Patent ID: 8396391

Claim:
A color electrophotographic image forming apparatus for forming a color image on a recording material, said color electrophotographic image forming apparatus comprising: a plurality of cartridge mounting portions for demountably mounting cartridges, each of said cartridges including a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum into a developed image and a developer accommodating portion for accommodating a developer to be used for development of the electrostatic latent image; a single intermediary transfer member that is provided opposed to said electrophotographic photosensitive drums and onto which the developed images are transferred from said electrophotographic photosensitive drums; an image forming unit containing said cartridge mounting portions and said intermediary transfer member, said image forming unit being movable between (i) a transfer position for transferring, onto the recording material, the developed images transferred onto said intermediary transfer member from said electrophotographic photosensitive drums and (ii) a mounting and demounting position for permitting mounting and demounting of said cartridges relative to said cartridge mounting portions; and an opening for permitting mounting and demounting of said cartridges relative to said cartridge mounting portions of said image forming unit taking the mounting and demounting position, wherein, when said image forming unit takes the transfer position, said cartridges take attitudes in which the developer in said developer accommodating portions is supplied to said developing roller by the weight thereof, and wherein said image forming unit is rotatable about a rotation axis of said intermediary transfer member between the transfer position and the mounting and demounting position.