Abstract: Density or reflectance targets for respective first and second marking engines of a document processing system are determined. A series of control patches is printed with the respective first and second marking engines. Relative reflectance values of each control patch printed with the first and second engines are determined. First marking engine relative reflectance error values of each control patch and second marking engine relative reflectance error values of each control patch are determined correspondingly based at least on (a) corresponding first engine relative reflectance value and target relative reflectance value and (b) corresponding second engine relative reflectance value and target relative reflectance value. Based at least on one of the first and second marking engine relative reflectance error values, at least one of the first and second engine relative reflectance targets is adjusted.

Abstract: A first series of control patches is printed with a first marking engine. A second series of control patches is printed with a second marking engine. Relative reflectance values of the patches printed with the first and second marking engines are measured with respective first and second engine response sensors. Based at least on a difference in the measured relative reflectance values of the control patches printed with the first and second marking engines, a relative engine to engine error is determined. The engine to engine error is decomposed into components. Based on the decomposition, adjustment of at least binary values of a digital image is determined so that print density of a first marking engine output substantially matches print density of a second marking engine output.

Abstract: Samples are printed on print media with at least first and second marking engines. A first lightness value of a solid area of a first sample printed with the first marking engine and a second lightness value of a solid area of a second sample printed with the second marking engine are determined. The first and second solid area lightness values are compared to one another. Based on the comparison, a lighter marking engine and a darker marking engine are identified. Tone reproduction curve of the lighter marking engine is adjusted to substantially match tone reproduction curve of the darker marking engine.

Abstract: Method embodiments herein print a test document using a multi-function printing device to produce a printed document. This printed document is examined in a first direction to determine a first skew of the printing device. The first skew comprises a combination of raster output scanner skew and media path skew. The printed document is also examined in a second direction to determine a second skew. However, this second skew only includes the media path skew of the printing device. Once these two skews are acquired, the method can subtract the media path skew from the first skew to calculate the raster output scanner skew of the printing device.

Abstract: A method of adjusting a printing system includes providing a printing system including a plurality of marking engines that include first, second and third actuators. The method includes setting each of the actuators of each marking engine to predetermined values, and generating a plurality of printed samples having a visually apparent background density using at least one of the marking engines. The method also includes evaluating the printed samples, and adjusting the first actuator of at least one marking engine based at least partially on the evaluation. A system is also disclosed.

Abstract: A Xerographic system includes an imaging device that forms an image on a substrate and a controller that applies one-half of a substrate error value as a correction value to adjust a position of the image prior to the imaging device forming the image on the substrate. A method of adjusting an image on a substrate including determining a substrate error and applying one-half of the substrate error value as a correction value to adjust a position of the image on the substrate prior to forming the image on the substrate.

Abstract: Measurements are taken of a first parameter associated with a first marking engine and of a second parameter associated with a second marking engine. The first and second measurements are compared to predetermined first and second reference values. An engine-to-engine difference is determined by calculating a difference between the first measured parameter and the second measured parameter. The difference values are compared to corresponding predetermined threshold values. Based on the comparison, a system controller selects a mode of operation of the document processing system.

Abstract: A full width array CCD sensor is incorporated in the media path to monitor fused pages by calculating area coverage from multiple engines in a Tightly Integrated Parallel Process (TIPP) architecture. With knowledge of the area coverage differences between print engines for a given pixel count to the ROS, a relative density difference of each engine is determined. Based on the determined relative density difference, an adjustment is calculated and applied to the engine with the largest error to match the area coverage(s) of the other engine(s).

Abstract: Using a document scanner or other image input device of an image or document processing system to periodically scan or image printed test images from a plurality of marking engines replaces internal sensors as a feedback means in image quality control. For example, image lightness (L*) is controlled by periodically printing mid-tone test patches, scanning the printed test patches with a main job document scanner and analyzing the scanned image to determine updated marking engine actuator set points. For instance, ROS exposure and/or scorotron grid voltages are adjusted to maintain image lightness consistency between marking engines.