Patent ID: 7359658

Claim:
A tension adjuster of a belt, the tension adjuster comprising: a tension roller configured to rotatably contact an inner surface of the belt; a fixed shaft being disposed a predetermined distance away from the tension roller; a fixed shaft gear located on the circumference of the fixed shaft; a plurality of gear trains interposed between a gear driving the belt and the fixed shaft gear to rotate the fixed shaft gear; a pair of swing arms connecting the fixed shaft to a shaft of the tension roller; a tension unit configured to rotate the swing arm on a circumference of the fixed shaft in a first direction so that the tension roller produces a tension on the belt, the tension unit comprising a friction clutch disposed on the circumference of the fixed shaft on an outward side of the swing arm, the fixed shaft gear being located on the circumference of the fixed shaft so that the friction clutch is disposed between the fixed shaft gear and the swing arm; and a tension releasing unit to apply torque to the swing arm on the circumference of the fixed shaft in a second direction opposite to the first direction, wherein, when the belt rotates, torque generated by the tension unit is greater than the torque generated by the tension releasing unit, so that when the belt is stopped, the belt is released by the torque of the tension releasing unit.