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: 11999165
    Abstract: A method for operating a printer can include draining a print material from a printer, placing a sacrificial metal into the printer, ejecting the sacrificial metal from a nozzle of the printer, and cooling to printer to a temperature that is below a melting point of the print material and the sacrificial metal. The print material can be or include aluminum and the sacrificial metal can be or include tin. The print material can be drained from the printer when the print material is in molten form, for example, from about 600° C. to about 2000° C. The sacrificial metal can be ejected from the nozzle at a temperature above the melting point of the sacrificial metal but below the melting point of the print material, for example, below about 300° C. The method can reduce or eliminate cracking of various printer structures such as the nozzle during a shutdown or cooling of the printer.
    Type: Grant
    Filed: June 27, 2022
    Date of Patent: June 4, 2024
    Assignee: ADDITIVE TECHNOLOGIES, LLC
    Inventor: Chu-heng Liu
  • Publication number: 20240173972
    Abstract: A printing system and method of inspecting drop ejection in a printing system is disclosed. The method includes capturing an image of each of a plurality of drops of a print material after ejection from an ejector of a printing system, creating a temporally averaged image from each image of the plurality of drops of print material, and classifying one of the plurality of drops of print material based on the temporally averaged image that was created. The use of a pretrained convolutional neural network for classifying one of the plurality of drops and comparing the temporally averaged image to another temporally averaged image to classify one of the plurality of drops may be employed. The printing system also includes a camera with a high-speed shutter where the shutter is synchronized to an ejector pulse, and a video analytic framework coupled to the ejector and the camera configured to generate a jetting result for each of the one or more drops of liquid print material.
    Type: Application
    Filed: November 29, 2022
    Publication date: May 30, 2024
    Applicant: XEROX CORPORATION
    Inventors: Peter KNAUSDORF, Sakib ZARGAR, Joseph C. SHEFLIN, Palghat S. RAMESH, Collin Alexander LADD, Chu-Heng LIU, Paul J. McCONVILLE
  • Patent number: 11931799
    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: Grant
    Filed: August 26, 2021
    Date of Patent: March 19, 2024
    Assignee: Additive Technologies LLC
    Inventors: Paul J. McConville, Douglas K. Herrmann, Seemit Praharaj, Jason M. LeFevre, Chu-Heng Liu
  • Patent number: 11934712
    Abstract: A method of automatically diagnosing media handling defects on sheets, the method including receiving a first image of a first sheet, determining that the first image includes a detected media handling defect, determining that the detected media handling defect matches one or more known media handling defects in a database, and displaying a rectifying action.
    Type: Grant
    Filed: November 17, 2021
    Date of Patent: March 19, 2024
    Assignee: Xerox Corporation
    Inventors: Jason LeFevre, Douglas K. Herrmann, Chu-heng Liu, Seemit Praharaj
  • Publication number: 20240083165
    Abstract: A method of operating a printer identifies image areas in ink image content data that are likely to affected by airflow disturbances to produce ink blur within an ink image. Inkjets farthest from these areas are selected to eject ink drops into these areas to form portions of an ink image. The image areas identified as being likely to produce ink blur are the leading edge, trailing edge, and side edge of the ink image content data. The ink drops ejected by these selected inkjets and their satellites are less likely to be affected adversely by the airflow disturbances.
    Type: Application
    Filed: September 14, 2022
    Publication date: March 14, 2024
    Inventors: Seemit Praharaj, Jason M. LeFevre, Douglas K. Herrmann, Chu-Heng Liu, Jorge A. Alvarez
  • Patent number: 11912045
    Abstract: A method of operating a printer evaluates the effect of printing a print job with two different orientations of the image content data for the print job. The orientation that produces the least increase in the cross-process direction displacement error for the inkjets in the printer is selected for printing the print job. By attenuating the increase in cross-process direction displacement error, the interval between printhead maintenance operations is increased.
    Type: Grant
    Filed: March 24, 2022
    Date of Patent: February 27, 2024
    Assignee: Xerox Corporation
    Inventors: Jason M. LeFevre, Seemit Praharaj, Douglas K. Herrmann, Chu-Heng Liu, Jorge A. Alvarez
  • Patent number: 11890673
    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: Grant
    Filed: July 13, 2021
    Date of Patent: February 6, 2024
    Assignee: ADDITIVE TECHNOLOGIES, LLC
    Inventors: Linn C. Hoover, Joseph C. Sheflin, Jason M. LeFevre, Seemit Praharaj, David Alan Vankouwenberg, Chu-Heng Liu, Douglas K. Herrmann
  • Publication number: 20240034079
    Abstract: Disclosed is a system and method for cooling paper within a printer assembly that includes at least one misting assembly designed to mist an aqueous solution onto an unprinted surface of paper stock after a first side is printed. At least one convection accelerator assembly is designed to accelerate evaporation of the aqueous solution before the printed paper stock arrives at the at least one printing station for printing on the unprinted surface. At least one or more of a paper temperature, machine temperature, printhead temperature, and humidity sensor are operationally coupled to at least one controller assembly programmed to control at least one or more of misting, humidity, and airflow. The at least one controller assembly is designed to determine the heat to be dissipated into the airflow from the printed paper stock to obtain a targeted paper temperature and, therefore, the amount and placement of aqueous solution misted.
