Patent ID: 7398025

Claim:
An electrophotographic image forming device comprising: a photoconductive unit; a charger unit operative to charge a surface of the photoconductive unit to a first voltage; an imaging unit forming a latent image on the surface of the photoconductive unit by selectively discharging the surface of the photoconductive unit to at least a second voltage by illumination thereof; a developer roller having a surface biased to a third voltage and operative to develop toner to the latent image on the surface of the photoconductive unit; a substrate onto which the developed image is transferred from the surface of the photoconductive unit; a sensing unit operative to detect a reflectance of the developed image on the substrate and a reflectance of a non-developed area on the substrate; and a controller operative to produce subsequent images while adjusting the third voltage until a desired reflectance of one of the subsequent images on the substrate is obtained, and then adjust the first voltage to produce a desired reflectance of the non-developed area on the substrate while maintaining the third voltage at the value resulting in the desired reflectance of the one subsequent image.