Abstract: An adiabatic liquid volume sensor system is described, which employs a main chamber in a back-to-back configuration with a reference chamber of known volume. The system measures liquid volume in the main chamber by making low frequency acoustic measurements of the acoustic pressure differences in the two closed chambers when driven with a sinusoidal frequency from the same speaker. Pressure transducers in each chamber measure acoustic adiabatic pressures in each chamber. The ratio of these pressures multiplied by the known volume of the reference chamber yields the volume of gas in the main chamber. The volume of liquid is equal to the known volume of the main chamber minus the calculated gas volume.

Abstract: A method for detecting a change in capacitance of a capacitive sensing element having a nominal capacitance value is disclosed. In an exemplary embodiment, the method includes coupling the sensing element to a first oscillator, the first oscillator generating a first frequency dependent upon the capacitance value of the sensing element. The first frequency is compared to a reference frequency generated by a second oscillator. The change in capacitance from the nominal capacitance value is detected if the first frequency differs from said reference frequency by a determined frequency value.

Abstract: An improved liquid crystal display cell (34) comprising two substrates (108, 124) spaced apart and containing a quantity of liquid crystal mixture (18) therebetween, in which the substrates have facing surfaces (108', 124') coated with a continuous, electrically conducting material (38, 36), is provided with an array of spacer pads (40) at a pre-selected distance apart from each other, having a pre-selected height to maintain a given spacing between the substrates, and having a pre-selected cross-section that avoids substantial interference with the display properties of the liquid crystal display cell.

Abstract: An ICR fuser includes a set of fusion rules for combining the outputs of multiple ICR systems. Each ICR system operates on a digital image to extract image component strings and provide a set of multiple candidate character strings and their associated confidence values. Each rule includes a test for determining whether that rule applies to the current ICR system outputs, a membership function for selecting a fused character string, and a confidence equation for assigning it a fused confidence value. The rules partition a decision space into subspaces to reduce the error rate between the fused character string and the image component string.

Abstract: An apparatus for combining a display image with the field of view of a viewer. Light from either a night vision system (14) of a CRT (12) is directed into an eyepiece assembly (18). The eyepiece magnifies and focuses the image into a combiner (30). The combiner (30) consists of an elongated optical element with two parallel sides (36) and (38) and two concave reflective surfaces (32) and (34) at each end. Light entering the combiner (30) is reflected off the first reflective surface (32) and then is reflected back and forth between the sides of the combiner (36) and (38) and then onto the second reflective surface (32). Light reflected off the second reflective surface (32) is combined with light entering from the field of view of the viewer through a prism element (44). The result is that the display image is superimposed in the field of view of the viewer. The system is light in weight, does not protrude significantly from the user's head, introduces minimal distortion and offers a wide field view.

Abstract: A membrane probe (10, 12, 14, 16, 58, 144) for testing integrated circuits (56,138) while still on the wafer upon which they are manufactured includes a flexible visually clear and self planarizing membrane (26) having circuit traces (20) and ground shielding planes (14), terminating resistor (152) and active buffer chips (172) formed thereon. Probe contact pads (36,38) electroplated on areas of the traces, and connector pads (32) plated on the membrane facilitate rapid detachable connection to a test fixture (50). The probe has a configuration, dimension and structure like that of the wafer itself so that automated pick and place equipment (136,142) employed for handling the wafers (138) may also be used to handle the probes (144). An unique test fixture (50) is adapted to receive and detachably secure a selected probe to the fixture.

Abstract: A low cost, compact projection display source that serves as a very bright image source for an automotive head up display. The present invention is comprised of a high intensity halogen light source and a liquid crystal display. The liquid crystal display is controlled by display electronics that write images onto the liquid crystal display that are to be displayed to the driver or passengers of a vehicle. Light output from the high intensity light source is transmitted through a piece of infrared energy absorbing glass, a decentered lens, such as a Fresnel lens, and a diffuser that uniformly backlights the liquid crystal display. Crossed polarizers are used on either side of the liquid crystal display. The high intensity light output transmitted by the liquid crystal display is passed through a yellow-orange output window which is projected onto a toric combiner for display to the driver of the vehicle.

