Patent ID: 7499663

Claim:
An electrophotographic image forming apparatus for forming an image on a recording material, said apparatus comprising: (a) a plurality of mounting portions that detachably mount cartridges, respectively, said cartridges each including: a developing roller that develops an electrostatic latent image formed on an electrophotographic photosensitive drum; a developer accommodating portion that accommodates a developer for use by the developing roller to develop the electrostatic latent image, a developer supply opening that supplies the developer to the developing roller from the developer accommodating portion; a sealing member that unsealably seals the developer supply opening; and an unsealing device that unseals the developer supply opening by removing the sealing member from the developer supply opening; (b) a motor; and (c) a driving force transmitting device that transmits a driving force selectively to one of the unsealing devices from said motor to unseal selectively one of the developer supply openings, said driving force transmitting device including: a gear, rotatable about an axis, that receives the driving force from said motor; a rotatable member rotatable about said axis; a planetary gear, rotatable relative to said rotatable member and revolvable about said axis by rotation of said rotatable member, that selectively transmits the driving force from said gear to one of said unsealing devices; a frictional portion that transmits the driving force from said gear to said rotatable member by a frictional force produced by being pressed between said rotatable member and said gear; a plurality of engaging portions, provided on said rotatable member, that stop said rotatable member at a plurality of positions where said planetary gear is capable of transmitting the driving force to the plurality of unsealing devices, respectively; and a trigger, engageable with one of the engaging portions, that stops rotation of said rotatable member against the frictional force.