Patents by Inventor Chu-heng Liu

Chu-heng Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11639067
    Abstract: A marker transport system and a method of operating the marker transport system. A group of print bars is located with respect to a marker transport platen and a marker transport belt. A vacuum source and a pneumatic solenoid block are associated with the marker transport platen. The marker transport platen includes airflow sections divided into process-direction slots and cross-section direction slots. The cross-section direction slots are located beneath the print bars and are connected to the vacuum source via the pneumatic solenoid block, which facilitates an individual control of each of the cross-process direction slots. Pneumatic valves are associated with the pneumatic solenoid block, which supplies a flow of vacuum to the cross-process direction vacuum slots. The pneumatic vales can be timed to allow the vacuum to be present when a sheet is present over a corresponding vacuum slot among the process-direction slots and the cross-section direction slots.
    Type: Grant
    Filed: November 10, 2019
    Date of Patent: May 2, 2023
    Assignee: Xerox Corporation
    Inventors: Jason M. Lefevre, Seemit Praharaj, Michael J. Levy, Douglas K. Herrmann, Paul McConville, Chu-Heng Liu, Linn C. Hoover, David A. VanKouwenberg
  • Publication number: 20230107102
    Abstract: A method of operating a printer distributes inkjet operations from frequently used inkjets to lesser used inkjets. The redistribution of the inkjet operations helps reduce the number of inkjets exhibiting cross-process direction error so printhead maintenance operations, such as purging, occur less frequently.
    Type: Application
    Filed: October 1, 2021
    Publication date: April 6, 2023
    Inventors: Jason M. LeFevre, Douglas K. Herrmann, Chu-Heng Liu, Varun Sambhy, Seemit Praharaj
  • Patent number: 11618086
    Abstract: An implementation of the present teachings includes inner shell for a printer, such as a liquid metal printer, that mitigates problems associated with the formation of dross. The inner shell can be installed in a reservoir of the printer during a printing process where, during the printing process, a dross can form on an interior sidewall of the inner shell. Subsequently, the inner shell can be removed and either cleaned or replaced. During printing, the inner shell can be raised and/or lowered, or otherwise repositioned, so that the dross forms over a larger surface area of the inner shell, and at a decreased thickness, compared to an inner shell that is not repositioned.
    Type: Grant
    Filed: December 22, 2020
    Date of Patent: April 4, 2023
    Assignee: XEROX CORPORATION
    Inventor: Chu-heng Liu
  • Patent number: 11613116
    Abstract: A method of operating a printer distributes inkjet operations from frequently used inkjets to lesser used inkjets. The redistribution of the inkjet operations helps reduce the number of inkjets exhibiting cross-process direction error so printhead maintenance operations, such as purging, occur less frequently.
    Type: Grant
    Filed: October 1, 2021
    Date of Patent: March 28, 2023
    Assignee: Xerox Corporation
    Inventors: Jason M. LeFevre, Douglas K. Herrmann, Chu-Heng Liu, Varun Sambhy, Seemit Praharaj
  • Patent number: 11607727
    Abstract: An ejector of liquid material to form spherical particles includes a crucible for retaining liquid material, an orifice area defining at least one orifice, and an actuator responsive to a voltage signal for causing material to be ejected from the crucible through the orifice. A method comprises applying a voltage signal of a first type and a second type to the actuator, causing a material droplet of a first size and a second size to be ejected through the orifice. Alternately or in addition, the orifice area defines a first orifice having a first diameter and a second orifice having a second diameter different from the first diameter, whereby a signal causes a material droplet of a first size to be ejected through the first orifice and a material droplet of a second size to be ejected through the second orifice.
    Type: Grant
    Filed: May 15, 2019
    Date of Patent: March 21, 2023
    Assignee: Xerox Corporation
    Inventors: Scott J Vader, Zachary S Vader, Chu-Heng Liu
  • Publication number: 20230063103
    Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with a movable directed energy source to melt hardened metal drops and form an oxidation layer. A metal support structure can be formed over the oxidation layer, an object feature can be formed over the oxidation layer, or both a metal support structure and an object feature can be formed over oxidation layers located at opposite sides of a metal support structure. The oxidation layers weakly attach the metal support structure to the object feature supported by the metal support structure so the support structure can be easily removed after manufacture of the object is complete.
    Type: Application
    Filed: August 26, 2021
    Publication date: March 2, 2023
    Inventors: Paul J. McConville, Douglas K. Herrmann, Seemit Praharaj, Jason M. LeFevre, Chu-Heng Liu
  • Publication number: 20230051340
    Abstract: The present disclosure discloses methods and systems for removing dross from a liquid metal chamber, such as would be used in magnetohydrodynamic (MHD) or metal 3D printing. The method and systems comprise inserting a dross removal tool into a liquid metal chamber. A seal is compromised, fluidically connecting an evacuated volume and the liquid metal chamber. Pressure equalizes between the fluidically coupled volumes through an inflow of gas, liquid, and solid components from the liquid metal chamber into the dross removal tool. The dross removal tool is removed from the liquid metal chamber.
