Patent ID: 8175506

Claim:
A belt driving controller, comprising: a driving roller connected to a driving axis; a plurality of driven rollers; an endless belt provided to surround the driving roller and the driven rollers in a tensioned state; a motor connected to the driving axis via a reduction mechanism; a first detector provided near the driving axis and configured to detect a rotation angle of the driving axis; a second detector configured to detect a displacement of the endless belt; and a control unit configured to control driving of the endless belt when driving by rotation of the motor, the control unit including: a first speed calculator configured to calculate a surface speed of the endless belt according a detected signal input from the second detector; a second speed calculator configured to calculate a driving axis speed according to a detected signal input from the first detector; a first speed control loop having a first speed compensator configured to compensate the surface speed of the endless belt by the comparison between a target speed of the endless belt and the surface speed of the endless belt calculated by the first speed calculator; and a second speed control loop having a second speed compensator configured to compensate the driving axis speed by the comparison between an output of the first speed compensator and an output of the second speed calculator.