Plural Color Responsive Patents (Class 356/45)
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Patent number: 5305091Abstract: A coordinate measuring system consists of multiple optical transceivers (transmitter-receivers) mounted onto a stable reference frame such as the walls of a room. The object to be measured is touched with a hand-held measuring probe. To measure, the probe triggers the transceivers to read the distance to two retroreflectors mounted on the probe. The location of the probe tip relative to the reference frame is computed from at least six transceiver readings (three for each retroreflector). The accurate determination of the distance between the transceivers and retroreflectors is done by measuring the phase shift of a high frequency modulation superimposed on light beams. To avoid ambiguity two high frequencies are used, one for coarse and one for fine resolution. The initial location of the transceivers can be found out by measuring an accurately known object and computing the transceiver locations. The transceivers include a beam steering device to track the position of the probe.Type: GrantFiled: December 7, 1992Date of Patent: April 19, 1994Assignee: Oreo Products Inc.Inventors: Daniel Gelbart, Michel G. Laberge
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Patent number: 5285252Abstract: An optical method and optical device for distance measurement, comprising the steps of emitting an incident light beam (13) comprising at least two waves of differing wavelengths (.lambda.1 and .lambda.2); separating this beam into a reference beam (15) and a measurement beam (17) which are reflected on, respectively, a reference reflector (16) and a zone (18) of a part (19), of which it is desired to measure the position in the direction of the measurement beam and recombine into a resultant beam (20), in which said waves exhibit conditions of polarization, the components of which rotate when the optical path of the aforementioned measurement beam varies and which determine, in the direction of the measurement beam, adjacent ranges at the ends of each one of which the angular positions of two corresponding components of these conditions of polarization are identical; determining, in the resultant beam (20), the angular positions (.alpha.1 and .alpha.Type: GrantFiled: December 28, 1992Date of Patent: February 8, 1994Assignee: France TelecomInventors: Aime Vareille, Andre Schiltz, Jean C. Hauuy
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Patent number: 5272512Abstract: An apparatus for detecting velocity of an object, includes a light source for generating light having a wavelength .lambda., a light-transmission block for receiving the light from the light source, and guiding the light onto the object, and a photosensor for detecting the light from the object on which the light from the light-transmission block is incident. The light-transmission block is integrally constituted by a diffraction grating for diffracting the light from the light source to produce two diffraction lights, and an optical element for causing the two diffraction lights from the diffraction grating to be incident onto the object at a predetermined incident angle. The diffraction grating and the optical element are arranged so as to have substantially constant sin.theta./.lambda. independently of a change in wavelength .lambda. of the light from the light source where .theta. is the incident angle of each diffraction light onto the object.Type: GrantFiled: December 21, 1992Date of Patent: December 21, 1993Assignee: Canon Kabushiki KaishaInventors: Hidejiro Kadowaki, Hiroshi Sugiyama, Yasuhiko Ishida, Makoto Takamiya
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Patent number: 5267016Abstract: A laser diode distance measurement device includes a laser diode 10 which emits light 20 to a lens 22 which provides focussed light 24 incident on a target 26. The light 24 is reflected from the target 26 back to the laser diode 10 which causes the laser diode 10 to emit a light 28 which exhibits intensity pulses (due to coherent interference) related to the distance L to the target 26. A photodetector 30 provides a feedback signal indicative of the intensity of the light 28 to a distance measurement circuit 18. The laser diode 10 is driven by an up-ramp signal that reduces electronic processing and at a frequency that reduces speckle noise. The distance measurement circuit 18 blanks-out a portion of the feedback signal during discontinuities of the laser diode drive signal to minimize associated noise from distorting the distance measurement.Type: GrantFiled: November 27, 1991Date of Patent: November 30, 1993Assignee: United Technologies CorporationInventors: Richard A. Meinzer, Bruce E. Zepke
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Patent number: 5263776Abstract: Multi-wavelength optical thermometry provides for non-contact measurement of the temperature of a sample where the front surface and the back surface of the sample are used in a interferometer to measure changes in optical path length. Laser beams at two different wavelengths are used and the beam phase of the two resultant interference signals is used to unambiguously measure the path length change over a broad temperature range.Type: GrantFiled: September 25, 1992Date of Patent: November 23, 1993Assignee: International Business Machines CorporationInventors: David W. Abraham, William M. Holber, Joseph S. Logan, Hemantha K. Wickramasinghe
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Patent number: 5265036Abstract: A pyrometer system for use in measuring the temperature of components in an operating jet engine corrects for random interference in the pyrometer temperature signal caused by radiation from the combustor flame. An optical beam from a periodically moving target engine component such as a turbine blade is provided to a detector module which splits the beam into two beams, one of which has a spectral width less than that of the target beam. Temperature signals are generated by a multiple spectral area pyrometer which are provided to a signal processor for correction. The signal processor compares present target temperature signal values sampled at selected phases during the target period with corresponding ones taken in an earlier period. Previous signals are averaged or replaced with current values if these meet criteria involving one or two temperature signals, noise band and magnitude.Type: GrantFiled: August 4, 1992Date of Patent: November 23, 1993Assignee: United Technologies CorporationInventors: Ernesto Suarez-Gonzalez, Raymond L. Oglukian, Christopher Steinauer
