Xerox Corporation

Paul Allen Hosier

Scott L Tewinkle

Jagdish C Tandon

Josef E Jedlicka

Robert Paul Herloski

Pravin N Kothari

Howard A Mizes

Martin Edward Banton

Roger Lee Triplett

Alain E Perregaux

Brian T Ormond

Jeffrey J Folkins

Roger Gaylord Leighton

Brian Robert Conrow

Robert J Kleckner

John Robert Uchal

Paul W Browne

Thomas Grimsley

Stuart Alan Schweid

Dale Robert Mashtare

Gaurav Sharma

James Edward Williams

Mark Steven Amico

David Keneth Ahl

Kraig A Quinn

David Peter Lomenzo

Terri A Clingerman

Thomas R Beikirch

Frederick O Hayes, Iii

Eugene A Rogalski, Jr

Nicholas J Salatino

Khan Lutful Kabir

Shen-Ge Wang

Xiao-Fan Feng

R Enrique Viturro

David Jon Metcalfe

Patricia Joanne Donaldson

Timothy Patrick Foley

Frank Berkelys Tamarez Gomez

Michael Quoc Lu

Kenneth Russell Ossman

Paul S Bonino

Scott J Phillips

Joseph Herman Lang

Mark A Adiletta

Jess Robert Gentner

Douglas E Proctor

Donald J Gusmano

Christine Ann Steurrys

Douglas Allen Gutberlet

Shawn Patrick Updegraff

Kenneth R Miller

Stephen J Wenthe, Jr

David Kenneth Ahl

Guido Nicholas Dimatteo, Iii

Mark P Haefner

Jeffrey L Baniak

Kaitlin M Tomeo

Fred O Hayes

A three-dimensional object printer ejects drops of a build material from a plurality of ejectors in a first printhead to form an object on a first region of a member and ejects drops of a support material from a plurality of ejectors in a second printhead to support the object on the first region of the member. The second printhead ejects drops of the support material onto a second region of the member that is separate from the first region to form a substrate layer. The first printhead ejects drops of the build material onto the substrate layer to form a printed test pattern. An image sensor generates image data of the printed test pattern to identify an inoperable ejector in the first printhead.

System and method for test pattern formation during three-dimensional object printing

A method for dynamically compensating for thermal expansion and contraction of a light emitting diode print bar having first and second light emitting diodes having first and second ideal positions, respectively, the method including: a) determining a first measured position of the first light emitting diode and a second measured position of the second light emitting diode; b) comparing the first measured position and the second measured position to the first ideal position and the second ideal position, respectively; and, c) correcting a first difference between the first measured position and the first ideal position and a second difference between the second measured position and the second ideal position based on results from the step of comparing.

Dynamic control of thermal expansion induced imaging errors from light emitting diode (LED) print bars

A printer compensates for variations in ejected material drop volumes occurring during production of the layers for the formation of an object in a three-dimensional printer. The printer includes an optical sensor that generates topographical and measurement data of each layer of the object after each layer is printed. Differences in height between columns of material being formed by the ejectors in the printhead are identified with reference to the data produced by the sensor and raster data used to operate the printhead are modified adjust the formation of a next layer in the object.

System for compensating for drop volume variation during three-dimensional printing of an object

A printer uses closed loop control to keep material drops ejected by a printhead within a predetermined range. The printer forms at least two objects on a support member and then operates a specular sensor array to obtain image data of the two objects on the support member. The two objects have different predetermined heights to enable a controller in the printer to identify the mass or volume of the material drops forming the objects to adjust operational parameters of the printer to maintain the mass or volume of the material drops in the predetermined range.

System and method for controlling material drop volume in three dimensional object printing

A system for focusing light including a gradient index lens array positioned at a first distance from a surface, and first and second positioning elements arranged to modify the first distance. The first and second positioning elements modify the first distance based on an analysis of an image formed on the surface across substantially a full width of a cross process direction of the surface.

Closed loop focusing system

A printer compensates for printing errors occurring during production of the layers for the formation of an object in a three-dimensional printer. The printer includes an optical sensor that generates data corresponding to edges of each layer of the object after each layer is printed. Differences between the raster data used to eject the material to form a layer and the data received from the optical sensor are used to modify the raster data that operates a printhead to form a next layer in the object.

System for adjusting operation of a printer during three-dimensional object printing using an optical sensor

LED printhead apparatus and printing systems are presented in which an LED array and a first high angle lens array are housed in an LED printbar assembly and a second low angle lens array is provided between the first lens array and a photoreceptor belt or drum in order to relay the output of the first lens array to the photoreceptor to provide a larger depth of focus and to reduce waterfront and tolerance issues near the photoreceptor.

