| 摘要 |
PURPOSE:To prevent such troubles that a transfer roll is stained and the inside of a machine is contaminated without sticking unnecessary toner to a developing roll by providing a toner specifying plate which contacts and leaves the developing roller freely and is displaced lengthwise. CONSTITUTION:When a copying form is of small size, a solenoid 14 is not in operation and the toner specifying plate 9 is applied with force by a spring 19 through a lever 18 to bring its front edge into contact with the developing roll 4; toner 7 does not stick to the surface of the developing roll 4 at the lower position and toner 7 sticking thereto lengthwise is specified to perform development in this state. Further, when the copying form is of large size, the solenoid 14 is operated to draw in the plunger 15 as shown by an arrow A, and a pin 16 is engaged with the lever 18, which is rotated as shown by an arrow B to rotate a movable shaft 12. The toner specifying plate 9 fixed thereto is associated operatively as shown by an arrow C to leave the surface of developing roll 4 and the toner 7 is conveyed over the entire surface of the developing roll 4 to perform development for the large size. |
