Patents by Inventor Wei Guo Liu

Wei Guo 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).

  • Publication number: 20190193271
    Abstract: An error compensation device comprises at least one photographing module, a comparison module and a compensation module compensation module. The photographing module establish a space coordinate system relative to the object and comprises a first photographer and a second photographer which respectively photograph a first non-deformed laser speckle image on a first surface and a second non-deformed laser speckle image on a second surface, the first surface differs from the second surface by an azimuth. The comparison module respectively compares the first non-deformed laser speckle image before and after the displacement with the second non-deformed laser speckle image to calculate a displacement value between the two surfaces. The compensation module controls the movement of the object according to the displacement value. The error compensation utilizes the displacement of the non-deformed laser speckle image to obtain the absolute error of the object and compensate the error.
    Type: Application
    Filed: December 27, 2017
    Publication date: June 27, 2019
    Inventors: YI-YUH HWANG, WEI-GUO CHANG, LI-CHUNG LIU
  • Patent number: 6896729
    Abstract: Group III-V, II-VI and related monocrystalline compounds are grown with a rigid support of a sealed ampoule, carbon doping and resistivity control, and thermal gradient control in a crystal growth furnace. A support cylinder provides structural support for the combined sealed ampoule crucible assembly, while low-density insulating material inside the support cylinder deters convection and conduction heating. Radiation channels penetrating the low-density material provide pathways for radiation heating into and out of the seed well and transition regions of the crystal growth crucible. A hollow core in the insulation material directly beneath the seed well provides cooling in the center of the growing crystal, which enables uniform, level growth of the crystal ingot and a flat crystal-melt interface which results in crystal wafers with uniform electrical properties.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: May 24, 2005
    Assignee: AXT, Inc.
    Inventors: Xiao Gordon Liu, Wei Guo Liu
  • Publication number: 20030037721
    Abstract: Group III-V, II-VI and related monocrystalline compounds are grown with a rigid support of a sealed ampoule, carbon doping and resistivity control, and thermal gradient control in a crystal growth furnace. A support cylinder provides structural support for the combined sealed ampoule crucible assembly, while low-density insulating material inside the support cylinder deters convection and conduction heating. Radiation channels penetrating the low-density material provide pathways for radiation heating into and out of the seed well and transition regions of the crystal growth crucible. A hollow core in the insulation material directly beneath the seed well provides cooling in the center of the growing crystal, which enables uniform, level growth of the crystal ingot and a flat crystal-melt interface which results in crystal wafers with uniform electrical properties.
    Type: Application
    Filed: July 3, 2002
    Publication date: February 27, 2003
    Inventors: Xiao Gordon Liu, Wei Guo Liu