Patents Assigned to Litton System, Inc.
  • Patent number: 6127779
    Abstract: A high power switching apparatus comprises an annular cathode having a surface capable of emitting a hollow electron beam therefrom and an anode cavity spaced from said cathode. The cavity has an annular opening smaller in dimension than a corresponding internal dimension that defines the cavity to provide a Faraday cage collector of the hollow electron beam. A control electrode, disposed between the cathode and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for modulation of the hollow electron beam. Arc suppressing electrodes, at approximately the same potential as the cathode, are disposed between the control electrode and the anode. An intermediate high voltage electrode, disposed between the arc suppressing electrodes and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for channeling of the hollow electron beam.
    Type: Grant
    Filed: November 9, 1998
    Date of Patent: October 3, 2000
    Assignee: Litton Systems, Inc.
    Inventor: Richard Brownell True
  • Patent number: 6121612
    Abstract: A night vision device includes an image intensifier tube having a photocathode responsive to light in the wavelength range extending from about 1 .mu.m to about 2 .mu.m. The photocathode releases photoelectrons in response to photons of light in this wavelength range. A photomultiplier tube includes such a photocathode to provide an image in response to light of such a wavelength. A method of making such a photocathode is set out.
    Type: Grant
    Filed: October 22, 1997
    Date of Patent: September 19, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Timothy W. Sinor, Joseph P. Estrera, David G. Couch
  • Patent number: 6121600
    Abstract: An integrated night vision device and laser range finder provides both night-time and day-time imaging by use of an image intensifier tube, as well as providing laser range finding operations both day and night. In a laser range finder mode of operation the device projects a pulse of laser light into a scene being viewed, and a power supply and laser range finder circuit of the device temporarily utilizes the image intensifier tube as a sensor to detect reflected laser light. During laser range finding, imaging is cut off for a very short time interval. Also, during imaging operations, the power supply and laser range finder circuit operates the image intensifier tube in a unique way in order to provide both improved automatic brightness control (ABC) and improved bright-source protection (BSP). The ABC and BSP functions are coordinated with the laser range finding function in order to prevent interference by the ABC or BSP functions with laser range finding operations.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: September 19, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Michael R. Saldana, Rodney Lynn Doster, Roland M. Morley, Joseph Paul Estrera
  • Patent number: 6122057
    Abstract: A sinusoidal phase generated carrier is used to demodulate signal output from an interferometric sensor array. Optical signals input to the array are modulated with a sinusoid. Output signals are sampled and integrated over portions of a period of the phase generated carrier. A key to this method of sampling is the existence of pairs of signals associated with integration over two 180.degree. out-of-phase portions of the phase generated carrier. This invention is a four step method involves the implementation of two pairs of such signals to determine the phase shift in each sensor in the array.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: September 19, 2000
    Assignee: Litton Systems, Inc.
    Inventor: David B. Hall
  • Patent number: 6122099
    Abstract: A method of achieving a focusing adjustment of an optical assembly, and of releasably locking this focusing adjustment, is described. A night vision weapon sight (10) which implements this method includes an objective lens assembly (14), an eyepiece lens (18), and an image intensifier tube (20) receiving light via the objective lens in order to provide an image via the eyepiece lens. The objective lens assembly includes a base portion (32) into which a lens housing (34) is threadably received. The threaded engagement of the base portion and lens housing is locked by a collet-like array of radially flexible fingers (42) each having a conical outer surface. A locking collar (44) having a conically tapering inner surface threadably engages the lens housing (34) and engages the collet fingers (42). Locking of the locking collar (44) is ensured by threaded engagement of a locking ring (54) with the locking collar (44) such that the prevailing torque tightens both of a pair of threaded engagements of opposite hand.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: September 19, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Clifford James Connors, Gary A. Wannagot, Timothy Roe Goebel
  • Patent number: 6116976
    Abstract: A novel photocathode and image intensifier tube include an active layer comprised substantially of amorphic diamond-like carbon, diamond, or a combination of both. The photocathode has a face plate coupled to an active layer. The active layer is operable to emit electrons in response to photons striking the face plate.
    Type: Grant
    Filed: July 22, 1999
    Date of Patent: September 12, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Timothy W. Sinor, Joseph P. Estrera, Keith T. Passmore
  • Patent number: 6115124
    Abstract: A method for measuring intensity-type polarization non-reciprocity (PNR) bias error in an interferometric fiber optic gyroscope (IFOG) using birefringence modulation. The counter-propagating waves in the fiber optic loop of the IFOG are modulated with a slowly varying voltage signal, such as a triangle wave, ramp or sine wave signal, to cause birefringence modulation. A peak-to-peak amplitude of a resultant output signal is measured to determine the intensity-type PNR bias error of the IFOG.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: September 5, 2000
    Assignee: Litton Systems, Inc.
