PURPOSE: To constitute a small-sized, simple device by using part of image formation processing equipment in common.
CONSTITUTION: A control grid 11 is provided near the opening of a corona discharging device 10 and a selective control means 12 is connected to the grid 11 to control the device 10 so that a photosensitive drum 1 is charged uniformly in mode I and a toner image formed on the drum 1 is transferred in mode II. This means 12 consists of a selecting means 13 and control means 13 and 14, and an output of necessary corona discharging is selected according to timing for distinguishing between the modes I and II from a device control part. For example, when a high output for transfer is necessary, the grid 11 is grounded through the means 14 having a high resistance value and when a low output for transfer is necessary, the grid 11 is grounded through the means 15 having a low resistance value.
NUKUSHINA ETSUJI
NAKAI YOSHIYUKI