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Patent number: 5260761Abstract: Apparatus for measuring the shape of a remote surface (10) comprises a laser (2) whose beam is split into a measuring beam (4) and reference beam (5). The reference beam is passed through a path length modulating mechanism (13, 14) to a datum point (18) while the measuring beam (4) is passed to a point (9) on the remote surface. The reflected beams return along the same paths and are combined at beam splitter (6). The interferometric pattern in the combined beams is analysed to determine the path length of the measuring beam while the transverse coordinates of the point (9) are determined from the position of a beam directing mechanism (12). This process is repeated for a number of points on the surface to measure the shape of the surface (10).Type: GrantFiled: December 5, 1991Date of Patent: November 9, 1993Assignee: Ometron LimitedInventor: Andrew J. Barker
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Patent number: 5260762Abstract: The device described for the measurement, without physical contact, of the speed, displacement distance and/or range of a reflecting object has a laser diode as light source, transmission and receiver optics for aiming the laser light from the laser diode at the object and for feeding part of the laser light reflected by the object back to the laser resonator, and a detector unit for detecting and analyzing the laser light emitted by the laser diode. Fitted to determine the modulation frequency of the laser light, which is frequency-modulated as a function of the feedback to the laser resonator, is a frequency discriminator, a photodiode and a processing circuit with a spectrum analyzer.Type: GrantFiled: December 18, 1991Date of Patent: November 9, 1993Assignee: Werner TabarelliInventor: Harald Telle
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Patent number: 5257090Abstract: A laser diode distance measurement device includes a laser diode assembly 10, comprising a laser diode and photodiode, which emits light 17 to a lens 19 which provides collimated light 20 incident on a float 22 which is covered with reflective tape on its top surface 24. The light 20 is reflected from the float 22 back to the laser diode assembly 10 which causes the assembly 10 to provide a signal having magnitude pulses (due to coherent interference) on a line 15 to a liquid level measurement circuit 14 related to the distance L to the float 22. Use of the collimated beam 20 and reflective tape on the float 22 minimizes speckle while providing adequate optical intensity feedback. The laser assembly 10 is driven by a sawtooth waveform signal that reduces electronic processing. The distance measurement circuit 14 blanks-out the feedback signal during discontinuities of the laser diode drive signal to minimize associated noise from distorting the distance measurement.Type: GrantFiled: November 27, 1991Date of Patent: October 26, 1993Assignee: United Technologies CorporationInventors: Richard A. Meinzer, Bruce E. Zepke
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Patent number: 5249142Abstract: A method of measuring the temperature of a matter accurately, in non-contact fashion and without setting any emissivity comprising obtaining a spectral characteristics of absorbing electromagnetic waves inherent to a matter whose temperature is to be measured, obtaining those absorption peak wavelengths of the electromagnetic waves which correspond to two or more high points of electromagnetic wave absorption rate obtained from the spectral characteristics, measuring amounts of the electromagnetic waves, which have the absorption peak wavelengths, radiated from the temperature-measured matter, and calculating the temperature of the matter from blues of the radiant amounts of the electromagnetic waves thus measured.Type: GrantFiled: April 3, 1992Date of Patent: September 28, 1993Assignees: Tokyo Electron Kyushu Limited, Kokusai Gljutsu Kaihatsu Co., Ltd.Inventors: Eiichi Shirakawa, Masafumi Nomura, Kimiharu Matsumura
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Patent number: 5235399Abstract: An apparatus for measuring the temperature of an object placed in a plasma by utilizing radiation includes measuring means for measuring the intensity of radiation from the object and the intensity of plasma light in different directions at the same time. The measuring means includes a first lens for receiving the radiation from the object and the plasma light, a second lens for converting the output beam of the first lens into parallel light rays, a third lens for focusing the parallel light rays, and an interference filter disposed rotatably between the second lens and the third lens.Type: GrantFiled: June 24, 1991Date of Patent: August 10, 1993Assignee: Hitachi, Ltd.Inventors: Tatehito Usui, Tomoji Watanabe, Junichi Kobayashi, Takehiko Ooshima, Shunji Sasabe
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Patent number: 5231595Abstract: A pyrometer includes a light source capable of emitting light to at least two wavelengths to a target to be measured. A light measuring member measures the light source and provides output signals representative of those two wavelengths. A second light measuring member measures light reflected by the target and provides second signals corresponding to the two wavelengths. A third light measuring member measures the intensity of the light radiated by the target with respect to those two wavelengths to produce third signals. An emissivity is assumed for the target based on the predetermined wavelengths, and a temperature is calculated on the basis of the minimum value of the difference between the assumed radiation intensity calculated according to the assumed emissivity of the target and the measured radiation intensity in accordance with the third signals.Type: GrantFiled: October 18, 1991Date of Patent: July 27, 1993Assignee: Minolta Camera Kabushiki KaishaInventors: Toshiro Makino, Hiroji Tsujimura, Jiro Arima
