Abstract: A discharge lamp lighting device which comprises a D.C. power supply, a load resonance circuit including an inductor, a capacitor and a discharge lamp; a polarity inverting circuit including at least a series circuit of first and second switching elements connected in parallel to the D.C. power supply for converting a D.C. power received from the D.C. power supply into an A.C. power to supply it to the load resonance circuit; and a control circuit for turning ON and OFF the switching elements alternately at a high frequency to alternately generate a first period during which an ON duration of the second switching element is longer than that of the first switching element and a second period during which the ON duration of the second switching element is shorter than that of the first switching element, to thereby apply a rectangular-shaped low frequency voltage to the discharge lamp. The control circuit superimposes a D.C.

Abstract: An optical waveguide network is formed in a substrate of an electrooptically active material. The optical waveguide has input and output facets where optical signals may be input to and output from the integrated optics chip. At least one lateral trench is formed in the substrate. The lateral trench is arranged to prevent light rays incident thereon from inside the substrate from propagating to the output facet. The lateral trench may be formed as a slot that extends toward the surface of the substrate where the optical waveguide network is formed, or the trench may be parallel to the plane of the optical waveguides.

Abstract: A fiber optic seismic sensor includes a central support assembly formed of a metal such as aluminum. A support plate has an inner portion retained within the central support assembly and an outer portion that extends beyond the central support assembly. A pair of hollow cylindrical substrates are mounted in axial alignment on opposite sides of the outer portion of the support plate with the central support assembly extending through the centers of the substrates. The central support assembly comprises a first central support member having a cavity in one end, and a second central support member having a projection extending therefrom and arranged to be received within the cavity in the first central support member. The support plate includes a passage arranged to receive the projection such that the inner portion of the support plate is retained between the first and second central support members.

Abstract: A housing for holding components of a fiber optic sensor array includes a base formed generally as an elongate rectangle with end caps connected to its ends. The sensor array includes an array cable formed of a plurality of constituent cables that each comprise an optical fiber and a tensile strength member corresponding to each optical fiber. Each end cap is formed to include a plurality of cable termination slots for connection to the strength members of selected constituent cables to which array components are connected and a plurality of cable bypass slots for routing constituent cables that are not connected to components around the housing.

Abstract: A fiber optic particle motion accelerometer has a housing with a mid-section mounted therein such that the mid-section flexes in response to acceleration along a sensing axis. A proof mass is mounted to an outer edge of the mid-section. A first spiral-wound optical fiber coil is mounted to a first side of the mid-section and a second spiral-wound optical fiber coil is mounted to a second side of the mid-section. A first hinge is formed in the mid-section adjacent the mounting of the mid-section in the housing, and a second hinge is formed in the mid-section between the proof mass and the first and second fiber optic coils. The optical fiber coils are included in an interferometer such that acceleration along the sensing axis produces a phase difference between optical signals propagating in the optical fiber coils.

Abstract: A threaded fastener for use with bolt comprises a housing having a central bore that includes a bolt insertion aperture and a plurality of cylindrical and frustoconical steps. A plurality of insert segments are placed within the central bore. Each insert segment includes an inwardly facing threaded portion and a front projection extending outwardly from the threaded portion. The front projection has a beveled edge arranged for sliding contact with a corresponding beveled portion of the housing. The front projection also has outwardly extending portion that cooperates with a ledge in the housing bore to limit longitudinal movement of the insert segment in the housing. A rear projection extends inwardly from the threaded portion and is arranged for sliding contact with a second beveled surface of the housing. An end cap retains the insert segments in the housing.

Abstract: An integrated optics chip includes an optical waveguide network formed on a surface of an electrooptically active material. The optical waveguide network has an input facet where an optical signal may be input to the optical waveguide network and an output facet where optical signals may be output from the optical waveguide network. One or more trenches is formed in the bottom surface of the surface and arranged to extend into the substrate toward the optical waveguide network to a depth of at least 70% of the thickness. The trenches prevent light rays incident thereon from inside the substrate from propagating to the output facet. In particular, the trenches prevent light scattered at the input facet or from scattering centers in the optical waveguide network from reflecting from the bottom surface of the substrate to the output facet. A cover may be mounted to the top surface of the substrate to provide structural strength to the integrated optics chip.

Abstract: An electromechanical sensor produces an electrical signal in response to a change in a physical parameter being monitored by the sensor. An optical phase modulator is arranged such that electrical signals from the electromechanical sensor cause a phase change in optical signals propagating in the two legs of the interferometer. The phase change is obtained by forming the interferometer to have a phase modulator in each leg. Applying the electrical signal to the phase modulators, which are connected in push-pull, changes the optical path length difference between the interferometer legs and produces an optical signal that can be transmitted to a remote location. A photodetector at the remote location converts the optical signal into an electrical signal that can be processed to measure changes in the parameter. The sensors may be used singly, or a plurality of sensors may be arranged in a geophone array.

