| 摘要 |
An image forming apparatus (1) according to one aspect of the invention comprises: a main unit (2); and a developer cartridge (28) detachably attached to the main unit. The developing cartridge (28) comprises: a rotation body (80) having a rotational axis and rotatable in a rotation direction; and one rotational arm (84) of a first rotational arm or two rotational arms (84,85) of the first rotational arm and a second rotational arm which are rotatable around the rotational axis. The main unit (2) comprises: a swingable detecting arm (93); an elastic member (94) that urges the detecting arm (93) toward a neutral position. When the developer cartridge (28) is attached to the main unit (2), the first rotational arm (84) contacts with the detecting arm (93) to swing in a first swing direction from the neutral position. When the rotation body (80) rotates by a predetermined rotation amount, the second rotational arm (85) contacts with the detecting arm (93) in a second direction from the neutral position. |