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Patent number: 5225883Abstract: An apparatus and method for providing a real-time video display and a temperature map display of an object, in particular a flame, comprises a single CCD video camera and optical equipment which focuses separate light bundles onto a photosensitive surface of the camera. A separate band pass filter is used in each light bundle to filter selected different wavelengths of light. The video signal from the camera is used in a video digitizer to obtain data which can be used to calculate a temperature map based on the different wavelengths of light of the two bundles. The video signal is also used to produce a real-time video display of the object.Type: GrantFiled: June 5, 1991Date of Patent: July 6, 1993Assignee: The Babcock & Wilcox CompanyInventors: Hudson R. Carter, John W. Berthold, Charles C. England
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Patent number: 5192979Abstract: A method and apparatus detects and identifies targets using a laser and operating in accordance with Doppler radar techniques. A laser sensor comprises a laser transmitter and an optical superheterodyne receiver and detects characteristic surface vibrations of targets and derives, from the laser echo signals, after frequency conversion and demodulation, low frequency oscillations having the frequencies of the vibration spectrum, from which, through comparison with patterns of known targets, provides detection and identification of the target.Type: GrantFiled: February 7, 1991Date of Patent: March 9, 1993Assignee: Siemens AktiengesellschaftInventors: Ludger Grage, Wolfgang Kranz, Gerhard Brumme
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Patent number: 5188458Abstract: Dual pyrometric detectors and method measure the temperature of a remote heated object in the presence of ambient radiation. One detector measures emitted radiation from both the remote object and from the environment, and the other detector measures radiation predominantly from the environment alone. The output signals from the two detectors are processed electronically to yield the detected radiation from the remote object alone. The result can then be electronically processed to display the pyrometrically-measured temperature of the remote object.Type: GrantFiled: September 9, 1991Date of Patent: February 23, 1993Assignee: A G Processing Technologies, Inc.Inventors: Thomas E. Thompson, Eugene R. Westerberg
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Patent number: 5184313Abstract: An A-phase pulse (S.sub.A) and a B-phase pulse (S.sub.B) are transmitted from a laser interferometic measuring device to a conversion device (5). When the distance-to-be-measured (l) is increasing, a conversion coefficient (D.sub.R) is added to or subtracted from an initial value in an arithmetic calculator (53) at the rising edge and the trailing edge of the pulses (S.sub.A, S.sub.B). The conversion coefficient has a digital value of M-digits and represents a reference distance .lambda./N, where .lambda. is the wavelength of a laser beam (LB.sub.1, LB.sub.2) employed in the laser measuring machine and M and N are positive integers. A predetermined unit distance in the metric system corresponds to a unit number in the (M+1)-th digit. A distance pulse signal (S.sub.L) is generated in response to a carry signal and a borrow signal from the arithmetic calculator, and is used in expressing a change of the distance in the metric system.Type: GrantFiled: May 31, 1990Date of Patent: February 2, 1993Assignee: Dainippon Screen Mfg. Co., Ltd.Inventors: Akira Kuwabara, Yasufumi Koyama
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Patent number: 5125739Abstract: An optical pyrometer for use with jet engines is characterized by the use of three spectral areas or bands in a temperature computation. A target temperature is optically distinguished from background radiation by dividing a received optical beam into three spectral components which are comprised of emitted and reflected radiation. A controller computes the measured power in each band as a function of the emitted power by the target and a ratio of reflected power in adjacent bands to yield signals of reflection corrected radiation. These are used with the reflected power ratios to determine values of temperature in adjacent bands. The difference between these computed temperatures is iteratively adjusted until the difference therebetween is approximately equal to a preselected value.Type: GrantFiled: January 14, 1991Date of Patent: June 30, 1992Assignee: United Technologies CorporationInventors: Ernesto Suarez-Gonzalez, Raymond L. Oqlukian
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Patent number: 5123739Abstract: There is provided a method of monitoring a firing condition in a cement kiln, by measuring an intensity of spectrum of a radiation which radiation is emitted from a clinker being fired in a cement kiln, and processing the intensity of the spectrum to produce a parameter for monitoring the condition in the kiln, by correcting the intensity profile of the spectrum by interpolating a profile (range) which is deformed by the absorption with alkali atom(s) in an atmosphere of the kiln. Further, the absorption intensity of the spectrum at a sodium absorption wavelength and potassium absorption wavelength should be continuously measured and corrected by interpolating so as to produce a parameter for monitoring.Type: GrantFiled: April 16, 1990Date of Patent: June 23, 1992Assignee: Mitsubishi Mining & Cement Company Ltd.Inventors: Takeyoshi Takenouchi, Masumi Nakagawa
