Patent ID: 8843028

Claim:
An image forming apparatus comprising: an apparatus main body including a transport unit configured to transport a print medium, and configured to allow a cartridge group and an alternative cartridge to be mounted therein; the cartridge group including a plurality of cartridges each including a developer container configured to contain a developer to visualize an electrostatic latent image, the plurality of cartridges being mountable simultaneously in the apparatus main body; the alternative cartridge including a developer container configured to contain a developer to visualize an electrostatic latent image, the developer container of the alternative cartridge having a larger capacity than each of the developer containers of the cartridge group; and plural mounting spaces in each of which a corresponding cartridge in the cartridge group is mounted, wherein if the cartridge group is mounted in the apparatus main body, the cartridges in the cartridge group occupy the corresponding mounting spaces, and if the alternative cartridge is mounted in the apparatus main body, the alternative cartridge occupies two or more of the plural mounting spaces, wherein the apparatus main body includes: an opening portion through which the cartridge group or the alternative cartridge is mounted in the apparatus main body; an opening/closing member movable between a closing position where the opening/closing member covers the opening portion and an opening position where the opening/closing member uncovers the opening portion; and plural biasing members provided corresponding to the plural mounting spaces, respectively, and configured to bias the cartridge group or the alternative cartridge towards the apparatus main body by being in contact with a biased surface of the cartridge group or the alternative cartridge when the opening/closing member is at the closing position, and wherein when the alternative cartridge is mounted in the apparatus main body, at least one of the plural biasing members is not in contact with the alternative cartridge, and the other biasing members are in contact with the alternative cartridge and thereby bias the alternative cartridge.