Patent ID: 8134741

Claim:
A system for controlling consistent color quality of overlay colors in a color printer or copier comprising: a first developer unit with first toner particles of a first color, wherein in forming a first test patch, the first developer unit transfers the first toner particles at a first target density, a controller subsequently determines a first actual density value of the first toner particles in the first test patch from an input of measurement of the first test patch, and determines a first error based on a difference between the first actual density value and the first target density, the first error having a positive or a negative value; a second developer unit with toner particles of a second color, wherein the second color is a different color than the first color, wherein in forming a second test patch, the second developer unit transfers the second toner particles at a second target density, and the controller subsequently determines a second actual density value of the second toner particles in the second test patch from an input of measurement of the second test patch, and determines a second error based on a difference between the second actual density value and the second target density, the second error having a positive or a negative value; and a coordinator, wherein the coordinator compares the first error to the second error, and wherein when the first error has a value opposite in sign to the value of the second error, the coordinator adjusts the density of the first toner particles to be applied by the first developer unit, the density of the second toner particles to be applied by the second developer unit, or both, so that the first error and the second error have a value with a same sign following the adjustment.