At Variable Angle To The Light Beam Patents (Class 356/340)
  • Patent number: 6774994
    Abstract: A method for determining absolute number densities of particles in a solution is disclosed based on a light scattering method. A light scattering photometer is calibrated to produce the Rayleigh ratio at each angle measured with respect to light scattered per unit incident intensity, per unit volume illuminated within the field of view of each detector per steradian subtended by said detector. In order that the numbers calculated be accurate, the illuminated particles should be effectively monodisperse. From the excess Rayleigh ratios measured at a plurality of angles with respect to the incident light beam illuminating said sample particles, an effective size is calculated which, in turn, is used to calculate the differential scattered intensity at each angle. The number of particles per unit volume element is then determined from the measured excess Rayleigh ratio divided by the corresponding differential scattered intensity.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: August 10, 2004
    Assignee: Wyatt Technology Corporation
    Inventors: Philip J. Wyatt, Miles J. Weida
  • Publication number: 20040085536
    Abstract: A methodology and concomitant system for the nonlinear reconstruction of an object from measurements of the transmitted intensity of scattered radiation effected by irradiating the object with a source of radiation. The transmitted intensity is related to either the absorption coefficient or diffusion coefficient, or both, of the object by an integral operator. The image is directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity of the scattered radiation. The mathematical algorithm includes computing a functional series expansion for the coefficient(s) in powers of the transmitted intensity.
    Type: Application
    Filed: November 1, 2002
    Publication date: May 6, 2004
    Inventors: John Carl Schotland, Vadim Arkadievich Markel, Joseph Andrew O'Sullivan
  • Publication number: 20030223063
    Abstract: Characterizing individual airborne particles in real time according to their absorption of optical energy at one or more wavelengths. The instrument can measure the two-dimensional angular optical scattering (TAOS) and/or the one-dimensional angular optical scattering (ODAOS) at one or more wavelengths. When two wavelengths are used, one is chosen to be on an absorption peak, the other is off of the absorption peak (preferably in the absorption valley).
    Type: Application
    Filed: June 19, 2003
    Publication date: December 4, 2003
    Applicant: U.S. Army Research Laboratory
    Inventors: Steven Clyde Hill, Ronald Gene Pinnick, Yong-Le Pan, Kevin Bruce Aptowicz, Kristan P. Gurton, Richard Kounai Chang
  • Patent number: 6630990
    Abstract: Methods and apparatus are disclosed for determining the volume, hemoglobin concentration, maturity and cell shape of mammalian red blood cells in a whole blood sample and simultaneously monitoring system standardization. Methods for distinguishing red blood cells from other cellular particles, prior to the red blood cell analysis are also disclosed. Red blood cells are passed through a beam of light in single file at a selected wavelength, obtaining an initial cytogram by means of the resultant magnitude of one light loss signal and one forward angle light scatter signal at a selected angular interval and a third side angle light scatter or two forward angle light scatter signals at a selected angular intervals and a third side-angle light scatter signal, projecting the cytogram, point by point, onto a pre-calibrated 3-dimensional surface containing grid lines of volume and hemoglobin concentration and determining accurate values of cell volume and hemoglobin concentration.
    Type: Grant
    Filed: June 5, 2001
    Date of Patent: October 7, 2003
    Assignee: Abbott Laboratories
    Inventors: Ronny van't Oever, Young Ran Kim, James C. Bearden, Jr., Marilou Z. Landayan
  • Patent number: 6600559
    Abstract: An on-line method for detecting particle size of a liquid during a process in which there is not a correlation between low absorbance with small particle size, the method comprises the steps of measuring a plurality of reference particle sizes each associated with a particular near infrared diffuse reflectance spectrum for creating a reference infrared diffuse reflectance spectrum having high absorbance with small particle size; measuring on-line a near infrared diffuse reflectance spectrum of the liquid during the process; and determining the particle size of the on-line liquid based on correlating the on-line-measured particle size with the reference near infrared diffuse reflectance spectrum.
