US 8,134,741 B2Granted

System and method for controlling consistent color quality

AssigneeXerox Corporation

InventorsSong-Feng Mo, Patricia J. Donaldson, Michael J. Martin

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Abstract

A system and method control a consistent color quality of overlay colors and single separations of color. The method determines a first error for a first separation of a first color, wherein the first error has a first sign. The method identifies a second error for a second separation of a second color, wherein the second color is a different color than the first color, wherein the second error is based on an actual density value for toner particles printed transferred from the second separation, wherein the second error has a second sign. The method compares the first sign of the first error and the second sign of the second error. The method converges the actual density value of the second separation to a target position when the first sign is a different sign than the second sign.

Claims18

Dependent claims

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.

2 more elements

A method for controlling consistent color quality of overlay colors and single separations of color in a color printer or copier comprising:

creating a first test patch of first toner particles of a first of color at a first target density with a first developer unit, wherein a controller determines a first actual density of the first toner particles of the first test patch, the controller compares the first actual density toner to the first target density, and the controller determines a first error for the first color, wherein the first error has a first sign of positive or negative with respect to the first target density,
creating a second test patch of second toner particles of a second color, wherein the second color is a different color than the first color, at a second target density with a second developer unit, wherein the controller determines a second actual density of the second toner particles of the second test patch, the controller compares the second actual density to the second target density and the controller determines a second error for the second color, wherein the second error has a second sign of positive or negative with respect to the second target density;
comparing the first sign of the first error and the second sign of the second error;
and
converging the actual density of one of the first color or the second color to a target position when the first sign is a different sign than the second sign by adjusting the density of the first toner particles to be applied by the first developer unit, the second toner particles to be applied by the second developer unit, or both, so that following the converging, the first sign and the second sign are the same.

2 more elements

Dependencies are inferred from the claim text.