Patent ID: 7831188

Claim:
An image forming apparatus, comprising: a photosensitive body on which to form an electrostatic latent image; an exposure device to irradiate light to the photosensitive body to form the electrostatic latent image; a developer adhering device to adhere a developer to the photosensitive body, on which the electrostatic latent image has been formed, to form a visible image; a transfer device to transfer the visible image formed on the photosensitive body onto a printing medium; and a fusing unit which includes: a press roller; a heating belt to closely contact the press roller to form a fusing nip to apply heat and pressure to the printing medium onto which the visible image has been transferred; a first support roller that is rotatably supported by a fixing frame having a plurality of guide ribs, and a second support roller that is rotatably supported by a moving frame having pairs of guide rails to form guide slots, the moving frame slidably coupled to the fixing frame by the plurality of guide ribs respectively moving in the guide slots of the guide rails, the first and second support rollers disposed apart from each other to circulatingly support the heating belt; and an elastic support device to elastically bias the first support roller and/or the second support roller in a direction away from each other to maintain a substantially constant tension of the heating belt.