    Type: Grant
    Filed: March 22, 2001
    Date of Patent: July 29, 2003
    Assignee: Eastman Kodak Company
    Inventors: Steven C. Switalski, Donald J. Majka
  • Patent number: 6586193
    Abstract: Method for specific detection of one or more analytes in a sample. The method includes specifically associating any one or more analytes in the sample with a scattered-light detectable particle, illuminating any particle associated with the analytes with light under conditions which produce scattered light from the particle and in which light scattered from one or more particles can be detected by a human eye with less than 500 times magnification and without electronic amplification. The method also includes detecting the light scattered by any such particles under those conditions as a measure of the presence of the analytes.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: July 1, 2003
    Assignees: Genicon Sciences Corporation, The Regents of the University of California
    Inventors: Juan Yguerabide, Evangelina E. Yguerabide, David E. Kohne, Jeffrey T. Jackson
  • Patent number: 6587203
    Abstract: A flow cytometer includes a temperature regulator that maintains the temperature of the piezoelectric actuator sufficiently constant so as to produce a consistent predetermined oscillation frequency, and corresponding consistent predetermined droplet break-off point.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: July 1, 2003
    Assignee: Cornell Research Foundation, Inc.
    Inventor: Christopher Colon
  • Patent number: 6570999
    Abstract: A soil analysis system for determining one or more categories of soil based upon the particle sizes in a soil sample. The soil analysis system includes an image sensor and an image analysis assembly. The image sensor produces an image to distinguish individual particles of a soil sample and calculates particle size. The image analysis assembly is coupled to the image sensor to determine a category for each particle based upon the size of the particles, percentage of each category of particles, and one or more categories of soil for the soil sample.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: May 27, 2003
    Assignee: Ag-Chem Equipment Co., Inc.
    Inventor: Robert J. Monson
  • Patent number: 6565815
    Abstract: The present invention provides a reaction vessel and apparatus for performing heat-exchanging reactions. The vessel has a chamber for holding a sample, the chamber being defined by a plurality of walls, at least two of the walls being light transmissive to provide optical windows to the chamber. The apparatus comprises at least one heating surface for contacting at least one of the plurality of walls, a heat source for heating the surface, and optics positioned to optically interrogate the chamber while the heating surface is in contact with at least one of the plurality of walls. The optics include at least one light source for transmitting light to the chamber through a first one of the light transmissive walls and at least one detector for detecting light exiting the chamber through a second one of the light transmissive walls.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: May 20, 2003
    Assignee: Cepheid
    Inventors: Ronald Chang, Lee A. Christel, Gregory T. A. Kovacs, William A. McMillan, M. Allen Northrup, Kurt E. Petersen, Farzad Pourahmadi, Steven J. Young, Robert Yuan, Douglas B. Dority
  • Patent number: 6544770
    Abstract: A method for determining the number or concentration of virus particles in a sample by use of a light scattering detector. The method may be used to quantitate purified virus preparations or virus samples containing contaminants, including ultraviolet light-absorbing contaminants, such as proteins. The method is useful for quantitation of viruses for use in gene therapy, oncolytic viruses for tumor cell lysis and virus-based vaccines.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: April 8, 2003
    Assignee: Mountain View Pharmaceuticals, Inc.
    Inventors: Mark G. P. Saifer, L. David Williams
  • Patent number: 6496258
    Abstract: Method and device for simultaneous in-situ determination of particle size and mass concentration of fluid-borne particles, wherein the device includes a sensor unit comprising a sending unit and a receiver, a laser coupled to the sensor unit, a detector coupled to the sensor unit, and a microprocessor coupled to the sensor unit, wherein the sensor unit is at least one of adjustable in cross section and variable in diameter and wherein the sensor unit is arranged to one of protrude into the fluid-borne particles and wrap around the fluid-borne particles. The method includes placing the sensor unit adjacent a pipe having a gas flow and simultaneously determining a particle size and a mass concentration of the fluid-borne particles in the gas flow.
    Type: Grant
    Filed: July 24, 2001
    Date of Patent: December 17, 2002
    Assignee: Esytec Energie-und Systemtechnik GmbH
    Inventors: Alfred Leipertz, Stefan Will, Stephan Schraml
  • Patent number: 6469786
    Abstract: Scattered light obtained by irradiating parallel laser beam to particles to be measured is condensed by a condenser lens in a wide angle area from 0° to over 40°, and an intensity distribution of the light is spatially continuously measured by an optical sensor positioned at a focal point of the condenser lens. Before a particle size distribution is calculated from the measured light intensity distribution, measuring error of the scattered light intensity distribution caused by an aberration by the condenser lens and an attenuation on the optical path is corrected by comparing with data obtained through a ray tracing in advance. Thus, the scattered light in a wider angle area are spatially continuously measured to thereby obtain a light intensity distribution with a high resolution in a submicron area.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: October 22, 2002
    Assignee: Shimadzu Corporation
    Inventor: Haruo Shimaoka
  • Publication number: 20020149763
    Abstract: The analytical method having both flow cytometery and cytodiagnosis functions comprises the steps of: preparing a sample containing particulate substances such as cells and viruses; injecting the sample into a plate-like sample container; centrifuging the sample container; and using the sample container in which a distribution of the particulate substances has been formed as a preparation for analysis. The preparation is scanned with laser beam to obtain analytical data. Analytical device for this method is also provided.
