Abstract: An image forming apparatus includes a rotatable belt member, a plurality of image forming members opposing the belt in an image forming region, a first detecting member configured to detect a position of the belt member with respect to a widthwise direction, a second detecting member configured to detect a moving direction, an adjusting roller configured to adjust the moving direction in the image forming region, the adjusting roller configured to adjust the moving direction in the image forming region, and a control portion configured to control a position of the adjusting roller on the basis of outputs of the first detecting member and the second detecting member without changing a position of the belt member in the image forming region in a direction perpendicular to a surface of the belt member.

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 apparatus includes a belt member, a first image bearing member, a second image bearing member provided downstream of the first image bearing member, and a first steering roller provided upstream of the first image bearing member for controlling a widthwise position of the belt member by inclining at a position. In addition, a second steering roller is provided downstream of the second image bearing member and controls the widthwise position of the belt member, a first detecting member detects a widthwise position of the belt member on the first image bearing member, and a second detecting member detects a widthwise position of the belt member on the second image bearing member.

Abstract: An image forming apparatus capable of accurately forming an image in a predetermined position on a sheet. An image forming unit forms a toner image on a drum. The toner image is transferred onto a belt. A motor drives the belt to convey the toner image to a transfer position where the toner image is transferred onto a sheet. An image position-detecting section detects that a patch image indicating the position of the toner image on the belt has reached a detection position upstream of the transfer position in an image conveying direction. A sheet position-detecting section detects that the leading edge of the sheet has reached a detection position upstream of the transfer position in a sheet conveying direction. An image speed-setting section controls the conveying speed of the belt based on timings of detection by the respective image position-detecting and sheet position-detecting sections.

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 a photosensitive drum; an image forming device for forming a toner image on the drum; an endless belt; first and second rollers supporting the belt; a first sensor for detecting a widthwise position of the belt; a first displacing device for displacing the first roller in accordance with an output of the first sensor; a second sensor for detecting a widthwise position of the belt; a second displacing device for displacing the second in accordance with an output of the second sensor; an adjuster for adjusting first and second reference positions such that a tangent line direction of the drum at a position at which the drum contacts the belt is parallel with a moving direction the belt.

Abstract: An image forming apparatus includes a belt member; a first drum for bearing a toner image to be transferred onto the belt member; a second drum, provided downstream of the first drum with respect to a rotational direction of the belt member, for bearing a toner image to be transferred onto the belt member; a first steering portion, provided upstream of the first drum with respect to the rotational direction of the belt member, for controlling a widthwise position of the belt member; and a second steering portion, provided downstream of the second drum with respect to the rotational direction of the belt member, for controlling the widthwise position of the belt member with a delay of a movement time of the belt member from the first drum to the second drum.

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

Abstract: An image forming apparatus includes a rotatable belt; an image forming station for forming an image on a belt or on a recording material carried on a belt in a region opposing the belt; a first detector, provided in one of upstream and downstream sides of the region with respect to a rotational direction of the belt, for detecting a position of the belt with respect to a widthwise direction; a second detector, provided in the other of upstream and downstream sides of the region with respect to a rotational direction of the belt, for detecting a moving direction in the region; a steering roller, disposed in the one side with respect to the rotational direction, for correcting a position of the belt with respect to the widthwise direction by inclining; a first controller for controlling an inclination of the steering roller on the basis of an output of the first detector; an adjusting roller, provided in the other of the sides with respect to the rotational direction, for adjusting the moving direction in the r