TONER REPLENISHING DEVICE

PURPOSE:To prevent toner from scattering by coupling one terminal of a toner feeding means with a toner hopper and the other terminal with a toner container, and supplying toner by utilizing negative pressure. CONSTITUTION:A developing device 7 has an agitator screw 8 and a rotatable sleeve 9 internally and the toner hopper 12 is provided above the developing device 7. A toner feed source 15 such as a fan and a vacuum pump is brought under rotary control of a motor 16. When this toner feed source 15 rotates, negative pressure is produced in a pipe, so the toner in the toner container 6 is sucked and sent in the toner hopper 18 through pipes 18 and 17. The toner hopper 12 is provided with an air vent member 19, through which only air is discharged. Part of toner- mixed air sent to the pipe 17 is returned to the toner container 6 through a pipe 22 to scatter and agitate the toner in the toner container 6. improving suction efficiency.