Patents by Inventor Ralph A. Patterson
Ralph A. Patterson 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).
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Patent number: 7280218Abstract: An apparatus and method is provided for facilitating ionization of a gas medium of a laser gyroscope. The apparatus and method employ a solid state light emitting device as a start aid for the laser gyroscope. The solid state light emitting device has a wavelength at or below a threshold wavelength based on a work function of a cathode coating material to prompt ionization of a gas medium within the laser gyroscope.Type: GrantFiled: January 6, 2005Date of Patent: October 9, 2007Assignee: Litton Systems Inc.Inventors: Robert A. Mitchell, Christine E. Geosling, Ralph A. Patterson
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Patent number: 7239135Abstract: An NMR gyroscope in one example comprises a support structure affixed within an enclosure, an NMR cell affixed to the support structure, a plurality of permanent magnets disposed about the NMR cell to produce a magnetic field within the cell, and a field coil disposed proximate the cell to produce a modulated magnetic field transverse to the magnetic field produced by the permanent magnets.Type: GrantFiled: December 20, 2005Date of Patent: July 3, 2007Assignee: Northrop Grumman CorporationInventors: Henry C. Abbink, Edward Kanegsberg, Ralph A. Patterson
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Publication number: 20060146335Abstract: An apparatus and method is provided for facilitating ionization of a gas medium of a laser gyroscope. The apparatus and method employ a solid state light emitting device as a start aid for the laser gyroscope. The solid state light emitting device has a wavelength at or below a threshold wavelength based on a work function of a cathode coating material to prompt ionization of a gas medium within the laser gyroscope.Type: ApplicationFiled: January 6, 2005Publication date: July 6, 2006Inventors: Robert Mitchell, Christine Geosling, Ralph Patterson
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Publication number: 20060139029Abstract: An NMR gyroscope in one example comprises a support structure affixed within an enclosure, an NMR cell affixed to the support structure, a plurality of permanent magnets disposed about the NMR cell to produce a magnetic field within the cell, and a field coil disposed proximate the cell to produce a modulated magnetic field transverse to the magnetic field produced by the permanent magnets.Type: ApplicationFiled: December 20, 2005Publication date: June 29, 2006Inventors: Henry Abbink, Edward Kanegsberg, Ralph Patterson
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Patent number: 6040908Abstract: A method and apparatus for reducing the temperature-dependent Shupe bias of a potted gyro sensor coil pack to near-zero is provided by selectively adjusting the manner in which CCW and CW fiber leads are attached to the coil pack or the coil mount. The invention recognizes the inevitable existence of a strain differential between the CW and CCW-wound portions of a symmetrically-wound fiber coil. Leads affixed to the ends of the CW and CCW-wound halves of the coil are selectively bonded in accordance with principles for creating a counteracting temperature-dependent stress differential whereby temperature-dependent Shupe bias is substantially eliminated from the gyro output.Type: GrantFiled: July 28, 1998Date of Patent: March 21, 2000Assignee: Litton Systems, Inc.Inventors: John P. Rahn, Ralph A. Patterson, Amado Cordova
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Patent number: 5856867Abstract: The invention is a method and apparatus for quantitatively characterizing the pressure-induced nonreciprocity of a fiber-optic coil where the pressure-induced nonreciprocity is a property of a fiber-optic coil which pertains to the degree to which light beams, initially in phase, differ in phase as a result of traversing the fiber-optic coil in reverse directions while the fiber-optic coil is being subjected to a time-varying pressure. The method comprises the steps of applying time-varying pressure to the fiber-optic coil for a predetermined time period, measuring the phase difference of light beams traversing the fiber-optic coil in reverse directions during the predetermined time period, and obtaining a measure of the nonreciprocity of the fiber-optic coil utilizing the measured phase difference.Type: GrantFiled: July 28, 1997Date of Patent: January 5, 1999Assignee: Litton Systems, Inc.Inventors: John P. Rahn, Ralph A. Patterson
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Patent number: 5818590Abstract: A rotation sensor for use in a fiber optic gyroscope includes a substantially-planar disk-like coil mounting member of titanium. A would sensor coil is supported by the member in an edgewise fashion, allowing free expansion of the sensor coil in the direction orthogonal to the plane of the member to minimize thermally-induced stressing of the sensor coil. In an alternative embodiment, the free-standing coil is effectively "split"; that is, one-half is mounted to one side of the member and the remainder to the other side in such a way that the sensitive axes are coincident. Edge ramps are provided in the member for guiding the continuous optical fiber comprising the coil segments from one side of the disk-like mounting member to the other without microbends.Type: GrantFiled: September 11, 1995Date of Patent: October 6, 1998Assignee: Litton Systems, Inc.Inventor: Ralph A. Patterson
