Xerox Corporation

R Enrique Viturro

Howard A Mizes

Lalit Keshav Mestha

Eric Scott Hamby

Yongsoon Eun

Eric Peeters

Jeffrey J Folkins

Joel A Kubby

Eric Michael Gross

Fred F Hubble, Iii

Stanley John Wallace

Alan J Werner, Jr

Kenneth Russell Ossman

Jess Robert Gentner

Edward Blair Caruthers

Todd W Thayer

Peter Paul

John F Knapp

Michael D Thompson

Michael D Borton

Tonya L Love

Anthony M Wallace

Joseph D Hancock

David Kalman Biegelsen

David Allen Mantell

Warren Bruce Jackson

Robert Arthur Sprague

Raj B Apte

James R Larson

George Amos Gibson

Patricia Joanne Donaldson

Yeqing Zhang

Frank J Bonsignore

Lars-Erik Swartz

Narayan V Deshpande

Nancy Beth Goodman

Shawn Patrick Updegraff

Douglas A Kreckel

Fong-Jen J Wang

James G Chase

Phillip Crispino

Robert P Loce

Chu-Heng Liu

Beilei Xu

John Richard Andrews

Joseph A Swift

Roger Gaylord Leighton

Paul Allen Hosier

Michael F Zona

Gerald A Domoto

Scott M Silence

Jack T LeStrange

Robert Paul Herloski

Cathie J Burke

Lingappa K Mestha

Constance J Thornton

Moritz Patrick Wagner

Ralph A Shoemaker

James F O'Neill

Brian Robert Conrow

Sohail A Dianat

Claude Fillion

Clark V Lange

Joseph M Wing

Daniel Edgardo Viassolo

Lisa A DeLouise

Edward B Caruthers, Jr

Joseph A Mastrandrea

Mark Sennett Jackson

Alan G Schlageter

Robert Edward Hildebrand

Brian J Perry

Fei Xiao

Michael J Rice

Raymond L Mongeon

Sean D O'Brien

Tyco Skinner

Jean A Maksymiak

Daniel E Viassolo

Systems and methods are provided for compensating for streak defects in images formed by an image forming device, such as a digital printer. The systems and methods include using both modulation of a raster output scanner (ROS actuation) and spatially varying tone reproduction curve (STRC actuation) in a common control system for improving streak correction. Low spatial frequency large amplitude streak defects are corrected using ROS actuation and high spatial frequency streak defects, as well as any residual low frequency defects, are corrected using STRC actuation.

Method of correcting streaks using exposure modulation and spatially varying TRCs

A method for calibrating in situ a plurality of printheads in an imaging device has been developed. Firing signals operate a plurality of printheads to form ink test patterns on an image receiving member. Reflectance measurements of light reflected from the test patterns and optical density measurements for a portion of the patterns formed by only one printhead in the plurality of printheads are used to adjust the firing signals and enable the printheads to print within a predetermined range about an average reflectance value and a predetermined optical density.

In situ calibration of multiple printheads to reference ink targets

A method for operating a web printing system enables web and roller changes arising from temperature changes to be identified and used to adjust operation of the reflex registration system. The method includes identifying a temperature change for at least one roller in a web printing system, identifying a temperature change for a web moving through the web printing system at one or more locations in the web printing system, modifying web velocity computations for a reflex registration system with reference to the identified temperature change for the at least one roller and the identified temperature change for the web, and operating printheads to eject ink onto the web at positions identified with reference to the modified web velocity computations.

Reflex Printing with temperature feedback control

A method of operating a printer enables compensation parameters to be generated and stored in association with system conditions detected at the time of the compensation parameter generation. Upon detection of corresponding system conditions at a later time, the printer is able to use the previously generated and stored compensation parameters to adjust the timing of printhead ejections to improve the registration in ink images formed by the system.

Method and system for reflex printing to compensate for registration errors in a continuous web inkjet printer

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.

System and method for operating a web printing system to compensate for dimensional changes in the web

A method enables a printing system to be operated in one of two registration control modes. The method includes operating at least one marking station with reference to a first velocity measurement of a web moving along a web path in response to a first registration control mode being active, the first velocity measurement corresponding to an angular velocity signal obtained from only a first roller in a web path, and operating the at least one marking station with reference to a second velocity measurement of the web moving along the web path in response to a second registration control mode being active, the second velocity measurement corresponding to at least two angular velocity signals obtained from at least the first roller and a second roller in the web path.