LED printhead with relay lens to increase depth of focus

A device including: a photoreceptor; an LED printbar; and a computer processor for: determining how long LEDs on the printbar are energized while the device is operated to generate an image output; determining that a first plurality of LEDs has been energized less than a second plurality of LEDs; energizing the first plurality of LEDs for a correction time period as the LEDs are aligned with an inter-document zone (IDZ); and de-energizing the second plurality of LEDs during the time period. Energizing the second plurality of LEDs is unrelated to energizing the LEDs for purposes of evaluating an image. The time period is concurrent with operation of the device to generate an image output.

Device and method for extending light emitting diode printbar life or improving image quality

A phase change inkjet printer is equipped with an agitator to prevent settling of metal particles in melted magnetic phase change ink. The agitator operates to agitate the melted magnetic phase change ink as the ink enters the printhead to maintain the metal particles in suspension within the melted ink.

Solid ink printer with magnetic ink mixing

A printhead wiper assembly includes an elongated member having a first and second wiper, a linkage, and an actuator. The linkage includes a clutch that enables the elongated member to move to a plurality of positions in response to the actuator activating a plurality of times. The sequence of positions enables first wiper and then the other wiper to contact the printhead face to remove purged ink from the face.

Three position printhead wiper assembly

A method of performing maintenance on printheads of an imaging device includes the detection of at least one missing or defective inkjet in a printhead. A first pressure is applied to ink in printheads in which at least one missing or defective inkjet was detected. The first pressure is configured to discharge ink from the plurality of apertures in an aperture plate of the printhead to reestablish fluid continuity through the inkjet. A second pressure is applied to all of the printheads to be wiped. The second pressure is configured to form a convex meniscus at the plurality of apertures in the aperture plate of all of the printheads to be wiped. A single actuator is then operated to move one or more wipers into engagement with the printheads to be wiped. During wiping the convex meniscus is encountered by a wiper to lubricate a printhead and prevent the printhead from being damaged by wiping. The single actuator then retracts the one or more wipers from the printheads.

Using low pressure assist (LPA) to enable printhead maintenance system simplification

In an inkjet printing apparatus, a heater heats a drip bib that is located below a plurality of inkjets in a printhead to a temperature that melts ink collected on a surface of the drip bib. Pressurized air is directed toward the surface of the drip bib to remove the melted ink from the surface of the drip bib.

Apparatus and method for removal of ink from an exterior of a printhead

A photosensitive apparatus including a full width array of photosensors and a first photosensor chip. The first photosensor chip including a linear array of photosensors having a plurality of pixels arranged in a long direction and a linear variable filter adapted to transmit at least ten unique bandwidths of wavelengths of light along a length of the linear variable filter where the linear variable filter is fixedly secured to the linear array. Each respective pixel receives a unique bandwidth of wavelengths of light as a light passes through the linear variable filter and the length is aligned with the long direction. The full width array of photosensors is arranged perpendicular to a process direction of a printing device.

In-line image sensor in combination with linear variable filter based spectrophotometer

What is disclosed is a novel system and method for reducing a size of a memory buffer used by an electronic registration correction system performing an electronic registration correction on a digital image. The present method uses column address segmentation to identify blocks of scanlines within a spatially mapped array of image pixels comprising a digital image. Advantageously, the present system and method reduces scanline buffer memory by a factor of 2, where n is the number of column address segments. Buffering can be performed at almost any upstream location in the image path. The present method is well suited for high resolution imaging equipment where memory is constrained by design, cost, or space limitations.

Reducing buffer size requirements in an electronic registration system

A method of processing image data from a multi-chip array with a plurality of photosensitive chips aligned substantially in a transverse direction, including: generating, using a processor for at least one specially programmed computer, a &#x394;y or &#x394;x optical error value equal to a difference in process and transverse directions, respectively, between actual and apparent locations for a first photosensor, the apparent location due to optical error; and storing, in a memory element for the specially programmed computer, respective outputs from the photosensors in the array for first and second scan lines. The actual location is included in the first scan line. The processor retrieves, for use as at least part of useful image data for the first photosensor, the stored output of: the first photosensor for the second scan line for a &#x394;y optical error, or a second photosensor for the first line for a &#x394;x optical error.

Image data compensation for optical or spatial error in an array of photosensitive chips

Growing community of inventors

Rochester, NY, United States of America

Paul Allen Hosier