Image forming apparatus including main housing, first drum cartridge having first photosensitive drum, and second drum cartridge having second photosensitive drum

An image forming apparatus comprising:

• a main housing;
• a first drum cartridge comprising a first photosensitive drum rotatable about a first axis extending in a first direction, the first drum cartridge being attachable to and detachable from the main housing;
• a second drum cartridge comprising a second photosensitive drum rotatable about a second axis extending in the first direction, the second drum cartridge being attachable to and detachable from the main housing, the first drum cartridge and the second drum cartridge being arranged in a second direction crossing the first direction in a state where both the first drum cartridge and the second drum cartridge are attached to the main housing;
• a first toner cartridge configured to accommodate toner therein, the first toner cartridge being configured to be coupled to the first drum cartridge in a third direction crossing both the first direction and the second direction;
• and
• a second toner cartridge configured to accommodate toner therein, the second toner cartridge being configured to be coupled to the second drum cartridge in the third direction,
• wherein the first drum cartridge further comprises:
• a first frame supporting one end portion in the first direction of the first photosensitive drum;
• a second frame supporting another end portion in the first direction of the first photosensitive drum;
• a third frame having a first passage opening configured to allow toner from the first toner cartridge to pass therethrough, the third frame being immovable relative to the first photosensitive drum;
• a developing housing configured to accommodate therein toner that has passed through the first passage opening, the developing housing being movable relative to the first photosensitive drum;
• and
• a sealing member positioned around and away from the first passage opening, the sealing member sealing a gap between the developing housing and the third frame.