| 摘要 |
PURPOSE:To eliminate the need for providing a special driving device on a retracting mechanism, to simplify constitution and further, to reduce the cost by providing the retracting mechanism releasing the action of a pressing device linked with the reverse action of a driving system. CONSTITUTION:The retracting mechanism 11 is provided with a shaft 12 rotatably supporting a lever 5b supporting the leaf spring 5a of the pressing device 5, a coil spring 13 energizing the lever 5b and the spring 5a in the direction where a developing unit 4 is pressed on a photosensitive body 1 and the wire 16 whose one end is connected to a rotary shaft 14 in a driving system via a one-way clutch 15 and other end is connected to the lever 5b. When the driving system is rotated forward, the shaft 14 is rotated in the direction of the arrow A, the lever 5b, the spring 5a and the wire 16 are returned by the tension of the spring 13 and the spring 5a pressed the developing unit 4 on the drum 1 with prescribed pressure. Since the mechanism 11 is driven by the shaft 14 of the driving system in this way, it is unnecessary that the special driving device such a motor and a rotary magnet is provided on the mechanism 11. |
