Abstract:
A flame rectification type flame sensor circuit and method in which a generator (51) injects periodic pulses of alternating voltage into a flame region (58), the voltage across the flame region (58) being processed by a filter/amplifier (60) which, in proper operation, produces a non-zero output signal only during the time a flame (58) is present and a pulse of alternating voltage is being supplied by the generator (51). Final indication of a flame (58) is produced only if a non-zero output signal occurs during the time a pulse of alternating voltage is being supplied, and not during the time between successive pulses of alternating voltage. Failure of an electrical component in the filter/amplifier (60) is indicated if a non-zero output signal occurs during the time between successive pulses of alternating voltage.
Abstract:
A media access protocol provides a fixed frame length and limited arbitration among certain predetermined users by providing limited arbitration during certain fixed time slots of a table driven proportional access system.
Abstract:
A process for fabricating a diode pumped laser is disclosed which allows the laser to be easily aligned with other components. Furthermore, the disclosed method provides a means for fabricating an entire diode pumped laser upon a single substrate, thus eliminating the complexity of positioning and alignment. Ion beam deposition is used to create many of the components, thus forming very efficient and very uniform components.
Abstract:
A hierarchial selection hardware synchronization arbitration technique. A plurality of redundant computers each include a sync master counter (38), which is set to reflect the hierarchial selection of each computer. The sync master counter will be inhibited if a sync master signal (60) is present when the computer is activated or if a sync activity signal is present from a higher ranking computer. The computers each have a physical ranking (22, 24, 26, 28) to achieve the hierarchial selection and otherwise can be identical. If the sync master computer generates a fault signal or a fault is detected, then the hierarchial selection of the remaining computers is again commenced.
Abstract:
A head mounted display having an image source, an optical relay system and a combiner for producing an image from the image source to the eye of a pilot in which the optical system includes at least one diffractive surface to compensate for aberrations and distortions in the display.
Abstract:
A system and method for modifying security levels within a security system. External modifications are allowed only if the security of a point is increased.
Abstract:
A method for fabricating single crystal islands (34) on a high temperature substrate (20), thereby allowing for the use of high temperature processes to further make devices incorporating the islands (34) such as, for example, high mobility thin film transistor integrated drivers (13) for active matrix displays (10). The method essentially includes depositing an etch stop layer (30) on a single crystal silicon substrate (18), depositing a single crystal silicon device layer (32) on the etch stop layer (30), bonding a quartz substrate (20) to the single crystal silicon device layer (32) at room temperature, sealing and securing with an adhesive the edges of the single crystal silicon substrate (18), the etch stop layer (30), the single crystal silicon device layer (32) and the quartz substrate (20), grinding away a portion of the silicon substrate (18) and a portion of the adhesive (22), etching away the remaining portion of the silicon substrate (18), removing the remaining portion of the adhesive (22), etching away the etch stop layer (30), applying a photoresist mask on the single crystal silicon device layer (32) for defining the islands (34) on the single crystal silicon device layer (32), etching single crystal silicon islands (34), and the first non-room-temperature process of diffusion bonding the single crystal silicon islands (34) to the quartz substrate (20).
Abstract:
A portable and compact room air purifier having an internal filter element (30) through which air is drawn by a centrifugal fan (32) and wherein the air is discharged generally uniformly and radially by passing between at least one generally arcuate scroll (41, 42) and a surrounding deflector (40). The purifier is automatically deactivated in the event of destruction or removal of the filter housing (11).
Abstract:
A method and apparatus for determining an altitude for a radar fuze (10). The method includes the steps of receiving a return signal (77) and transmitting a transmitted signal (76). The return signal (77) and the transmitted signal (76) are mixed and a mixed signal (44) representing an altitude is responsively generated therefrom. The mixed signal (44) is amplified (18) to generate an amplified signal (45). The amplified signal (45) is filtered to generate a filtered signal (48) which is envelope detected to provide a detected signal (54) responsive to the filtered signal (48). The detected signal (54) is integrated responsively to the detected signal (54). The integrated signal level (56) is compared against a track threshold reference signal (59) and a track/no-track comparator signal (58) is provided responsively to the integrated signal level (56) and the track threshold reference signal (59). System timing is controlled by generating a plurality of control signals (68) responsive to the track/no-track comparator signal (58) and proportional to an altitude (100). A modulation signal (70) responsive to the plurality of control signals (68) is provided wherein the modulation signal (70) is representative of an altimeter range as determined by the plurality of control signals (68). The transmitted signal (76) is generated responsively to the modulation signal (70).
Abstract:
A helmet mounted display utilizing a pair of image sources mounted low on the helmet of a pilot and projecting an image across in front of the pilot's face to the opposite partly reflecting portions of the visor of the helmet to create an image for each of the pilot's eyes, which image is combined with the scene being viewed through the visor by the pilot.