Patents by Inventor Randolph J. Dziendziel

Randolph J. Dziendziel 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).

  • Tandem filters using frequency selective surfaces for enhanced conversion efficiency in a thermophotovoltaic energy conversion system
    Patent number: 7790978
    Abstract: This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: September 7, 2010
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Randolph J. Dziendziel, Paul F. Baldasaro, David M. DePoy
  • Tandem filters using frequency selective surfaces for enhanced conversion efficiency in a thermophotovoltaic energy conversion system
    Patent number: 7166797
    Abstract: This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: January 23, 2007
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Randolph J. Dziendziel, David Moore DePoy, Paul Francis Baldasaro
  • Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system
    Patent number: 5700332
    Abstract: A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength .lambda..sub.IF approximately equal to the bandgap wavelength .lambda..sub.g of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5.lambda..sub.IF to .lambda..sub.IF and reflect from .lambda..sub.IF to about 2.lambda..sub.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: December 23, 1997
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Edward J. Brown, Paul F. Baldasaro, Randolph J. Dziendziel