Abstract: A method of operating a printer enables a controller in the printer to operate electrical motors for aligning printheads in the printer with greater accuracy. The method includes generating a test pattern on media with a plurality of printheads, identifying a first position for each printhead in the plurality of printheads from test pattern image data, operating an electrical motor operatively connected to one of the printheads to move the printhead in a first direction in the cross-process direction by a predetermined distance, generating a second test pattern on the media, identifying a second position for each printhead, comparing the second position of the printhead with the first position of the printhead to measure a distance moved by the printhead, identifying a first calibration parameter with reference to the predetermined distance and measured distance, and operating the electrical motor with reference to the first calibration parameter.

Abstract: A printer operating method enables a controller to identify process direction errors in an optical imaging system. The method includes identifying a printhead roll error for each printhead in a plurality of printheads in a printer, moving each printhead by an amount that corrects the printhead roll error for the corresponding printhead, generating a plurality of dashes on media with the plurality of printheads as the media moves past the plurality of printheads, identifying a position for each dash in the process direction from image data of the plurality of dashes on the media, identifying a displacement in the process direction for each optical detector in a linear array of optical detectors used to generated the image data of the plurality of dashes, the displacement being identified with reference to the identified positions for the dashes, and operating the printer to compensate for the identified displacements of the optical detectors.

Abstract: A method compensates for changes in drop velocity of drops emitted by inkjets in a printhead of an ink jet imaging device. The method includes operating inkjet ejectors in a plurality of printheads to eject ink in a pattern of structured dashes on an image receiving member, the structured dashes corresponding to a predetermined image data pattern, generating image data corresponding to the pattern of structured dashes on the image receiving member, identifying a process direction correction parameter for each ejector in the plurality of printheads with reference to the generated image data, modifying image data to be printed by the plurality of printheads with reference to the process direction correction parameter identified for at least one of the ejectors, and operating the plurality of printheads with reference to the modified image data.

Abstract: A method enables changes in the operation of a web printing system in response to web dimensional changes being detected. The method includes identifying a cross-process dimensional change in a web moving through a printing system, comparing the identified cross-process dimensional change to a predetermined threshold, and changing operation of a component in the web printing system in response to the cross-process dimensional change exceeding the predetermined threshold.

Abstract: A test pattern printed by printheads in an inkjet printer enables image analysis of the test pattern that identifies positions of the printheads and the inkjets operating in the printheads. The test pattern includes a plurality of arrangements of dashes, each arrangement of dashes having a predetermined number of rows and a predetermined number of columns, each dash in a row of dashes in the arrangement of dashes being separated by a first predetermined distance and each dash in a column of dashes in the arrangement of dashes being separated by a second predetermined distance, each dash in a column of an arrangement of dashes being ejected by a single inkjet ejector in a printhead of the inkjet printer, and a plurality of unprinted areas interspersed between the plurality of arrangements of dashes.

Abstract: A computer-implemented method for performing color registration on template media having template markings thereon.

Abstract: A method analyzes image data corresponding to a test pattern generated on an image receiving member by a printer to identify positions for and registration between printheads in the printer.

Abstract: A printing apparatus has a substantially shiny photoreceptor imaging surface, and a photosensor array disposed to receive specularly-reflected light from the imaging surface. A quantity of toner is placed on the imaging surface, and data is derived based on light reflected from the imaging surface. The reflected light is filtered to a color effectively complementary to the toner color. The system avoids noise caused by diffusely-reflected light from powdered toner.

Abstract: A method compensates for changes in drop velocity of drops emitted by inkjets in a printhead of an ink jet imaging device. The method includes adjusting image data used to generate firing signals for an inkjet ejector in a printhead of an inkjet imaging device with an initial ink drop correction parameter, adjusting a portion of the adjusted image data with another ink drop correction parameter in response to the portion of the adjusted image data corresponding to a predetermined firing pattern mask, generating firing signals for the inkjet ejector from the adjusted image data, and transmitting the generated firing signals to the inkjet ejector in the printhead.

Abstract: A system removes a light sensor artifact from a light sensor in a printer that is used to obtain reflectance measurements from test patterns printed on an image substrate.

