| 摘要 |
PURPOSE:To eliminate the bad influence based on formation of a toner layer, by preventing this toner layer from being formed undesirably in regions of both end parts of a coat sleeve 2. CONSTITUTION:A length L5 of a magnet roll 3 in a developing sleeve 1 is set to be slightly longer than a maximum copy paper width LP, and a length L4 of a magnet roll 4 in a cost sleeve 2 is set to be slightly longer than the length L5. Scooping members 26 and 26 which coincide with the end face of the magnet roll 4 in the sleeve 2 or get slightly inside this end face are so provided that they are brought lightly contact with or are about 0-0.5m/m apart from circumferential face regions L2 and L2 of both end parts of the coat sleeve 2. By this constitution, no toner layer or a very thin toner layer is formed on the circumferential face in both ends of the coat sleeve 2, and only a toner having the same properties such as tribo-property completely is formed on the sleeve surface between these both ends, and thus, a uniform thin layer is formed on the developing sleeve 1. |
