Patent ID: 8000617

Claim:
An image forming apparatus to form an image according to a four-color developing method using yellow, magenta, cyan, and black (Y, M, C, and K) developing units or a multi-color developing method using Y, M, C, and K developing units and at least one auxiliary developing unit, the image forming apparatus comprising: a first developing part including the Y, M, C, and K developing units, each developing unit including a developer storage unit to store Y, M, C, and K developers, respectively; a second developing part including the at least one auxiliary developing unit including a developer storage unit to store a developer other than the Y, M, C, and K developers; and a plurality of photosensitive media, one photosensitive medium formed in each of the Y, M, C, and K developing units and the auxiliary developing unit, wherein the developer storage unit of at least one of the Y, M, C, and K developing units is larger than the developer storage unit of the auxiliary developing unit.