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Patent number: 5123730Abstract: The apparatus of the present invention includes a light source for producing a coherent beam of light. A beam splitter is provided for splitting the beam of light into a first, transmitted beam segment and a second, local oscillator beam. A mechanism is provided for frequency shifting the frequency of one or both beam segments and for directing the first beam segment to a target. A remote target for scattering the first beam is provided. A mechanism is provided for combining the scattered first beam segment returning from the target and the second beam segment into a combined beam, and detecting the combined beam. A detector is operative to generate a signal indicative of the crosswind along the path of the directed first beam segment. A mechanism for determining the wind speed normal to the path from the generated signal is also provided.Type: GrantFiled: August 9, 1988Date of Patent: June 23, 1992Assignee: The Oregon Graduate Institute of Science & TechnologyInventors: J. Fred Holmes, Farzin Amzajerdian, John M. Hunt
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Patent number: 5114226Abstract: A three-dimensional optical scanning vision system capable of producing high-resolution images in real-time includes an optical source for producing a source light beam. The source light beam is directed to a beam splitter which splits it into a local oscillator beam and a signal beam. The local oscillator beam is directed toward a photodetector, while the signal light beam is directed toward a target. Light reflected from the target is received by the beam splitter and directed toward a retroreflector which returns the beam to the beam splitter interface. Quarter wave plates and the retroreflector insure that the return light beam and the local oscillator beam are collimated and have the same polarization state. Mixing of the local oscillator beam and the return light beam occurs at the beam splitter interface, thus providing coherent optical detection by the photodetector. The photodetector thus provides an output signal providing a high degree of information about the target.Type: GrantFiled: September 28, 1990Date of Patent: May 19, 1992Assignee: Digital Optronics CorporationInventors: Frank E. Goodwin, Dana Simonson
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Patent number: 5110207Abstract: An interferometer for transmitting a beam of electromagnetic energy toward a target, portions of the transmitted beam reflected by the target being directed onto a detecting surface of a detector element with a local oscillator beam to provide a beat frequency signal representative of, for example, target range. The interferometer comprises a first lens for focusing the target-reflected return beam onto substantially a point on a detecting surface. The interferometer additionally comprises a second lens, for example, for focusing the local oscillator beam through a focal point onto the first lens. The first and second lenses are disposed to align such focal point of the second lens with a focal point of the first lens to thereby direct the local oscillator beam onto the detecting surface of the detector element with a substantially uniform intensity distribution thereon.Type: GrantFiled: May 6, 1991Date of Patent: May 5, 1992Assignee: Raytheon CompanyInventor: Clarke E. Harris
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Patent number: 5069545Abstract: The invention is directed to a laser radar method for measuring velocity of moving objects wherein the laser light reflected from the measured object is coupled back into the laser resonator and then conducted to a heterodyne receiver. An amplification effect is produced by the interaction of the reflected signal with the laser active medium and the resonator and this amplification effect produces an improved signal/noise-ratio and makes possible a simpler configuration of the measuring arrangement.Type: GrantFiled: March 1, 1990Date of Patent: December 3, 1991Assignee: Carl-Zeiss-StiftungInventor: Alexander Hinz
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Patent number: 5061084Abstract: Dual pyrometric detectors and method measure the temperature of a remote heated object in the presence of ambient radiation. One detector measures emitted radiation from both the remote object and from the environment, and the other direction measures radiation predominantly from the environment alone. The output signals from the two detectors are processed electronically to yield the detected radiation from the remote object alone. The result can then be electronically processed to display the pyrometrically-measured temperature of the remote object.Type: GrantFiled: February 7, 1991Date of Patent: October 29, 1991Assignee: AG Processing Technologies, Inc.Inventors: Thomas E. Thompson, Eugene R. Westerberg
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Patent number: 5035506Abstract: A coherent optical detector has increased sensitivity for detecting a coherent optical signal by applying the coherent optical signal to be detected to a solid non linear medium pumped by two optical signals of opposite directions and coming from an auxiliary laser. The signal to be detected gives rise to an amplified signal applied with an auxiliary optical signal from the auxiliary laser, to a detector for causing these two optical signals to beat and detecting the beat and so the signal to be detected.Type: GrantFiled: November 9, 1989Date of Patent: July 30, 1991Assignee: SAT (Societe Anonyme de Telecommunications)Inventor: Michel M. Ouhayoun
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Patent number: 5026156Abstract: A system and method for pulse interval modulating signals in accordance with a code wherein the code resides in the spacing between adjacent pulses. The invention has particular utility in connection with laser designators and laser seekers and, while clearly not limited to this application, is disclosed hereinafter mainly in connection with laser designators and seekers. In connection with this laser environment, the invention may include a pulse interval modulation encoder for encoding the laser designator output signal and a pulse interval modulation decoder for decoding by the laser seeker of the encoded designator signal. The encoder preferably employs an ordered arrangement of unique pulse interval pairs which cyclically repeats after a relatively long time period. Because of the length of the time period and the apparent randomness of the intervals forming the unique interval pairs, the code appears to enemy countermeasures to be random.Type: GrantFiled: July 24, 1972Date of Patent: June 25, 1991Assignee: Martin Marietta CorporationInventors: Thomas E. Bayston, Roy C. Weidler, Jr., Arthur B. Thompson, Jr., Allen C. Layton
