| 摘要 |
PURPOSE:To perform the self-cleaning of contamination due to foreign matter and maintain recovering performance extremely stably by inverting the polarity of a voltage impressed between a scavenger roller and a counter electrode for a specific period. CONSTITUTION:The scavenger roller 42 in a residual toner recovering device 30 is impressed with a voltage having the polarity opposite to the electrostatic charging polarity of toner from a DC power source 50, and the counter electrode 44 is impressed with a voltage having the same polarity with the toner. Then, the polarities of said impressed voltages are switched by a voltage polarity switching device 52. Consequently, the foreign matter other than toner carried with a fur brush 38 is prevented almost completely from being deposited to stick to the roller 42 or electrode 44, and the recovering performance is improved extremely stably by the self-cleaning operation. |
