Adaptive process controller for electrophotographic printing

An electrophotographic printing machine of the type having processing stations and a photoconductive member with a solid area density region, a half-tone density region and a highlight density region developed thereon, wherein the improvement includes:

• a sensor for detecting densities of the solid area density region, half-tone density region and highlight density region developed on the photoconductive member and transmitting a solid area density signal, a half-tone density signal and a highlight density signal indicative of the solid area density region, half-tone density region and highlight density region;
• an updater, in communication with said sensor, for generating a solid area density correction signal, a half-tone density correction signal and a highlight density correction signal in response to the solid area density signal, half-tone density signal and highlight density signal transmitted thereto from said sensor;
• and
• a controller, responsive to the solid area density signal, halftone density signal and highlight density signal from said sensor and the solid area density correction signal, half-tone density correction signal and highlight density correction signal from said updater, for transmitting control signals to the processing stations to regulate the processing stations.

A method of controlling parameters of processing stations in a printing machine having a photoconductive surface with a variable density image developed thereon, including the steps of:

• detecting densities of the variable density image developed on the photoconductive surface and transmitting density signals indicative thereof;
• generating correction signals in response to the density signals transmitted thereto;
• and
• transmitting control signals, in response to the density signals and the correction signals, to the processing stations to regulate the processing stations.