Image forming apparatus having developing unit in which developing device is movably disposed

摘要

An image forming apparatus includes: a main body; a photosensitive drum rotatably supported in the main body; a developing unit detachably accommodated in the main body in a direction along an axis of the photosensitive drum in a state where the photosensitive drum is disposed in the main body. The developing unit includes: a developer carrying member configured to carry developer for supplying the developer to the photosensitive drum; a developing frame supporting the developer carrying member; and a supporting assembly configured to support the developing frame such that, in a state where the developing unit is accommodated in the main body, the developing frame is movable between a proximity position where the developer carrying member and the photosensitive drum being positioned adjacent to or in contact with each other and a separation position where the developer carrying member and the photosensitive drum being separated from each other.

主权项

1. An image forming apparatus comprising:
a developing unit including:
a developer carrying member configured to carry developer;a developing frame supporting the developer carrying member; anda coupling configured to receive a driving force; a main body including:
a main casing;a photosensitive drum supported by the main casing and configured to receive the developer from the developer carrying member, the photosensitive drum being configured to rotate about a rotational axis; anda guide member configured to guide movement of the developing unit relative to the main casing in a first direction parallel to the rotational axis during attachment or detachment of the developing unit relative to the main casing; a movable member movable between a first position and a second position in accordance with input of the driving force, the movable member being configured to move the developing frame from a separation position to a proximity position while the movable member moves from the second position to the first position in a state where the developing unit is attached to the main casing, the developer carrying member contacting the photosensitive drum when the developing frame is at the proximity position, the developer carrying member being separated from the photosensitive drum when the developing frame is at the separation position; and a supporting assembly configured to support the developing frame, the supporting assembly comprising:
a first spring configured to apply a force to move the developing frame in a direction from the separation position toward the proximity position; anda second spring configured to apply a force to move the movable member in a direction from the first position toward the second position.