    Type: Application
    Filed: April 10, 2002
    Publication date: October 17, 2002
    Inventor: Mamoru Tsukada
  • Patent number: 6466318
    Abstract: The invention is a submersible laser scattering instrument that measures particle total volume, particle total area and Sauter mean diameter. It allows a single calibration for all particle sizes 1.2-250 &mgr;m. A beam of laser light is directed across a void where a sample of water containing particles is admitted. After passing through the water, the light which is forward scattered out of the direct beam falls on two detectors at the same time. The first detector has an active surface shape which is configured to produce an output signal proportional to total particle area at varying total particle areas. The second detector has an active surface shape which is configured to produce an output signal proportional total particle volume varying total particle volumes. Each detector falls within in a radius surrounding the unscattered beam of light.
    Type: Grant
    Filed: November 8, 2000
    Date of Patent: October 15, 2002
    Assignee: Sequoia Scientific, Inc.
    Inventors: Yogesh C. Agrawal, Henry Charles Pottsmith
  • Patent number: 6411383
    Abstract: A method is described to determine the 2nd virial coefficient of an ensemble of molecules dissolved in a selected solvent. Two distinct classes are described: monodisperse and polydisperse molecules. If the molecules are monodisperse, they must be prepared for a chromatographic separation and suitable columns selected. Following standard chromatographic separation procedures such as exemplified by the method of size exclusion chromatography, the sample passes through the separation columns, a multiangle light scattering detector, and a concentration detector. The effect of the columns is to produce a concentration profile of said sample that appears as a peak as it passes through the light scattering and concentration detectors. For each elution interval, &ngr;i, a corresponding concentration value ci and set of excess Rayleigh ratios Ri(&thgr;j) is measured for each scattering angle &thgr;j.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: June 25, 2002
    Assignee: Wyatt Technology Corporation
    Inventor: Philip J. Wyatt
  • Patent number: 6407812
    Abstract: A laser beam optical adjusting mechanism for a particle size distribution measuring apparatus includes a light source to provide a laser beam for irradiating a sample cell and an optical detector unit for receiving an intensity pattern representing the impact of the laser beam on a cell. A mirror assembly is positioned adjacent the light source to reflect the laser beam to irradiate the sample cell. An actuator unit is provided for adjusting the mirror assembly to line an optical axis of the light source with an optical detector. The actuator unit can be automatically driven by a controller and can be of a compact configuration by the use of a pair of lever members that are pivotally supported and respectively driven by actuators.
    Type: Grant
    Filed: April 12, 2000
    Date of Patent: June 18, 2002
    Assignee: Horiba, Ltd.
    Inventors: Takuji Kurozumi, Kazuyuki Ikemoto
  • Patent number: 6404494
    Abstract: An integrating nephelometer is modified to measure 180° backscattering from an aerosol. A laser is mounted outside a housing of the nephelometer and produces a coherent light beam that is directed into a sample volume of the nephelometer, substantially along an optical sensing axis (<4° off the optical axis). Light from the laser beam that is reflected by an aerosol travels back along the optical sensing axis toward a photomultiplier tube (PMT) light detector, which thus produces a signal indicative of the backscattering from the aerosol. A portion of the laser beam is conveyed into the housing of the nephelometer through an optical fiber for use as a reference beam. A motor-driven chopper disk disposed across the optical axis is divided into an open sector, a calibration sector (with a very low transmission), and a flat black light absorbing sector.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: June 11, 2002
    Assignee: University of Washington
    Inventors: Sarah J. Masonis, Theodore L. Anderson, Robert J. Charlson
  • Patent number: 6403037
    Abstract: The invention provides a reaction vessel and temperature control system for performing heat-exchanging chemical reactions, such as nucleic acid amplification. The vessel has a body defining a reaction chamber, and a loading structure extending from the body for loading a sample into the chamber. The loading structure has a loading reservoir, an aspiration port, and respective fluid channels connecting the loading reservoir and aspiration port to the chamber. To load the sample into the vessel, the sample is first dispensed into the loading reservoir and then drawn into the chamber by application of a vacuum to the aspiration port. The vessel also includes a seal aperture extending over the outer ends of the loading reservoir and aspiration port. A plug is inserted into the aperture after loading the sample into the chamber to simultaneously seal the chamber, loading reservoir, and aspiration port from the external environment.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: June 11, 2002
    Assignee: Cepheid
    Inventors: Ronald Chang, Douglas B. Dority, Lee A. Christel, Kurt E. Petersen
