Patents by Inventor Robert C. Rumbaugh

Robert C. Rumbaugh 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: 6559819
    Abstract: A field emission display (100) includes a cathode plate (104) having a plurality of electron emitters (112), ballast resistors (118), an anode plate (120) having an anode (124), and a scan mode control circuit (130). The scan mode control circuit (130) is coupled to a video control circuit (160) via a scan mode switching circuit (150). The scan mode control circuit (130) cooperates with the scan mode switching circuit (150) and the video control circuit (160) to automatically switch between a single scan mode of operation and a multi-scan mode of operation.
    Type: Grant
    Filed: July 17, 2000
    Date of Patent: May 6, 2003
    Assignee: Motorola, Inc.
    Inventors: Robert C. Rumbaugh, Ken Foo
  • Patent number: 6246177
    Abstract: A partial discharge method for operating a field emission display (100) having an anode (125), a spacer (106), and a plurality of electron emitters (116) includes the steps of causing electron emitters (116) to emit electrons (130), applying a scanning mode anode voltage to the anode (125), where the scanning mode anode voltage is selected to cause electrons (130) to be attracted toward anode (125), and, thereafter, applying a partial discharge voltage to anode (125). The partial discharge voltage is equal to about a maximum discharge voltage, where the maximum discharge voltage is defined as the maximum voltage that can be applied to anode (125) during the discharge mode of operation while maintaining invisibility of spacer (106).
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: June 12, 2001
    Assignee: Motorola, Inc.
    Inventors: Chenggang Xie, James E. Jaskie, Robert C. Rumbaugh
  • Patent number: 6060840
    Abstract: A method for controlling an emission current (134) in a field emission display (100) includes performing at start-up the steps of providing at an anode (138) a voltage less than an operating anode voltage, receiving emission current (134) at anode (138), concurrently measuring a power output of a power supply (146) connected to anode (138), and using the measured power output to adjust an offset voltage applied to a gate extraction electrode (126). A field emission display (100) includes a control circuit (111), which has a sensor (150), a current controller (154), and a gate voltage source (158). Sensor (150) is designed to be connected to power supply (146). Gate voltage source (158) is connected to gate extraction electrode (126) and applies thereto the offset voltage, which is manipulated by current controller (154) in response to an output signal (152) of sensor (150).
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: May 9, 2000
    Assignee: Motorola, Inc.
    Inventors: Ken Kok Foo, Robert C. Rumbaugh
  • Patent number: 6031336
    Abstract: A field emission display (100) includes a cathode plate (110) having a plurality of electron emitters (114), an anode plate (122) having an anode (124) connected to a potential source (126), and an anode voltage pull-down circuit (127) having an input (106) and an output (104). Output (104) is connected to anode (124), and input (106) is connected to potential source (126). Preferably, anode voltage pull-down circuit (127) causes an anode voltage (120) at anode (124) to drop to about ground potential prior to generation of a discharge current by electron emitters (114) for neutralizing positively electrostatically charged surfaces (137, 138) within field emission display (100).
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: February 29, 2000
    Assignee: Motorola, Inc.
    Inventors: Robert C. Rumbaugh, Robert T. Smith, Johann Trujillo, Chenggang Xie, Scott V. Johnson, Curtis D. Moyer, David M. Rice
  • Patent number: 4554468
    Abstract: A self latching comparator circuit has upper and lower input offset voltages associated therewith to establish hysteresis in response to a differential input signal. The comparator circuit comprises a differential amplifier adapted to receive a differential input signal and first and second parallel current mirror circuits for producing upper and lower input offset voltages when each are respectively activated. Antisaturation means are provided for preventing the current mirror circuits from saturating. An output circuit is also provided which does not load the differential output and therefore provides for a well controlled hysteresis.
    Type: Grant
    Filed: July 1, 1983
    Date of Patent: November 19, 1985
    Assignee: Motorola, Inc.
    Inventors: Robert C. Rumbaugh, Ira Miller
  • Patent number: 4536663
    Abstract: The input voltage signals to a comparison circuit may vary between levels substantial equal to the first and second supply voltages (e.g. typically 5 volts and ground). A first transistor circuit is coupled to a current mirror circuit and to an output node for supplying a mirrorable current to the current mirror circuit which in turn reduces the voltage at the output node when the first input voltage approaches the upper supply voltage, and supplies a current to the output to increase the voltage thereat when the second input approaches the upper supply voltage. A second transistor circuit is also coupled to the current mirror and to the output for supplying a mirrorable current to the current mirror means so as to reduce the voltage at the output when the second input voltage approaches ground, and supplies current to the output to increase the voltage thereat when the first input voltage approaches ground.
    Type: Grant
    Filed: July 1, 1983
    Date of Patent: August 20, 1985
    Assignee: Motorola, Inc.
    Inventors: Ira Miller, Robert C. Rumbaugh, John J. Price, Jr.
  • Patent number: 4446843
    Abstract: An electronic ignition system which is responsive to timing signals generated in timed relationship for providing a substantially constant percent excess dwell time. The timing signals are developed across a sensor coil that is floated between first and second inputs of the system. A capacitor is coupled through a buffer circuit to one of the inputs of the system wherein the timing signal is superimposed onto the voltage developed across the capacitor. A charge and discharge circuit comprising a pair of resistive current sources is utilized to charge and discharge the capacitor during operation. The ratio of the resistive components produces a constant percent excess dwell time that is substantially independent to temperature and process variations.
    Type: Grant
    Filed: October 4, 1982
    Date of Patent: May 8, 1984
    Assignee: Motorola Inc.
    Inventors: Robert C. Rumbaugh, Robert B. Jarrett