Abstract: An RFID system and method for communicating between a host computer, one or more interrogators connected to the host computer, and a large body of transponders distributed within an area covered by the interrogators. Each transponder originally has a common identification code, and upon initialization by the host computer internally generates a unique identification code based upon an internally generated random number. The host, through the interrogators, reads each of the identification codes associated with each transponder by iteratively transmitting a read identification code command along with a controlled variable. Each transponder compares the received controlled variable to an internally generated random number, and selectively transmits its identification code based upon the outcome of this comparison. After the completion of each read identification code iteration, the host adjusts the controlled variable based upon the responses received in the previous iteration.

Abstract: An apparatus for electronically determining whether a tax or duty has been paid for the contents of that container. A radio frequency identification (RFID) tag is placed on the container which includes information indicative of whether the tax has been paid. The RFID tag includes a substrate, a radio frequency transceiver circuit mounted upon the substrate and connected to an antenna having a fixed length that is also mounted upon the substrate, and, preferably, a protrusion affixed to or a slot in the substrate. Preferably, the RFID tag is placed within the container's cap, such that, when mounted on the container, the cap mates with a ratchet wheel connected to the container that engages the protrusion or slot such that removing the cap from the container will cause the substrate to fracture and thereby cause the RFID tag to become permanently disabled.

Abstract: An RFID system and method for communicating between a host computer, one or more interrogators connected to the host computer, and a large body of transponders distributed within an area covered by the interrogators. Each transponder originally has a common identification code, and upon initialization by the host computer internally generates a unique identification code based upon an internally generated random number. The host, through the interrogators, reads each of the identification codes associated with each transponder by iteratively transmitting a read identification code command along with a controlled variable. Each transponder compares the received controlled variable to an internally generated random number, and selectively transmits its identification code based upon the outcome of this comparison. After the completion of each read identification code iteration, the host adjusts the controlled variable based upon the responses received in the previous iteration.

Abstract: An RFID tag system which communicates with a base station at a predetermined frequency for a container having a metal closure comprising an insulator mounted to an exterior surface of the metal closure and a radio transceiver system coupled to the insulator. The radio transceiver system further comprises an antenna tuned to the predetermined frequency mounted to an exterior surface of the metal closure and an RFID IC chip coupled to the antenna and coupled to the metal closure. In a first embodiment, the RFID IC chip is mounted outside the metal closure. In a second embodiment, the RFID IC chip is mounted within the metal closure and connected to the antenna outside the metal closure through an electrical feedthrough connection in the metal closure.

Abstract: An apparatus for detecting the authenticity of a container sealed with a cap (or other closure) which automatically disables itself when the cap is first removed. A radio frequency identification (RFID) tag includes a substrate, a radio frequency transceiver circuit mounted upon the substrate and connected to an antenna having a fixed length that is also mounted upon the substrate, and a protrusion affixed to or a slot in the substrate. A cap for a container includes the RFID tag mounted on an inner surface adjacent to the closed end. When mounted on the container, the cap mates with a ratchet wheel connected to the container that engages the protrusion or slot such that removing the cap from the container will cause the substrate to fracture and thereby cause the RFID tag to become permanently disabled.

Abstract: An apparatus for electronically determining whether a tax or duty has been paid for the contents of that container. A radio frequency identification (RFID) tag is placed on the container which includes information indicative of whether the tax has been paid. The RFID tag includes a substrate, a radio frequency transceiver circuit mounted upon the substrate and connected to an antenna having a fixed length that is also mounted upon the substrate, and, preferably, a protrusion affixed to or a slot in the substrate. Preferably, the RFID tag is placed within the container's cap, such that, when mounted on the container, the cap mates with a ratchet wheel connected to the container that engages the protrusion or slot such that removing the cap from the container will cause the substrate to fracture and thereby cause the RFID tag to become permanently disabled.

Abstract: An apparatus for detecting tampering with a container sealed with a cap. The apparatus includes a radio frequency transceiver for transmitting a signal upon receipt of a transmit command and an antenna attached thereto. In a first embodiment, the radio frequency transceiver and the antenna are mounted on a substrate attached to the container and the cap. The radio frequency transceiver is disabled when the antenna is separated into two portions upon breaking the seal between the container and the cap. In a second embodiment, the apparatus is mounted within a cap and includes a logic circuit and a probe that detects changes in the level of contents within the container. The probe produces an output relative to the level of contents in the container. The logic circuit then either prevents the radio frequency transceiver form communicating or causes it to transmit an alternative signal.

