Belt driving device and image forming apparatus

A belt driving device for driving a endless belt, the belt driving device comprising:

• a plurality of rollers configured to stretch the belt, said rollers including first and second steering rollers being provided in an upstream side and a downstream side of an image receiving surface of the belt for receiving a image, respectively, and being configured to change a position of the belt in a direction crossing with a moving direction of the belt by inclining respectively;
• a pivoting unit configured to pivot said first and second steering rollers, respectively;
• a detecting unit for detecting an inclination amount of the belt with respect to a direction crossing with a feeding direction of the belt;
• and
• a controller configured to pivot said first and second steering rollers in opposite directions by said pivoting unit on the basis of a result of detection of said detecting unit.

A belt driving device for driving an endless belt, the belt driving device comprising:

• a plurality of rollers configured to stretch the belt, said rollers including first and second steering rollers being provided in an upstream side and a downstream side of an image receiving surface of the belt for receiving a image, respectively, and being configured to change a position of the belt in a direction crossing with a moving direction of the belt by inclining respectively;
• first and second pivoting mechanisms configured to pivot said first steering roller and second steering roller in accordance with respective pivoting instruction values;
• a first detecting member and a second detecting member configured detect a position of the belt with respect to a widthwise direction crossing with a moving direction of the belt;
• a first setting portion configured to set a first pivoting instruction value and a second pivoting instruction value through which said first steering roller and said second steering roller are pivoted in the same direction, respectively, on the basis of results of detections of said first detecting member and second detecting member;
• a second setting portion configured to set a third pivoting instruction value and a fourth pivoting instruction value through which said first steering roller and said second steering roller are pivoted in the opposite directions, respectively, on the basis of a result of detection of at least one of said first detecting member and second detecting member;
• and
• a controller configured to pivot said first steering roller by said first pivoting mechanism on the basis of an addition value of the first pivoting instruction value and the third pivoting instruction value, and configured to pivot said second steering roller by said second pivoting mechanism on the basis of an addition value of the second pivoting instruction value and the fourth pivoting instruction value.