An image forming apparatus in which the rotational speed of register rollers
is
calculated at first to fourth stations at a transfer belt drive system, and transfer
feedback control for varying the speed of a transfer drive motor is carried out
on the transfer drive motor so that the speed of movement of a transfer belt is
maintained at a predetermined value. The transfer feedback control is carried out
on the image forming apparatus so as to vary the speed of the transfer drive motor
so that the speed of movement of the transfer belt is maintained at a predetermined
value or so as not to vary the speed of the transfer drive motor as a result of
not carrying out the transfer feedback control.