Patents by Inventor Walter Duval

Walter Duval 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).

  • Transparent multi-zone crystal growth furnace and method for controlling the same
    Patent number: 6176924
    Abstract: A crystal growth system, comprising: a furnace; a plurality of heating elements coupled to said furnace, each said plurality of heating elements defining a heat zone, each said heating element set to a desired temperature value; a plurality of thermocouples associated with respective heat zones to detect a temperature value; a translation system for passing an ampoule containing crystal growth material through said furnace into said heat zones and providing a positional location of said ampoule and; a multi-variable self-tuning temperature controller connected to said plurality of heating elements, said plurality of thermocouples and said translation system, said controller monitoring each said zone temperature value and upon considering the thermal interaction of heating zones and the moving thermal inertia of the ampoule, adjusting voltage input to said heat zones to obtain optimal crystal growth within said ampoule.
    Type: Grant
    Filed: May 18, 2000
    Date of Patent: January 23, 2001
    Assignees: The University of Akron and Nasa, The United States of America
    Inventors: Walter Duval, Celal Batur, Robert J. Bennett
  • Transparent multi-zone crystal growth furnace and method for controlling the same
    Patent number: 6139627
    Abstract: A crystal growth system, comprising: a furnace; a plurality of heating elements coupled to said furnace, each said plurality of heating elements defining a heat zone, each said heating element set to a desired temperature value; a plurality of thermocouples associated with respective heat zones to detect a temperature value; a translation system for passing an ampoule containing crystal growth material through said furnace into said heat zones and providing a positional location of said ampoule and; a multi-variable self-tuning temperature controller connected to said plurality of heating elements, said plurality of thermocouples and said translation system, said controller monitoring each said zone temperature value and upon considering the thermal interaction of heating zones and the moving thermal inertia of the ampoule, adjusting voltage input to said heat zones to obtain optimal crystal growth within said ampoule.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: October 31, 2000
    Assignee: The University of Akron
    Inventors: Walter Duval, Celal Batur, Robert J. Bennett