| 摘要 |
PURPOSE:To improve the accuracy of detecting toner concentration, to prevent erroneous detection and to perform the appropriate control of the supply of toner. CONSTITUTION:Before the toner concentration detecting action by a toner concentration sensor 8, the revolving speed of a stirring paddle 4 is set to be high. When the toner concentration detecting action is finished, the revolving speed thereof is restored to the ordinary one. An aperture part 41c for discharging developer may be provided in the center part of the carrying tube 41 of the paddle 4 above the sensor 8. Further, a film having a smooth surface may be stuck to the detection surface 8a of the sensor 8. |
