| 摘要 |
PURPOSE:To constitute the compact developing device by providing a means which impresses an electric field for recovering toner on a toner carrier to a toner supply member after development between the toner carrier and toner supply member. CONSTITUTION:The toner carrier 13 and a sleeve 15 are impressed with voltages V1 and V2 (V1>V2) through a voltage switching device 22 selectively. Then, the voltage switching device 22 is held in a state A (solid line) during development; the toner carrier 13 is impressed with the voltage V1 and the sleeve 15 is impressed with the voltage V2. Consequently, only the toner sticks on the toner carrier 13 with an electric field directed from the toner carrier B to the sleeve 15 and magnetic carriers are attracted by a magnet 16 and held on the sleeve 15. Then, the device 22 is switched to a state B (solid line) during cleaning operation and the voltages V2 and V1 are impressed to the toner carrier 13 and sleeve 15 respectively, so that the toner remaining on the toner carrier 13 is recovered in the developer container 18 of the toner supply member. |
