Print Quality Measurements for High-Speed Electrophotographic Printers

Described here are some of the characteristics that make electrophotographic printing esthetically pleasing, and the use of a recently developed computer-controlled scanner for measuring those characteristics. New print quality measurements are described (for example, measurements of modulation, image gray-scale fidelity, and tangential-edge roughness) that allow the monitoring of the advanced printing functions made possible by all-point addressability. The requirements for and implementation of the scanner are discussed. Also discussed are the effects and limitations on print quality measurement resolution imposed by the algorithms used and the scanner; the effect of light scatter by the paper; and the usefulness of the print quality measurements as an aid in making design trade-off decisions and in manufacturing control.