Abstract: An avalanche photodiode quenching circuit (20) incorporates an avalanche photodiode (APD) (22) and a first comparator (C1) responsive to reduction in APD voltage. The comparator (C1) is arranged to activate an APD quench circuit (38) in response to APD avalanche initiation. The circuit (20) also includes a second comparator (C2) arranged to reset the first comparator input (N2) in response to a further reduction in APD voltage caused by initiation of quenching. The second comparator (C2) is also connected to a monostable circuit (48) arranged to latch the first comparator output response to resetting. The monostable circuit (48) maintains the first comparator output level constant until the APD (22) has recharged.

Abstract: A polarizerless optic sensor is provided that uses a random domain magneto-optic film and a modulated normal magnetic field to vary or modulate the energy distribution in a diffraction pattern. Light is transmitted through the film and is diffracted according to a domain duty cycle so that the center beam intensity is a function of the Faraday rotation angle of the material and the intensity of the applied normal magnetic field. The polarizerless sensor can be used to realize a speed and torque sensor, an optical switch, a magnetic field sensor and many other types of devices. The invention can be used with polarized and unpolarized input light. The sensor can be implemented using a random domain film or a stripe domain film to create a phase grating diffraction pattern.

Abstract: The presence of a burner flame, in a multiple burner installation, is monitored by sensing a signal indicative of the spectrum of the fluctuating component in the radiation of the flame over a range of frequencies. In the lower frequency range a measure is obtained of the difference of signal strength at two predetermined frequency levels. The signal strength is also measured at a higher frequency. At the higher frequency there is a significant difference in signal intensity between the flame-on and flame-off conditions, while the change of signal strength between the spectra of flame-on and flame-off conditions in the lower frequency range is sensitive to frequency. By processing the two measures together they can augment each other and produce an enhanced change of signal between flame-on and flame-off conditions, making detection easier.

Abstract: A position detector detects a light incident position on one of a plurality of scintillators with a photomultiplier having a number of anodes smaller in number than the scintillators and with a simple circuit configuration. A plurality of anodes are provided in one-to-two or one-to-three correspondence to the plurality of scintillators. An anode receiving photoelectrons is detected from a specific output produced from one of a plurality of first group comparators. Further, either one of two anodes adjacent the detected anode at which the major part of the photoelectrons are received is determined from the outputs of second comparators, whereby one of the plurality of scintillators can be identified.

Abstract: Sensing apparatus based on the use of Raman spectroscopy for detecting the presence and location of a species of interest in a medium comprises a light transmissive optical fibre (4) with an elongate sensing length along at least a portion thereof, a light source means (1) for transmitting pulses of light along the fibre, and a detector (6) for detecting at the same end of the fibre as the light source Raman signals resulting from species (c) of interest at the interface of the sensing length and a medium in which it is located. The time difference between the transmission of an excitation pulse and detection of a Raman emission signal caused by that pulse is determined, and is used to determine the position of the species along the fibre.

Abstract: An opto-electronic scale reading apparatus comprises a light source (20) which projects light via an index grating (22) onto a reflective scale (10). Light is reflected from the scale (10), passes through an auxiliary grating (36) and is incident upon an analyser grating (28), at which a plurality of periodic light patterns are formed. Light from the light source (20) travels initially parallel to the scale plane, and is subsequently deflected through 90.degree. by a beam splitter cube (26); the light is thus incident upon and reflected and off the scale (10) at 90.degree. to the scale plane. This arrangement enables large movements of the readhead in a direction perpendicular to the scale.

Abstract: An imager comprises a lens 31 focusing radiation onto a sensor array 32, and a chopper comprising sectors which refract radiation in different directions such that an image is microscanned upon the sensor array 32. The chopper 4 is driven by motor 34 which also drives a polygon 37. The sensor array is read line by line and displayed on a linear array of LEDs 36 which appear to an observer observing through eye piece 38 as a complete two dimensional image as seen by the sensor ray 32. This is due to the persistence vision. Each facet of the polygon 37 is cut such that it compensates for the offset produced by the microscan.

Abstract: A system for measuring the value of a parameter, e.g., structural strain, includes an optical waveguide, a laser or equivalent light source for launching coherent light into the waveguide to propagate therein as multi modes, an array of a plurality of spaced apart photodetectors each comprising a light receptor surface and signal output, said array being arranged to have light emitted from said waveguide output portion irradiate said light receptor surfaces, an artificial neural network formed of a plurality of spaced apart neurons, connectors to impose weighted portions of signal outputs from the photodetectors upon the neurons which register the parameter value on a meter or like output device.

Abstract: An image reading apparatus comprises a plural-line sensor comprising a plurality of one-dimensional sensor arrays disposed on one and the same substrate, an imaging optical system for imaging an object on the sensor, and a brazed diffraction grating disposed in the optical path between the imaging optical system and the sensor for color-resolving a light beam from the object into a plurality of lights and directing the color-resolved lights to the sensor arrays corresponding thereto, the number of steps of the staircase structure of the diffraction grating being four or more.

