| 摘要 |
PURPOSE:To uniformize a mixing ratio of recovered toner to unused toner by limiting an aperture, through which unused toner is supplied to a toner carrying pipe, to the position in the upstream side of the toner carrying pipe. CONSTITUTION:When a toner discharging screw 33 on the photosensitive body unit side and a toner carrying screw 28 on the developing unit side start rotation together with the start of the image forming cycle, the recovered toner passes in an inner tube 32 from a toner carrying path 15C, enters into a toner carrying pipe 26 and is carried into a developing device to be used again. At this time, the toner carried into the pipe 26 receives the flowing unused toner only in an aperture part 26A in the upstream of the pipe 26 and is mixed with it, and therefore, the mixture ratio is kept constant after toner passes the aperture part 26A, and this mixed toner is dropped into the developing device from a toner dropping hole 26B with a uniform distribution little by little while moving in the depth direction of the developing device. Thus, the fluidity of the developer is kept satisfactorily to form an image of good quality. |