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Patent number: 5020901Abstract: A laser system includes a multimode laser diode positioned at a range from a target. Backscatter from the target returns into the diode and to modify the emission. An induced modulation frequency in the emission effects oscillatory mode transitions to create an amplitude modulation in mode power for a selected mode, the mode being selected by an optical spectrum analyser or an interference filter. The diode is positioned initially for a minimum in the amplitude modulation, and readjusted by a selected increment in response to an incremental change in target position so as to reestablish the amplitude modulation to the minimum. The incremental change thereby equals the selected increment.Type: GrantFiled: January 30, 1990Date of Patent: June 4, 1991Assignee: The Perkin-Elmer CorporationInventor: Peter de Groot
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Patent number: 4980847Abstract: A temperature measuring device is disclosed which comprises a light source for emitting light the spectrums of which are constant with respect to time, a photoelectric transducer for sensing the emitted light with a plurality of predetermined different wavelengths to generate electrical outputs for each wavelength, and a microcomputer for computing a ratio based on the outputs generated from the transducer and for generating an output signal representing temperature corresponding to the ratio.Type: GrantFiled: March 7, 1985Date of Patent: December 25, 1990Assignee: Omron Tateisi Electronics Co.Inventor: Masao Hirano
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Patent number: 4979133Abstract: A pyrometer according to the present invention calculates a temperature of a target to be measured by means of light emitting device for emitting reference light having three wavelengths to the target, and light measuring portions for measuring the intensity of the reference light, the intensity of light reflected by the target, the intensity of light transmitted through the target and the intensity of light radiated by the target, respectively with respect to each of the three wavelengths. The transmitted light measured value of the reference light transmitted through the target is used for temperature calculation in addition to the measured values of the reference light, the reflected light and the radiated light, and therefore even if the target is a semi-transparent object, the true temperature thereof can be calculated.Type: GrantFiled: February 8, 1989Date of Patent: December 18, 1990Assignee: Minolta Camera Kabushiki KaishaInventors: Jiro Arima, Hiroji Tsujimura
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Patent number: 4979134Abstract: A method for measuring the surface temperature of a wafer substrate and a heat-treating apparatus are both used in a semiconductor device-manufacturing process wherein a reference light including infrared rays is intermittently emitted toward a wafer substrate. Infrared rays of a plurality of different types whose wavelengths are shorter than 1 .mu.m and differ from each other are selectively detected from the reference light emitted toward the wafer substrate, the reference light reflected by the wafer substrate, and the light radiated from the wafer substrate itself. On the basis of the detection performed with respect to the emitted reference light, the reflected reference light and the radiated infrared rays, the surface temperature of the wafer substrate is calculated. A substrate-heating element is controlled on the basis of the calculated temperature.Type: GrantFiled: July 14, 1989Date of Patent: December 18, 1990Assignees: Minolta Camera Kabushiki Kaisha, Tokyo Electron LimitedInventors: Jiro Arima, Hiroji Tsujimura, Tomonori Narita, Hiroki Takebuchi
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Patent number: 4973153Abstract: A range finder for finding a distance to an object comprising an outgoing light guiding wave path, a reference light guiding wave path, and an incoming light guiding wave path. The finder further comprises wavelength changing means for changing the wavelength of the beam of light emitted from the light source, wavelength detecting means for detecting the wavelength of the beam of light emitted from the light source, and calculating means for detecting at least two peaks of the signal coming from the light receiving element when the wavelength of the light source is changed by the wavelength changing means, finding the wavelengths of the light source, respectively, from the wavelength detecting means at the time when the signal exhibits the two peaks, and calculating the distance to the object according to an operation expression memorized beforehand with reference to such obtained two wavelengths.Type: GrantFiled: July 28, 1988Date of Patent: November 27, 1990Assignee: Kabushiki Kaisha TopconInventors: Takashi Yokokura, Nobuo Hori, Hiroaki Shimozono, Satoru Niimura
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Patent number: 4973154Abstract: A three-dimensional object is imaged by providing a coherent beam of light with a periodic variation in frequency and dividing the beam into a probe beam and a pump beam. The probe beam is directed toward the object, such that the frequency profile of the probe beam after reflection from the object is determined by the depth profile of the object. The pump beam and the reflected probe beam are directed into a nonlinear medium, such that two-wave mixing between the beams occurs in the medium, the two-wave mixing process causing the frequency profile of the probe beam to be converted to an intensity profile. The method may be further refined by adjusting the optical path length of the pump beam in order to adjust the accuracy range of the depth profile which is imaged.Type: GrantFiled: April 27, 1989Date of Patent: November 27, 1990Assignee: Rockwell International CorporationInventors: Ian C. McMichael, Mohsen Khoshnevisan
