Abstract: The apparatus disclosed herein employs a grating (13) which concentrates light at a preselected wavelength into the positive (33) and negative (35) first orders while minimizing the zeroth order (31). The grating (13) is illuminated with monochromatic light of the selected wavelength and a poly-phase periodic detector (25) has its sensing plane spaced from the grating a distance less than ##EQU1## where W is the width of the illuminated region of the grating. The period of the poly-phase detector is equal to P/2 so that each detector element (51) or phase responds principally to the natural interference between the positive and negative first orders without requiring magnification or redirection of the diffracted light. Preferably, the distance of the sensing plane from the grating (13) is greater than ##EQU2## so that the detector response does not include substantial components from diffraction orders higher than the first.

Abstract: A single-channel gas concentration measurement method and apparatus. According to the method, a radiant source is employed to generate a measuring signal, the measuring signal is subsequently directed to a measurement object containing a gas mixture to be measured, the measuring signal is subsequently bandpass filtered using at least two passband wavelengths, and the filtered measuring signals are detected by a detector. According to the invention, the bandpass filtering step is implemented by a single electrostatically tunable, short-resonator Fabry-Perot interferometer.

Abstract: An opto-electronic, threaded parts inspection device. The device includes a source for generating a thin, planar beam of collimated light which is disposed on one side of a parts carrier. The laser light beam is rotatable about two axes, normal to one another and both normal to the longitudinal axis of parts passing through the beam. A sensor unit is disposed on the other side of the parts carrier so that the light beam falls thereupon. The threaded parts inspection device can be adjusted to pass light over different features of the threaded parts as they are moved past the inspection device by the parts carrier. By measuring how much of the light is interrupted by the profile of the passing threaded parts, it is possible to detect deviations in the pitch angle and major and minor diameters of the threaded workpieces.

Abstract: A high reliability portable incandescent illumination system for use in applications which require a reliable, high output light source such as heliport markers, runway lights, warning lights, road hazard and obstruction lights. The required elements of the invention are a battery to provide an energy source, a DC/DC converter to step up the battery voltage to a level required to drive a high output light source. The DC/DC converter is driven by a controller which generates a pulse stream to the DC/DC converter based upon inputs from a soft start circuit, a filament temperature sensor, an optical spectrum sensor, a power sensor and a filament break sensor. The optical spectrum sensor is coupled to the light source by a fiber optical element. An improvement in results in the performance of portable beacons by using high voltage lamps with low voltage batteries via voltage step-up electronics.

Abstract: A sample liquid containing particles are caused to flow through a transparent flow cell. An image capturing device is used to capture different images for a single particle existing in an image capturing area of the flow cell. The image capturing device further preferably captures different images of the single particle from different directions. Further, the image capturing device can capture different images at different focal positions. The different images can include fluorescence images and chemiluminescence images.

Abstract: In the present invention, an extraneous substance inspection optical system having an extraneous inspection area of a predetermined scanning width in subscanning direction of a matter to be inspected is positioned in such a manner that the extraneous substance inspection area at a moment when the matter to be inspected is started to move in main scanning direction is arranged at a position in the main scanning direction corresponding to a head portion of the matter to be inspected; the matter to be inspected is moved in the main scanning direction to be subjected to a forward scanning for the matter to be inspected to thereby detect possible extraneous substances in the extraneous inspection area; and the matter to be inspected is rotated by 180.degree.

Abstract: A scanning system for wood products to detect grain defects and product geometry simultaneously. Multiple scanner sets cast parallel beams of light at an angle of incidence in a plane that is normal to the surface of the wood product. Scanner sets are provided to scan both the top and bottom surfaces of the wood product. The scanner sets include detector arrays to detect the reflected light of the beams off the surface of the product. One array of each set is positioned strategic to the angle of incidence and another is positioned strategic to the angle of specular reflection. The magnitudes of the detector are compared to determine clear wood or grain defect. The time of detection is used to calculate thickness/geometry.

Abstract: A hole burning measurement system realizes accurate analysis of a photochemical hole burning effect in an optical device.

Abstract: The invention relates to dispersion interferometers for measuring a dispersion portion of the refractive index of an investigated medium by an interferometric method and can be used in the optical industry and in the composition of diagnostic complexes of various plasma installations of the type of Tokamak, Stellarator, gas-discharge lasers. The dispersion interferometer comprising a radiation source, two nonlinear optical doublers of frequency at a distance ensuring a location of an object under examination therebetween, a light filter means and a recording device, all arranged along an optical axis. Additionally provided is a polarization beam splitter, and the two non-linear optical frequency doublers are so oriented that the directions of polarization of fast waves are orthogonal to each other and do not coincide with ones separated by the beam splitter and the radiation source.

Abstract: The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Abstract: An image in which a feature corresponding to a reference mark formed at a predetermined position in an exposure apparatus is formed at a predetermined position in an arbitrary area is stored as a reference image, and a reference image including an image corresponding to the reference mark is detected from an image to be processed obtained by picking up an image near the reference mark to detect the position of the reference mark in the image to be processed, thus enabling detection of the positional relationship between a reference in the exposure apparatus and substrate alignment means.