Abstract: A relative position transducer for determining the angular position of a first member angularly movable relative to a second member includes a coded track on the first member, a read head mounted on the second member, drive means for oscillating the read head to scan over and read a limited region of the coded track, and a microcomputer for interpreting the code read by the read head as the position. A first sensor detects when the read head is in a predetermined reference position and a second sensor detects the end points and direction of the read head scan. The sensor outputs are connected to the computer for correct interpretation of the read head output. An interplation is used to improve the accuracy of the position determination.

Abstract: A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Abstract: A wire bonding inspecting apparatus for inspecting wires bonded between a semiconductor chip and leads comprises an imaging device for optically taking an image of the wire and converting the optical image into electric image signals; a moving device for moving the imaging device; an image processing inspecting unit for obtaining wire positional coordinates on the basis of image signals and inspecting the wire on the basis of the positional coordinates; and a main controller.

Abstract: Hermetic package designs for HDMI substrates are discussed. The designs for a hermetically sealed, perimeter-leaded package may have the following features:a) a flat monolithic dielectric base, the base having a flat upper surface and a flat lower surface;b) a zone on the upper surface, in which zone the HDMI device would reside;c) a seal ring surrounding the zone;d) a cover adapted to be hermetically sealed to the seal ring, thereby protecting the HDMI device located in the zone;e) a plurality of conductive vias (inner vias) extending from the upper surface inside said zone downwardly toward the lower surface;f) a plurality of perimeter conductive lead pads located on or in the upper surface about the perimeter of the zone inside the seal ring; wherein(1) the perimeter lead pads are electrically connected to the inner vias, and(2) the inner vias are electrically connected to a surface of the base outside the zone.

Abstract: A scanning microscope comprises a sample supporting member for supporting a sample, and a light source for producing a light beam including a light component, which has been polarized linearly in a first direction, and a light component, which has been polarized linearly in a second direction that intersects perpendicularly to the first direction. A first polarizer transmits only the light component, which has been polarized linearly in the first direction. A second polarizer transmits only the light component, which has been polarized linearly in the second direction. A light projecting device forms a small spot of the light beam composed of the light components, which have respectively passed through the first and second polarizers. The sample is scanned with the light spot.

Abstract: A radiation sensitive device comprising several rings and a middle section formed by a conventional charge coupled device. Drain means for radial draining of the charges generated in the circular sections by the incident radiation and drain means for the charge coupled device are provided. The device has a retina-like structure and can be advantageously applied in robotics.

Abstract: A method and apparatus for generating and detecting changes in interference patterns such as may be used to measure small displacements. A collimated beam is diffracted to produce a standing wavefront along a surface. The surface is coincident with the surface of a device which emits a signal in response to changes in the intensity of the wave front. In one embodiment, the diffracting means is a grating and the signal emitting means includes a beam splitter that generates an interference pattern responsive to the intensity of the wave front. In another embodiment, the signal emitting means is a membrane that emits a signal in response to changes in the wavefront. The apparatus and method can be used in applications which include measurement of displacement and measurement of force in which no displacement takes place.

Abstract: Detection apparatus employs a plurality of conduits, a plurality of photosensors, and a laser in a multi-port forward-scattering geometry to detect particles for each of a plurality of spatial sections (S.sub.1, . . . S.sub.n) of an enclosure. The photosensors are provided in two sets arranged at two different scattering angles to discriminate smoke from other particulate matter in sample flows which flow along the conduits and intersect the laser beam. The sample flows are discharged into a plenum and removed from the plenum via a single manifold. The laser can be backed up by an auxiliary laser.

Abstract: A displacement detector comprises a beam irradiation device for irradiating beams almost equal in wavelength on a diffraction grating provided on an object to be measured from two directions different each other, a photoelectric detector for detecting an interference intensity of specific diffracted rays generated from the diffraction grating, and a measuring device for measuring a displacement of the object to be measured with reference to a grating pitch direction of the diffraction grating according to an outgoing signal of the photoelectric detector; the photoelectric detector is equipped with a first photoelectric detector for detecting an interference intensity of diffracted rays of an angle of diffraction running in the said direction from the diffraction grating, and a second photoelectric detector for detecting an interference intensity of diffracted rays different in angle of diffraction running in the same direction from the diffraction grating; the measuring device has a first measuring portion fo

Abstract: A scanning force microscope having a sensor head and a base wherein a moveable sample holder is housed in the base and is positioned relative to a probe housed in the sensor head, such sample being monitored by an optical deflection detection system. The detection system is configured to provide direct visual observation of the probe with respect to the sample. The mirror of the detection system is mounted in a cut away portion of a sphere and defines the axis of rotation of a kinematic mount, such providing ease of fine adjustment of the detection system. The sensor head is in communication with the base by a stage kinematic mount, such providing ease of position adjustment of the sensor head with respect to the base.

Abstract: This invention comprises a pair of light deflecting members disposed in an optical path formed between a light source and an objective lens, and a pair of relay lenses disposed in an optical path formed between the pair of light deflecting members; and a slit member disposed in an optical path formed between the pair of relay lens.