| 摘要 |
PURPOSE:To make it possible to adjust the exposure light quantity to the photosensitive material stably and accurately, by changing the electric field intensity between the corona discharging equipment and the photosensitive material to an intensity corresponding to the selected circumferential speed of the photosensitive material to control corona discharge given to the photosensitive material. CONSTITUTION:The reference current is flowed to corona discharging equipment 21 for primary charging and corona discharging equipment 22 for electricity removal while photosensitive material 10 is rotated in a circumferential speed corresponding to the selected copying magnification, and the bright part potential and the dark part potential on the surface of the photosensitive material are measured alternately by sensor 29. These signals of the bright part potential and the dark part potential are input to operation control circuit 32 through amplifying circuit 31. The signal set previously of target potential constant signal generating means 33 and the detection signal of sensor 29 are compared with each other, and their difference is calculated, and the calculated correction current according to the correction expression set previously is added to the reference current. This added current is applied to corona discharging equipment 21 for primary charging and corona discharging equipment 22 for electricity removal through power sources 34 and 35. |
