Abstract: Radially extending fibers are disposed over a conical surface at predetermined sites. The sites correspond to vertices of a pattern of contiguous congruent isosceles triangles inscribed onto the surface of a sector of a circle which may be conformally mapped onto the conical surface so that vertices of the pattern coincide along the join line meridian of the conical surface. Fibers are disposed between the radially extending fibers in three different directions which respectively correspond with the sides of the triangles. The material obtained exhibits an invariant fiber volume fraction along the axis of the conical surface. The material may be used to reinforce a conical object. Also, an object, such as a preform, having a conical surface and method for reinforcing an object having a conical surface, in accordance with the present invention, are described.

Abstract: The invention relates to an imager for simultaneously obtaining two images of differing color bands of the same object field using a single two dimensional photodetector array. A Fresnel-biprism with two different color filters on the respective left and right aperture halves convergently displaces the two images. An objective lens focuses the filtered convergent images upon a photodector array, the left and right halves of which are covered by a second filter pair. The second pair of filters pass the same color bands as the first pair of filters but the order of the color bands bands is reversed from left to right. As a result of the filtering and convergence, the photodetector array, aligned with its columns parallel to the filter boundaries, responds with its left half to one color image and with its right half to the other color image.

Abstract: A dither scanned IR imaging system is disclosed for achieving panoramic coverage. For complete 360.degree. azimuth coverate, the field of view is divided into eight sectors, each imaged by a separate objective lens upon a loose packed 2D photodetector array. The photodetectors are tight packed in the array columns while the columns are loose packed, being on centers spaced by integral numbers of photodetector dimensions (i.e., pixels). The image is dithered the distance between columns over the array by a pair of counter rotating IR refractive discs of wedge shaped cross section. A full-frame partial-sample of the image is taken each time the image advances one pixel until the image has been fully sampled. Tight packed arrays may also be employed if additional means are provided to partially sample the image. In achieving 360.degree.

Abstract: A hybrid interconnection structure is disclosed having application to the fine pitch interconnection of delicate semiconductor chips. The invention entails the use of a beam lead interconnect in which patterned conductor runs are provided on the upper surface of a silicon chip. The conductor runs extend beyond the chip to form a paired set of beam leads. One set of beam leads makes contact with terminals on the upper surface of one chip and the other set of beam leads makes contact with terminals on the upper surface of another chip. The interconnect chip is set on a substrate common to the interconnected chips with its top surface slightly (normally less than 1-2 mils) above the top surfaces of the interconnected chips. This limits any downward deformation of the beam leads in the bonding process to insure reliability of the bond for fine pitch application.

Abstract: The invention relates to a monolithically integrated RC oscillator in which the frequency is of reduced dependency upon process variations, supply voltage variations or temperature. The circuit employs two RC circuits, typically not integrated, each capacitor of which is alternately charged via a transistor switch to the supply potential. The discharge of each capacitor takes place through the shunting resistance to a potential set by the switching voltages of two buffer amplifiers in the forward gain path of the oscillator. If the switching voltages are set midway between the supply voltages, and identical buffer amplifiers are employed, the temperature, voltage and other process variables tend to produce compensatory changes in frequency. The circuit is also optimized to minimize transient delays and thereby further decrease the dependence of oscillator frequency upon voltage, temperature, or process variations affecting the integrated active circuitry. The circuit is carried out in the (CMOS) process.

Abstract: In a computer image generation system, as a viewpoint approaches a surface of an object and is closer than a predetermined threshold distance from the surface, a texture pattern obtained from cell data becomes fuzzy, and may not provide adequate motion cues for training, such as piloting an airplane. In accordance with the present invention, apparatus and method provide random data at a predetermined derived level of detail for combining with cell data to define the surface including texture of the object when the object is closer to the viewpoint than the threshold distance. The apparatus may be readily retrofitted into an existing system.

