| 摘要 |
A drive transmission mechanism includes a driving coupling element having a first engaging portion and a first operating portion; and a holder having a second engaging portion and a second operating portion, wherein when the first and second engaging portion are engaged, the driving coupling element is held in a middle position to be prevented from moving therefrom to a projected position. When the driving coupling element is moved from the middle position toward a retracted position, the first and second operating portions contact each other so that the driving coupling element rotates to a second angular position where they are disengaged from each other. By the driving coupling element rotating from the first angular position to the second angular position, the driving coupling element is enabled to move to the projected position. |
