Belt driving unit and image forming apparatus

A belt driving unit comprising:

• a plurality of rollers including a driving roller that is rotationally driven;
• an endless belt stretched round the plurality of rollers;
• a driving unit that conveys the endless belt by rotating the driving roller;
• a control unit that controls driving of the driving roller by the driving unit;
• and
• a detection unit that detects the position of the endless belt in a widthwise direction that is perpendicular to a conveying direction of the endless belt, wherein
• the driving roller includes a first driving roller and a second driving roller arranged side by side in the widthwise direction;
• a direction in which the first driving roller forwards the endless belt and a direction in which the second driving roller forwards the endless belt are nonparallel to each other;
• and
• the control unit controls the position of the endless belt in the widthwise direction by driving the first driving roller and the second driving roller at different speeds on the basis of a detection result of the detection unit.