Patents by Inventor John H. Pollard

John H. Pollard 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: 4629322
    Abstract: An apparatus and method for determining the relative proportions of two eents of a ternary compound from light reflected off a sample of the compound. The light is varied in wavelength and a graph of reflectance vs wavelength is stored. For a given compound of general form A.sub.x B.sub.1-x C, x may be determined by converting the stored graph to a graph of reflectance vs photon energy of the light, determining the photon energy of the light for the longest wavelength peak on the converted graph, and computing x from the equation E.sub.1 =a+bx+cx.sup.2 wherein a, b, and c are predetermined constants, and E.sub.1 is the photon energy in electron volts of the peak of interest.
    Type: Grant
    Filed: October 29, 1984
    Date of Patent: December 16, 1986
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: John H. Pollard
  • Patent number: 4445269
    Abstract: An array of semiconductive photoconductor detectors is formed on a substr with which the array forms a heterojunction. The array has a whole or partial overlayer of the same material as the substrate. Ohmic connections are made on the detectors and conductive read-out leads are connected to these connections; the leads are made of a conductor that forms a Schottky barrier with the substrate and overlayer. Ohmic connections are made to the substrate and overlayer such that a voltage bias may be applied between the substrate-overlayer combination and the array. The bais is used to control the accumulation layer in the substrate beneath the array in order to maximize sesitivity.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: May 1, 1984
    Assignee: The United States of America as represented by the Scretary of the Army
    Inventor: John H. Pollard
  • Patent number: 4439912
    Abstract: A mercury-cadmium-telluride (HgCdTe) epitaxial detector array is formed on a cadmium telluride (CdTe) substrate. Connecting leads to the detectors are a molybdenum layer covered by a gold-germanium layer. These leads have excellent matches for the thermal coefficients of expansion of the HgCdTe and CdTe and provide ohmic contacts such that the D* of the array is greater than that of arrays made by prior processes using known lead materials, and the noise level is reduced by a factor of approximately three.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: April 3, 1984
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: John H. Pollard, John B. Ramsey, Jr.
  • Patent number: 4273596
    Abstract: An infrared (IR) detector device comprised of a solid state, radiation ha and high resolution monolithic IR focal plane array for imaging applications. The monolithic IR focal plane array has a heterostructure injection scheme that prevents charged-coupled device (CCD) "well filling" by using a heterojunction barrier between the absorber, or detector layer, and the transfer layer. Injection of signal charge into a CCD multiplexer is controlled by establishing a punch through condition between the absorber layer and the CCD channel. The detector layer and the CCD multiplexer are on different planes of the focal plane array.
    Type: Grant
    Filed: January 2, 1980
    Date of Patent: June 16, 1981
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: William A. Gutierrez, John H. Pollard
  • Patent number: 4228365
    Abstract: An infrared (IR) detector device comprised of a solid state, radiation ha and high resolution monolithic IR focal plane array for imaging applications. The monolithic IR focal plane array has a heterostructure injection scheme that prevents charge coupled device (CCD) "well filling" by using a heterojunction barrier between the absorber, or detector layer, and the transfer layer. Injection of signal charge into a CCD multiplexer is controlled by establishing a punch through condition between the absorber layer and the CCD channel. The detector layer and the CCD multiplexer are on different planes of the focal plane array.
    Type: Grant
    Filed: October 3, 1978
    Date of Patent: October 14, 1980
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: William A. Gutierrez, John H. Pollard