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Patent number: 4969736Abstract: A system for measurement of a distance to a target. Light is emitted from a multi-mode laser and coupled to a sensor assembly. A portion of the light at the sensor assembly is reflected back into the fiber optic cable from which it came. The other portion of the light from the sensor assembly is projected towards the target. Light is reflected from the target and also connected into the optical cable as a target beam. The target beam and the reference beam then are connected through a path of variable length. When the target beam and the reference beam interface with one another, the path length is determined to be equal to the length to the target.Type: GrantFiled: June 17, 1988Date of Patent: November 13, 1990Inventor: Anthony R. Slotwinski
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Patent number: 4929077Abstract: In a range finder for measuring absolute distances, a time partially coherent light source is provided. A beam emitted by it is split into a reference beam (B), which passes along a reference path, and a testing or measuring beam (A), which can be focused onto a testpiece (4). The radiation (A') reflected by the testpiece is brought to interference with the reference beam (B). In a position-sensitive detector array, the testing and reference beam are superimposed. The coherence of the two waves is directly determined from the intensity distribution on the detector array. The distance of the test-piece is calculated from the intensity distribution on the detector. Preferably, upstream of the detector array is connected an optical grating (6) with a grating spacing at least approximately corresponding to the spacing of the interference fringes on the detector array.Type: GrantFiled: March 22, 1988Date of Patent: May 29, 1990Assignee: Wild Leitz AGInventor: Andre Huisen
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Patent number: 4927263Abstract: An optical radar system for coherent ranging and velocimetry. Modulation of a laser diode by light backscattered from a target is used to determine distance and velocity of a target. An array of laser diodes are used to determine the velocity and topography of a target. Three laser diodes are used to determine speed and orientation of a rotating disk.Type: GrantFiled: August 15, 1988Date of Patent: May 22, 1990Assignee: The Perkin-Elmer CorporationInventors: Peter J. de Groot, Steven H. Macomber, Gregg M. Gallatin
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Patent number: 4915499Abstract: The device according to the invention comprises a wide spectrum lighting source (60), a first interferometer (FP1) serving as a filter, a second interferometer (FP2) with the same characteristics as the first and a photodetector (66). The identity of the characteristics of the two interferometers makes it possible to work with higher lighting power levels than in the prior art. The two interferometers are advantageously constituted by a single apparatus used twice.Application to the measurement of the position, displacement or speed of a surface, particularly in detonics.Type: GrantFiled: January 12, 1988Date of Patent: April 10, 1990Assignee: Comissariat a l'Energie AtomiqueInventors: Serge Gidon, Gilles Behar
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Patent number: 4906092Abstract: A self-referencing target imaging system 10 capable of long range imaging at visible wavelengths is disclosed herein. The imaging system 10 of the present invention includes a transmitter 20 for illuminating a target 30 with a series of electromagnetic pulses P. The present invention further includes an apparatus 35, 40 and 45 for redirecting first R1 and second R2 reflections of each illuminating pulse P from first 32 and second 34 portions of the target 30, respectively. A frequency modulator 50 driven by a generator 55 shifts the frequency of each first reflection R1 to produce a reference reflection R1' corresponding to each illuminating pulse P. The present invention further includes an arrangement of reflective elements 60 and 65 for respectively combining the reference R1' and the second R2 reflections of each illuminating pulse P to generate a series of combined reflections. A detector 70 generates an imaging signal in response to the series of respectively combined reflections.Type: GrantFiled: September 19, 1988Date of Patent: March 6, 1990Assignee: Hughes Aircraft CompanyInventor: Thomas R. O'Meara
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Patent number: 4902125Abstract: A laser radar system having amplification of the optical beam. In a system where it is desired to achieve greater information content or greater system sensitivity, one or more laser amplifiers in the beam paths provide greater optical power for increased distance. Eleven system architectures are disclosed for use with a modified Mach-Zehnder interferometer, eleven are disclosed for use with a Fizeau interferometer, and three are disclosed for use in a noncoherent optical system. The embodiments are distinguished by the number and placement of the laser amplifiers in the optical paths of the system.Type: GrantFiled: June 30, 1988Date of Patent: February 20, 1990Assignee: Raytheon CompanyInventors: Wayne H. Keene, Albert V. Jelalian, David B. McVicker
