Patent ID: 8891996

Claim:
An image forming apparatus, comprising: an image bearing member to bear a toner image on a surface thereof; a transfer unit including a transfer device to transfer the toner image onto a recording medium, disposed opposite the image bearing member; a control circuit board to control the transfer unit; and a power supply module, the power supply module including: a power source to apply, between the image bearing member and the transfer device, an AC-DC superimposed bias in which an alternating current (AC) voltage is superimposed on a direct current (DC) voltage to form a transfer electric field to transfer the toner image from the image bearing member onto the recording medium; an AC power source to supply an AC voltage; metal planar members to surround a top and bottom, and sides of the power supply module; a harness supplied with a high AC voltage by at least the AC power source; and an insulating guide member to guide the harness such that the harness does not contact with the metal planar members.