Patent ID: 8682207

Claim:
An image forming apparatus, comprising: an image forming unit configured to form an image to be transferred onto a transfer medium; a seamless belt configured to move in a predetermined conveying direction to convey the transfer medium in an image transfer range, the seamless belt comprising: a first section that extends from a first roller through the image transfer range to a second roller and faces the image forming unit; and a second section that extends from the first roller to the second roller and does not face the image forming unit, wherein the second section is on an opposite side of the first and second rollers than the first section; a pair of belt rollers, including the first and second rollers, which are arranged in positions to define a most downstream portion and a most upstream portion of a stream of the belt moving in the predetermined conveying direction and configured to support the belt in a flattened condition; a tensile force applier configured to contact the first section of the belt and generate resistance against the belt moving in the predetermined conveying direction to apply tensile force to the first section of the belt in the image transfer range, and configured to apply tensile force to flatten the first section in the image transfer range of the belt; and a controller configured to control the tensile force applier to apply the tensile force to the belt in the image transfer range during an imaging period, in which operations including an image transfer operation are executed, and control the tensile force applier to one of reduce and clear the tensile force being applied to the belt during a non-imaging period, which is a time period excluding the imaging period.