive portion but the insulating portion of other conductive fibers opposes the surface of the intermediate transfer member.