Color electrophotographic image forming apparatus including a rotary drive transmission mechanism

A color electrophotographic image forming apparatus for forming an image on a recording medium, the color electrophotographic image forming apparatus comprising:

• an electrophotographic photosensitive member;
• a rotatable supporting member which supports a number V of developing devices (where V is a natural number) for developing an electrostatic latent image formed on the electrophotographic photosensitive member;
• an electric actuator;
• a rotary member having the number V of engaging portions engageable with the electric actuator, and rotated integrally with the rotatable supporting member;
• and
• a drive transmission mechanism including a rotatable supporting member gear having a gear portion engageable with a driving member rotated in one direction and the number V of toothless portions, one of the toothless portions, facing the driving member in a state in which the electric actuator is engaged with one of the engaging portions, the rotatable supporting member gear being rotated integrally with the rotatable supporting member, and when one of the developing devices is located at a developing position, one of the engaging portions is located at a position in which the one of the engaging portions engages with the electric actuator and one of the toothless portions is located at a position in which the one of the toothless portions is opposed to the driving member,
• wherein each time one of the engaging portions is engaged with and disengaged from the electric actuator, the gear portion of the rotatable supporting member gear which is rotated in synchronism with the rotary member is engaged with the driving member so that the rotatable supporting member is rotated by an angle W which satisfies (360°/V) and stopped.