Drive transmission unit and image forming apparatus including same

A drive transmission unit, comprising:

• a first input rotary body to rotate in a first direction;
• a second input rotary body;
• a rotation input shaft to bear rotatably and coaxially the first input rotary body and the second input rotary body,
• a first switching device disposed on the rotation input shaft to switch between a power transmitting state and a non-transmitting state between the first input rotary body and the second input rotary body;
• a first output rotary body disposed in a radial direction of the first input rotary body, to receive from the first input rotary body a driving force in a second direction opposite the first direction;
• a second output rotary body disposed in the radial direction of the second input rotary body, to receive from the second input rotary body a driving force in the same direction of rotation as that of the second input rotary body;
• a rotation output shaft to bear rotatably and coaxially the first output rotary body and the second output rotary body, and
• a second switching device disposed on the rotation output shaft to switch between the power transmitting state and the non-transmitting state between the first output rotary body and the second output rotary body.