  • Patent number: 6377345
    Abstract: A smoke detector is disclosed in which smoke particles are detected by the collection and detection of blue light and infra-red radiation which are emitted into a predetermined path through a scattering volume where the particles may be present. The scattered blue light and the scattered infra-red radiation are collected by an ellipsoidal mirror and focussed onto a suitable detector and then compared to produce an output which indicates either that the detected particles are smoke particles or that they are not smoke particles. The radiation collected by the mirror has been scattered through angles substantially less than 45° and preferably between about 10° and 35°.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: April 23, 2002
    Assignee: Kidde Fire Protection Limited
    Inventor: Brian Powell
  • Patent number: 6316185
    Abstract: A method for determining the number or concentration of virus particles in a sample by use of a light scattering detector. The method may be used to quantitate purified virus preparations or virus samples containing contaminants, including ultraviolet light-absorbing contaminants, such as proteins. The method is useful for quantitation of viruses for use in gene therapy, oncolytic viruses for tumor cell lysis and virus-based vaccines.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: November 13, 2001
    Assignee: Mountain View Pharmaceuticals, Inc.
    Inventors: Mark G. P. Saifer, L. David Williams
  • Patent number: 6315955
    Abstract: The present invention includes a method and an apparatus for the quantitative determination of particles in fluid. The apparatus of the invention includes an emitters set of one or more light emitters, in combination with a detector set of one or more light detectors sensitive to the output of the emitters. During analysis of the sample, data from a plurality of signal paths between the emitter and detector sets are gathered. This information is subsequently evaluated by comparison with known data for different fluid particle contents. Some differentiation between different particles in a fluid sample are possible in many embodiments. Typical uses include analysis of milk and dairy fluids, blood samples, lubricants, suspensions of pigments, etc.
    Type: Grant
    Filed: January 16, 1998
    Date of Patent: November 13, 2001
    Assignee: DeLaval International A.B.
    Inventor: Cornelis Klein
  • Patent number: 6232125
    Abstract: A method and apparatus for differentiating and enumerating the five major sub-populations of leukocytes in a blood sample (i.e., lymphocytes, monocytes, eosinophils, neutrophils and basophils) uses multiangle light scatter and DC (Coulter) volume measurements. Light scattering characteristics of the leukocytes are determined within five different angular ranges, all being lower than 40 degrees. The invention is particularly useful in differentiating and enumerating the basophil sub-population which has heretofore required more complex apparatus and/or chemical processing.
    Type: Grant
    Filed: August 9, 1999
    Date of Patent: May 15, 2001
    Assignee: Coulter International Corp.
    Inventors: Chiranjit Deka, Mark A. Wells, Carlos M. Rodriguez, Carlos Reyes
  • Patent number: 6118532
    Abstract: The present invention relates to an instrument for determining the light scattered by a sample comprising a platform rotatable about an axis of rotation; a sample holder disposed along the axis of rotation; a light source for producing a beam of coherent light that can be focused on a sample in the sample holder; and a plurality of detectors disposed and rotatable about the axis of rotation and adapted so that each detector can be adjusted to focus on a common point along the axis of rotation by reference to the beam.
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: September 12, 2000
    Assignee: ALV-Laser Vertriebsgesellschaft mbH
    Inventor: Wilhelm Peters
  • Patent number: 6118531
    Abstract: The invention relates to a method for identifying the particles contained in a gaseous or liquid or carrier medium by measuring scattered light aimed at the medium. The method of the invention identifies particles of very small size and also measures the geometric shape of the particles. This is accomplished by simultaneously operating at least three light sources aimed at the volume to be analyzed, and detecting the scattered light with at least three detectors. The measured values of the detected light are correlated and evaluated to identify the particles.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: September 12, 2000
    Inventors: Martin Hertel, Torsten Wappler
  • Patent number: 6104486
    Abstract: A method of fabricating a semiconductor device includes the steps of illuminating a structure formed on a surface of a substrate by an incident optical beam incident to the structure with a predetermined incident angle with respect to the surface, measuring a polarization state of an exiting optical beam exiting from the structure in response to an illumination of the structure by the incident optical beam, and evaluating a size of the structure in a direction parallel to the surface from the polarization state of the exiting optical beam, and adjusting a parameter of production of a semiconductor device in response to the size.
