JPS643257B

PURPOSE:To expell the scraped developer immediately from a developing roller and prevent the developing roller from degrading by capturing and conveying the one- component type developer scraped from the developing roller and returning the same to the upper part of a developer vessel. CONSTITUTION:The insulating toner scraped from a developing roller 1 by an elastic scraper 3 is gathered in the central direction of the developer roller 1 by a screw 4 and is further conveyed to the upper part of a hopper 11 by a screw 5. It is then mixed in the toner in the hopper in a region 9. The screw 4 is cut with grooves 4a of opposite directions with the center as a boundary. In the case of a magnetic toner, the toner scraped from the magnet sleeve 1' by the scraper 3 is captured by a magnet roll 6 and the toner is conveyed to the upper part of the hopper 11 by the magnetic force between the roll 6 and an opposing magnetic roller 7 rotating at the same speed, thus it is mixed into the toner in the hopper in the region 9. Eaves 10 prevent a conveying path 12 from being exerted with the pressure of the toner in the hopper.