Patent ID: 7792453

Claim:
An image forming apparatus, comprising: a main body; a fusing device mounted in the main body, the fusing device including a frame having an inlet to introduce the paper into the frame and an outlet to discharge the paper from the frame; a first paper guide hingedly coupled to the frame adjacent to the outlet; a second paper guide mounted opposite to the first paper guide over the outlet; an opening/closing member opening and closing the outlet of the fusing device, the opening/closing member hingedly coupled to the frame at one end portion by a hinge shaft and being contacted with the second paper guide at the other end portion; a cam member moving the opening/closing member between a first position in which the opening/closing member closes the outlet to prevent heat in the fusing device from being emitted through the outlet and a second position in which the opening/closing member opens the outlet to permit the paper to pass through the outlet; a driving part rotating the cam member; a control unit controlling the driving part to determine a rotational position of the cam member; a first sensor sensing a front end of the paper entering the fusing device at the inlet of the fusing device; and a second sensor sensing a rear end of the paper leaving the fusing device at the outlet of the fusing device; wherein the opening/closing member opens the outlet of the fusing device when the first sensor senses that the front end of the paper enters the fusing device and closes the outlet of the fusing device when the second sensor senses that the rear end of the paper leaves the fusing device.