    Type: Grant
    Filed: December 27, 1996
    Date of Patent: August 15, 2000
    Assignee: Fujitsu Limited
    Inventor: Hiroshi Arimoto
  • Patent number: 6078040
    Abstract: A light source image, i.e., a near field pattern of the light-emitting face of a laser diode which emits laser light having the electric field component in a predetermined direction is formed by an imaging lens at an image forming position of a smoke detecting area through which a flow of sucked air passes. A light receiving device is disposed on an optical axis which passes through the image forming position of a light source image in the smoke detecting area and which is set in a plane that is substantially parallel to the direction of the electric field component of the laser light, and receives scattered light due to a smoke particle passing through the imaging position of the light source image and the vicinity of the imaging position.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: June 20, 2000
    Assignee: Hochiki Corporation
    Inventors: Ichiro Endo, Yukio Yamauchi
  • Patent number: 6067158
    Abstract: A method for detecting abnormality in the morphology of erythrocytes, which comprises:(1) mixing a sample containing erythrocytes with a sphere-forming reagent;(2) introducing the sample treated in the preceding step into a detector area of a flow cytometer;(3) measuring at least one scattered light at an angle reflecting the morphology of erythrocyte among the scattered lights emitted from the sample to obtain cell distribution data; and(4) comparing the cell distribution data with cell distribution data on normal erythrocytes that were determined beforehand.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: May 23, 2000
    Assignee: Sysmex Corporation
    Inventors: Yuji Itose, Kayo Hatanaka, Tomohiro Sakurai
  • Patent number: 6055052
    Abstract: System for, and method of, monitoring airborne particulate, including particulate of the PM.sub.2.5 class. The system for monitoring airborne particulate includes an optical sensor to measure size characteristics of sampled airborne particulate and a humidity sensor to measure relative humidity. An adjusted airborne concentration value is then produced in response to the measured size characteristics and to the humidity measurement. According to one embodiment the optical sensor is implemented as a multi-wavelength nephelometer, e.g., two-wavelength nephelometer. According to another embodiment the humidity sensor is placed relatively near the optical sensing region and makes a relative humidity measurement.
    Type: Grant
    Filed: January 26, 1998
    Date of Patent: April 25, 2000
    Assignee: MIE Corporation
    Inventor: Pedro Lilienfeld
  • Patent number: 6041020
    Abstract: The investigation, development and application of a laser-based ultrasonic inspection system to the problems of evaluating polymer/graphite composite materials has been realized. The use of lasers to generate and detect ultrasonic waveforms in materials provides a means to detect material properties remotely. The study consisted of three main aspects: 1) A confocal Fabry-Perot (CFP) based system has been devolved which uses light reflected from the CFP interferometer to derive the ultrasonic signal. This allows higher frequency components of the detected waveforms to be discerned when compared to a CFP-based system using light transmitted through the CFP interferometer. 2) Thermoelastic and ablative laser generation of acoustic pulses in polymer/graphite composite materials has been investigated. Thermoelastic generation of ultrasound occurs when thermal energy deposited by a pulsed laser creates a localized expansion in the material.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: March 21, 2000
    Assignee: University of Delaware
    Inventors: James N. Caron, James B. Mehl, Karl V. Steiner
  • Patent number: 6005662
    Abstract: Apparatus and method for measuring the concentration of airborne fibers are provided. The apparatus includes a flow channel for providing laminar flow to a portion of the fibers in an air sample and a light source for generating a light beam directed to the laminarly flowing fibers to produce a scattered light. The apparatus further includes a sensor for sensing a portion of this scattered light and for producing an output from which a fiber concentration estimate can be measured.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: December 21, 1999
    Assignee: CertainTeed Corporation
    Inventor: Brian M. Ence
  • Patent number: 5956139
    Abstract: A method and apparatus for analyzing a fluid containing light scattering components. The apparatus includes a laser adapted to direct abeam of light into the fluid such as a liquid containing particles, and at least two detectors to receive light scattered by the fluid, which received light is used to calculate a physical property of the fluid. A focusing lens may be used to focus the light beam to a focal waist in the fluid to enhance the degree of spatial coherence of the scattered light. The two detectors are aligned onto the focal waist and are adapted to send a signal to a data processor which correlates the signal received from said two detectors. The two detectors are spaced a substantially equal distance from the focal waist and are oriented at substantially the same angle with respect to the direction of propagation of the incident beam. The data processor is adapted to cross-correlate the signals received from the two detectors.
