Patent ID: 8116664

Claim:
An image forming apparatus for forming a color image on a recording material, comprising: (i) mounting means for detachably mounting a plurality of process cartridges, each of which includes a photosensitive drum and a developing roller that develops an electrostatic latent image formed on the photosensitive drum, the process cartridges including a black process cartridge containing a black developer and a non-black process cartridge containing a non-black developer; (ii) a driving source; (iii) a first clutch that connects and disconnects said driving source and the developing roller of the black process cartridge, and that selects driving force transmission to the black process cartridge; (iv) a second clutch that connects and disconnects said driving source and the developing roller of the non-black process cartridge, and that selects driving force transmission to the non-black process cartridge; (v) a movable first member, actable on said first clutch, that switches between an operation state for transmitting a driving force from said driving source to the developing roller of the black process cartridge and a non-operation state of not transmitting the driving force thereto; (vi) a movable second member, actable on said second clutch, that switches between an operation state for transmitting the driving force to the developing roller of the non-black process cartridge and a non-operation state of not transmitting the driving force thereto; and (vii) a switching member, actable on said first member and said second member, that switches among (a) a first mode for transmitting the driving force to the developing rollers of all of the process cartridges, (b) a second mode for not transmitting the driving force to any one of the developing rollers, and (c) a third mode for transmitting the driving force only to the developing roller of the black process cartridge, wherein said switching member includes a first portion that contacts said first member to move said first member, said first portion being rotatable, and a second portion that contacts said second member to move said second member, said second portion being rotatable, and wherein said first portion and said second portion are rotatable only in a predetermined direction.