System and method for switching registration control modes in a continuous feed printer

A computer-implemented method for performing color registration on template media having template markings thereon. The method comprising sensing the template media using a linear array sensor to obtain first image data; printing a test pattern on the template media; sensing the template media along with the test pattern printed thereon to obtain second image data; transforming the first image data and the second image data into an absorbance space to obtain a first absorbance and a second absorbance, respectively; calculating a difference between the first and the second absorbances to obtain an output absorbance; transforming the output absorbance into a reflectivity space to obtain an output data; determining a process direction misregistration and a cross-process direction misregistration from the output data; and adjusting a cross-process position and a process position of print heads based on the process and cross-process direction misregistration to provide accurate color registration on subsequent template media.

Color registration strategy for preprinted forms

A method of operating a printer enables printheads mounted on print bars to be operated to compensate for misalignment of printheads in the process direction. The method includes identifying a position in the process direction for each printhead in a plurality of printheads, selecting one of the identified printhead positions as a reference printhead position, identifying a printhead timing parameter for each printhead mounted to at least one print bar, generating a firing signal for the printheads mounted to the at least one print bar, and adjusting delivery of the firing signal by the identified printhead timing parameter for each corresponding printhead mounted to the at least one print bar to coordinate actuation of inkjet ejectors in the printheads mounted to the at least one print bar and compensate for misalignment of the printheads in the process direction.

Method and system to compensate for process direction misalignment of printheads in a continuous web inkjet printer

A method enables a controller to align printheads in a printer. The method includes identifying a first cross-process position for each printhead in a plurality of printheads in a printer with reference to image data of a test pattern printed by the plurality of printheads on a media substrate, identifying a second cross-process position for each printhead in the plurality of printheads, calculating a printhead cross-process position error between the identified first cross-process position and the identified second cross-process position for each printhead, comparing a maximum printhead cross-process position error to a predetermined threshold, and operating a plurality of actuators with reference to the calculated printhead cross-process position errors to reposition the printheads in the plurality of printheads in response to the maximum printhead cross-process position error being equal to or less than the predetermined threshold.

Method and system for printhead alignment to compensate for dimensional changes in a media web in an inkjet printer

A method of measuring and correcting the Young's Modulus inline to eliminate its impact on image length variation during print runtime. The method includes intentionally perturbing the nominal operating condition of the web printing system which is controlled by the double reflex printing controller. The perturbation creates misregistration in a control target printed image that is detectable by in-situ sensors, from which Young's Modulus is estimated. Specifically, the web tension before the print zone is set differently from the web tension in the print zone to create misregistration. The error is detected by the inline sensors, and it is used to calculate the actual Young's Modulus. The implementation of the method consists of measuring the Young's Modulus at various frequencies. The correct Young's Modulus in then incorporated into the double reflex printing algorithm.

Method and system for continuous feed printing systems

A method compensates for thermal expansion of rollers in a web print zone. The method includes receiving an angular velocity signal from a first encoder for a roller in a print zone of a moving web printing system, receiving a signal from a first temperature sensor corresponding to a temperature of the roller, modifying a first diameter for the first roller with a first predetermined distance in response to the temperature of the first roller being different than a first predetermined temperature, identifying a velocity of a moving web in the print zone of the moving web printing system with reference to the modified first diameter, and delivering a firing signal to a first printhead proximate the first roller to energize the inkjet nozzles in the first printhead and eject ink onto the web at a position corresponding to the identified moving web velocity.

System and method for compensating for registration errors arising from heated rollers in a moving web printing system

Methods and systems are provided to increase or optimize the illumination used with a sensor to measure printed ink colors on a substrate at high speed (up to 3 m/s) and high resolution. By modifying the number of light sources, their wavelengths and/or their relative intensities, the optical contrast can be increased or optimized to yield a higher signal-to-noise ratio and improved accuracy for the measurement of multiple colors. In one implementation, multiple LEDs with selected output peak wavelength may be used to achieve higher contrast imaging for each color.

Systems and methods for increasing or optimizing the optical contrast response of multiple colors

A method for calibrating a printing system including a plurality of printers includes designating one of the plurality of printers as a reference printer and defining color values for a desired response for one or more printed test patches on a control page. Through a first process aimed toward achieving the desired response, a printed control page is generated with the reference printer, the control page including one or more of the test patches which, when measured, has a measured response which approaches the desired response. Through a second process aimed toward achieving a desired response, the desired response being the measured response of the reference printer, a printed control page is generated with a second of the printers, the control page including one or more of the test patches which, when measured, has a response which approaches the measured response of the reference printer.

Gray balance for a printing system of multiple marking engines

Growing community of inventors

Rochester, NY, United States of America

R Enrique Viturro