    Type: Grant
    Filed: August 4, 1997
    Date of Patent: September 21, 1999
    Assignee: Ohio Aerospace Institute
    Inventors: William V. Meyer, David S. Cannell, Padetha Tin, H. Michael Cheung, J. Adin Mann, Jr., Thomas W. Taylor, James A. Lock, Jixiang Zhu, Anthony E. Smart
  • Patent number: 5939727
    Abstract: A contamination sensor is provided for use in a fluid system and machinery to continuously monitor the level of contaminants in a fluid. The contamination sensor includes a source of light that is directed into the fluid stream with three photodetector arrangements detecting light scattered by contaminants contained in the fluid. The first photodetector arrangement is located near the origin of the source of light. The second photodetector arrangement is located farther away from the source of light. The third photodetector arrangement is located perpendicular to the axis of the light beam and spaced from the source of light along the axis of the light beam. The simultaneous detected scattered light from a contaminant in the fluid is converted to electrical signals by the photodetectors, conditioned by a signal conditioning circuit and transferred to a signal processing unit for interpretation.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: August 17, 1999
    Assignee: Caterpillar Inc.
    Inventor: Holger T. Sommer
  • Patent number: 5841534
    Abstract: A device is disclosed for measuring light scatter by particles (3) suspended in a carrier medium with a view to ascertaining the density, size or size distribution of the particles. The device comprises: at least one light source (8) which directs light onto a light-scattering center (2) in the carrier medium with the suspended particles (3); a receiver (4) to pick up a portion of the scattered light from the light-scattering center; and an evaluating device connected downstream of the receiver (4). The invention provides for an elongated detection chamber bounded radially around its central axis by the wall of a housing (1) which also acts as a duct for the through-flowing carrier medium with the suspended particles (3). Each light source (8) is mounted on the wall of the housing (1) and points toward the central axis of the detection chamber.
    Type: Grant
    Filed: January 13, 1997
    Date of Patent: November 24, 1998
    Assignee: Gerhard Lorenz Innovative Technik + Messgeratebau
    Inventor: Gerhard Lorenz
  • Patent number: 5831730
    Abstract: An improved method of monitoring particulates in stacks or ducts utilizes transmissometer/particulate monitor of the type which has an optical assembly containing a solid state light source of visible light such as a light-emitting diode or a solid-state laser. The light source emits a collimated beam that is split, part of which is focused onto a reference detector that monitors the intensity of the light source, while the other part is directed to a beam-steering apparatus that causes the beam to accurately pass through a gaseous sample to a desired location such as a retro-reflector. A position-sensing detector is used in a closed-loop manner to control the beam-steering apparatus. The ratio of the total energy of the detected light beam, relative to the reference detector output, is used to determine the opacity of the gaseous sample for the purpose of providing a basis for correlation to particulate loading of that portion of the particulates that are of a size comparable to the wavelength of light.
    Type: Grant
    Filed: May 14, 1997
    Date of Patent: November 3, 1998
    Assignee: United Sciences, Inc.
    Inventors: John E. Traina, Richard Myers, Edward A. Smierciak
  • Patent number: 5781291
    Abstract: A smoke detector incorporates a porous plastic material which carries a hydrophilic agent alone or in combination with a surfactant which can be sprayed or deposited onto structural elements of the detector. The detector can include a molded removable plastic element that carries a hydrophilic agent. The element can be arranged to surround a light beam injected into a sensing region of a photoelectric detector.
    Type: Grant
    Filed: October 22, 1996
    Date of Patent: July 14, 1998
    Assignee: Pittway Corporation
    Inventors: Bernard Y.C. So, George A. Shoenfelder, Juliette C. Daly
  • Patent number: 5758653
    Abstract: A method for the direct reconstruction of the absorption and diffusion images from measurements of the transmitted intensity of the scattered radiation effected by irradiating the object with a time-domain source. The transmitted intensity is related to the absorption and the diffusion coefficients by an integral operator. The images are directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: June 2, 1998
    Assignee: Bell Communications Research, Inc.
    Inventor: John Carl Schotland
  • Patent number: 5746211
    Abstract: A method for the direct reconstruction of an object from measurements of the transmitted intensity of the scattered radiation effected by irradiating the object. The transmitted intensity is related to the image by an integral operator. The image is directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity.
    Type: Grant
    Filed: January 4, 1995
    Date of Patent: May 5, 1998
    Assignee: Bell Communications Research, Inc.
