Xerox Corporation

Xerox Corproation

James Patrick Calamita

Daniel W Costanza

Mark A Atwood

Patricia Joanne Donaldson

Paul J McConville

David Allen Mantell

Barry Paul Mandel

James J Spence

Michael John Martin

Michael F Leo

Michael B Monahan

James Lawton Giacobbi

Shawn Patrick Updegraff

Robert P Loce

Santokh Singh Badesha

Anthony Salvatore Condello

Roger Gaylord Leighton

James Edward Williams

Martin Edward Hoover

David Clark Craig

David Mark Kerxhalli

Abu Saeed Islam

Brian Robert Conrow

Joseph M Wing

Anthony Yeznach

Jeffrey Russell Kohne

Edward B Caruthers, Jr

Vincent M Williams

Douglas Raymond Taylor

Alan G Schlageter

Brian J Perry

Thomas R Race

Rene E Sanchez

Gregg Anthony Guarino

Andrey Podzorov

According to aspects of the embodiments, there is provided methods to measure characteristics of line width and density of printed test patterns. By printing the test patterns and capturing with an in-line scanner or optical device, the analytical results of these test patterns can be used as feedback to a control system that adjusts both impression and inking levels without the need of a skilled operator.

Print targets and image analysis for feedback control of flexographic printing devices

A printer is configured with at least two printheads that are separated from one another in a cross-process direction by an integral multiple of printhead widths. This configuration enables parallel swaths of material to be ejected and then movement of the printheads in the cross-process direction by a distance corresponding to one or more integral numbers of the printhead width enables the area between the swaths to be completed and the area outside of the original swaths printed.

Printer having a separated printhead array

A printing system includes a pair of encoders to compensate for encoder noise in the velocity of a media transport as the transport moves past a plurality of printheads. One encoder monitors a roller that positioned at a location of low thermal stress and the signal generated by this encoder is used by a controller to maintain a constant velocity for the media transport. The second encoder monitors a roller used to drive the media transport and is positioned close to the print zone opposite the printheads. The signal from the second encoder is used to identify a corrected distance between each tic in the tics generated by the second encoder and the corrected distance is used to count a firing distance for generation of a dot clock signal to activate ejectors in a printhead when a substrate has traveled the firing distance.

Dual encoder system to minimize reflex printing variation

According to aspects of the embodiments, there is provided process and architecture for enabling multiple digital micromirror devices (DMDs) that include optical modulation elements configured to modulate light outputting from a light source, and a projection unit configured to project light modulated by the optical modulation elements on a printing plate. Image defects due to misalignment in the cross-process direction of the output from the DMDs are discovered by using a single test pattern image and combined with knowledge of how individual pixels are rendered to register printing elements which can render a variable number of pixels. Misalignment errors can be corrected by selecting a different set of mirrors for a given DMD.

Method for measuring beam to beam stitch error in the presence of variable width beams

Printer having separated printhead array and method for operating a printer having a separated printhead array

A printing system facilitates the registration of printheads in the system. The system includes a plurality of printheads, a planar member having at least three pins along a first edge of the planar member and a plurality of pins on a second edge of the planar member that is orthogonal to the first edge, a plurality of actuators, an optical imaging device, and a controller. The controller operates one of the printheads to form a registration target on the media sheet and processes image data of the planar member and the media sheet received from the optical imaging device to identify positions for the registration target and at least two of the three pins on the planar member. Error distances are identified from the positions for the registration target and the at least two pins on the edge of the planar member and are used to register the printheads.

System and method for aligning images on media or platens

A method of analyzing a printed test pattern includes printing first and second rows of marks, each row including at least two pluralities of marks. A gap between two pluralities of marks in the first row is located in a first position in a cross-process direction that is different than a second position of another gap between pluralities of marks in the second row. A controller identifies the first row of marks with reference to a predetermined set of image data corresponding to the first row of marks including the first plurality of marks, the second plurality of marks, and the gap in the first row.

System and method for identification of marks in printed test patterns

A computer-based apparatus for preventive maintenance detection for a color printer including a photoreceptor belt (PB) arranged to displace in a process direction, including a memory element for storing a threshold value, computer readable instructions, and registration data for a plurality of markings on a surface of the PB, including for each marking, a respective registration difference, in a lateral direction orthogonal to the process direction, between a respective actual location and a respective original location. The apparatus includes a processor configured to execute the computer readable instructions to: determine that at least one marking from the plurality of markings is out of compliance with the at least one threshold value; and in response to determining that at least one marking from the plurality of markings is out of compliance with the at least one threshold value, transmit a signal, indicating that maintenance is required for the PB, for display.

