Image forming apparatus, rotation type development unit, and toner replenishment container

An image forming apparatus, comprising:

• a casing;
• a rotation type development unit having a plurality of developers and a rotational body that is rotatably supported on the casing, the plurality of developers being able to be mounted with a toner replenishment container filled with toner, and being disposed on a peripheral surface of the rotational body;
• the casing defining a replacement hole that is provided in a position that links to a mounting position of the toner replenishment container of one of the developers is to be mounted when the rotational body stops rotating at a predetermined position, the toner replenishment container inserting into the replacement hole when the toner replenishment container mounts into the developer;
• a replacement door that opens the replacement hole when the replacement door is opened, and closes the replacement hole when the replacement door is closed;
• and
• a replacement door fastening mechanism that, after the replacement door is closed in a state that the toner replenishment container is inserted into the replacement hole and after the toner replenishment container is pressed by the replacement door and mounted into a mounting position of the developer by being pushed inside the replacement hole by the replacement door, causes the replacement door to return and stop at a closed position and fastens the replacement door in a state that the replacement door and the rotation type development unit are apart in the closed position.

A rotation type development unit, comprising:

• a rotational body that rotates around a rotational shaft;
• a plurality of developer bodies that are arranged on a peripheral surface of the rotational body and that have a toner holding chamber for holding toner taken in from a toner replenishment outlet and a developing agent supporter that develops an electrostatic latent image formed on an image carrier using toner supplied from the toner holding chamber;
• a toner replenishment container that inserts in a direction parallel to the rotational shaft between a first developer body and a second developer body neighboring each other and that replenishes toner into the toner holding chamber through a replenishment outlet linking to the toner replenishment outlet;
• a first guiding portion provided at the toner replenishment container;
• and
• second guiding portions provided at an area of the first developer body and an area of a second developer body that are opposed to an area in which the first guiding portion of the toner replenishment container that is inserted is arranged,
• wherein, in a process of inserting the toner replenishment container, the toner replenishment container being guided in a direction parallel to the rotational shaft of the rotational body by the first guiding portion and the second guiding portion, and the first guiding portion and the second guiding portion being apart from each other after the toner replenishment container is inserted.