Abstract: A system and method for monitoring the state of a crystal (C) which is suspended in a solution is disclosed which includes providing a light source (10) for emitting a beam (12) of light along an optical axis (X). A collimating lens is arranged along the optical axis for collimating the emitted beam to provide a first collimated light beam (16) consisting of parallel light rays. The solution and crystal are contained in a transparent container (18). By passing the first collimated light beam through the container, a number of the parallel light rays are deflected off of the surfaces of said crystal being monitored according to the refractive index gradient to provide a deflected beam (19) of deflected light rays. A focusing lens (22) is arranged along the optical axis for focusing the deflected rays (32, 34, 48, 50) towards a desired focal point (24a). A knife edge (24) is arranged in a predetermined orientation at the focal point; and a screen (26) is provided.

Abstract: An optical plummet mechanism for compensating an error due to an inclination of a surveying instrument comprises a first pendulum suspended in the instrument body interior, a second pendulum suspended in a perpendicular relation to the first pendulum, a first reflector provided on the first pendulum for reflecting light incident in the direction of a collimation axis of a collimation lens in the direction of a substantially horizontal collimation axis lying in the plane of swinging of the first pendulum, and a second reflector provided on the second pendulum and being a double reflecting surface reflector for reflecting light incident in the direction of a collimation axis lying the the plane of swinging of the first pendulum in the direction of a vertical collimation axis. Collimation errors due to inclination of the instrument body in two directions, i.e.

Abstract: Non-contact measurement of signals up to and beyond 100 GHz is provided by electro-optical sampling the field in a transmission line. A first laser signal is employed to optically generate signals in a III-V compound semiconductor such as gallium arsenide. The signal is transmitted to microstrip on the semiconductor surface, and a second polarized laser signal is passed through the crystal and its polarization is modulated by the electric field in the microstrip. The polarization presents a measure of the field strength and hence the signal. By varying the relative delay between two beams, an equivalent time representation of the sampled signal is obtained.

Abstract: Fiber optic probe apparatus usable for measuring temperatures with increased dynamic range and frequency domain response and desirable measurement accuracy. A black body signal source, fiber optic signal coupling, and extension of the transducer dynamic range with optical multiplexing are employed; the instrument operates in the range of 1.6 micrometers of optical energy wavelength and preferably employs recently improved indium gallium arsenide photodiode transducer devices and transducer frequency domain compensation. Use of the instrument in measuring combustion flame transient temperatures is disclosed.

Abstract: A micro-dimensional measurement apparatus for precise non-contact measurement of distances between edges formed upon a surface, basically comprising an acousto-optical element for scanning a light beam across the surface with the scanning distance varying in accordance with a deflection voltage, a photo-sensor for sensing the intensity of resultant light reflected from the surface, and a data-processing circuits for determining when the rate of change of the reflected light intensity reaches maximum values, corresponding to positions of surface edges, and for measuring the distance between a pair of edges on the surface based upon a change in the deflection voltage occurring between the corresponding two maximum values.

Abstract: A control system for processing the signals sensed by a continuous cell target in a laser measurement system is disclosed involving electronic circuitry and components for indicating incidence of the beam on the target, for shifting the electrical sensing center of the cell to the center of the target housing, and for compensating for variations in laser beam intensity.

Abstract: A first linear sensor tracks the movement of an object through an inspection station and a second linear sensor views the object transverse to the object path to acquire a line image of the object, and a synchronizing arrangement responds to the sensed position of the object to trigger the second sensor at spaced object positions to obtain a plurality of line images which cummulatively represent the object image. The image is compared, line-by-line, as acquired with a stored model of the object to determine the correlation between the object and the model.

Abstract: The present invention relates to a method of and apparatus for measuring the width of an object. The object is moved across a first beam and a photodetector produces a signal indicating when the object is eclipsing the beam. An interferometer is trained on a device for moving the object across the beam and is used to calculate the distance the moving device travels while the object is eclipsing the beam. From that distance, the width of the object can be calculated.

Abstract: An apparatus for detecting an image area of a thin plate is provided having a housing having a vertical side plate at one side thereof, the vertical side plate having an opening; a door movable to close/open the opening; a holder for holding the thin plate in a location which covers the opening when the door is closed; a camera mounted inside the housing so as to oppose the vertical side plate; the florescent lamps mounted on the inner surfaces of upper and lower plates and side plates of the housing which are perpendicular to the vertical side plate so that illumination directions of the florescent lamps are directed toward the thin plate.

Abstract: An opto-acoustic fuel quantity gauging system, including: a tank; an ultrasonic energy source; an optical power source; a fiber optic cable; an ultrasonic sensor; an optical detector and a signal conditioning circuit. The ultrasonic energy source is connected to the tank. The ultrasonic energy sensor is connected to the tank. The optical power source is connected to the fiber optic cable. The ultrasonic energy source is connected to the fiber optic cable. The ultrasonic energy sensor is connected to the optical detector by the fiber optic cable. The circuit is connected to the optical detector.

Abstract: An optical fault seeking apparatus has a light scanning apparatus (21) and a light line receiving apparatus (14) which receive the light reflected from the material to be investigated and direct it onto a photoelectric converter. The light beam which forms the light line 11 impinges at an acute angle (.alpha.) onto the surface (13) of the article or web (18) under investigation. The image forming optical light line receiving apparatus (14), effectively consists of two light receivers (14, 14') positioned away from the normally reflected beam (23) and arranged to receive light from respective ones of two spaced apart strip-like regions (11', 11") extending parallel to and partly overlapping the line of light (11). In this way the device is able to detect faults (e.g. lumps or depressions) in fleece-type webs with irregular surface structures which are normally very difficult to monitor with optical fault seeking apparatus (FIG. 1).

