Abstract:
An image registration system for registering images on a screen (16). A registration pattern (28) is projected on the screen (16) as part of the image to be registered and in a fixed position in that image. Where there are multiple images to be registered with each other on a common screen (16), a sensor apparatus (18, 20) is used for each image. The sensor apparatus (18) has three photodetectors (22, 24, 26) disposed in a right angle relationship which sense the illumination of the associated registration pattern (28). The position of the registration pattern (28) on the screen (16) is determined by comparing the outputs of the three photodetectors (22, 24, 26) to each other. Difference signals (50, 52) are produced by the comparisons and are used to reposition the projected image to bring it into registration. Where multiple images are projected on a common screen (16), the sensor apparatus (18, 20) and image registration patterns are disposed on the screen and in the images respectively in particular positions so that when the associated registration pattern is in register with the associated sensor apparatus (18, 20), the images are in register with each other on the screen (16).
Abstract:
A four-quadrant frame of reference (encompassing axes X and Y in Fig. 3), established with respect to a sensed target image, effectively converts the image into a composite target regardable as the union of four, quadrant-based target-segments (T1, T2, T3 and T4). Four subgates (G1, G2, G3 and G4), each established within a different reference-frame quadrant (Q1, Q2, Q3 and Q4) become in union a composite tracking gate. As the effectualization of the actual gate-sizing, the degree of conformity between the composite gate and the composite target is then optomized by optimizing the degree of conformity between the subgates and the associated target-segments.
Abstract:
A dual field of view sensor, particularly adapted for use as a forward-looking infrared night vision detector, includes a single detector (24) for receiving a light signal and developing an output electrical signal therefrom. A rotating polygon scanner (16) having a plurality of reflective facet (14) thereon receives light (12, 34) from two separate optical systems (10, 32) and directs the light onto the facets (14) of the scanner (16) at positions offset by one-half the facet angle such that the light beams alternately strike a facet and the juncture between two facets. The reflected light is then directed through a beam splitter 40 onto the detector in an alternating, interleaved sweeping motion. The beam splitter permits only one at a time of the light (12, 34) from entering the detector. In one embodiment, both optical systems include a steerable dual field of view telescope. In a second embodiment, a transparent display (60) such as an LCD panel, impresses a data image on one light beam (52) and the signals developed from that and another light beam are combined to drive a display. In a third embodiment, the two light beams represent the input to a stereoscopic viewing system, and the separate signals developed therefrom are used to drive a pair of small helmet-mounted displays for individual viewing by the wearer's left and right eyes to provide stereoscopic night vision viewing.
Abstract:
A modulator system (30) for converting a three-channel input microwave signal to a single-channel output microwave signal is formed of two (upper and lower) microwave sections which are joined together by a hybrid divider (94) at their inputs and by a hybrid combiner (96) at their outputs. Each of the microwave sections includes a pair of couplers (82 and 84, 88 and 90) which are joined by a Faraday rotator (86, 92). First and second microwave input signals (48, 52) are applied to a first port of the input coupler (82, 88) in each of these sections. A third microwave signal (50) is directed by the hybrid divider (94) to a second imput port in the input couplers (82, 84) of each of the microwave sections. Polarization of the third signal is vertical and is maintained through the two sections. Polarization of the first and second signals is horizontal and is maintained through the two sections. With activation of the rotator, a shift in polarization occurs resulting in appearence of the signals in both the horizontal and vertical components of an output coupler in each of the sections. The vertical component of the output couplers in each of the sections is combined by the hybrid combiner to produce the single-channel microwave signal (54). Synchronous detectors are utilized for subsequent extraction of the first and second input signals, the synchronous detectors and the Faraday rotators being driven by common sources of modulation signals wherein the rotator in one section is modulated at a rate different from the rotator in the second section.
Abstract:
A semiconductive substrate (1), such as a silicon wafer, is mounted on a baseplate (3), for inclusion in an optical device such as a liquid crystal light valve. An optical flat (9) presses the top surface of the silicon wafer toward the baseplate and against a ring seal (5) surrounding a fluid adhesive (7). The fluid adhesive hydrostatically distributes the force of compression to guarantee optical flatness and self-compensation for the amount fluid adhesive surrounded by the O-ring. The optical flatness of the semiconductor substrate is limited only by the flatness of the optical flat against which it is compressed. Parallel alignment of the optical flat (9), the substrate (1) and the baseplate (3) is achieved by reflecting a laser beam (20) through the semiconductive substrate and observing the interference fringes therein, while adjusting the relative alignment so as to maximize the distance between fringes.
