| 摘要 |
PURPOSE:To control so that various corona discharges provided in a copying machine execute corona discharge in accordance with each function, by controlling the corona discharge in a unit copying cycle set in advance, in accordance with a controlled variable. CONSTITUTION:When output voltage VO corresponding to control voltage of the previous copying cycle is outputted to a discharge electrode 2a, a photosensitive drum current ID corresponding to a discharge condition in that case flows, and it is read in a control unit 5 as a terminal voltage value of a resistance 34. Operations of (1) ID>IDMAX (the maximum set value) and (2) ID<IDMIN (the minimum set value) are executed by an operating circuit 53, by the operation sequence of a sequence controller 52, and when (1) is formed, the control voltage is dropped by 1 level each, and when (2) is formed, the control voltage is raised by 1 level each, by which the output voltage V0 is controlled so that (3) IDMIN<ID< IDMAX is formed. When (3) is formed, the control voltage in that case is stored in a memory 6, until a present unit copying cycle ends, corona discharge is executed by the output voltage V0 corresponding to this stored control voltage. |