Apparatus and method for lateral color registration performance and preventive maintenance detection

When reading calibration chevrons during mark-on-belt (MOB) sensor timing calibration, cyan portions or legs of printed chevrons are detected in order to determine a timing window offset adjustment. Depending on which of the six cyan legs on the left side of the chevrons are detected, a determination can be made regarding whether the window needs to be started earlier or later. If only the first two cyan legs on the left side of the chevron are detected, then the MOB sensor timing window is beginning (and ending) too early and an appropriate adjustment can be made to cause the timing window to initiate later. If only the last two cyan legs on the left side of the chevron are detected, then the MOB sensor timing window is beginning (and ending) too late, and appropriate adjustment can be made to cause the timing window to initiate earlier.

Automatic mob sensor timing adjustment

A method for aligning a printhead to compensate for printhead roll has been developed. The method includes simultaneously operating a plurality of inkjets in a printhead to eject ink drops to form a plurality of marks on an image receiving member. A plurality of cross-process direction distances between one mark formed by a reference inkjet and each of the marks formed by the other inkjets is identified. A magnitude of a difference between an angular orientation of the printhead and the cross-process direction with reference to the plurality of identified cross-process direction distances indicates any printhead roll.

Method and system for identifying printhead roll

A method for aligning a printhead to compensate for printhead roll when an image receiving member moves laterally during printing has been developed. The method includes generating at different times a plurality of marks in a process direction with different inkjets in a printhead and identifying relationships between marks in each plurality. Lateral motion is thereby detected and removed from the analysis identifying the magnitude of the roll corresponding to the locations of the marks in the pluralities of marks.

Method and system for correcting media shift during identification of printhead roll

A system and method is provided for detecting and correcting color-to-color process direction misregistration errors, including a printer capable of printing in a plurality of colors, the printer having a sensor for generating a signal including information corresponding to a color registration pattern printed on a substrate by the printer. The system and method further include a processor for receiving the signal from the sensor and analyzing the signal for detecting color-to-color process direction misregistration via an algorithm. The color registration pattern includes a plurality of segments, each segment associated with a different color of the plurality of colors and each segment including at least one different dimension from at least one other segment of the plurality of segments.

System and method for detecting color-to-color misregistration

In one embodiment, a method of measuring color-to-color registration includes: a) marking test pattern images on an image receiving member using a reference color separation station and a first color separation station over a process direction span in relation to selected target media and a cyclic characteristic of a multicolor marking platform, b) detecting each test pattern image, c) determining a registration measurement associated with the first color separation in relation to the reference color separation for each test pattern image, and d) determining a repeatable registration error pattern associated with the first color separation and the selected target media in relation to the cyclic characteristic based at least in part on the registration measurements determined in c). In one embodiment, the multicolor marking platform includes a marking engine, a controller, an image receiving member, a sensor, color registration measurement logic, and repeatable registration error determining logic.

Method and apparatus for measuring color-to-color registration

A method for detecting, in-situ, a cross-process linearity error in an image printing system that prints on an image bearing surface movable in the process direction is provided. The method includes placing marking material to form of a row of registration marks on the image bearing surface, detecting a position in a cross-process direction of each registration mark in the row using a linear array sensor that extends in the cross-process direction, and determining a correction function with a processor using the positions of the registration marks as detected by the linear array sensor to compensate for an error in the positions in the cross-process direction of the registration marks. The row of registration marks extends in a cross-process direction transverse to the process direction.

Use of registration marks and a linear array sensor for in-situ raster output scanner scan line nonlinearity detection

A method for monitoring an image printing system that prints color images on an image bearing surface movable in a process direction is provided. The method includes placing marking material to form a row comprising a plurality of registration marks on the image bearing surface, wherein each row of registration marks extends along a cross-process direction transverse to the process direction; detecting a position of each registration mark using a linear array sensor extending in the cross-process direction, wherein the position of each registration mark is detected in both the process and cross-process direction; determining a process direction misregistration between the registration marks of each row in the process direction and cross-process direction misregistration between registration marks from each of the rows.

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Spencerport, NY, United States of America

James Patrick Calamita