REVELATION DEVICE, REVELATION CARTRIDGE, ELECTRO-PHOTO IMAGE FORMATION FOR FORMING AN IMAGE ON A RECORDING MATERIAL, AND COUPLING ELEMENT

摘要

A coupling member (150) usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft (180) rotatable by a motor and having a rotating force applying portion (182), and a movable member, said coupling member being effective to transmit a rotating force from the driving shaft in a developing roller which is movable in a direction (X4) substantially perpendicular to an axial direction of the driving shaft, said coupling member comprising: a rotating force receiving portion (150a) engageable with the rotating force applying portion to receive the rotating force from the driving shaft; and a rotating force transmitting portion (150b) for transmitting the rotating force received through said rotating force receiving portion to said developing roller, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller through the rotating force transmitting portion, a pre-engagement angular position in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position.