Abstract: An LED luminaire is formed such that a plurality of LED chips are disposed three-dimensionally on an MID (molded interconnection device) substrate in a rectangular plate shape, by mounting three LED chips on bottom face of respective dents provided lengthwise and crosswise in one surface of the MID substrate, the LED chips including at least two types mutually diffferent in luminous color, desirably three types of red, blue and green colors. Any optional light distribution characteristic is made thereby easily obtainable depending on a configuration of the substrate, luminaire module can be thinned, and such delicate color difference as white color and day-light color of luminescent lamps is enabled by mixing the luminous colors of the respective LED chips.

Abstract: A pump light source provides pump light to an optical fiber arranged to guide the pump light to a first optical isolation device. Light output by the first optical isolation device is input to a wavelength division multiplexer. A gain fiber is connected to the wavelength division multiplexer and arranged to be optically pumped by the pump light such that the gain fiber emits broadband light that propagates to the wavelength division multiplexer. An output optical fiber is connected to the wavelength division multiplexer and arranged to guide a portion of the broadband light emitted by the gain fiber to a second optical isolation device for input to a fiber optic rotation sensor.

Abstract: A dithered Coriolis acceleration sensor system has a proof mass that is free of feedback in the accelerometer servo loop at the dither frequency by totally notching out all feedback torque at this frequency. The proof mass relative motion is then a direct measure of the rate because there is no feedback torque to alter the proof mass response to the acceleration. The feedback modulation system according to the invention captures the Coriolis-sensor output such that the phase and gain of the signal generated from the sensor are of no concern in maintaining good scale factor.

Abstract: A multilayer printed wiring board is formed with a plurality of conductor layers laminated as a whole with insulating layers interposed, a non-penetrating via hole provided in the insulating layer as bottomed by the conductor layer exposed, a plated layer provided inside the via hole for electric connection between the conductor layers, the via hole being formed to be of a concave curved surface of a radius in a range of 20 to 100 &mgr;m in axially sectioned view at continuing zone of inner periphery to bottom surface of the via hole, whereby the equipotential surfaces occurring upon plating the plated layer are curved along the continuing zone to unify the density of current for rendering the plated layer uniform in the thickness without being thinned at the continuing zone.

Abstract: An optical waveguide is formed on a first side of an integrated optics substrate. The optical waveguide is included in a first arm of an interferometer that is arranged to produce an interference pattern. The integrated optics substrate is mounted and arranged such that acceleration of the integrated optics substrate along a selected axis produces a change in the interference pattern. Changes in the interference pattern are monitored and correlated with the acceleration.

Abstract: This invention is a modular electronics mounting system according that is easy to install and that can be used with a wide variety of electronics components. A support plate includes a grid of holes arranged in at least one pair of columns spaced apart by a selected distance. The holes in each of the columns are spaced apart by a predetermined interval. The support plate is configured to be mounted to a wall such that the grid is spaced apart from the wall. A module formed generally as a plate such that an electronic component may be mounted thereto. The module includes a pair of hooks extending from a first edge of the plate. The hooks are spaced apart by the column spacing such that the hooks may be arranged to extend through first and second holes in the grid. A locking pin extends from the module such that the locking pin extends into a corresponding third hole in the grid to restrain the module against movement parallel to the support plate.

Abstract: A foldable net includes a flexible frame that may be formed from a single wire or form a plurality of flexible tubes connected end-to-end. The frame is arranged to have an upper frame portion and a lower frame portion. The lower frame portion forms a base that supports the upper frame portion in a generally upright orientation on a generally horizontal surface with the base extending in a forward direction relative to the upper frame portion. A fabric section is connected to the frame and arranged for a projectile to be incident thereon. A plurality of straps is connected between portions of the frame to constrain it to a predetermined configuration for supporting the fabric in a position for receiving the projectile.

Abstract: An infrared sensor is formed with a first infrared detecting element for infrared detection disposed in a container through a supporting substrate, and a second infrared detecting element for temperature compensation also disposed in the container to be shielded by the supporting substrate of the first infrared detecting element from incident infrared within the container, while a temperature sensing section of the first infrared detecting element is born in non-contacting state with respect to a supporting part of the substrate for the element, whereby the sensitivity can be remarkably improved with a simpler arrangement while keeping a high precision and inexpensiveness.

Abstract: An internal combustion engine comprises a piston arranged to move reciprocally in a predetermined direction relative to an engine block. A drive shaft is mounted in the engine block and arranged to be driven by the piston in rotational motion about a first axis perpendicular to the direction of motion of the piston. Rotational motion of the drive shaft is transferred to a first shaft that is mounted in the engine block parallel to the drive shaft. Rotational motion of the first shaft is then transferred to a second shaft such that the engine produces a rotational output about an output axis that is parallel to the direction of reciprocal motion of the piston.