Abstract: A multicolor developing device having a plurality of developing mechanisms for executing developing with differrent colors. The developing device includes a stationary frame member, a movable frame member mounted on the stationary frame member to reciprocally move in a predetermined direction, and a moving device for reciprocally moving the movable frame member. The plurality of developing mechanisms are mounted on the movable frame member and maintaining a distance in the said predetermined direction. Any one of the plurality of developing mechanisms is selectively positioned at a developing zone depending on the movement of the movable frame member. The moving device includes a screw device having a threaded shaft extending in the predetermined direction and a nut engaged with the threaded shaft, a stepping motor for rotating the threaded shaft, and a nonexcited operation-type electromagnetic brake.

Abstract: Guided through a sliding member by a guide member set before a photoreceptor, a plurality of developing units approach the photoreceptor in turn and face the photoreceptor, thereby to develop, at an open portion of the guide member with being projected by an enforcing member.