US Patent 7349650 Printer apparatus

An image forming apparatus includes an image forming portion disposed in a detachable manner, an opening and closing member taking a closed position and an open position, a transfer unit disposed at the opening and closing member, as facing the image forming portion, having a belt disposed in a freely drivable manner and transferring a developer image, and a medium conveyance member for forming a conveyance route conveying a medium and for opening the conveyance route in association with movement of the opening and closing member from the closed position to the open position.