Patent ID: 7933538

Claim:
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 a number M of engaging portions (where M is a natural number) engageable with the electric actuator; and a drive transmission mechanism including a transmission gear having a number X of teeth (where X is a natural number), to which a rotation force is transmitted from a driving member rotated in one direction, and a rotary rotatable supporting member gear having a number Y of teeth (where Y is a natural number), the rotatable supporting member gear engaged with the transmission gear so as to be integrally rotated with the rotary rotatable supporting member, each value of the natural numbers being set to satisfy a relation that (X/M) is an aliquot part of (Y/V), wherein each time one of the engaging portions is disengaged from the electric actuator, the rotary member makes a 1/M revolution, and once every 1/M revolution, a rotation force is transmitted from the transmission gear which is rotated integrally with the rotatable member to the rotatable supporting member gear, and the rotatable supporting member is stopped after being rotated by an angle W which is an aliquot part of (360°/V), to sequentially move each of the plurality of developing devices to a development position in which the electrostatic latent image is developed.