Method for controlling image formation in electrophotography by pre-exposure step

In an electrophotographic machine including a reusable photosensitive member having a photoconductive layer and an overlying insulating surface layer;

• means for supporting said photosensitive member for endless movement;
• means for applying a primary charge of a predetermined polarity to said photosensitive member;
• means for exposing said photosensitive member to imaging light after the application of the primary charge;
• means for discharging or applying a secondary charge having a component of a polarity opposite to said predetermined polarity to said photosensitive member substantially simultaneously with exposure of said photosensitive member to imaging light by said imaging light exposing means;
• means for uniformly exposing the surface of said photosensitive member to light after the image light exposure to form an electrostatic latent image on said photosensitive member;
• means for utilizing the electrostatic latent image formed on the surface of said photosensitive member;
• and means for preparing the surface of said photosensitive member for repetitive use after the electronic latent image is utilized, the improvement comprising:
• image density adjusting means for causing fatigue of the photoconductive layer of said photosensitive member by applying light thereto so as to adjust image density, wherein said image density adjusting means uniformly applies light of a predetermined intensity to said photosensitive member, when said primary charge applying means, imaging light exposure means, discharging means, uniform exposure means, utilizing means and preparing means are to be repeatedly operated in sequence to form and utilize a plurality of electrostatic latent images, prior to the first application of primary charge during the sequential operation and applies uniform light of an intensity lower than said predetermined intensity prior to a subsequent application of primary charge during the sequence of image forming operations.