| 摘要 |
PURPOSE:To prevent a developer form scattering out of a developing container by opening a shutter means during developing operation and releasing the pressure in a developing device to the outside. CONSTITUTION:When a rotary developing device 4 moves as shown by an arrow Y and the developing device moves from the position of a developing device 4BK to the position of a developing device 4Y, a shutter lever 54c operates on a cam 50a fixed on a center shaft 50 and is rotated and a shutter plate 54a which closes a window 52a rotates around a pivot 54b to open the window 52a. At this time, a lid 47a closing the opening 47 of the developing device at a development position falls by gravitation and the opening 47 is opened. Consequently, the inside of the developing device 4Y communicates with the air chamber 52 in a cylindrical member 51 through a duct 53 to prevent a developer form being blown out of a developing opening 41a, so that images of good quality having no scatter are obtained. |
