A belt fuser includes fuser and tension rollers rotatably supported in a
frame. A belt reeved over the fuser and tension rollers holds at least two
idler rollers in place and forms a nip with the fuser roller. The tension
roller is connected to a tension control mechanism that applies, through
the tension roller, a tension force in the belt and a normal force against
the fuser roller throughout the nip. Because the belt holds the idler
rollers in place, they can be of low-cost, light-weight, compact
construction and require no additional support. Fusing nip length, dwell
time, and thermal efficiency are greatly improved over two roll fusers,
and the fusing temperature can be significantly reduced as a result. The
belt fuser is more compact than previous belt fusers, occupying only
slightly more space than conventional two roll fusers.