Abstract: An infrared detection system is disclosed in which a re-imaging optical system produces a non-axisymmetric aperture stop image at an exit pupil point in or near the cold shield entrance aperture. To achieve high cold shield efficiency notwithstanding the asymmetry of the aperture stop image and the resulting astigmatism in such image, two exit pupil stop members disposed in non-coplanar relation are provided adjacent the exit pupil point. The stop aperture in one such member has its radially extending edges congruent with the corresponding edges of the aperture stop image and is disposed in the plane of best exit pupil formation for those edges; the aperture in the other exit pupil stop member is correspondingly configured and oriented with respect to the circumferential edges of the aperture stop image.

Abstract: A data processor includes an array of a plurality of processing elements haivng ports connected to neighboring elements. Elements at each end of a column have interconnected ports so that data can be sequentially cycled through the column elements. Elements at each end of a row have switchably interconnected ports so that in one mode data can be sequentially cycled through the row elements. The processor further includes a shift register switchably coupled to each row and memory apparatus coupled to the shift registers. The shift registers are switchable such that in a second mode data can be sequentially cycled through the shift registers and the corresponding row elements. The processor also includes an input shuffle matrix for reformatting data for facilitating data storage and recall during processing, thereby increasing overall system throughput.

Abstract: The human eye is more sensitive to brightness than to color. Accordingly, color definition is defined by a luminance or brightness (Y) component, an in-phase component (I) and a quadrature component (Q) and which are appropriately processed before being converted to more traditional red, green and blue (RGB) components for color display control. Scaling and redesignating YIQ data permits representation by fewer bits than a RGB scheme during processing. Also, Y values may be processed at one level of detail while the corresponding I and Q data values may be processed at a lesser level of detail. Translucency information may also be accommodated.

Abstract: A method for clipping a source polygon to a view window permits the valid (i.e. potentially visible) edges or portions of edges of the source polygon and of the view window boundary edges to be sequentially output for further processing, while determining the valid parts in a predetermined direction around the perimeter of the source polygon, without having to store (other than for a first entry point) the value of exit points from or entry points to the view window. Only an end point of an edge of the source polygon is considered at a time so that a maximum of two intersection point determinations between the source polygon edge and view window boundary planes outside of which the source polygon edge lies are required to ascertain if a portion of the source polygon edge is valid.

Abstract: A semiconductor material is overlayed with sequentially stacked layers including a protective layer, an affinity layer having an affinity for a second implant blocking material comprising tungsten, a first implant blocking layer and a masking layer having a first pattern. A portion of the first blocking layer not being masked is removed to expose a first portion of the affinity layer and a first dopant is implanted into the underlying semiconductor through the exposed first portion of the affinity layer. The mask is removed to expose the first blocking layer and a second blocking layer is formed from the second blocking material over the exposed first portion of the affinity layer but not over the exposed first blocking layer. The first blocking layer is removed to expose a second portion of the affinity layer which constitutes a second pattern. A second dopant is implanted into the underlying semiconductor through the exposed second portion of the affinity layer.

Abstract: The invention relates to a variable gain distributed amplifier for use at microwave frequencies, and fabricated in a monolithic microwave integrated circuit format. In the amplifier, the attenuation is varied, based upon digital control of a dual gate segmented FET. The amplifier has a nearly flat insertion phase and amplitude response, and an insertion phase response that varies only slightly between gain settings. The amplifier employs segmented dual gate field effect transistors as the gain elements, having their signal input and signal output electrodes which provide shunt capacities (C.sub.G1S, C.sub.DS) interconnected with serial inductances to form separate low pass transmission lines having relatively high cut-off frequencies. The amplifier has means to insure stability and uses Chebyshef equal ripple techniques to linearize the amplitude and insertion phase response.

Abstract: A cover for an elongated antenna window of a nose cone of a reentry type missile includes a four directional composite material. A respective portion of a plurality of fibers are disposed in each of the four directions. The directions are oriented so that the fibers provide increased resistance to expected aerodynamic pressure-induced shear forces, especially during reentry, in the plane of the longitudinal axis of the window. The fibers comprise a refractory ceramic such as silica, boron nitride, alumina, aluminum nitride or a combination thereof having a filler material including a refractory ceramic disposed in the interstices between the fibers.

