Patent ID: 7502584
Filing Date: 2009-03-10
Classification: G03G

Abstract:
1. An image forming apparatus for forming a superposed image by transferring an image formed on an image carrier to an intermediate image transfer belt, said image forming apparatus comprising: a plurality of belt position sensors configured to sense a position of the intermediate image transfer belt in a direction perpendicular to a direction of movement of said intermediate image transfer belt each, said plurality of belt position sensors being located between rollers over which said intermediate image transfer belt is passed at positions different from each other in said direction of movement in a plane of said intermediate image transfer belt; and a displacement calculator configured to produce a difference between sensed values output by said plurality of belt position sensors at a plurality of any belt positions of the intermediate image transfer belt and then sequentially add said difference to a difference between sensed values output from said plurality of belt position sensors at belt positions different from said any belt positions for thereby determining a displacement of said intermediate image transfer belt in the direction perpendicular to the direction of movement.