Abstract: Optical measurement apparatus, for example for the measurement of displacement, comprises a radiation source 2 coupled to an optical fibre 1 connected to a sensing head 12 comprising a Y-coupler 8 supplying an optic fibre tip 5 and a parallel path incorporating a delay 10 and terminating in a tip 11. A lens 4 of appropriate focal length is positioned between tip 5 and a reflector 3 to focus light onto reflector 3 so that the amount of light reflected back to tip 5 is a function of the position of the reflector. A signal detector 6 is also coupled to fibre to detect and measure the reflected light. Tip 11 is positioned at the focus of lens 4 so that the light reflected back to tip 11 is independent of the position of reflector 3. The ratio of the two reflected signals detected in detector 6 is calculated to give the position of reflector 3 with compensation for the effects of deterioration of the parts of the apparatus in which there is a common path for the two quantities of light.

Abstract: An autoalignment system for an unstable laser resonator includes means for measuring the angular position of a convex mirror and adjusting the concave mirror to a new optic axis defined by the convex mirror.

Abstract: The invention relates to a method and an apparatus for calibrating a positioning system, including control means (209) sending command signals to the positioning apparatus (204) intended during a working state to locate an object (203) in relation to an operating area (206), the situation of the apparatus being sensed and converted to an actual value signal which is sent to the control means. The positioning apparatus has a working state which is interrupted at given intervals by a calibrating state, during which the positioning apparatus is accurately put in register with at least one detector (208), situated within the operating area in a given position. The output signals from the detectors are allowed to activate the control means, whereafter the actual value signal is determined and the positioning apparatus calibrated in response to the determined actual value signal.

Abstract: An apparatus for aligning objects on the basis of a signal obtained by scanning marks formed on the objects. A position datum representing the relative position between the objects is extracted on the basis of an extraction level. The marks are scanned a plurality of times and an average is obtained by the plural data provided on the basis of the extraction datum. Those operations are repeated with one or more different extraction levels. In each of the data group corresponding to one of the extraction data, a peculiar or exceptional datum is determined. Among the peculiar data obtained for individual sets of data, a minimum is selected. Thus, an extraction datum which results in the minimum peculiar datum is determined. The average of the position data obtained with this extraction datum is used for bringing the objects into alignment with each other.

Abstract: An observation device usable with an apparatus for aligning two members each having alignment marks. The device includes an optical path for the beam reflected by the alignment marks, which at least partially is not common with an optical path for the beam directed to the alignment marks. In the uncommon optical path for the scanning beam or for the reflected beam, there is a 90 degree image rotator to provide, in the observation view field, a scanning direction which is traverse to a direction connecting the alignment marks, thus enabling an operator to observe images in natural forms.

Abstract: A mask aligner includes a photo-mask having a plurality of first marks used to align the photo-mask with a wafer and a plurality of second marks used to align the photo-mask with the mask aligner, the number of the second marks being equal to that of the first marks; a wafer having a plurality of third marks associated with the first marks; a mark providing section having a plurality of fourth marks associated with the second marks; and a detector for detecting an error in alignment between the first and third marks and also an error in alignment between the second and fourth marks, the detector including a plurality of sensors for sensing various marks in different positions, a basic form produced when the first and third marks are placed one above another being substantially the same as that produced when the second and fourth marks are placed one above another.

Abstract: A system for preventing contact between an analyzing head and a transparent drum in a color scanner includes a drum reader for identifying which one of several transparent drums is installed on the scanner, and a head position reader for identifying the selected position of the analyzing head in a direction at right angles to a subscanning direction. The system further includes decision means for deciding whether the position of the analyzing head is suitable for the installed drum, and means for inhibiting movement of the analyzing head in the subscanning direction if the decision means determines that the position of the analyzing head is incompatible with the installed drum.

Abstract: A rotating analyzer type ellipsometer comprises a rotating analyzer for receiving light which is impinged on a sample with a predetermined incident angle and reflected by the sample, a rotary phase detecting apparatus provided so as to rotate unitarily with the rotating analyzer for generating a rotary phase signal as the rotary phase detecting apparatus rotates, a rotating mechanism for rotating the rotating analyzer and the rotary phase detecting apparatus, a photodetector for producing an output responsive to light which is passed through the rotating analyzer, and a computer for obtaining a phase difference between the rotating analyzer and the rotary phase detecting apparatus from a phase difference .phi..sub.o with which a difference between an output I.sub.p of the photodetector and a theoretical value I.sub.o becomes a minimum or substantially zero by entering into the computer the output I.sub.p of the photodetector and calculating the theoretical value I.sub.

Abstract: A comparison-type dimension measurement system in which a laser 1 provides linearly polarized light that is directed by a polarization beam splitter 5 into a microscope system in which a specimen 13 is mounted. The reflected polarized light is rotated 90.degree. by a quarter wave plate 9 and passes through the beam splitter to a multi-element line sensor 19. The laser light is scanned by a rotatable mirror 3 over the specimen. Threshold intensities are determined on indicia of known separation on a reference specimen and used to calibrate the distance measured by the line sensor.