Patent ID: 7024138

Claim:
An image forming apparatus comprising a single electrostatic latent image bearing member and a cyclic image forming unit group i) which is provided in a circular arrangement with a plurality of image forming units each having a replenishing developer cartridge containing a replenishing developer, and a developing assembly, and forming respective different-color toner images on the electrostatic latent image bearing member and ii) which is so constructed that each image forming unit is rotatively movable to a development position; an exposure position and a development position at the time of forming respective-color toner images being the same for each color; the respective-color toner images formed on the electrostatic latent image bearing member being superimposingly transferred under registration onto a recording medium via, or not via, an intermediate transfer member, and the respective-color toner images formed on the electrostatic latent image bearing member being transferred to the recording medium or the intermediate transfer member at the same transfer position; at least one of the image forming units being a special-color image forming unit having a special-color replenishing developer cartridge containing a special-color color component replenishing developer, and at least one of the other image forming units being a non-special-color image forming unit having a non-special-color replenishing developer cartridge containing a non-special-color color component replenishing developer other than the special-color color component replenishing developer; the special-color image forming unit performing image formation by the use of a two-component developer containing a carrier and a toner; the special-color replenishing developer cartridge having a volume larger than the volume of the non-special-color replenishing developer cartridge; and the special-color color component replenishing developer containing a carrier and a toner.