Abstract: Systems and methods are provided for calibrating a sensory array to ensure a robust cross-process registration measurement. The calibration is implemented using a calibration step that determines the signature error amount of a given image reading sensor. The signature error amount for the sensor is stored in a signature error look-up table. When the sensors are used to sense print head alignment, the correction may be implemented by accessing the signature error look-up table for the given sensor when calibrating the print heads. The signature error look-up table provides an amount of offset for each sensor that is used in determining the appropriate head position of a given print head to calibrate the print heads for the signature error associated with the given sensor.

Abstract: A method enables an inkjet printing system to attenuate image noise in an image of a test strip obtained as print media bearing the test strip travels over a roller in the printing system.

Abstract: A test target is written in a non image zone at set time intervals. The test target is sensed. At least one of frequency, amplitude and phase of banding, which is inherent in a printing device, is determined based on the sensed test target. At least one banding compensation parameter based at least on one of the determined frequency, amplitude and phase of banding is determined. Characteristics of producing an image based on the determined banding compensation parameter are adjusted to compensate the banding inherent in the printing device.

Abstract: Systems and methods are provided for detecting intermittent, weak or missing jets of a printer. The detection is implemented using a test pattern. Detected failed jets may be confirmed using a verification target. A printhead containing nozzles corresponding to detected failed jets may be wiped or purged.

Abstract: A system and method that enables web paper skew detection by monitoring print head motor position. An inline full width array sensor actively tracks the alignment of the print heads across the print zone and actively moves the heads to maintain alignment. If the paper starts to skew across the print zone, a color misregistration error will be detected and the print units will be moves with respect to each other to maintain alignment. The absolute position of the print heads can be monitored by tracking the steps sent to each motor to maintain alignment.

Abstract: An apparatus prints on a continuous web moving in a process direction. A fiducial marker prints on a portion of the web a repeating pattern of fiducial marks at a predetermined spacing along the process direction. At least two printing stations are operatively disposed downstream of the fiducial marker, each printing station including a printhead for placing marking material suitable for a partial image on the web. A photosensor reads a fiducial mark on the web moving relative to the printing station.

Abstract: What is disclosed is a novel system and method for reducing process color banding due to printhead non-uniformities in a direct marking device. In one example, a first measurement of a printhead spatial non-uniformity is obtained along a first line in a color space which produces a spatial uniformity when a target primary color is printed alone. A first spatial tone reproduction curve is generated. A second measurement of the printhead spatial non-uniformity is obtained along a second line in color space in a coverage area of a process color which maximally changes a halftone structure of the target primary color. A second spatial TRC is generated. The first and second spatial TRCs are combined using a weighted average which balances the primary and process colors. A modified spatial TRC is generated. The printhead is adjusted at a location of the target primary color according to the modified spatial TRC.

Abstract: A system and method for achieving registering of side 1 and side 2 images includes sensing marks on both sides of a web with a single IOWA sensor and relying on light transmission through paper to sense side 1 marks. Side 1, the side not facing the IOWA sensor utilizes increased contrast (black toner), mark width, and repeats in order to make effective image “show through.” The image of the marks on both sides of the sheet is compared with respect to each other and adjustments to some combination of position, timing, and image magnification are made as required.

Abstract: A registration system for use with an imaging device includes sensors for detecting a web speed and a web tension of a moving web and a control system configured to generate a first timing offset for at least one marking station based on the detected web speed and web tension. An image sensor is configured to generate a signal indicative of a position of a marking material applied to the moving web by at least one of the marking stations. The control system is configured to generate a second timing offset for the at least one marking station based on the position of the marking material indicated by the third signal, and to adjust an actuation time for the at least one marking station using the first timing offset and the second timing offset.

Abstract: Systems and methods are provided for calibrating a sensory array to ensure a robust cross-process registration measurement. The calibration is implemented using a calibration step that determines the signature error amount of a given image reading sensor. The signature error amount for the sensor is stored in a signature error look-up table. When the sensors are used to sense print head alignment, the correction may be implemented by accessing the signature error look-up table for the given sensor when calibrating the print heads. The signature error look-up table provides an amount of offset for each sensor that is used in determining the appropriate head position of a given print head to calibrate the print heads for the signature error associated with the given sensor.