Patents Examined by Carolyn E. Fields
  • Patent number: 6849855
    Abstract: A method of marking and identifying an object (10) by the marking consists of applying to an object (10) an up-conversion material (12), then irradiating the object (10) with infrared electromagnetic radiation (16) and, finally, observing the irradiated object to detect the spectrum of emitted electromagnetic radiation (18). A suitable up-conversion material (12) is selected from a group of up-conversion materials consisting of CaF2, BaF2, CdF2, LaF2 and SrF2 doped with erbium, praseodymium, neodymium or dysprosium. The objects (10) may be observed to detect emitted electromagnetic radiation (18) from that part of the electromagnetic spectrum that is visible to the naked eye. The objects (10) may also be observed to detect specific wavelengths of electromagnetic radiation which are known to be emitted by the up-conversion material (12) when the up-conversion material (12) is irradiated by designated wavelengths of infrared electromagnetic radiation.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: February 1, 2005
    Assignee: Raytheon Company
    Inventors: I-Fu Shih, David B. Chang
  • Patent number: 5834782
    Abstract: A large area image detecting apparatus made by arranging a plurality of small area sensors in a stepped arrangement so that the inactive regions of the small sensors are covered by a active area of another small sensor. The apparatus may be used to detect light or radiation. A fiber optic assembly may be used to guide light from a flat scintillator plate onto the small sensors.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: November 10, 1998
    Assignee: Schick Technologies, Inc.
    Inventors: David B. Schick, Daniel A. Neugroschl, David B. Plass, Jonathan Singer
  • Patent number: 5811809
    Abstract: A threshold detector circuit (2) suitable for use with a nuclear event detector for sensing an ionising radiation pulse has a high tolerance to ambient temperature fluctuations. The threshold detector (2) comprises an amplifier stage (3) which includes a pair of complementary transistors (Q2, Q3) and a comparator stage (6) which includes a third transistor (Q4) and a voltage reference (7). Temperature compensation is achieved by the addition of a feedback loop (5) in the amplifier stage (3) including a fourth transistor (Q1) whose temperature coefficient is closely matched to that of the third transistor (Q4).
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: September 22, 1998
    Assignee: British Aerospace Public Limited Company
    Inventors: Geoffrey Smith, Jiapal S. Brar
  • Patent number: 5804819
    Abstract: A method for quantitative verification of line-wise scanning geometry in a digital radiographic read out system. An x-ray transparent phantom substrate with an embedded ruler having a number of equidistant parallel strips that are opaque on top of a photostimulable phosphor screen so that the ruler is parallel with the direction of line-wise scanning. After x-ray exposure and scanning, the position in the scanning direction of the center of each ruler strip is computed. At least one of the following parameters is determined: average pixel sampling distance, geometric distortion value, and total scanned width.
    Type: Grant
    Filed: October 24, 1995
    Date of Patent: September 8, 1998
    Assignee: AGFA-Gevaert
    Inventors: Pieter Vuylsteke, Walter Jacobs
  • Patent number: 5796112
    Abstract: A fluorescent microscope includes a laser scanning unit having a stage for supporting a fluorescent sample, a laser beam generator and a beam scanning unit for causing a laser beam from the generator to spot scan a sample to cause fluorescence generated by multi-photon absorption. A first detector detects fluorescence emitted from a side of the sample on which the laser beam is incident to output a first signal corresponding to detected fluorescence. A second detector detects fluorescence emitted from a side of the sample from which the laser beam, having been transmitted through the sample, is emitted from the sample. The second detector produces a second signal corresponding to the detected fluorescence. The first and second signals are summed and amplified. A display is provided for a microscopic image of the sample in synchronization with the scanning of the laser beam, based on the amplified summed signals.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: August 18, 1998
    Assignee: Hamamatsu Photonics K.K.
    Inventor: Koji Ichie
  • Patent number: 5753920
    Abstract: An integrated charge monitor for measuring a level of cumulative radiation exposure includes semiconductor devices having characteristics that change with a cumulative level of radiation to which the devices are exposed, different amounts of radiation shielding associated with each of the devices, and circuitry operable to separately address each of the devices to measure a change in the characteristic of the selected device due to radiation exposure. The monitor may be implemented on a single integrated circuit chip. The monitor may also be employed in performing a spectrometric analysis of radiation based on the affect of the radiation on characteristics of multiple, differently-shielded semiconductor devices.
