Abstract: An image forming apparatus includes an image bearing member; a rotatable belt member; a rotatable supporting roller for stretching the belt member; and a steering roller controlled by motors for stretching the belt member and for moving the belt member in a widthwise direction by an inclining operation. A number of sensors detect the position of the belt member in the widthwise direction and produce an output, causing a first controller to change the amount of the inclining operation of the steering roller in order to counter the force moving the belt member in the widthwise direction. The output of the sensors also causes a second controller to change the amount of the inclining operation of the steering roller in short intervals to reduce the rapid positional deviation of the belt member attributable to the inclination of the steering roller.

Abstract: An image forming apparatus includes a rotatable belt member; an image forming station; first and second detecting members for detecting widthwise positions of the belt member; first and second steering rollers for correcting the widthwise positions of the belt member by inclination; a control portion configured to control inclinations of the first and second steering rollers on the basis of an output of the first or second detecting member; a first executing portion configured to execute, in a period other than an image formation period, an operation in a correction mode of, in a state that the first steering roller is at a first reference inclination, controlling the second steering roller to correct a second reference inclination of the second steering roller; and a second executing portion configured to execute, in a period other than that of the correction mode operation, an operation in a control mode of controlling the first and second steering rollers on the basis of the first and second reference incl

Abstract: An image forming apparatus includes an image bearing member; a rotatable belt member for carrying a toner image transferred from the image bearing member or for carrying a recording material carrying a toner image transferred from the image bearing member; a rotatable supporting roller for stretching the belt member; a steering roller for stretching the belt member and for moving the belt member in a widthwise direction by inclining operation; detecting means for detecting a position of the belt member with respect to the widthwise direction; first control means, responsive to an output of the detecting means, for controlling an amount inclining operation of the steering roller to control a force of moving the belt member in the widthwise direction; and second control means, responsive to an output of the detecting means, for controlling an amount inclining operation of the steering roller to displacing the belt member in the widthwise direction.

Abstract: An image forming apparatus includes a rotatable belt member; an image forming station for forming an image on the belt member or a recording material carried on the belt member in a region opposing the belt member; first detecting means for detecting a position of the belt member with respect to a widthwise direction of the belt member; a first steering roller for correcting the position of the belt member with respect to the widthwise direction by inclination; first controller for controlling an inclination of first steering roller on the basis of an output of the first detecting means; second detecting means for detecting the position of the belt member; a second steering roller for correcting the position of the belt member with respect to the widthwise direction by inclination; calculating means for calculating such an amount of inclination of the second steering roller that a movement distance of the belt member is not more than a predetermined value in a state that an inclination of first steering rolle