    Type: Application
    Filed: August 1, 2022
    Publication date: February 1, 2024
    Inventors: Seemit PRAHARAJ, Jason LEFEVRE, Douglas K. HERRMANN, Jorge A. ALVAREZ, Chu-Heng LIU, Yumeng WU
  • Patent number: 11878349
    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: Grant
    Filed: August 3, 2021
    Date of Patent: January 23, 2024
    Assignee: Xerox Corporation
    Inventors: Seemit Praharaj, Douglas K. Herrmann, Thomas J. Wyble, Jason M. LeFevre, Chu-Heng Liu, Paul J. McConville
  • Publication number: 20240015258
    Abstract: Methods and systems for securely rendering a security feature with image data to be printed, can involve providing within the image data, data relating to a group of spots, and within the image data, mixing spots of two or more spot sizes among the group of spots to embed information within a stochastic or frequency modulation halftone image. In an embodiment, operations may be implemented for rendering a part of the image with a first spot among the group of spots and a remaining portion of the image with a second spot among the group of spots, wherein the second spot is smaller in size than the first spot.
    Type: Application
    Filed: July 7, 2022
    Publication date: January 11, 2024
    Inventors: Chu-heng Liu, Jorge A. Alvarez, Douglas L. Herrmann, Jason Matthew LeFevre, Seemit Praharaj
  • Patent number: 11858276
    Abstract: An implementation of the present teachings includes a resistor structure for measuring a level of a print material such as a liquid metal print material within a reservoir of a printer such as a magnetohydrodynamic printer. The resistor structure includes a first electrode and a second electrode that are physically and electrically separated from each other. When positioned within the reservoir, the liquid metal physically contacts the first electrode and the second electrode. An electrical resistance between the first and second electrodes changes depending on the level of the print material within the reservoir. As the level of the print material decreases, the electrical resistance between the first electrode and the second electrode increases. The electrical resistance can be measured and used to determine a level of the print material within the reservoir.
    Type: Grant
    Filed: December 22, 2020
    Date of Patent: January 2, 2024
    Assignee: Additive Technologies, LLC
    Inventors: Chu-heng Liu, Paul J. McConville, David L. Knierim
  • Patent number: 11850842
    Abstract: A printing system comprises a print fluid deposition assembly, a media transport device, and an air flow control system. The print fluid deposition assembly comprises a carrier plate and a printhead arranged to eject a print fluid through an opening of the carrier plate to a deposition region. The media transport device holds a print medium against the movable support surface by vacuum suction and transports the print medium through the deposition region. The air flow control system comprises an air supply unit comprising air flow guide structure extending into the opening of the carrier plate between the carrier plate and the printhead to flow air through the opening. The air flow control system controls the air supply unit to selectively flow the air based on a location of a print medium relative to the printhead.
    Type: Grant
    Filed: March 29, 2021
    Date of Patent: December 26, 2023
    Assignee: XEROX CORPORATION
    Inventors: Patrick Jun Howe, John Patrick Baker, Brian M. Balthasar, Glenn Batchelor, Anthony Salvatore Condello, Ali R. Dergham, Timothy P. Foley, Douglas K. Herrmann, Richard A. Kalb, Peter John Knausdorf, Jason M. LeFevre, Jack T. Lestrange, Chu-Heng Liu, Paul J. McConville, Seemit Praharaj, Palghat S. Ramesh, Joseph C. Sheflin, Emmett James Spence, Robert Jian Zhang, Megan Zielenski
  • Patent number: 11853629
    Abstract: A method of operating an inkjet printer identifies a thermal load that will be imposed on the printheads in the inkjet printer during execution of a print job and identifies a remedial action to reduce the thermal load if the thermal load increases the temperature of the printheads above an upper threshold of a predetermined temperature range. The thermal load is identified from the ink image content data for the print job, the print job parameters for the print job, and environmental condition measurements received from sensors in the printer. The remedial actions include manipulation of the print job queue, alteration of print job parameters, and active cooling to remove heat from the printheads or media within the printer.
