Image forming apparatus having photosensitive member and intermediate transfer member subjected to driving rotation control independently

An image forming apparatus comprising:

• an photosensitive member configured to have a tone image formed thereon;
• an intermediate transfer member configured to be rotatable in contact with said photosensitive member, for having the toner image on said photosensitive member transferred thereon;
• a first drive unit configured to drive said photosensitive member for rotation;
• a second drive unit configured to drive said intermediate transfer member for rotation;
• a first speed detection unit configured to detect a rotational speed of said photosensitive member;
• a second peed detection unit configured to detect a rotational speed of said intermediate transfer member;
• and
• a control unit configured to control said first drive unit and said second drive unit,
• wherein said control unit performs control other than control for normal printing operation, such that said second drive unit drives said intermediate transfer member with a predetermined rotational torque, in a state causing said photosensitive member to rotate at a predetermined rotational speed, and
• sets, based on a detection value from said second speed detection unit in a state in which said intermediate transfer member is friction-driven by said photosensitive member at a contact surface of said photosensitive member and said intermediate transfer member, which detection value is obtained by the control other than the control for the normal printing operation, a target value of said second speed detection unit for making a surface speed of said photosensitive member and a surface speed of said intermediate transfer member during the normal printing operation equal to each other, and controls said second drive unit such that the target value becomes a detection value.