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Patent number: 5761225Abstract: A power boosted source of broadband optical power comprising a broadband light source, optical fiber amplifier and a relative intensity noise reduction system. The optical fiber amplifier amplifies the power level of the optical input signal to provide a power boosted source of broadband optical power out of an output port. A coupler samples a portion of the broadband optical power out of the output port as a sample portion signal. A detector and transimpedance amplifier detect the optical signal and provide a buffered signal having an instantaneous amplitude that faithfully characterizes the intensity of the sample portion signal. A bandpass amplifier amplifies the buffered signal and provides an output control signal to a light source responsive to a composite bias and control current for providing an output optical signal. The output optical signal is coupled to the input of the optical fiber amplifier to be the optical input signal to the optical fiber amplifier.Type: GrantFiled: May 23, 1996Date of Patent: June 2, 1998Assignee: Litton Systems, Inc.Inventors: Bernard C. Fidric, Ronald James Michal, James Ross Steele, Eric Lee Goldner, Ralph A. Patterson
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Patent number: 5742390Abstract: A potted sensor coil for a fiber optic gyroscope includes an inter-layer stress relief layer of lubricating material. The coil is wound into a known pattern. Various coil configurations can be realized in which a coating layer of lubricant relieves stressing at the interface between the outer jacket of the fiber and the coil potting material.Type: GrantFiled: November 19, 1996Date of Patent: April 21, 1998Assignee: Litton Systems, Inc.Inventors: Amado Cordova, Robert J. Hoover, Thomas McLean, Ralph A. Patterson, John P. Rahn
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Patent number: 5598489Abstract: A fiber optic sensing coil formed in a polarization-maintaining optical fiber has two optical fiber leads extending therefrom. A multifunction integrated optics chip linearly polarizes optical signals input to the sensing coil. Fiber optic leads formed of polarization-maintaining optical fiber extend from the multifunction integrated optics chip. The fiber optic multifunction integrated optics chip leads are arranged such that the linear polarization of optical signals output from the multifunction integrated optics chip is directed along one of the principal axes of birefringence of each of the fiber optic multifunction integrated optics chip leads. Splices are formed between corresponding the first sensing coil leads and the multifunction integrated optics chip leads. The sensing coil leads and the multifunction integrated optics chip leads are arranged such that their corresponding principal axes of birefringence are at angles of approximately 45.degree. relative to one another.Type: GrantFiled: July 27, 1994Date of Patent: January 28, 1997Assignee: Litton Systems, Inc.Inventors: George A. Pavlath, Ronald J. Michal, Ralph A. Patterson, Sidney X. Y. Huang
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Patent number: 5333214Abstract: Apparatus for suppressing the bias errors induced by the Faraday effect in the output of a sensor coil exposed to a magnetic field. Arrangements are formed at two leads of the sensor coil for compensating the bias shifts. One of such arrangements comprises at least one loop of optical fiber for compensating the effect induced by the magnetic field component oriented transverse to the axis of the sensor coil while the other comprises at least one loop oriented at a predetermined pitch angle for compensating the effect induced by a magnetic field component along the axis. In each case, a predetermined degree of twist of a preselected fiber twist mode is imposed upon the compensator loop for creating a counteracting, corrective Faraday effect. Cross-coupling does not occur between the two compensators as their twist rate perodicities are unequal.Type: GrantFiled: February 12, 1993Date of Patent: July 26, 1994Assignee: Litton Systems, Inc.Inventors: Sidney X. Huang, Ronald J. Michal, Ralph A. Patterson, George A. Pavlath
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Patent number: 5329349Abstract: A method for tuning a sensor coil for a fiber optic gyroscope. The coil is initially wound in a known pattern. One end of the fiber of the wound coil is then adjusted relative to the other end so that a known differential is obtained that effectively displaces the midpoint of the winding pattern. The coil is then attached to an interferometer test apparatus and performance measured. After successive observations a "trimmed" coil is obtained of acceptable performance characteristics.Type: GrantFiled: May 10, 1993Date of Patent: July 12, 1994Assignee: Litton Systems, Inc.Inventors: Ralph A. Patterson, John D. Wilde