    Inventors: John R. Hall, Edward Kanegsberg
  • Patent number: 6115125
    Abstract: The invention is a method and apparatus for determining the rotation of a medium through which a light beam propagates by modulating the light beam with a primary pseudorandom bit sequence consisting of a plurality of contiguous P subsequences. Each P subsequence consists of a start sequence of predetermined length followed by a sequence of trailing bits. The method comprises three steps. The first step consists of deriving a feedback bit from each generating sequence in a P subsequence in accordance with a specified rule where a generating sequence is any sequence of contiguous bits in the P subsequence having the same length as the start sequence. The bit that follows a generating sequence is called the trailing bit for that generating sequence. The second step of the method consists of determining a sequence of one or more modifier bits to be used in modifying the P subsequence. The third step of the method consists of modifying the P subsequence utilizing the one or more modifier bits.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: September 5, 2000
    Assignee: Litton Systems Inc.
    Inventors: Daniel A. Tazartes, John G. Mark, David I. Tazartes
  • Patent number: 6111692
    Abstract: A multi-function day/night observation, ranging, and sighting device includes a single objective lens and a single eyepiece lens, and at the eyepiece lens provides an image of a scene. The single objective lens leads to a visible-light first optical path, and to an invisible-light second optical path. The invisible-light second optical path includes an image intensifier tube providing a visible image. The first and second optical paths converge with visible images being provided by each pathway overlaying at a reticule plane. A single light path leads from the reticule plane to the eyepiece lens. A lens group includes a lens through which light from the scene is transmitted to be focused at an image plane. A focus cell body carries at least one lens of the lens group, and a support structure of the device movably supports the focus cell body for controlled lateral relative movement.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: August 29, 2000
    Assignee: Litton Systems, Inc.
    Inventor: Kenneth Warren Sauter
  • Patent number: 6110758
    Abstract: An improved photocathode and image intensifier tube are disclosed along with a method for making both the tube and photocathode. The disclosed photocathode and image intensifier tube have an active layer comprising two or more sublayers. The first sublayer has a first concentration of a group III-V semiconductor compound while the second sublayer has a second concentration of the group III-V semiconductor compound. The multilayer active layer is coupled to a window layer.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: August 29, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Joseph P. Estrera, Keith T. Passmore, Timothy W. Sinor
  • Patent number: 6108086
    Abstract: A system and method for providing scale factor stabilization of a broadband light source used in fiber optic gyroscopes is provided. A primary bandpass filter is positioned in the propagation path of the light emitted by the broadband light source to narrow the spectral width of the optical signal transmitted to the fiber optic gyroscope, which reduces the centroid wavelength shift resulting when the broadband light source is exposed to ionizing radiation and other harsh environmental conditions. The filtered optical signal is then passed through the fiber optic gyroscope, where the filter optical signal is processed to measure the amount of rotation of the fiber optic gyroscope. The scale factor stabilization system further includes the spectral monitor array arranged to perform direct optical wavelength measurements of the filtered optical signal to determine whether a scale factor shift in the optical signal has occurred.
    Type: Grant
    Filed: March 4, 1999
    Date of Patent: August 22, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Ronald J. Michal, David M. Rozelle, John P. Rahn
  • Patent number: 6105427
    Abstract: A precision, micro-mechanical semiconductor accelerometer of the differential-capacitor type comprises a pair of etched opposing cover layers fusion bonded to opposite sides of an etched proofmass layer to form a hermetically sealed assembly. The cover layers are formed from commercially available, Silicon-On-Insulator ("SOI") wafers to significantly reduce cost and complexity of fabrication and assembly. The functional semiconductor parts of the accelerometer are dry-etched using the BOSCH method of reactive ion etching ("RIE"), thereby significantly reducing contamination inherent in prior art wet-etching processes, and resulting in features advantageously bounded by substantially vertical sidewalls.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: August 22, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Robert E. Stewart, Arnold E. Goldman
  • Patent number: 6104849
    Abstract: Unidirectional and bi-directional fiber optic rotary joints are disclosed for coupling at least one optical signal across a rotary interface. The unidirectional joint includes a stator having a waveguide. A rotor is rotatable through a full 360.degree. revolution and is concentric to the stator. Light transmitters are positioned on a first circumference and connected to one of the stator and the rotor. Each of the transmitters emits an optical signal. Light receivers are positioned on a second circumference and connected to the other one of the stator and the rotor. Each of the transmitted optical signals is emitted tangentially into the waveguide and is reflected in short chordal lengths along the waveguide. Each optical signal is received by at least one of the second plurality of light receivers through the full 360.degree. revolution of the rotor. The number of light receivers is greater than the number of light transmitters. Certain receivers do not receive an optical signal during a portion of the 360.