Abstract: A full color real time cell texture generator uses a tapered quantization scheme for establishing a small set of colors representative of all colors of a source image. A source image to be displayed is quantitized by selecting the color of the small set nearest the color of the source image for each cell of the source image. Nearness is measured as Euclidian distance in a three-space coordinate system of the primary colors: red, green and blue. In a specific embodiment, an 8-bit modulation code is used to control each of the red, green, blue and translucency content of each display pixel, thereby permitting independent modulation for each of the colors forming the display image.

Abstract: A helmet mountable display system includes separate optical paths for providing a respective image to the left and right eye of an observer for stereoscopic viewing. Each of a first and second plurality of spaced apart, substantially point light sources supply a respective group of modulated rays of light. The rays of each group are collimated by a respective input lens and the collimated rays from each input lens are directed so that their envelopes all intersect at the same point. A horizontal and a vertical deflecting surface are disposed on opposite sides of the intersection point. Electro-mechanical drivers move the surfaces which scan all the collimated rays. The scanned rays from each group are focused onto a respective screen by a respective output lens to form a raster scanned image. The screens are divided into a plurality of contiguous zones with a ray from each light source assigned to a corresponding zone, which reduces the vertical scan angle excursions required.

Abstract: A tri-element carbon based heat shield has an outer layer including a carbon-carbon composite, a middle layer including pyrolytic graphite deposited onto an inner surface of the outer layer and an inner layer including carbon felt or foam having low density and high mechanical compliance. The thickness of each layer is selected for optimizing thermal protection over the expected operating temperature range. Although a carbon-carbon composite has a higher thermal diffusivity (inversely related to thermal insulation efficiency) than pyrolytic graphite, the carbon-carbon is selected as the outer layer in a minimum thickness sufficient to satisfy the structural strength, ablation and recession requirements of the heat shield. The resulting thickness of the outer layer determines the operating temperature range of the middle layer.

Abstract: A power supply for a Xenon lamp of a projection television includes a pulse-width-modulator that is included in a power regulating outer feedback loop and in a current-mode inner feedback loop. A current sensing transformer, responsive to a current in a chopper arrangement of the power supply, generates a signal that is coupled to a lowpass filter. The filter generates a ramping portion of each pulse of a control signal that is coupled to a current sensing terminal of the pulse-width-modulator. A switch operating synchronously with a horizontal sync signal is coupled across a capacitor of the lowpass filter to completely discharge the capacitor prior to the beginning of each ramping portion.

Abstract: In a computer image generation system, the choice of a path for a vehicle model over a landscape is not restricted. Objects and features in an image to be displayed are defined by polygons. Plumb vectors, having a predetermined relationship with the vehicle model, are used to obtain samples of the terrain at the intersection between the vectors and polygons defining the ground in the vicinity of the vehicle model. The vectors may sample in advance of the vehicle model in the direction of motion or under the vehicle model. The polygons may be encoded with characteristics of the terrain they define so that appropriate noise cues can be generated from information extracted at the intersection of the plumb vectors and polygons. Predetermined ones of the sample points are interpolated for inferring the contour and slope of the terrain before interaction between the vehicle model and interpolated terrain is determined.

Abstract: A real time computer image generation system incorporating comprehensive distortion correction in which a predistorted image is computed and placed on a projection raster prior to projection onto a view screen in order that the image as seen by a viewer appears correct. A method for implementing comprehensive distortion correction in real time utilizes fixed transfer characteristics of a projection lens coupled with scene by scene translation of each of a plurality of predetermined points from a projection raster to a location on a view screen. Each image is divided into a plurality of spans and the span corners are mapped from the projection raster to the view screen. The location of image vertices on the view screen are determined with respect to the viewer and the vertices are mapped to corresponding locations on the projector raster.

Abstract: Radially extending fibers are disposed over a conical surface at predetermined sites. The sites correspond to vertices of a pattern of contiguous congruent squares inscribed onto the surface of a sector of a circle which may be conformally mapped into the conical surface. Vertices of the pattern coincide along the join line meridian of the conical surface. Fibers are disposed along element paths between the radially extending fibers and preferably, a continuous fiber is used. The material obtained is without any seams or discontinuities and exhibits an invariant fiber volume fraction along the axis and circumference of the conical surface. The material may be used to reinforce an object having a conical surface or to fabricate a preform.