    Inventors: John Scott Leigh, John Carl Schotland
  • Patent number: 5748305
    Abstract: A method for foreign particles inspection includes illuminating an inspection surface of an inspection object with a beam which is, one of s-polarized and p-polarized relative to the inspection surface of the inspection object. The illumination utilizes an optical axis which is generally parallel to the inspection surface or which intersects the inspection surface at an angle that is greater than or equal to 1.degree. and less than 5.degree.. Reflected and scattered light is detected utilizing an optical axis which makes an acute angle with the inspection surface and which makes a differential angle of 30.degree. or less with the optical axis of the illumination beam. The detection of foreign particles is accomplished by detecting the component of the reflected and scattered light which is the other of s-polarized and p-polarized relative to the inspection surface.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: May 5, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ken Shimono, Tatsuo Nagasaki, Kenji Takamoto, Masami Ito, Kanji Nishii
  • Patent number: 5737078
    Abstract: A cytoanalyzer includes a flow cell for aligning cells and permitting the same to pass therethrough, a semiconductor light emitting device for emitting a laser beam to the cells passing through the flow cell, and a light-detecting device having at least two separate photosensing portions capable of sensing two types of light scattered by each of the cells. The alignment of the cytoanalyzer may be achieved by comparing intensities of light on the at least two separate photosensing portions.
    Type: Grant
    Filed: August 8, 1995
    Date of Patent: April 7, 1998
    Assignee: TOA Medical Electronics Co., Ltd.
    Inventors: Kaoru Takarada, Takashi Sakata, Yoshihiro Hyosa, Chihiro Kouzuki
  • Patent number: 5684585
    Abstract: A particle counter including a modulator to allow electronically determining calibration. The modulator is connected to a driving circuit of a source of light to cause the light to emit a beam of a constant amplitude, representing at least one particle of predefined size. Light transmitted along an optical axis changes in intensity in response to a signal produced by the modulator. A detector is positioned to sense the change in intensity to produce signals proportional to the light sensed. A displaying device, such as a pulse height analyzer, is in electrical communication to receive the signals produced by the detector to quantitatively display the change in intensity of the light.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: November 4, 1997
    Assignee: Met One, Inc.
    Inventor: Kenneth L. Girvin
  • Patent number: 5587790
    Abstract: A light scattering type smoke sensor of the present invention has a plurality of labyrinth members for facilitating an inflow of smoke entering from the outside, and for cutting off light entering from the outside; a plurality of smoke inlets each of which is formed by a space between paired ones of the labyrinth members being adjacent to each other; a smoke detecting chamber which is formed in a center portion by the labyrinth members; light emitting device for radiating light toward the smoke detecting chamber; and light receiving device for detecting light which is scattered by the smoke in the smoke detecting chamber, the light receiving device having an optical axis which intersects in the smoke detecting chamber an optical axis of the light emitting device at a scattering angle in the range of 60.degree. to 80.degree.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: December 24, 1996
    Assignee: Hochiki Corporation
    Inventor: Tetsuya Nagashima
  • Patent number: 5559037
    Abstract: A method and a device for the simultaneous and quantitative, flow cytometric analysis of nucleated red blood cells (NRBC) and white blood cells (WBC) in a whole blood sample.
    Type: Grant
    Filed: December 15, 1994
    Date of Patent: September 24, 1996
    Assignee: Abbott Laboratories
    Inventors: Young R. Kim, Michael W. Yee, Suresh N. Mehta, Josefino C. Sagala, Johanna Kantor
  • Patent number: 5540494
    Abstract: A method and apparatus are described for flow cytometric absolute sizing of individual biological particles and for determining and reporting fluorescence data which is surface area or volume normalized.
    Type: Grant
    Filed: June 3, 1994
    Date of Patent: July 30, 1996
    Inventors: Norman B. Purvis, Jr., Todd D. Giorgio
  • Patent number: 5528365
    Abstract: Methods of imaging objects with diffused light. The methods preferably can comprise the steps of illuminating the object with a source of light which can be scattered by the object, collecting the scattered light with a detector from multiple positions surrounding the object, measuring a mean free path of photons scattered from the object from the collected scattered light, and determining a diffusion constant for the photons scattered from the object as a function of the measured mean free path, and determining in the transmission of the photons between the source and the detector as a function of the diffusion constant, thereby imaging the object. Methods and apparatus described herein efficiently image objects with diffuse light by taking into account source-detector orientation and boundary effects.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: June 18, 1996
    Assignee: The Trustees of the University of Pennsylvania
    Inventor: Constantine P. Gonatas
  • Patent number: 5402228
    Abstract: The two-dimensional medium-pass filter principle is used to acquire a sharpened image initially In practice the sharpened image is obtained from the difference of a linear array signal of a partially out-of-focus image from another linear array signal of the same image but in focus. Integrated intensity of dirt specks higher than a user selected threshold are measured and accumulated. Each integrated intensity value is converted into its corresponding speck size with the use of a predefined fined look-up table. The counter generates a dirt speck histogram and statistical data within a preselected time interval or area coverage.
