Color order in predicting pile height constraints in a xerographic color printing system

Abstract

Abstract A digital color printing method is described for printing process black over a background color, which makes use of color order information--that is, the order in which process colorants are transferred to paper--in determining and satisfying pile height constraints for optimal quality. In certain printing systems such as xerographic systems, printing problems can occur when process black, composed of a mixture of colorants such as cyan, magenta, yellow, and black, is printed over a color background. One such problem for example occurs when a process black containing all colorants at maximum or near-maximum value is printed on a color field. In this case, the excessive toner pile height of such a process black can sometimes cause objectionable deletions in the surrounding color field, caused by interference in the transfer of toner to the background color field surrounding the process black. Systems have been described which calculate the pile height of the process black in relation to its background color and reduce the process black colorant levels to conform to parametric pile height requirements. However, the minimal reduction of process black colorants is desired in order to avoid other potential printing problems. This invention proposes that in some systems, the order in which colorants are transferred to the paper may be taken into account in calculating total pile height, and the information of colorant order may be used to minimize the reduction of the colorant levels in process blacks.

Inventors

• 👤 Robert M. Coleman

Bibliographic Details