Image forming apparatus performing image quality adjustment based on period image forming assembly unloaded and forming final image while image forming assembly replaced

Abstract

An image forming apparatus includes individually replaceable image forming assemblies forming images of different colors; a storage portion that stores time when at least one image forming assembly currently loaded into the apparatus is unloaded; a calculating portion that calculates an unloaded-engine storage period, time elapsed from when a newly loaded image forming assembly is unloaded last time to when the image forming assembly is newly loaded; and a controller that performs image quality adjustment depending on the unloaded-engine storage period calculated before the newly loaded image forming assembly is used for image formation. The apparatus receives image data of an image that contains a color other than colors that currently loaded image forming assemblies form. The apparatus forms a final image based on the image data on a sheet through image forming operations on the same sheet while at least one of the loaded image forming assemblies is replaced.