| 摘要 |
A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft having a rotating force applying portion, and a rotary, the device being mountable to the rotary, and the device being movable in a direction perpendicular to an axial direction of the shaft in response to movement of the rotary in one direction with the device mounted to the rotary, wherein the shaft is not movable in a direction perpendicular to an axis thereof, the device including i) a developing roller rotatable about an axis, wherein the roller is contacted to and separated from the drum in response to movement of the rotary; and ii) a coupling member for transmitting a rotating force to the roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the roller to the roller, a pre- engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre- engagement angular position, wherein in response to a movement of the device when the rotary moves in the one direction, the coupling member moves from the pre- engagement angular position to the rotational force transmitting angular position, and wherein when the rotary makes a further movement in the one direction, in response to the further movement, the coupling member is moved from the rotational force transmitting angular position to the disengaging angular position to disengage the coupling member from the shaft, and wherein the roller is contacted to the drum in response to the movement of the device in a state that roller is being rotated through engagement between the coupling member and the rotating force applying portion. |