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Patent number: 4900161Abstract: The invention involves a method for measuring the temperature in a heating system of the type having an electrically heated hot plate with a filled cooking vessel on it and a radiation pick-up located at varying distances from the side of the vessel and pointed at it which emits a signal indicating the temperature of the substance in the vessel based upon radiation from an area on the side of the vessel as detected by the radiation measurement field of the radiation pick-up, the radiation intensity of which decreases as a square of increasing distance. To compensate for the effect on measurements of spurious radiation form the changing position of the vessel on the hot plate, the invention involves adjusting the angle of a non-intersecting radiation measurement field to obtain corresponding reduction in the area of radiation detetion on the vesel for increasing distances between vessel and radiation pick-up.Type: GrantFiled: December 4, 1987Date of Patent: February 13, 1990Assignee: Fissler GmbHInventors: Kurt Wolf, Wolfram Andre
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Patent number: 4895441Abstract: An improved method and apparatus for precision ranging is described using a frequency-modulated signal source to stimulate creation of interference fringes at a rate proportional to absolute distance to a target. According to the invention, a low frequency modulating signal modulates a relatively high frequency signal source having a predetermined long coherent length compared to the distance to be measured. The resulting frequency-modulated signal is transmitted to the target to generate a reflected version thereof. Because of the long coherent length of the signal source, the transmitted frequency-modulated signal maintains spatial coherence as it travels to and from the target. Moreover, the low frequency modulating signal stimulates production of 360.degree. instantaneous phase differences between the transmitted and received frequency-modulated signals when these signals are superimposed. The number of these 360.degree.Type: GrantFiled: March 19, 1987Date of Patent: January 23, 1990Assignee: Pandel Instruments, Inc.Inventor: C. Cameron Allen, Jr.
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Patent number: 4886353Abstract: A measuring device employing laser interferometry, and featuring a device for tracking a mobile target; which tracking device is located between a light source and a semireflecting mirror, for the purpose of eliminating any inaccuracy due to the construction of the aforementioned measuring device.Type: GrantFiled: March 17, 1988Date of Patent: December 12, 1989Assignee: D.E.A. Digital Electronic Automation S.p.A.Inventor: Bernard Fondeur
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Patent number: 4881823Abstract: A method of determining true temperatures of a heated target material by its radiation based on prior knowledge of an emissivity function which describes the relationship between two spectral emissivities for the target material, comprising measuring two radiances corresponding to said two spectral emissivities from the target material, assuming a temperature of the target material, then calculating a pair of emissivities which satisfy the emissivity fuction whereat the assumed temperature is the true temperature of the target material.Type: GrantFiled: March 29, 1988Date of Patent: November 21, 1989Assignee: Purdue Research FoundationInventors: Fumio Tanaka, David P. DeWitt
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Patent number: 4866362Abstract: The invention relates to a target tracking system comprising two identical stationary and mutually distant sub-systems (5, 6), each sub-system including a laser source (7, 8) and two perpendicularly pivotable mirrors (10, 11), such that a laser beam can be directed by each sub-system towards the moving target (4). Each sub-system further includes a lateral effect photodetector (18) receiving the light beam after its reflection on the target, which is a reflecting target (4) of the cat's eye type. The pivot positions of the mirrors (10, 11) are adjustable in accordance with control signals derived from the detector (18) such that the respective beam tends to approach the center of the target (4) and that it is reflected in itself. Each mirror is pivoted by a brushless DC motor (12, 13). The common pivot shaft of the motor and of the mirror is further coupled to a digital angle encoder (16, 17) which delivers signals to calculator means (27, 29) for evaluating the present 3D coordinates of the target.Type: GrantFiled: September 9, 1988Date of Patent: September 12, 1989Assignee: European Economic CommunityInventors: Graham A. Parker, Rene J. R. Mayer, Ian G. Taylor, David G. Bailey
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Patent number: 4859065Abstract: A method of measuring temperature comprises the steps of consecutively launching (1, 2) input pulses of light at two different wavelengths into a temperature sensing element in the form of an elongate optical fibre (3); passing Raman scattered light from said element and deriving from said input pulses to intensity detectors (7, 8); obtaining from the detectors (7, 8) output signals indicative of the intensity of the Raman scattered light; and processing said output signals to provide a temperature measurement. A known position (10) along the optical fibre (3) is maintained at a known temperature to provide a reference for deriving temperature measurements at other positions along the optical fibre.Type: GrantFiled: October 7, 1986Date of Patent: August 22, 1989Assignee: Central Electricity Generating BoardInventor: Geoffrey W. Bibby
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Patent number: 4846571Abstract: A laser is provided for generating a beam of continuous wave (CW) electromagnetic energy having a nominal frequency and amplitude. The frequency of the CW beam is modulated (FM) from the nominal frequency. The amplitude of the frequency modulated beam is modulated (AM) from the nominal amplitude to produce an amplitude and frequency modulated continuous wave (AM-FM CW) beam of energy. A local oscillator beam is produced from the frequency modulated CW beam. The AM-FM CW beam is directed for reflection by a target. The target-reflected return portions of the AM-FM CW beam are combined with the frequency modulated local oscillator beam to produce a beat frequency signal which is subsequently detected, the beat frequency signal having a frequency component representative of the range of the target. Such arrangement, when implemented in a radar system, provides such radar system with accurate target range measurements unambiguous over large ranges.Type: GrantFiled: November 3, 1986Date of Patent: July 11, 1989Assignee: Raytheon CompanyInventors: Albert V. Jelalian, Wayne H. Keene, Nathan Freedman
