| 摘要 |
PURPOSE:To control the image density quickly and accurately, by detecting the quantity of a toner stuck to an image carrier in the state of stabilized development characteristics to control the sticking of the quantity of the toner. CONSTITUTION:The surface potential of a photosensitive drum 1 as an image carrier is set to a value near zero volt of the saturated residual potential by the uniform exposure of a prescribed quantity of light due to an erase lamp 4 and a prescribed bias voltage to a developing roller 17 due to switching connection of a switch 27 to a contact 27a through a timing circuit 25. Meanwhile, the switch 27 is switched through the circuit 25, and the bias voltage of the roller 17 is set to a prescribed value, and the developing voltage is set to a prescribed voltage. Thus, development characteristics are stabilized, and the image of a drum 1 is developed in this state, and a toner can be stuck. The quantity of this toner is detected by a photodetector 7 and a density detecting circuit 26, and a toner supply device 35 of a developing device 5 is controlled through a toner supply controlling circuit 34 to adjust the quantity of the toner stuck to the drum 1, thereby controlling the image density quickly and accurately. |
