To provide an image forming apparatus in which the shape of a belt roller unit is substantially reduced by a simple structure.
In the primary transfer belt unit 14 of the image forming apparatus, a drive roller is disposed on one side and an idle roller 20 is disposed on the other side, a tension roller 21 is disposed between the drive roller and the idle roller 20, and a primary transfer belt 15 is wound around the rollers. The primary transfer belt unit 14 is detachably attached to the image forming apparatus. The primary transfer belt unit 14 includes a swing arm 34, one end of which is pivotally supported by the stationary part of the primary transfer belt unit 14 so as to be freely rotated and the other end of which is a free end. The shaft 21a of the tension roller 21 is pivotally supported by the free end of the swing arm 34 so as to be rotatable. The free end is pressed from the inside of the primary transfer belt 15 to its outside by an elastic member via the tension roller 21.
UEDA HIROYUKI
TAKENAKA SHUSUKE
ODA TOMOYUKI
HOBO JUNPEI
Sachiko Okunuki