Patents by Inventor Fredrick A Stewart

Fredrick A Stewart 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).

  • Digital control servo system
    Patent number: 7200464
    Abstract: An improved servo system for galvanometers, scanners and similar devices which uses digital processing to increase the dynamic range and provide greater effective resolution. The system provides digital control of a reference point that directly influences the excitation, which in turn directly influences the gain of the circuit. A high and low resolution switching path is provided to optimize dynamic range. Wide angle torque compensation improves uniformity of response at large angular deflections from zero. Improved thermal protection allows safe operation near system thermal limits. A graphical user interface allows adjustments and changes response on the fly for tuning due to input conditions or user control.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: April 3, 2007
    Assignee: GSI Group Corporation
    Inventors: Michael B Nussbaum, Michael R Shannon, Fredrick A Stewart
  • Digital control servo system
    Publication number: 20020049513
    Abstract: An improved servo system for galvanometers, scanners and similar devices which uses digital processing to increase the dynamic range and provide greater effective resolution. The system provides digital control of a reference point that directly influences the excitation, which in turn directly influences the gain of the circuit. A high and low resolution switching path is provided to optimize dynamic range. Wide angle torque compensation improves uniformity of response at large angular deflections from zero. Improved thermal protection allows safe operation near system thermal limits. A graphical user interface allows adjustments and changes response on the fly for tuning due to input conditions or user control.
    Type: Application
    Filed: September 21, 2001
    Publication date: April 25, 2002
    Inventors: Michael B. Nussbaum, Michael R. Shannon, Fredrick A. Stewart