Image forming apparatus

An image forming apparatus comprising:

• a plurality of toner image forming devices, each comprising:
• a rotating photoconductor;
• a charging device that uniformly charges a surface of the photoconductor;
• a latent image forming device that forms an electrostatic latent image on the surface of the charged photoconductor;
• a developing device that develops the electrostatic latent image on the surface of the photoconductor to a toner image;
• and
• a developing container that contains toner used by the developing device, wherein
• a diameter of the photoconductor of at least one toner image forming device of the plurality of toner image forming devices is formed larger than a diameter of the photoconductor of the other toner image forming devices,
• each developing container of all the toner image forming devices is formed in equal-sized, and
• a center of rotation of a developing roll of each developing device is arranged in a position upper than a center of rotation of each photoconductor.