Patent ID: 7151902
Filing Date: 2006-12-19
Classification: G03G

Abstract:
1. A module included in a plurality of tandemly arranged modules in an electrophotographic color printer, said module associated with a process control system, said module comprising: a photoconductive image-recording member; a charging device to establish on said photoconductive image-recording member a uniform surface potential having a voltage magnitude adjustable via said process control system; an exposure device to modulate said uniform surface potential and thereby form a latent image on said photoconductive image-recording member; a development station to develop said latent image and thereby form a toner image on said photoconductive image-recording member; a transfer station for electrostatically depositing said toner image onto a receiver member in a transfer nip, said transfer station having a transfer roller and a constant-current power supply for delivering to said transfer roller a transfer current; a controller responsive to said voltage magnitude, said controller to control said constant-current power supply so as to generate said transfer current according to a functional relationship between said transfer current and a control voltage parameter derived from said voltage magnitude; wherein in accordance with said functional relationship said transfer current has a predetermined constant magnitude if a magnitude of said control voltage parameter is less than or equal to a critical control voltage magnitude; wherein in accordance with said functional relationship and if said magnitude of said control voltage parameter is greater than said critical control voltage magnitude, said transfer current has a linear increase of magnitude with increase of said magnitude of said control voltage, said linear increase of said transfer current characterized by a predetermined slope; and wherein a toner control patch is produced from time to time so as to have a density substantially equal to a reference maximum density, said toner control patch derived from a patch latent image formed on said photoconductive image-recording member by said charging device and said exposure device, said patch latent image developed by said development station, said photoconductive image-recording member having been charged to said voltage magnitude prior to creating said patch latent image thereon.