    Type: Grant
    Filed: October 27, 2022
    Date of Patent: December 26, 2023
    Assignee: Xerox Corporation
    Inventors: Chu-Heng Liu, Jason M. LeFevre, Seemit Praharaj, Jorge A. Alvarez, Douglas K. Herrmann
  • Patent number: 11845227
    Abstract: A three-dimensional (3D) printer is configured to introduce a liquid metal onto a first part and a second part while the first part and the second part are in contact with one another. The liquid metal subsequently solidifies to join the first part and the second part together to produce an assembly.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: December 19, 2023
    Assignee: Additive Technologies, LLC
    Inventors: Jason M. LeFevre, Douglas K. Herrmann, Paul J. McConville, Chu-Heng Liu, Seemit Praharaj
  • Publication number: 20230398778
    Abstract: A method of operating a printer identifies image areas and image features in ink image content data that are likely to produce ink blur within an ink image. The ink image content data for these areas and features is modified to attenuate the appearance of ink blur. The image areas identified as being likely to produce ink blur are the trailing edge and the side edges of the ink image content data. The modification of the ink image content data for the features and predetermined areas improves the quality of the printed ink image.
    Type: Application
    Filed: June 9, 2022
    Publication date: December 14, 2023
    Inventors: Jorge A. Alvarez, Jason M. LeFevre, Seemit Praharaj, Chu-Heng Liu, Douglas K. Herrmann
  • Patent number: 11839916
    Abstract: A three-dimensional (3D) metal object manufacturing apparatus is equipped with an orifice cleaning system that removes metal drops that have adhered to a plate, an orifice in the plate, and a nozzle ejecting melted metal drops through the orifice during object forming operations. The orifice cleaning system includes an orifice cleaning tool that consists essentially of a soft carbon material, such as graphite. The orifice cleaning tool is configured with a handle that is gripped by an articulated arm to move the orifice cleaning tool against the plate, the orifice, and a portion of the nozzle at the orifice.
    Type: Grant
    Filed: January 20, 2022
    Date of Patent: December 12, 2023
    Assignee: Additive Technologies LLC
    Inventors: Viktor Sukhotskiy, Joseph C. Sheflin, Brian M. Balthasar, Peter Knausdorf, Chu-Heng Liu
  • Patent number: 11787211
    Abstract: A multi-sheet cooling buffer suitable for use in a printing device and a method of sheet processing with the cooling buffer are described. The cooling buffer includes an inlet and an outlet and a sheet cooling mechanism. An array of cooling stations, intermediate the inlet and the outlet, are each configured to receive print media sheets independently from the inlet and direct cooled sheets towards the outlet. In the cooling buffer, multiple print media sheets are able to be cooled contemporaneously in respective ones of the cooling stations.
    Type: Grant
    Filed: March 9, 2022
    Date of Patent: October 17, 2023
    Assignee: Xerox Corporation
    Inventors: Jason M. LeFevre, Douglas K. Herrmann, Seemit Praharaj, Chu-heng Liu, Jorge A. Alvarez
  • Publication number: 20230302833
    Abstract: A method of operating a printer evaluates the effect of printing a print job with two different orientations of the image content data for the print job. The orientation that produces the least increase in the cross-process direction displacement error for the inkjets in the printer is selected for printing the print job. By attenuating the increase in cross-process direction displacement error, the interval between printhead maintenance operations is increased.
    Type: Application
    Filed: March 24, 2022
    Publication date: September 28, 2023
    Inventors: Jason M. LeFevre, Seemit Praharaj, Douglas K. Herrmann, Chu-Heng Liu, Jorge A. Alvarez
  • Publication number: 20230309404
    Abstract: An inkjet printer includes a pair of temperature regulation modules mounted on opposite sides of each printhead in the printer. Each temperature regulation module includes a thermoelectric cooling device that is activated by a controller when the temperature of the printhead exceeds a predetermined setpoint. By cooling the printheads, the temperature of the printheads can be kept in a temperature range that enables fast drying inks to obtain their optimal performance and that prevents duplex printing operations from raising the temperature of the printheads significantly above the predetermined setpoint.
    Type: Application
    Filed: March 24, 2022
    Publication date: September 28, 2023
    Inventors: Douglas K. Herrmann, Jason M. LeFevre, Seemit Praharaj, Chu-Heng Liu, Jorge A. Alvarez
  • Patent number: 11766829
    Abstract: Nozzles for an additive manufacturing device and methods for improving wettability of the nozzles are disclosed. The method may include subjecting the nozzle to a surface treatment. The surface treatment may include contacting a surface of the nozzle with one or more surface modifying agents. The surface modifying agents may include one or more of an oxidizing agent, an acid, a base, or combinations thereof. The one or more surface modifying agents may increase an oxygen content of the surface of the nozzle. An inner surface of the nozzle may have a water contact angle of greater than 1° and less than about 90°. The inner surface of the nozzle may be free or substantially free of a coating.
    Type: Grant
    Filed: September 10, 2020
    Date of Patent: September 26, 2023
    Assignee: XEROX CORPORATION
    Inventors: Santokh S. Badesha, Varun Sambhy, Chu-Heng Liu, Peter M. Gulvin, Mark A. Cellura, George Shannon, Gary D. Redding, Lyle G. Dingman