    Type: Grant
    Filed: July 15, 1998
    Date of Patent: August 15, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Norris Earl Lewis, Anthony Lee Bowman, Robert Thomas Rogers, Sr., Michael P. Duncan
  • Patent number: 6104846
    Abstract: The length of optical cable affected when splicing in sensors is reduced by cutting and splicing two distribution fiber lines and two return fiber lines to each sensor. The cable includes a spare distribution fiber line and a spare return fiber line. The optical cable is first stripped back to expose the optical fibers therein. For both the distribution and return lines, one fiber is cut at the proximal end of the stripped back portion of the cable, and another fiber is cut at the distal end of the stripped back portion. These fibers are then fused to respective ports on the sensor. Thus, each of the optical channels is formed from more than one optical fiber. The resulting cable is less stiff and more flexible.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: August 15, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Craig W. Hodgson, Donald A. Frederick
  • Patent number: 6100845
    Abstract: A method and apparatus for determining from a moving observer the location, in terms of latitude, longitude, altitude, and velocity, of a stationary or moving radar emitting a pulsed or continuous-wave signal. The moving observer extracts from the radar signal significant electronic support measures (ESM) parameters, including frequency, pulse repetition interval, and pulse width, and determines from those parameters whether a radio frequency (RF) or pulse repetition frequency (PRF) measurement technique is appropriate, and whether the radar signal angle-of-arrival (AOA) must be computed. The emitter location is computed using a ratio of sequential frequency measurements, and the moving observer continues to collect frequency measurements until the location of the emitter can be established to within a predetermined degree of certainty.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: August 8, 2000
    Assignee: Litton Systems Inc.
    Inventor: Conrad M. Rose
  • Patent number: 6094607
    Abstract: The apparatus of the present invention uses radar altimeter measurements and stored terrain altitude profiles to provide pre-filtered observations to a Kalman filter for estimating barometric offset at the airport runway, and barometric scale factor for offsets above the runway. These offsets are used with the smoothed baro-inertial output from an inertial reference system to provide 3 dimensional constant rate of descent approach procedures to replace non-precision approach procedures based on constant barometric altitude step approaches. The horizontal positions used as reference for the stored terrain altitude profiles are obtained from a prior art navigation apparatus. The integrity of all measurements is assured by using long term averages of the Kalman filter residuals to detect failures. In addition, the estimated baro offset at the runway is compared for consistency with the baro offset obtained by the pilot from the airport by radio.
    Type: Grant
    Filed: November 27, 1998
    Date of Patent: July 25, 2000
    Assignee: Litton Systems Inc.
    Inventor: John W. Diesel
  • Patent number: 6094304
    Abstract: A multi-function day/night observation, ranging, and sighting device includes a single objective lens group and a single eyepiece lens and provides an image of a scene. The single objective lens group leads to a visible-light first optical path and to an invisible-light second optical path. It will be understood that the terms visible-light and invisible-light are used merely to distinguish the two optical paths, and not as a limitation. In other words, some visible light will pass to the image intensifier tube, and this tube is capable of providing an image in response to light in the visible portion of the spectrum. On the other hand, some light in the infrared portion of the spectrum may pass along the visible-light optical path. As mentioned, the invisible-light second optical path includes an image intensifier tube providing a visible image. The first and second optical paths converge with visible images provided by each pathway being overlaid at a reticule plane.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: July 25, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Robert E. Wallace, Wayne Isbell
  • Patent number: 6087660
    Abstract: A night vision device (NVD) includes a control circuit having an acceleration-responsive switch. When the NVD is in a generally horizontal use position, the acceleration-responsive switch enables a circuit allowing voltage to be applied to an image intensifier tube of the night vision device, so that night vision is provided. On the other hand, when the device is flipped up to a stowed position allowing the user of the device unobstructed natural vision, the acceleration-responsive switch senses the changed orientation of the gravitational acceleration vector, and turns off the image intensifier tube as well as other light-emitting sources of the night vision device.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: July 11, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Terry Duane Morris, Marcus Leslie Sutton
  • Patent number: 6088810
    Abstract: A synchronous serial bus with timing information implemented in the bus standard protocol is provided for a bi-directional serial multi-channel data interchange between locally dedicated measuring instruments in a distributed configuration and/or with a data processing unit. This provides synchronized interchange of data between the instruments wherein each instrument is provided with an allocated controller. The invention permits one to employ a simple, preferably standardized, bus protocol. Wiring structure is considerably simplified for a complex multi-sensor system.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: July 11, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Mauricio Ribes, Gunter Spahlinger
  • Patent number: 6087649
    Abstract: A night vision device with an image intensifier tube includes an improved power supply which operates the image intensifier tube of the device according to a variable duty cycle either at a design voltage level for the tube or at a voltage level simulating a dark-field. This duty cycle variation is effected as a function of the current flow in the image intensifier tube in order to provide automatic brightness control and bright source protection. An improved service life for the image intensifier tube is achieved. Also, a microchannel plate of the image intensifier tube need not carry an ion barrier film, resulting in an improved light amplification for the image intensifier tube.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: July 11, 2000
    Assignee: Litton Systems, Inc.
    Inventors: Joseph P. Estrera, Timothy W. Sinor, Michael R. Saldana