Abstract: A steering mechanism (17) in which axial motion of an optical structure (12) is constrained electrically through a closed loop servo control system. The steering mechanism includes three magnetic actuators (19a, 19b, 19c) each having a push rod (20a, 20b, 20c) magnetically coupled thereto for being translated by the magnetic actuator along a translation axis (A). Each of the push rods has an end coupled to a peripheral region (1a, 1b, 1c) of the optical structure for exerting a displacing force thereon in response to the push rod being translated along the translation axis. A non-contact displacement sensor (10c) provides a feedback signal for the closed loop servo control system.

Abstract: A hand-held instrument (10) and associated method for providing optical measurements of the contour, range and motion of an object, such as a tympanic membrane of an ear, in real time, and to provide for simultaneous visualization of the object. The instrument (10) includes an illumination source (22) that projects an optical beam (24) through a grating (26) onto a gradient of refractive index lens (32) to project light and dark fringes onto the object at stepped phases determined by the grating position. Light reflected from the object is collected and focused onto an eye piece (18) to be observed by the operator. Simultaneously, reflected light from the object is focused onto a camera (46). The camera (46) generates an electrical signal in proportion to the light intensity received by the camera (46) to generate an image of the object. The image is then transmitted to processing systems to compute phase relationships in the reflected grating image to generate a contour map of the object.

Abstract: A computer system and a method for the protected distribution of certificate and keying material between a certification authority and at least one entity in the certification authority's domain, including the steps of sending keying material, including a password, generated by the Certifying Authority to the entity via a secure medium; generating and protecting, by the entity, a public and a private key pair using the keying material provided it by the certifying authority; generating, protecting and sending a request for a certificate to the certifying authority using the keying material provided it by the certifying authority; requesting, by the certifying authority, that the public key and address of the entity be sent to the certifying authority; protecting and sending the public key and address of the entity to the certifying authority using the keying material provided it by the certifying authority; assembling and issuing the certificate to the entity from the certifying authority and recording the pu

Abstract: An improved eyepiece for an optical system. In general, the inventive eyepiece (10) includes a refractive element (16) and an optical arrangement for relaying the entrance pupil of the system to the refractive element. In a specific implementation, the optical arrangement includes a concave primary mirror (12) and a secondary mirror (14). The mirrors are mounted to communicate an image from the refractive element (16) to the entrance pupil (40). In the specific implementation, the refractive element (16) is one or more refractive lenses. The use of a reflective optical arrangement allows for the long eye relief. The placement of the entrance pupil close to the pupil of the lens allows for the use of a compact optical arrangement with high ratio of eye relief to effective focal length with a compact optical arrangement. The system affords minimal lateral chromatic aberration and good image quality.

Abstract: Self leveling apparatus that includes a frame, a device that is to be leveled, and a leveling mechanism such as a double ring gimbal having an inner gimbal ring and an outer gimbal ring. The outer gimbal ring is secured to the frame and the inner gimbal ring is secured to the device and to the outer ring. The inner ring comprises a viscous or preloaded bearing that allows the device to swing around an inner ring axle to thereby level itself in that axis and prevent spurious movement of the device. The outer gimbal ring and inner gimbal ring are attached by outer axles that comprise a viscous or preloaded bearing that allow the inner gimbal ring to swing around the outer axles thereby level the inner gimbal ring in that axis and prevent spurious movement of the device. A disclosed embodiment of the invention includes a magnetometer sensor that is coupled to signal processing and telemetry electronics and a power source that are leveled to keep axes of the sensor oriented along horizontal and vertical axes.

Abstract: A system for testing an embedded control processor for a spacecraft comprises an Emulated Spacecraft Control Processor (24) which contains the embedded processor (26), a simulation engine (12), and a host computer (14). The Emulated Spacecraft Control Processor (24), executing embedded application software, provides an emulated input/output interface for the embedded processor (26) to communicate simulated sensor data, command data, actuator command data, and telemetry data to the simulation engine (12) and the host computer (14). The Emulated Spacecraft Control Processor (24) processes the simulated sensor data and the command data to form the actuator command data and the telemetry data. The simulation engine (12) processes the actuator command data from the Emulated Spacecraft Control Processor (24) to simulate the system dynamics of the spacecraft in real-time, and to thereby produce the simulated sensor data.

