Patent ID: 8406665

Claim:
A belt driving device comprising: an endless belt that is stretched over and supported by a plurality of supporting rollers including a steering roller for correcting belt meandering; an inclining mechanism that performs an operation of inclining the steering roller by a driving force from a driving source; a belt-width direction displacement detecting unit that detects displacement of the endless belt in a belt-width direction; an inclination controlling unit that determines an inclination amount of the steering roller based on a detection result obtained by the belt-width direction displacement detecting unit, and controls the operation of the inclining mechanism to incline the steering roller by the inclination amount such that meandering of the endless belt is corrected by changing the inclination amount of the steering roller; a displacing member that is displaced integrally with the steering roller according to the inclination amount of the steering roller; and a position detecting unit that detects a position of the displacing member when the steering roller is in a predetermined reference inclined position, wherein the inclination controlling unit causes the inclining mechanism to perform the operation of inclining the steering roller to the reference inclined position based on a detection result obtained by the position detecting unit every time predetermined adjustment timing arrives and, using an amount of the operation performed by the inclining mechanism as an operation reference, controls the operation of the inclining mechanism based on the operation reference.