IMAGE FORMING APPARATUS

摘要

An image forming apparatus capable of suppressing a charging lateral stripe liable to generate at a last stage of a lifetime of a photosensitive member while suppressing a density fluctuation is provided.;A constitution which includes a photosensitive member 1, a charging portion 2, a charging voltage source S1, an exposure portion 3, a developing portion 4, an obtaining portion 120 for obtaining information relating to a cumulative operating amount and a controller 110 for effecting control so that a discharging operation for discharging the photosensitive member 1 by exposing the photosensitive member 1 to light by the exposure portion 3 is executed is used.

主权项

1. An image forming apparatus comprising:
a rotatable photosensitive member; a charging portion, rotatably contacting said photosensitive member, for electrically charging said photosensitive member by electric discharge under application of a DC voltage; a charging voltage source for applying the DC voltage to said charging portion; an exposure portion for exposing said photosensitive member charged by said charging portion to light to form an electrostatic image on a surface of said photosensitive member; a developing portion for developing, with a toner, the electrostatic image formed on the surface of said photosensitive member by said exposure portion to form a toner image on the surface of said photosensitive member; a transfer device for transferring the toner image formed on the surface of said photosensitive member onto a transfer material at a transfer portion, wherein image formation is effected without the exposure of said photosensitive drum to light in a position downstream of the transfer portion and upstream of said charging portion with respect to a rotational direction of said photosensitive member; an obtaining portion for obtaining information relating to a cumulative operating time; and a controller for effecting control so that the surface of said photosensitive member is exposed to light by said exposure portion over not less than one full turn of said photosensitive member during post-rotation after completion of formation of a final electrostatic image and before stop of rotation of said photosensitive member in a period of successive rotation of said photosensitive member, on the basis of the information obtained by said obtaining portion, wherein said controller effects control so that when the cumulative operating time of said photosensitive member obtained by said obtaining portion is a first time, an exposure amount of said photosensitive member by said exposure portion is a first exposure amount during the post-rotation, and when the cumulative operating time of said photosensitive member obtained by said obtaining portion is a second time longer than the first time, the exposure amount is a second exposure amount larger than the first exposure amount.