    Type: Application
    Filed: August 12, 2021
    Publication date: February 16, 2023
    Applicant: XEROX CORPORATION
    Inventors: Chu-Heng Liu, Jason M. Lefevre, Joseph C. Sheflin, Seemit Praharaj, Douglas K. Herrmann, David A. Vankouwenberg, Linn C. Hoover
  • Patent number: 11577503
    Abstract: A drag force sensor on a fountain solution carrier roller surface measures drag force of a fountain solution layer on the fountain solution carrier roller surface in real-time during a printing operation. The measured drag force is used in a feedback loop to actively control the fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during a printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.
    Type: Grant
    Filed: February 17, 2021
    Date of Patent: February 14, 2023
    Assignee: Xerox Corporation
    Inventors: Jack T. Lestrange, Joseph C. Sheflin, Palghat S. Ramesh, Anthony S. Condello, Brian M. Balthasar, Seemit Praharaj, Chu-heng Liu, Paul J. Mcconville, Douglas K. Herrmann, Jason M. Lefevre
  • Publication number: 20230037539
    Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with two solid metal moving mechanisms that are independently operated to move two different metals into the receptacle of a vessel in a melted metal drop ejecting apparatus. The ejector is operated to form object features with melted metal drops of one of the two different metals and to form support features with melted metal drops of the other of the two different metals. The thermal expansion coefficients of the two metals are sufficiently different that the support features easily separate from the object features after the object and support features cool.
    Type: Application
    Filed: August 3, 2021
    Publication date: February 9, 2023
    Inventors: Seemit Praharaj, Douglas K. Herrmann, Thomas J. Wyble, Jason M. LeFevre, Chu-Heng Liu, Paul J. McConville
  • Publication number: 20230034213
    Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with a vessel having a receptacle that holds melted metal. The vessel has a divider that prevents metal dross formed at a solid metal inlet of the receptacle to migrate to a portion of the receptacle where a melted metal level sensor directs light.
    Type: Application
    Filed: August 2, 2021
    Publication date: February 2, 2023
    Inventors: Jason M. LeFevre, Douglas K. Herrmann, Chu-Heng Liu, Seemit Praharaj, David A. VanKouwenberg, Linn C. Hoover
  • Patent number: 11565475
    Abstract: A method operates a three-dimensional (3D) metal object manufacturing system to compensate for errors that occur during object formation. In the method, thermal image data and dimensional image data of a metal object being formed by the 3D metal object manufacturing system is generated prior to completion of the metal object. Thermal conditions are identified from these data and compared to predetermined ranges corresponding to the identified thermal conditions to identify one or more errors. For identified errors outside a corresponding predetermined difference range, the method performs an error compensation technique. The error compensation includes modification of a surface data model, modification of machine-ready instructions, or operation of a subtractive device.
    Type: Grant
    Filed: April 10, 2020
    Date of Patent: January 31, 2023
    Assignee: Xerox Corporation
    Inventors: David A. Mantell, Christopher T. Chungbin, Chu-Heng Liu, Scott J. Vader, Zachary S. Vader, Viktor Sukhotskiy, Denis Cormier, Kareem Tawil
  • Patent number: 11565516
    Abstract: According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is measured by using phase shifted monochromic light to produce optical path differences through the fountain solution film. The intensity of the reflected light through the fountain solution film is very sensitive due to the phase shifted light so interference fringes are easier to delineate and fountain solution thickness measurement more reliable.
    Type: Grant
    Filed: December 30, 2020
    Date of Patent: January 31, 2023
    Assignee: Xerox Corporation
    Inventors: Paul J. McConville, Chu-heng Liu, Jason M. LeFevre, Seemit Praharaj, Douglas K. Herrmann
  • Publication number: 20230015142
    Abstract: A dross extraction system for a printer is disclosed, which includes an ejector defining an inner cavity associated therewith, the inner cavity retaining a liquid printing material. The dross extraction system also includes a first inlet coupled to the inner cavity of the ejector, a probe external to the ejector, which is selectably positionable to contact the liquid printing material to attract dross thereto, thereby extracting dross from the liquid printing material when the probe is withdrawn from the liquid printing material. A method of extracting dross from a metal jetting printer is also disclosed, which includes pausing an operation of the metal jetting printer, advancing a probe into a melt pool within a nozzle pump reservoir in the metal jetting printer, extracting dross from the metal printing material and onto the probe, retracting the probe from the nozzle pump reservoir, and resuming the operation of the metal jetting printer.
    Type: Application
    Filed: July 13, 2021
    Publication date: January 19, 2023
    Applicant: XEROX CORPORATION
    Inventors: Linn C. Hoover, Joseph C. Sheflin, Jason M. LeFevre, Seemit Praharaj, David Alan Vankouwenberg, Chu-Heng Liu, Douglas K. Herrmann, JR.
