Patents by Inventor John H. Erdmann

John H. Erdmann 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).

  • Liquid crystal light valves using internal, fixed spacers and method of incorporating same
    Patent number: 6049370
    Abstract: An improved liquid crystal display cell (34) comprising two substrates (108, 124) spaced apart and containing a quantity of liquid crystal mixture (18) therebetween, in which the substrates have facing surfaces (108', 124') coated with a continuous, electrically conducting material (38, 36), is provided with an array of spacer pads (40) at a pre-selected distance apart from each other, having a pre-selected height to maintain a given spacing between the substrates, and having a pre-selected cross-section that avoids substantial interference with the display properties of the liquid crystal display cell.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: April 11, 2000
    Assignee: Hughes Aircraft Company
    Inventors: Willis H. Smith, Jr., John H. Erdmann, Philip G. Reif
  • Asymmetrical scribe and separation method of manufacturing liquid crystal devices on silicon wafers
    Patent number: 5963289
    Abstract: A method of manufacturing liquid crystal on silicon devices uses asymmetric placement of scribes on silicon and glass substrate layers to maximize the yield of processed active matrix silicon wafers. Asymmetrical scribing minimizes a dimension from a gasket seal between the substrates to a lower bond pad edge. An opposite glass overhang provides an interconnect redundancy for an ITO plate or a repair site for electrical contact to the ITO plate. Methods of device separation employing partial sawing are also employed.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: October 5, 1999
    Assignee: S Vision
    Inventors: Michael E. Stefanov, John H. Erdmann, Christopher Frank, Yimin Ji
  • Dual PDLC-projection head-up display
    Patent number: 5729242
    Abstract: An optical system is provided that produces bright, high contrast head-up display images which are not adversely affected by the direct exposure to sunlight of the system's virtual image source. The optical system comprises a light source system which projects a focused light beam to a segmented, electronically-addressed polymer-dispersed liquid crystal ("PDLC")-type film, which serves as a primary image source. Selected segments of the image source are made transmissive while other selected segments scatter light. Accordingly, the portions of the focused light beam incident to transmissive segments are transmitted to form a real image, while the balance of the focused light beam is scattered. A stray light-blocking means, such as a lens/aperture combination, is employed to block the scattered light. The real image is projected onto an unsegmented, electronically-addressed PDLC-type film serving as an image screen.
    Type: Grant
    Filed: May 8, 1996
    Date of Patent: March 17, 1998
    Assignee: Hughes Electronics
    Inventors: J. David Margerum, John H. Erdmann, Khoon-Cheng Lim