Patents by Inventor Samuel Kay Doran

Samuel Kay Doran 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).

  • REAL TIME MEASUREMENT OF LEAKAGE CURRENT IN HIGH VOLTAGE ELECTRON GUNS
    Publication number: 20020145396
    Abstract: A method and a apparatus are provided for operating an E-beam system including an E-beam source for generating an E-beam directed along a column axis and an electrode aligned with the column axis direct the E-beam towards means for measuring the E-beam. A signal proportional to leakage current emitted from the E-beam is generated. When the result of a comparison with a desired value is excessive, an excess leakage signal is generated. The excess leakage signal can be provided as an emergency output signal and/or produce an OFF signal for stopping production of the E-beam by turning OFF voltage/power sources for producing the E-beam in response to the excess leakage signal. Preferably, a filament is heated by an electric current and a cathode is bombarded with electrons from the filament to produce the E-beam. Then a filament control signal is employed for controlling the filament heating current.
    Type: Application
    Filed: February 3, 2001
    Publication date: October 10, 2002
    Inventors: Michael Stuart Gordon, Samuel Kay Doran
  • Real time measurement of leakage current in high voltage electron guns
    Patent number: 6456019
    Abstract: A method and a apparatus are provided for operating an E-beam system including an E-beam source for generating an E-beam directed along a column axis and an electrode aligned with the column axis direct the E-beam towards means for measuring the E-beam. A signal proportional to leakage current emitted from the E-beam is generated. When the result of a comparison with a desired value is excessive, an excess leakage signal is generated. The excess leakage signal can be provided as an emergency output signal and/or produce an OFF signal for stopping production of the E-beam by turning OFF voltage/power sources for producing the E-beam in response to the excess leakage signal. Preferably, a filament is heated by an electric current and a cathode is bombarded with electrons from the filament to produce the E-beam. Then a filament control signal is employed for controlling the filament heating current.
    Type: Grant
    Filed: February 3, 2001
    Date of Patent: September 24, 2002
    Assignee: Nikon Corporation
    Inventors: Michael Stuart Gordon, Samuel Kay Doran
  • Precision tool control system for a workpiece positioning apparatus
    Patent number: 5739654
    Abstract: A servo controlled tool and stage positioning system. A circuit in the tool positioning servo control circuit removes unwanted glitches. Glitches are generated by servo control DACs when the servo is at rest. The circuit selectively blocks these glitches from being passed to the tool positioning circuit only when the stage is at rest.
    Type: Grant
    Filed: September 19, 1996
    Date of Patent: April 14, 1998
    Assignee: International Business Machines Corporation
    Inventors: Samuel Kay Doran, Erwin Ernst Weissmann