Abstract:
In the fabrication of a variety of articles, organic contaminants become affixed to the surfaces of these articles and must subsequently be removed. The disclosed method is effective for the removal of organic contaminants from a variety of articles, and is efficient to enable the rapid removal of such contaminants without damage to the article. The method has special utility in the cleaning of components used in aerospace applications. In the disclosed method, a structural component bearing the contaminant is contacted in a pressure vessel with a gas under super-critical conditions of temperature and pressure whereby the contaminant is absorbed by the gas. The gas, having the contaminant absorbed therein, is then purged from the vessel to obtain the cleaned component.
Abstract:
Method of fabricating a semiconductor on insulator composite substrate comprised of a semiconductor layer adjacent an insulator substrate, the defect density profile of the semiconductor layer being low and relatively uniform, a relatively thin region of the semiconductor layer at the semiconductor/insulator interface having a substantially greater defect density. The method comprises the steps of depositing the semiconductor layer (12a) adjacent the insulator substrate (10), amorphizing a buried portion (14) of the semiconductor layer without damaging the insulator substrate such as to release contaminants into the semiconductor layer, recrystallizing the amorphous portion of the semiconductor or layer, removing a portion of the semiconductor layer so as to expose the recrystallized layer (38), and depositing an additional semiconductor layer (40) of the recrystallized layer to provide an essentially defect free semiconductor layer of any desired thickness. The provision of semiconductor layers formed by either appropriately selecting the depth within the semiconductor layer at which the amorphization occurs and the width of the amorphized region or permitting self-annealing to occur during the amorphization, or both, having a desired high defect density and interposed between the recrystallized layer and the insulator substrate are also disclosed.
Abstract:
An emitter-dispenser housing (48) for a controlled porosity dispenser cathode manufactured of a single material as a unitary piece by a chemical vapor deposition process in which a configured mandrel (20) is coated with a layer of material (36 and 40) such as tungsten, for example, so that when the mandrel (20) is removed from the coating of material (36), a hollow housing (48) is formed having a side wall (36 and 40) and an end wall (42) which define a reservoir (44). In addition, intersecting strips (28 and 30) of this same material as the coating, which had been placed in the mandrel (20), extend transversely across the reservoir (44) with the edges thereof bonded by atomic-crystalline growth to the coating (36 and 40) during the chemical vapor deposition to form a unitary piece. Thereafter, an array of apertures (46) is formed in the end wall (42) of the housing by laser drilling to create an emitter-dispenser (42).
Abstract:
A sulfide layer is formed on the surface of a semiconductor substrate to provide an insulator layer or an antireflective coating in devices such as infrared radiation detectors. The formation of such sulfide layers requires high temperatures or generates charged particles or high energy radiation that damage the substrate and prevent optimum electrical performance of the device. This problem is overcome by exposing the substrate (20) at low temperature to a vapor phase reactant containing a chosen metal (from chamber 26), such as dimethyl zinc, in the presence of neutral, charge-free sulfur atoms formed in a manner which avoids the generation of charged particles and high energy radiation that would damage the substrate. The sulfur atoms react with the vapor phase reactant to form the sulfide thereof, such as zinc sulfide, which deposits as a layer on the surface of the substrate (20). The neutral sulfur atoms are generated by the photochemical dissociation of a sulfur-containing precursor (from chamber 28) by radiation of a selected wavelength (from means 16). In addition, a native sulfide layer may be formed on the surface of a chosen substrate by exposing the substrate to neutral, charge-free sulfur atoms which do not damage the substrate.
Abstract:
A heat pipe cooling module assembly (20) for cooling electronic components (28) includes a plurality of heat pipe modules (22) comprising condenser and evaporator sections (24, 26) and working fluid therein. In a preferred embodiment, each evaporator section comprises a sandwich construction of a pair of flat outer plates (34), a pair of wick pads (36) and a separator plate (38) comprising channels extending from the evaporator section into the condenser section.