    Type: Grant
    Filed: July 26, 1995
    Date of Patent: May 19, 1998
    Assignee: California Institute of Technology
    Inventors: Martin G. Buehler, Brent R. Blaes, George A. Soli
  • Patent number: 5753917
    Abstract: A scintillation camera is provided with a scintillation crystal assembly having multiple crystal layers for interacting with various photon energy levels. The camera performs imaging of conventional nuclear medicine radioisotopes as well imaging of high energy isotopes used in PET (Positron Emission Tomography) applications. The multiple crystal layers have the effect of doubling the sensitivity of the camera to high energy photons, while retaining the performance characteristics needed for conventional low energy photon imaging.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: May 19, 1998
    Inventor: John C. Engdahl
  • Patent number: 5747807
    Abstract: Contaminants are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. A diode laser-pumped solid-state laser (the ILS laser) is employed as a detector. The ILS laser comprises an ion-doped crystal medium contained in a laser cavity optically pumped by a diode laser pump laser. A gas sample containing gaseous contaminant species is placed inside the laser cavity and on one side of the ion-doped crystal. The output signal from the ILS laser is detected and analyzed to identify the gaseous species (via its spectral signature). The concentration of the gaseous species can be determined from the spectral signature as well. Advantageously, the diode laser pump laser is relatively small and compact in comparison to other sources of optical pumping.
    Type: Grant
    Filed: July 3, 1996
    Date of Patent: May 5, 1998
    Assignee: Innovative Lasers Coropration
    Inventors: George H. Atkinson, Esmail Mehdizadeh
  • Patent number: 5747825
    Abstract: A latent image is formed on a stimulable phosphor plate (10) by irradiating the phosphor plate with x-rays from an x-ray source (14). To develop the stimulable phosphor plate, the plate is irradiated with light of a different wavelength from developer light source (32). The light from the developer light source causes the stimulable phosphor plate to give off light of yet another characteristic wavelength. Light from the stimulable phosphor plate is filtered (38) to remove the wavelength of the developer light and focused (42) on a light sensing element (46) of a time delay and integration video camera (34). The stimulable phosphor plate and the video camera are moved relative to each other and the rate of movement is monitored (60).
    Type: Grant
    Filed: November 20, 1992
    Date of Patent: May 5, 1998
    Assignee: Picker International, Inc.
    Inventors: David L. Gilblom, Peter S. Castro
  • Patent number: 5731589
    Abstract: The invention relates to a radiation dosimeter comprising a sensor arranged in a dosimeter casing and including at least one measuring field and a calibrating zone (64). To provide a dosimeter which can be readily manufactured and comprises a wide measuring range with high precision, it is provided, according to the invention, that the calibrating zone (64) of the sensor (56) is inserted into a radiation-shielded clearance (66) of a double-wall element (68) being formed by folding a radiation-proof web-like material.
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: March 24, 1998
    Assignee: Deutsche Forschungsanstalt fur Luft-und Raumfahrt e.V.
    Inventors: Rolf Sief, Petra Rettberg, Gerda Horneck
  • Patent number: 5729016
    Abstract: A low cost night vision system for use in connection with law enforcement vehicles, marine vessels, and other nonmilitary surface vehicles. The invention includes a night vision camera having an array of uncooled detectors. A mechanism is provided for adjusting the pointing angle of the night vision camera in response to scan control signals. Output signals from the uncooled detectors are further processed into a standard video format and displayed on a conventional display located, for example, within a vehicle or marine vessel.
    Type: Grant
    Filed: August 26, 1996
    Date of Patent: March 17, 1998
    Assignee: Hughes Aircraft Company
    Inventors: Stuart H. Klapper, Howard Laitin, Alex L. Kormos, Lacy G. Cook, David M. Masarik, Paul R. Salvio
  • Patent number: 5729017
    Abstract: The specification describes pulse generators and detectors for the far infra-red and operating at frequencies of the order of 10.sup.10 to 10.sup.13 Hz (the Terahertz range). These devices rely on electric field interactions with optical beams in biased metal semiconductor microstructures. The electric field is created between metal electrodes on the semiconductor surface and the electric field is enhanced, according to the invention, by configuring the electrode gap geometry with sharp electrode features.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: March 17, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Igal M. Brener, Douglas Raymond Dykaar
  • Patent number: 5723864
    Abstract: Contaminants are detected optically at concentrations below 1 part-per-million (ppm) and extending to a level approaching 1 part-per-trillion (ppt) by using intracavity laser spectroscopy (ILS) techniques. An optically-pumped solid-state laser (the ILS laser) is employed as a detector. The ILS laser comprises an ion-doped crystal medium contained in a linear laser cavity which may be optically pumped by a diode laser pump laser. A gas sample containing gaseous contaminant species is placed inside the laser cavity and on one side of the ion-doped crystal. The output signal from the ILS laser is detected and analyzed to identify the gaseous species (via its spectral signature). The concentration of the gaseous species can be determined from the spectral signature as well. Advantageously, the linear cavity is relatively small and compact in comparison to other ILS systems.