Abstract: A system that provides live television programming to passengers by integrating direct broadcast satellite services into an in-flight aircraft entertainment system. The present invention is a satellite television system that has an antenna disposed on the aircraft that is pointed at a plurality of satellites that are part of a direct broadcast satellite system. The antenna is controlled by an antenna controller and antenna interface unit that send control signals and process status signals to steer the antenna. The antenna is steered to lock it onto RF signals transmitted by the satellites. The antenna interface unit downconverts the received RF signals to provide left hand circularly polarized RF signals and right hand circularly polarized RF signals that contain different sets of television channels. The downconverted RF signals are processed by a receiver/decoder that decodes them to provide video signals corresponding to different television channels.

Abstract: A digital information system delivers virtual on-demand information over existing, as well as the next generation, digital transport systems by offloading a portion of the systems' peak bandwidth requirements to the local subscribers. A collaborative filtering system synthesizes the preferences of all of the subscribers and then predicts those items that each subscriber might like, and therefore request. Each subscriber is provided with a local storage device for storing, during off-peak hours, those items recommended by the collaborative filtering system. As a result, only a relatively few subscriber requests must be serviced directly from the central distribution system.

Abstract: A projection system wherein two or more separate display sources, such as high brightness sources, or active matrix liquid crystal display (AMLCD) or other flat panel displays are used to write information directly onto a display screen, or onto a photoactivated reflective light valve for projection onto the display screen. Sequential imaging apparatus is used to alternately generate first and second images for display. For example, such images are coupled to the photoactivated reflective light valve and an illumination source is employed to illuminate the light valve and project a composite image onto the display screen. The flat panel displays may be transmissive, reflective, or self-emissive with the use of an optical shutter. A writing illumination source is used for non-self-emissive flat panel displays. Using high brightness display sources, the images may be directly written onto the display screen without the use of the reflective photoactivated light valve and the illumination source.

Abstract: An adhesive is provided for bonding cyanate ester composite parts together which is also plateable with metal once chemically etched. The adhesive comprises a polymeric matrix and a filler of cyanate ester polymer. The polymeric matrix comprises at least one polyepoxide resin and a curing agent, while the cyanate ester polymer filler is present in the adhesive as a powder. In practice, the present adhesive is applied to the surface of cyanate ester composite articles to be bonded and is allowed to cure at room temperature. Thereafter, the surface of the assembly is chemically etched and then plated with metal. The present adhesive enable the complete coverage of the cyanate ester composite assembly with the plated metal, including the adhesive bondlines.

Abstract: A holographic stoplight system that includes a stoplight hologram (21, 21') supported adjacent the inside surface of a rear window (211) of a vehicle, and a light source (29, 31) for providing a converging beam that is vertically converging and predominantly horizontally colimated. The stoplight hologram is illuminated with the vertically converging beam, or with a predominantly collimated beam provided by a collimating lens (27) that collimates the vertically converging beam.

Abstract: An article includes a substrate having a thermal control coating formed of 1 part by weight of a silicone polymeric matrix having from about 3 to about 4 parts by weight aluminum-doped zinc oxide pigment particles distributed therein. The article may be either relatively thick or flexibly thin, and the coating may be greater than 0.0015 inches thick so as to have a low solar absorptance. The coating has an absorptance of about 0.2-0.3 and an emittance of about 0.9, and is sufficiently electrically conductive to dissipate electrostatic charges.

Abstract: A low cost infrared camera (1) for night vision. The camera (1) is disposed within a housing (2) having an infrared transmissive window (6) disposed at an input aperture (5) thereof. A compact optical arrangement (10) is disposed within the housing (2) to focus energy from the window (5) onto a focal plane array (20). A chopper disk (19) is positioned between the reflective optical arrangement (10) and the focal plane array (20) to establish a reference level for the array (20) and to facilitate a sequential readout thereof. A signal processing circuit (100) is included for processing the output of the array (20) for display on a standard video screen. Thus, the problems with uncooled detectors are overcome by use of a fast optical system in combination with an uncooled detector. The fast optical system provides a high signal level to the uncooled detector, thereby compensating for losses in collection of thermal radiation.