Patents by Inventor David H. Xu

David H. Xu 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: 6047082
    Abstract: An automatic system for inspecting contact lenses that are suspended in a saline solution within a lens holder. In the manufacturing process a first electronic image is taken of each lens disposed in its holder. Thereafter a second image is taken of the lens after the holder has been rotated and the solution and lens have moved. The two images are compared and any dark spots on the first image that move with respect to the second image are eliminated as artifacts that are caused by contaminants in the solution or marks on the lens holder. The rim of the lens, optical zone, printed logo and colored iris area of the lens are automatically inspected by a computer program for defects. The lens is rejected if defect features are found in any of the inspected areas.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: April 4, 2000
    Assignee: Wesley Jessen Corporation
    Inventors: Harvey E. Rhody, Billy C. Leung, David H. Xu
  • Patent number: 5980040
    Abstract: A contact lens comprising an optically transparent lens body having a concave surface adapted to the patient's eye curvature and a convex surface. The lens has three regions: (1) an annular region of a first optical power; (2) at the center of said annular region, which is also at the optical center of said lens, a substantially pinhole-like aperture; and (3) a second larger annular region exterior to the first annular region.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: November 9, 1999
    Assignee: Wesley Jessen Corporation
    Inventors: David H. Xu, David Miller, Leroy Meshel