  • Patent number: 11547771
    Abstract: An apparatus includes, among other components, a frame adapted to be connected to the exterior surface of a device that has a touchscreen. A retractable cover is operatively connected to the frame. The size of the retractable cover is equal to at least the size of the touchscreen, and the retractable cover is positioned to extend so as to cover the touchscreen. At least one ultraviolet light is also operatively connected to the frame. The ultraviolet light is positioned to direct ultraviolet lighting toward the touchscreen when the retractable cover extends to cover the touchscreen.
    Type: Grant
    Filed: February 17, 2021
    Date of Patent: January 10, 2023
    Assignee: Xerox Corporation
    Inventors: Seemit Praharaj, Douglas K. Herrmann, Chu-Heng Liu, Paul J. McConville, Jason M. LeFevre, Linn C. Hoover, David A. VanKouwenberg
  • Publication number: 20220410560
    Abstract: A coefficient of friction (COF) sensor on a carrier roll surface wetted with fountain solution transferred from an imaging member measures COF of the wetted carrier roll surface in real-time, even between or during printing operations. The transferred fountain solution may be concentrated and/or chilled to solidify before the measurement. The measured COF is used in a feedback loop to actively control the fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during an imaging or other printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.
    Type: Application
    Filed: June 25, 2021
    Publication date: December 29, 2022
    Inventors: Seemit PRAHARAJ, Chu-heng LIU, Paul J. MCCONVILLE, Douglas K. HERRMANN, Jason M. LEFEVRE
  • Publication number: 20220410302
    Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with a vacuum system and a hold-down plate to secure a metal foil to the hold-down plate during manufacture of a metal object. The melted metal drops ejected by the apparatus to form the object bond to the metal foil to form the base layer of the object. When the vacuum system is deactivated after manufacture of the object is complete, the object and foil are removed from the apparatus intact and the foil not part of the base layer is trimmed from the object.
    Type: Application
    Filed: June 28, 2021
    Publication date: December 29, 2022
    Inventors: Jason M. LeFevre, Paul J. McConville, Douglas K. Herrmann, Chu-Heng Liu, Seemit Praharaj, Robert R. Reed
  • Publication number: 20220401303
    Abstract: A medicament delivery product is provided in which one or more medicaments are fixed on a sheet according to a patient-specific pre-defined pattern. The sheet is formed into a three-dimensional or non-planar shape to facilitate ingestion by the patient. The pre-defined patterns for the medicaments are configured for controlled release or absorption of the corresponding medicament after ingestion by the patient. The medicaments can be in a liquid or a powder form and applied to the surface of the sheet in an appropriate manner. The one or more medicaments can be any combination of drugs, medicines, vitamins, nutritional supplements and the like.
    Type: Application
    Filed: June 17, 2021
    Publication date: December 22, 2022
    Inventors: Chu-heng Liu, Jason M. LeFevre, Paul J. McConville, Seemit Praharaj, Douglas K. Herrmann
  • Publication number: 20220402060
    Abstract: A three-dimensional (3D) metal object manufacturing apparatus is configured to increase the oxidation of ejected melted metal drops for the formation of metal support structures during manufacture of a metal object with the apparatus. The oxidation can be increased by either increasing a distance between the ejector head and a platform supporting the metal object or by providing an air flow transverse to the direction of movement of the melted metal drops, or both.
    Type: Application
    Filed: June 21, 2021
    Publication date: December 22, 2022
    Inventors: Chu-Heng Liu, Paul J. McConville, Jason M. LeFevre, Douglas K. Herrmann, Seemit Praharaj
  • Publication number: 20220402023
    Abstract: A dross abatement system for a printer is disclosed. The dross abatement system includes a print head ejector, a pump in communication with the print head ejector having an inner cavity, a first inlet coupled to the inner cavity, a supply of printing material external to the print head ejector, a heating element configured to heat the printing material in the ejector, and a supply of absorbent material external to the print head ejector. A method of abating dross in a metal jetting printer is also disclosed, which includes pausing an operation of the printer, advancing an absorbent material into a melt pool within a nozzle pump reservoir, wherein the melt pool may include a metal printing material, absorbing dross from the metal printing material, removing the absorbent material including the dross, and resuming operation of the metal jetting printer.
    Type: Application
    Filed: June 16, 2021
    Publication date: December 22, 2022
    Applicant: XEROX CORPORATION
    Inventors: Seemit Praharaj, Jason M. LeFevre, Douglas K. Herrmann, Chu-Heng Liu, David Alan VanKouwenberg, Linn C. Hoover
  • Patent number: 11528386
    Abstract: A method of operating a printer separates the image data content of a sheet in a print job into multiple color separations. The first color separation printed on the sheet includes at least two fiducials printed in the least perceptible color of ink in the printer. The at least two fiducials are used to identify the process direction and skew of the printed sheet before the remaining color separations are printed on the sheet with the first color separation.
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: December 13, 2022
    Assignee: Xerox Corporation
    Inventors: Douglas K. Herrmann, Seemit Praharaj, Chu-Heng Liu, Jason M. LeFevre, Varun Sambhy