    Type: Grant
    Filed: October 28, 1992
    Date of Patent: March 28, 1995
    Assignee: Pulp and Paper Research Institute of Canada
    Inventors: Byron D. Jordan, Nam G. Nguyen
  • Patent number: 5396333
    Abstract: A device for observation and analysis of a cross-sectional portion of a stream of material, which may be either a particle or a fluid stream, includes a laser light source for generating a beam of light. A focusing lens is disposed in an optical path between the laser source and the stream and a plano-cylindrical lens of a selected focal length is disposed in the optical path between the focusing lens and the stream. The focusing lens and the plano-cylindrical lens convert the beam of light from the laser light source to a plane of light which may be projected through the stream to illuminate a selected cross-section of the stream for observation and analysis thereof.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: March 7, 1995
    Assignee: General Electric Company
    Inventors: Stephen Aleshin, Vanon D. Pratt
  • Patent number: 5373367
    Abstract: A multiple angle and redundant visibility sensor includes a plurality of optical transmitter/receiver pairs, each pair cooperatively coupled so as to transmit and receive in conically controlled beams along a common optical axis such that each transmitter faces, and directs optical energy directly into, its receiver pair. The plurality of pairs are staggered in angular orientation with respect to each other, with a common volume of intersection through which the approximate center of each optical axis passes. Each transmitter propagates a substantially conical beam of light which passes through an aerosol media which causes molecular scattering of the light. A single transmitter outputs optical energy at any given time, and the receiver intercept the appropriate scattered energy at different scattering angles depending on the relative axial orientation with respect to the scattering volume and the incident radiation.
    Type: Grant
    Filed: October 21, 1992
    Date of Patent: December 13, 1994
    Assignee: Qualimetrics, Inc.
    Inventors: Richard N. DeGunther, Wilbert I. Marsh
  • Patent number: 5350697
    Abstract: An apparatus in which scattered light is measured, said apparatus having a light source aligned to direct illumination toward an interface between a sample container and an aqueous solution at an angle less than the critical angle. A detector to measure the scattered light is located at a place outside the envelope of the critical angle.
    Type: Grant
    Filed: August 28, 1990
    Date of Patent: September 27, 1994
    Assignee: Akzo N.V.
    Inventors: C. Hermas Swope, John G. Link, Jones M. Hyman
  • Patent number: 5350922
    Abstract: An underwater light scattering sensor includes a light source, light stop and a light detector mounted on a planar support capable of measuring nearly all suspended particle concentrations found in natural waters, 1 .mu.g/l to 3 g/l. The sensor is designed to measure light scattered at nearly all angles, which includes forward scattering, back scattering, and multiple scattering, from suspended particles in water through a very short light path length. The small and simple design of the sensor allows it to be produced at low cost, permitting its use in both expendable and non-expendable applications for the detection or measurement of suspended particulate concentrations in water. The magnitude of the scattered light measured by the sensor is proportional to the suspended particle concentration in water, provided the nature of the particles does not change.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: September 27, 1994
    Inventor: Robert Bartz
  • Patent number: 5313542
    Abstract: A portable scatterometer and/or an angular radiated light measurement instrument that uses a measurement head which includes a double tapered fiber optic bundle with a concave front face to simultaneously collect partial or full hemispherically scattered light reflected from a point on a surface illuminated by a depolarized, telescopically focused, laser diode source, the light rays being received by each fiber normal to its face. The image of the collected light beams is minified and coupled by the fiber optic bundle into an anti-blooming CID camera with an x-y scanning area array which converts the light beams to electrical signals. In a unique real time, computer-controlled, data acquisition and reconstruction process, a frame grabber and a unique algorithm are used to collect over 200,000 points of light, reconstruct the data into a 2D or 3D scatter profile and display the results, all within one second.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: May 17, 1994
    Assignee: Breault Research Organization, Inc.
    Inventor: Raymond J. Castonguay