DRIVE TRANSMISSION MECHANISM, DRIVE DEVICE AND IMAGE FORMATION DEVICE

To reduce a dimension along an axial direction of drive transmission means for transmitting and releasing rotation drive force, relative to a drive structure comprising: a drive force transmission member which is driven to rotate by a drive source; and a coupling member which is movable in an eccentric direction and an axial direction with the drive force transmission means and coupled to the drive force transmission member so as to transmit rotation thereto.SOLUTION: A drive transmission mechanism comprises: drive means comprising a drive transmission shaft 581 on whose outer periphery, a plurality of salients are formed, and being driven to rotate; drive transmission means which is attached movably along an axial direction of the drive transmission shaft through an attachment hole comprising on its inner periphery, a plurality of recesses engaged to the plurality of salients, and to which rotation drive force is transmitted from the drive means; and gap formation parts each of which is provided on one of a tip of the drive transmission shaft and a base end of the attachment hole, and forms a gap for allowing inclination of the drive transmission shaft in a state in which the salients and recesses are engaged.SELECTED DRAWING: Figure 12 【課題】駆動源によって回転駆動される駆動力伝達部材と、駆動力伝達部材と偏心方向及び軸方向に移動可能で且つ回転伝達可能に連結する連結部材とを備えた駆動構造に比較して、回転駆動力の伝達及び解除を行う駆動伝達手段の軸方向に沿った寸法を小さくする。【解決手段】外周に複数の凸部が設けられた駆動伝達軸５８１を有し、回転駆動される駆動手段と、前記複数の凸部と係合する複数の凹部を内周に有する装着孔を介して前記駆動伝達軸の軸方向に沿って移動可能に装着され、前記駆動手段から回転駆動力が伝達される駆動伝達手段と、前記駆動伝達軸の先端及び前記装着孔の基端に設けられ、前記凸部と前記凹部が係合した状態で前記駆動伝達軸の傾斜を許容する間隙を形成する間隙形成部と、を備える。【選択図】図１２