ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS, DEVELOPING APPARATUS, AND COUPLING MEMBER

摘要

A developing device usable with an electrophotographic image forming appa ratus, and movable in a direction substantially perpendicular to an axial di rection of a driving shaft comprising a coupling member for transmitting a r otating force to the developing roller, capable of taking a rotational force transmitting angular position for transmitting the rotational force, a pre- engagement angular position which is taken before the coupling member is eng aged with the rotating force applying portion and in which the coupling memb er is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member t o disengage from the driving shaft and in which the coupling member i inclin ed away from the rotational force transmitting angular position in a directi on opposite to the pre-engagement angular position; wherein in response to a movement of the developing device, the coupling member moves from the pre-e ngagement angular position to the rotational force transmitting angular posi tion to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the same direction, the coupling member is dise ngaged from the driving shaft by moving from the rotational force transmitti ng angular position to the disengaging angularposition.