Abstract: A apparatus for sensing flow and/or other characteristics of a fluid, including an emitter adapted to project a light beam, a detector adapted to transmit a signal in response to receiving the light beam and a rotatable member for transmitting the beam of light from the emitter to the detector through a quantity of the fluid. Optic fibers/light pipes may be used to transmit light to the emitter from a light source, through the rotatable member and to a processor remote from the detector. The rotatable member may also include reflective and nonreflective zones for transmitting light passing through the fluid to the detector. A plurality of light pipes, blades, emitters and detectors may be used on the rotating member depending on a particular application of the present invention.

Abstract: An apparatus for turning the external circumference of an optical lens mount, a collimator is optically aligned with the turning axis (y-y). A fixture is mounted on the apparatus to accommodate the lens assembly. The fixture provides a translatory adjustment motion transverse to the axis (y-y) and a pivot motion about a universal joint. Electromechanical adjustment actuators operatively engage the fixture to move the optical axis of the lens assembly into alignment with the axis (y-y). An electronic deviation control system converts the light output of the collimator into an axis deviation signal which is encoded according to the rotary position of the lens assembly to generate translatory and pivot motion adjustment signals which control the action of the adjustment actuators.

Abstract: The present invention is a directional reflectometer that measures the optical bidirectional reflectance distribution function [BRDF] of a surface in situ on a finished article, e.g. a vehicle, to provide information on its surface emissivity. The light wavelength may be IR, near-IR or visible. Light, preferably focused to a small spot on the surface, is projected onto the surface at an angle adjustable in azimuth and elevation. A wide angle mirror and/or lens system transfers light scattered from the surface onto an imaging sensor, preserving scattering angle information and thereby permitting the BRDFs for a given incidence angle and all scattering angles to be measured simultaneously. A hand held or laptop computer sets the incidence angle, reads the sensor outputs and renders judgments on the quality of the surface in a factory or field environment.

Abstract: A display screen inspecting method wherein, a plurality of display picture elements are selected, as markers, from a display screen and light receiving picture elements corresponding to the display picture elements are selected. The light amounts of the display picture elements are measured using the light receiving picture elements and each of the light amounts thus measured is fitted to a predetermined function form symmetric with respect to the center thereof such that the center of each display position is obtained. The difference in position between each of the center positions and each of the specified corresponding light receiving picture elements is obtained and based on such positional differences, a strain of the display screen or a positional shift between the display screen and an inspection screen, in terms of a positional function, is obtained.

Abstract: Test reticle patterns (reticle pattern images) are transferred by exposure onto an unexposed wafer in a plurality of rows parallel to a predetermined direction, and a rotation angle of each reticle pattern image is obtained from an amount of positional displacement in the vertical direction (direction Y) (Steps 102 to 104). A rotation angle of each reticle pattern image is obtained from the bend of a moving mirror within an exposure range on a wafer stage which is obtained by correcting an amount of positional displacement in a horizontal direction (direction X) by the rotation angle obtained from the positional displacement in the vertical direction and the bend of the moving mirror assumed in a region outside the exposure range, and a residual rotation error between the thus obtained rotation angle and the actual rotation angle is obtained (Steps 105 to 107).

Abstract: A laser interferometer, used for measuring displacement over long distances (e.g. 100 meters) includes an integral laser/detector unit 10, which emits a beam 12 of laser light. The fraction of the beam 12B which passes undiverted through a beam splitter 14 is laterally displaced by a periscope 18, which is positioned close to the laser 10. After passage through the periscope 18, the undiverted beam is incident upon a large retroreflector 20, whose size is such that the beam reflected by retroreflector 20 is laterally displaced by an amount greater than the lateral displacement due to passage of the beam through the periscope 18. Opaque housing 26 of the periscope 18 is used to screen reflected light from entrance into the laser cavity.

Abstract: A zone analysis system and method (211) optimize speed and minimize adverse effects resulting from noise in an inspection system (90) for measuring disparity between two surfaces. In particular, the zone analysis system and method (211) can be implemented in an inspection system (90) for contactlessly measuring undercut or protrusion of an optical fiber (26) relative to a surrounding support material (36) at the endface (79) of an optical fiber termination (37). In structure, the inspection system (90) has a measurement apparatus (91) with an interferometer (98) controlled by a machine vision system (92) for determining the degree of disparity. The inspection system (90) measures an offset of an interferometric fringe (113') produced by the interferometer (98) over the target (82) in the image in order to determine the disparity. Further, the machine vision system (92) employs the zone analysis system and method (211) for optimizing the performance thereof.

Abstract: All critical wheel wear measurements on a static or in-motion train wheel are taken using a non-contact method/system. The train wheel is measured using a modulated point beam of energy impinging the wheel surface from an orthogonal direction, moving the point beam across the wheel surface, and sensing the unique modulated reflection of the wheel using energy sensors that produce analog signals. The analog signals are digitized and processed to produce all critical wheel wear measurements without removing the wheel from the train.

Abstract: An optical measuring system comprises an illumination arrangement including a light source, grating, and lens, and an image acquisition arrangement, including a lens, grating, and camera. A mechanical translation device moves the grating in a plane parallel to a reference surface to effect a phase shift of a projected image of the grating on the contoured surface to be measured. A second mechanical translation device moves the lens to effect a change in the contour interval. A first phase of the points on the contoured surface is taken, via a four-bucket algorithm, at a first contour interval. A second phase of the points is taken at a second contour interval. A controller, including a computer, determines a coarse measurement using the difference between the first and second phases. The controller further determines a fine measurement using either the first or second phase.