Patent ID: 7236725

Claim:
An image formation device, comprising: an image carrier in which latent images are formed; and; a development device into which a plurality of development units housing developing material are detachably installed, wherein when development units with a plurality of colors to form color images are installed in a plurality of installation positions of said development device, respectively, the image formation device operates in color printing mode; and wherein when at least one black development unit among said development units of the plurality of colors is installed in any position among said plurality of installation positions, and at least one among said development units of a plurality of colors other than black is not installed, even if at least one among said development units of the plurality of colors other than black is installed, the image formation device operates in monochrome printing mode; and wherein said development units have storage means for storing color information and remaining amount information for the developing material housed therewithin; and said image formation device further comprises: control means for deciding said color printing mode or monochrome printing mode, according to the color information of said storage means of development units installed in said development device; and display means for displaying, for each of said plurality of installation positions, information indicating whether said development unit is installed, and color information and remaining amount information for the developing material of an installed development unit; wherein said control means access the storage means of said development unit, as necessary, writes developing material amount remaining information for said development unit, reads color information and amount remaining information for said developing material, and for each of said plurality of installation positions, causes to be displayed on said display means information indicating whether a development unit is installed, and color information and amount remaining information for the developing material of an installed development unit.