Patent ID: 8010029

Claim:
An image forming apparatus having a fusing device, the fusing device comprising: a fusing belt; a heat source disposed in an interior of the fusing belt; a supporting member to support at least a portion of an inner surface of the fusing belt; a press member mounted while opposing the fusing belt to form a fusing nip; and a nip forming part formed with an opening portion to enable heat emitted from the heat source to be transferred to the fusing belt at a position corresponding to the fusing nip, the nip forming part being provided with a plurality of gap maintaining parts to prevent change of a gap of the opening portion, wherein the plurality of gap maintaining parts are arranged in a width direction of paper passing through the fusing nip and the heat emitted from the heat source is transferred through spaces between the plurality of gap maintaining parts, and wherein the area of the opening portion is larger than the sum of each area of the plurality of gap maintaining parts.