Patents by Inventor J. Thomas Tiedje

J. Thomas Tiedje 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: 6116779
    Abstract: An optical method for measuring the temperature of a substrate material with a temperature dependent band edge. In this method both the position and the width of the knee of the band edge spectrum of the substrate are used to determine temperature. The width of the knee is used to correct for the spurious shifts in the position of the knee caused by: (i) thin film interference in a deposited layer on the substrate; (ii) anisotropic scattering at the back of the substrate; (iii) the spectral variation in the absorptance of deposited layers that absorb in the vicinity of the band edge of the substrate; and (iv) the spectral dependence in the optical response of the wavelength selective detection system used to obtain the band edge spectrum of the substrate. The adjusted position of the knee is used to calculate the substrate temperature from a predetermined calibration curve.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: September 12, 2000
    Inventors: Shane R. Johnson, J. Thomas Tiedje
  • Patent number: 5999307
    Abstract: A method and apparatus for facilitating controllable switching an interface between a reflective state in which light incident upon the interface undergoes total internal reflection, and a non-reflective state in which total internal reflection is prevented at the interface. The apparatus incorporates a member (preferably an elastomer) which is deformable with respect to the interface. The member's Young's Modulus in portions of the member adjacent the interface is substantially greater (i.e. stiffer) than the member's Young's Modulus in portions of the member away from the interface. The stiffened portion of the member adjacent the interface may be in the form of a microstructure. A pair of electrodes coupled to a voltage source can be provided to controllably deform the member into optical contact with the interface, within a continuously variable range of optical contact values, to produce the non-reflective state in selectably varying degrees.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: December 7, 1999
    Assignee: The University of British Columbia
    Inventors: Lorne A. Whitehead, J. Thomas Tiedje, Robin John Noel Coope
  • Patent number: 5568978
    Abstract: An optical method for measuring the temperature of a substrate material with a temperature dependent bandgap. The substrate is illuminated with a broad spectrum lamp and the bandgap is determined from the spectrum of the diffusely scattered light. The spectrum of the light from the lamp is sufficiently broad that it covers the spectral range above and below the bandgap of the substrate. Wavelengths corresponding to photon energies less than the bandgap of the substrate are transmitted through the substrate and are reflected from the back surface of the substrate as well as from the front surface while the wavelengths corresponding to photon energies larger than the bandgap are reflected only from the front surface. If the front surface is polished the front surface reflection will be specular while if the back surface is rough the reflection from the back surface will be non-specular. The back surface reflection is detected with a detector in a non-specular location.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: October 29, 1996
    Inventors: Shane R. Johnson, Christian Lavoie, Mark K. Nissen, J. Thomas Tiedje
  • Patent number: 5388909
    Abstract: An optical method and apparatus for measuring the temperature of a substrate material with a temperature dependent bandgap. The substrate is illuminated with a broad spectrum lamp and the bandgap is determined from the spectrum of the diffusely scattered light. The spectrum of the light from the lamp is sufficiently broad that it covers the spectral range above and below the bandgap of the substrate. Wavelengths corresponding to photon energies less than the bandgap of the substrate are transmitted through the substrate and are reflected from the back surface of the substrate as well as from the front surface while the wavelengths corresponding to photon energies larger than the bandgap are reflected only from the front surface. If the front surface is polished the front surface reflection will be specular while if the back surface is rough the reflection from the back surface will be non-specular. The back surface reflection is detected with a detector in a non-specular location.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: February 14, 1995
    Inventors: Shane R. Johnson, Christian Lavoie, Mark K. Nissen, J. Thomas Tiedje
  • Patent number: 4867840
    Abstract: A method for making a layered metal chalcogenide catalyst wherein the catalyst has a crystalline structure with increased edge sites produced by lithographic methods.
    Type: Grant
    Filed: March 29, 1988
    Date of Patent: September 19, 1989
    Assignee: Exxon Research and Engineering Company
    Inventors: Charles B. Roxlo, Harry W. Deckman, J. Thomas Tiedje
  • Patent number: 4701366
    Abstract: A high surface area substrate with controlled pore size and slot geometry is made by depositing at least two materials in alternating layers. The film is then broken up and one of the materials is etched away to produce a slotted surface structure. These slots can add size and shape selectively to separations and catalytic processes which because of the uniform and controllable dimensions (>5A) would be superior to that obtainable from zeolites and clays.
    Type: Grant
    Filed: July 1, 1985
    Date of Patent: October 20, 1987
    Assignee: Exxon Research and Engineering Company
    Inventors: Harry W. Deckman, Richard B. Stephens, J. Thomas Tiedje, Benjamin Abeles
  • Patent number: 4684565
    Abstract: The present invention is an X-ray mirror including a multi-layered material in which the composition of the layers repeat, the repeat distance being between 8 and 250 A., In one embodiment, the mirror is produced by CVD. In another embodiment, the layers forming the structure are made of amorphous semiconductor or insulator material.
    Type: Grant
    Filed: November 20, 1984
    Date of Patent: August 4, 1987
    Assignee: Exxon Research and Engineering Company
    Inventors: Benjamin Abeles, Wolfgang U. Eberhardt, J. Thomas Tiedje
  • Patent number: 4598164
    Abstract: A semiconductor device which includes an active region including a superlattice amorphous material wherein the energy gap has a predetermined value. A preferred embodiment of the device is a solar cell. In another embodiment of the present invention, the device is a tandem solar cell which includes a first active region including a superlattice material wherein the bandgap has a first predetermined value; a second active region including a second superlattice material wherein the bandgap has a second predetermined value different from said first predetermined value; a means for electrically interconnecting said first and second active regions such that current may flow between said first and second active regions.
    Type: Grant
    Filed: October 6, 1983
    Date of Patent: July 1, 1986
    Assignee: Exxon Research and Engineering Co.
    Inventors: J. Thomas Tiedje, Benjamin Abeles
  • Patent number: 4578641
    Abstract: A contactless rf technique for measurement of the carrier lifetime from the photoconductivity induced in silicon wafers by a flash of infrared light. The carrier lifetime is inferred from the photoconductivity decay.
    Type: Grant
    Filed: September 24, 1982
    Date of Patent: March 25, 1986
    Assignee: Exxon Research and Engineering Co.
    Inventor: J. Thomas Tiedje
  • Patent number: 4546009
    Abstract: The present invention teaches a combination of parameters for the glow discharge decomposition of silane deposition of an amorphous silicon semiconductor having non-dispersive high mobility transport of majority carriers through the semiconductor material, useful in switching devices such as diodes, transistors and the like.
    Type: Grant
    Filed: May 9, 1980
    Date of Patent: October 8, 1985
    Inventors: Exxon Research and Engineering Co., J. Thomas Tiedje, Don L. Morel, Benjamin Abeles