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Patent number: 4833525Abstract: A device performs color balance adjustment on the basis of color temperature information obtained by adding up measured color information outputs sampled from color sensors which obtain measured color information from an object to be photographed.Type: GrantFiled: October 7, 1988Date of Patent: May 23, 1989Assignee: Canon Kabushiki KaishaInventors: Masao Suzuki, Seiji Hashimoto, Akihiko Tojo, Tsutomu Takayama, Toshio Kaji
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Patent number: 4830486Abstract: An apparatus and a method for measuring the distance to an arbitrary target includes a radiation source producing a beam of coherent radiation the frequency of which is continuously varied. The beam is divided into a ranging beam and a reference beam. The ranging beam is coupled to a ranging interferometer, which directs a portion of the ranging beam at the target. The ranging interferometer produces a first signal indicative of the phase difference between a portion of the ranging beam directed at and scattered by the target and another portion of the ranging beam which has traveled over a path of fixed length. The reference beam is coupled to a reference interferometer. A portion of the reference beam is directed by the reference interferometer along a reference path of a predetermined length, and the phase difference between the portion of the reference beam directed along the reference path and another portion of the reference beam which has travelled over a path of a fixed length is measured.Type: GrantFiled: March 16, 1984Date of Patent: May 16, 1989Inventor: Frank E. Goodwin
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Patent number: 4824240Abstract: An instrument of measuring motion of a vibratory system, such as an ultrasonic bonder, employs a laser (10) that receives within its lasing cavity light transmitted (24) to the object (26) to be monitored and retroreflected (24), so that oscillations within the laser cavity experience interference peaks corresponding to the phase relation between the outgoing and incoming laser beams (24). The interference peaks of the beam within the cavity are counted to provide an indication of motion of the reflecting object. Sensitivity is enhanced by choosing a front reflector (14) of the laser cavity to have a transmissivity at the frequency of interest that is selected to achieve maximum interference peak values. The laser cavity length is selected to cause the laser to have no more than two modes at the output frequency of interest, thereby avoiding beat frequencies that approach the frequency of vibration of the mechanical system of which motion is being observed.Type: GrantFiled: April 15, 1986Date of Patent: April 25, 1989Assignee: Hughes Aircraft CompanyInventor: Christopher S. Myers
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Patent number: 4824251Abstract: A precision optical distance measuring device utilizes coherent optical detection for extreme precision, and polarization preserving fiber to enable its use in limited access environments. A laser diode provides a linearly polarized source light beam which is directed to a polarizing beam splitter. The source beam passes through the beam splitter and is focused by a lens into a polarization preserving fiber where it travels along one optical axis toward a probe head disposed at the target location. In the probe head, the source beam is focused by a lens onto the target. After focusing, the source beam is passed through a quarter-wave plate. The interface between ambient air and the target-side of the quarter-wave plate reflects a local oscillator beam back through the quarter-wave plate. Meanwhile, the source beam is reflected from the target as a return beam.Type: GrantFiled: September 25, 1987Date of Patent: April 25, 1989Assignee: Digital Signal CorporationInventors: Anthony R. Slotwinski, Stephen C. Kenyon
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Patent number: 4818102Abstract: An optical pyrometer makes a temperature measurement of a remote body that is insensitive to spurious radiation by modulating the temperature of the body of optical irradiation in a first optical wavelength range at a low modulation frequency and synchronous detection of emitted optical radiation in a second optical wavelength range, together with modulation in the second optical wavelength range and detection in the first wavelength range. The measurement so made are combined to form a parameter representative of the body temperature that is insensitive to the environment of the body.Type: GrantFiled: December 22, 1986Date of Patent: April 4, 1989Assignee: United Technologies CorporationInventor: William H. Glenn
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Patent number: 4815841Abstract: The sensing head of a two-color band ratioing pyrometer of a known type using a fiber optic cable to couple radiation to dual detector photodiodes is improved to have high spatial resolution by focusing the radiation received through an objective lens (i.e., by focusing the image of a target area) onto an opaque sheet spaced in front of the input end of the fiber optic cable. A two-mil hole in that sheet then passes radiation to the input end of the cable. The detector has two channels, one for each color band, with an electronic-chopper stabilized current amplifier as the input stage followed by an electronic-chopper stabilized voltage amplifier.Type: GrantFiled: August 3, 1987Date of Patent: March 28, 1989Assignee: California Institute of TechnologyInventors: Donald B. Bickler, Paul K. Henry, D. Daniel LoGiurato