    Type: Grant
    Filed: July 3, 1996
    Date of Patent: March 3, 1998
    Assignee: Innovative Lasers Corporation
    Inventors: George H. Atkinson, Esmail Mehdizadeh
  • Patent number: 5723865
    Abstract: An x-ray imaging device. One surface of a flat single crystal CsI crystal is supported on an optically transparent support plate. The opposite surface, i.e. an x-ray illumination surface of the crystal is coated with an x-ray transparent optical reflector to provide an x-ray scintillation sandwich having an optical mirror at the x-ray illumination surface of the CsI crystal. An optical camera is preferably focused on the illumination surface of the CsI crystal. In a preferred embodiment an index of refraction matched optical adhesive is used at the x-ray illumination surface to attach the reflector and to reduce Fresnel reflections.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: March 3, 1998
    Assignee: ThermoTrex Corporation
    Inventors: Richard Trissel, Stephen Horton, Brett Spivey, Lee Morsell
  • Patent number: 5721430
    Abstract: Multichannel infrared detector assemblies for use in the detection and monitoring of gas concentrations are provided.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: February 24, 1998
    Assignee: Engelhard Sensor Technologies Inc.
    Inventor: Jacob Y. Wong
  • Patent number: 5719400
    Abstract: A gamma ray detection and locating system comprising an array of scintillator crystals connected to a multichannel photomultiplier tube by discrete optical fibers, each fiber connecting a single crystal to a corresponding specific location on the face of the photomultiplier tube. Also described is an improved system for identifying the location of specific electrodes in the photomultiplier tube receiving electrons generated by photons flowing from the crystal along the fiber to the tube.
    Type: Grant
    Filed: August 7, 1995
    Date of Patent: February 17, 1998
    Assignee: The Regents of the University of California
    Inventors: Simon R. Cherry, Yiping Shao, Stefan B. Siegel, Robert W. Silverman
  • Patent number: 5719397
    Abstract: An apparatus for detecting the presence of a target material such as a multicomponent gas is disclosed. The apparatus includes a source of electromagnetic radiation and a device for dispersing the radiation into different frequency bands for targeting the material at different wavelengths corresponding to absorption bands in the material. Spaced apart optoelectric transducers detect the different frequency bands. A processor detects the changes in the output of the transducers occasioned by partial absorption of the electromagnetic radiation from the source by the target material. Processing means also compensates for temperature variations in the source.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: February 17, 1998
    Assignee: Spectrasense Limited
    Inventors: William A. Hallett, Joshua D. Silver
  • Patent number: 5717217
    Abstract: A method for monitoring the properties of a coating comprising the steps of adding a fluorescence probe to a coating composition which has the ability to undergo microscopic changes in viscosity, the ratio of the intensity of the fluorescence emission of said probe at two wavelengths changing in response to said changes in said viscosity of said coating composition; curing said coating; causing said compound to fluoresce; measuring the fluorescence of said compound; calculating the ratio of the intensities of fluorescence emission of said compound at two or more wavelengths; relating said ratio to the monitored property of said coating.
    Type: Grant
    Filed: May 5, 1994
    Date of Patent: February 10, 1998
    Assignee: Spectra Group Limited, Inc.
    Inventors: Douglas C. Neckers, Jian Chang Song, Afranio Torres-Filho
  • Patent number: 5717212
    Abstract: A rotating gantry (20) is rotatably mounted to a stationary gantry for rotation around an axis of rotation. Gamma camera detector heads (22a, 22b, 22c) are mounted to the rotating gantry for rotation about a patient receiving region (14). A patient is supported on a first, cantilevered patient support portion (10) which is adjustable in height, and which selectively extends toward and away from a slab defined by the detector heads. In one mode of use, the first patient support portion (10) is supported on a second support surface (16) when fully cantilevered to minimize vibration and movement. In a second mode, the first patient support portion (10) is separated by a gap from the second support portion (16) and the region of interest of the patient is positioned over the gap. In this manner, radiation passing from the region of interest of the patient to the detector heads is not attenuated by a patient support structure. Further, the detector heads are mounted on tracks (30, 32) by rollers (44, 46).
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: February 10, 1998
    Assignee: Picker International, Inc.
    Inventors: James M. Fulton, Steven J. Plummer
  • Patent number: 5717215
    Abstract: An electronic apparatus comprising a material having photoconductivity, an energy bandgap, and trap levels. The material is typified by a thin film of polycrystalline diamond. The material is illuminated with first light having photon energies smaller than the energy bandgap of the material. Then, the material is illuminated with second light having photon energies greater than the energy bandgap of the material to thereby induce a photocurrent. The amount of the first light can be known by measuring the induced photocurrent.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: February 10, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takashi Inushima, Rimantas Vaitkus, Satoshi Teramoto