Patents by Inventor Gregory B. Stephenson

Gregory B. Stephenson 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: 7331714
    Abstract: A multifunctional hard x-ray nanoprobe instrument for characterization of nanoscale materials and devices includes a scanning probe mode with a full field transmission mode. The scanning probe mode provides fluorescence spectroscopy and diffraction contrast imaging. The full field transmission mode allows two-dimensional (2-D) imaging and tomography. The nanoprobe instrument includes zone plate optics for focusing and imaging. The nanoprobe instrument includes a stage group for positioning the zone plate optics. The nanoprobe instrument includes a specimen stage group for positioning the specimen. An enhanced laser Doppler displacement meter (LDDM) system provides two-dimensional differential displacement measurement in a range of nanometer resolution between the zone-plate optics and the sample holder. A digital signal processor (DSP) implements a real-time closed-loop feedback technique for providing differential vibration control between the zone-plate optics and the sample holder.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: February 19, 2008
    Assignee: UChicago Argonne, LLC
    Inventors: Deming Shu, Jorg M. Maser, Barry Lai, Franz Stefan Vogt, Martin V. Holt, Curt A. Preissner, Robert P. Winarski, Gregory B. Stephenson
  • Patent number: 5947206
    Abstract: An annulus vent valve is provided to vent gas or other production fluids from below a packer set within a well in deep-set applications. The valve may broadly include: a body member having a first end, a second end, an outer surface, a longitudinal bore adjacent the second end, and at least one flow port extending from the longitudinal bore to the outer surface; a closure member mounted within the longitudinal bore to control fluid flow therethrough; a mechanism for biasing the closure member to a normally closed position to prevent fluid flow through the longitudinal bore; a closure member actuator disposed for movement within the longitudinal bore to open and close the closure member; a mechanism for biasing the closure member actuator away from the closure member; a piston connected to the closure member actuator and having a first end and a second end; and a gas chamber disposed within the body member and in communication with the second end of the piston.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: September 7, 1999
    Assignee: Camco International Inc.
    Inventors: David E. McCalvin, Gregory B. Stephenson, Dwayne E. May
  • Patent number: 5636258
    Abstract: A non-contact in-situ temperature measurement apparatus for a single crystal substrate such as a semiconductor wafer using X-ray diffraction. Utilizing the Bragg condition for X-ray diffraction, the lattice constant of the semiconductor substrate can be determined either by measuring the diffraction angle for a monochromatic X-ray (monochromatic approach) or by measuring the wavelength of an X-ray diffracted with a certain scattering angle (polychromatic approach). The lattice constant, as a well-known function of temperature, is finally converted into the temperature of the semiconductor substrate.
    Type: Grant
    Filed: October 24, 1995
    Date of Patent: June 3, 1997
    Assignees: Siemens Aktiengesellschaft, International Business Machines Corporation, Kabushiki Kaisha Toshiba
    Inventors: Katsuya Okumura, James G. Ryan, Gregory B. Stephenson, Hans-Joerg Timme