Patent ID: 6011576
Filing Date: 2000-01-04
Classification: G03G,H04N

Abstract:
An electrophotographic printing apparatus, comprising:a photosensitive member having a surface;a light source;means for placing marking material of a first type on the surface of the photosensitive member, thereby developing a first image scanline on the photosensitive member;a light collector disposed to collect light from the light source interacting with the photosensitive member at an image area being exposed by the light source, the light collector outputting a signal related to intensity of the interacting light, thereby determining whether marking material of the first type was placed on said image area;means for causing the light source to expose a plurality of image areas forming a second image scanline on the surface of the photosensitive member; andmeans for controlling the exposure of light from the light source on an image area when exposing the second image scanline, based on whether marking material of the first type was placed on said image area.