| 摘要 |
PURPOSE:To effectively prevent print from color mixing due to the drop of mixed toner by inverting the charged polarity of a prestage developing device into which toner is mixed by frictional charge with the carrier of a post stage developer and discharging the toner from a duct to the outside of a device. CONSTITUTION:The charged polarity of developer in the prestage developing device mixed into a post stage developing device A is inverted by frictional charge with the carrier of the post stage developer to weaken the coupling force. A suction port 20 is formed on a side wall 21 on which toner dispersed in the developing device is easily stagnated near the feeding port of a toner hopper 16 and connected to an air duct 19. Thereby, prints can be effectively prevented from color mixing due to the drop of mixed toner from the side wall or the like of the device. |