Abstract: An RFID system and method for communicating between a host computer, one or more interrogators connected to the host computer, and a large body of transponders distributed within an area covered by the interrogators. Each transponder originally has a common identification code, and upon initialization by the host computer internally generates a unique identification code based upon an internally generated random number. The host, through the interrogators, reads each of the identification codes associated with each transponder by iteratively transmitting a read identification code command along with a controlled variable. Each transponder compares the received controlled variable to an internally generated random number, and selectively transmits its identification code based upon the outcome of this comparison. After the completion of each read identification code iteration, the host adjusts the controlled variable based upon the responses received in the previous iteration.

Abstract: An RFID system and method for communicating between a host computer, one or more interrogators connected to the host computer, and a large body of transponders distributed within an area covered by the interrogators. Each transponder originally has a common identification code, and upon initialization by the host computer internally generates a unique identification code based upon an internally generated random number. The host, through the interrogators, reads each of the identification codes associated with each transponder by iteratively transmitting a read identification code command along with a controlled variable. Each transponder compares the received controlled variable to an internally generated random number, and selectively transmits its identification code based upon the outcome of this comparison. After the completion of each read identification code iteration, the host adjusts the controlled variable based upon the responses received in the previous iteration.

Abstract: In a receiver, a system and method are disclosed for providing improved detection of data from a transmitted sequence of pulse width modulated (PWM) pulses. The disclosed system includes a pulse detector having an adjustable critical duty cycle for distinguishing between first and second pulses based upon their respective long and short duty cycles at which they are received. The disclosed system further includes an element which determines the duty cycle of the received pulses and an element which adjusts the critical duty cycle based on the duty cycle which is so determined. The duty cycle may be determined by determining the correspondence between information obtained from an initial pulse sequence and reference information at the receiver. In the disclosed method, the duty cycle of pulses in an initial sequence is first determined and then checked against a predetermined limit. If the duty cycle falls outside the limit, the critical duty cycle is adjusted prior to further pulses being detected.

Abstract: A frequency cancelling system is disclosed which improves reception of a communication signal which is transmitted at a communication frequency in the presence of an interference signal which occurs at the same communication frequency. The frequency cancelling system generates a reference signal at the communication frequency, and adjusts the reference signal to be opposite in phase and equal in amplitude to the interference signal. The reference signal and the communication signal are then combined to cancel the interference signal. In a preferred embodiment, the reference signal is generated from the same source as that from which the interference signal arises. Preferably, the interference signal is received during an interval in which the communication signal is not being transmitted, and the reference signal is adjusted to be opposite in phase and equal in amplitude to the interference signal during that interval.

Abstract: A transponder adapted to be used in a checkout or inventory control system is disclosed which transmits by modulating and re-radiating a transponder signal frequency derived from a carrier frequency received on a transmitting antenna. The transponder includes a dual mode antenna and circuitry which selectively operates the antenna to suppress undesired emission of the transponder signal frequency when the transponder is not transmitting. A terminating circuit is further disclosed which suppresses undesired emission of the transponder signal frequency by a demodulator portion of the transponder.

Abstract: An apparatus and method for measuring the real-time volumetric flow rate of grain in a field harvester, comprising: a transmitting acoustical transducer for transmitting acoustic signals at a selected frequency, the transmitting acoustical transducer being disposed in the harvester with respect to a flow path of an airborne stream of grain during operation of the harvester so as to transmit the acoustic signals through the airborne stream of grain, whereby the transmitted acoustic signals are attenuated or scattered when passing through the airborne stream of grain; a receiving acoustical transducer for receiving the attenuated or scattered acoustic signals after passing through the flow path of the airborne stream of grain; and a computer in communication with the transmitting acoustical transducer and the receiving acoustical transducer for measuring the real-time volumetric flow rate of the airborne stream of grain as a function of the attenuation or scattering of the transmitted acoustic signals and a flo

Abstract: A system and method for storage and communication of information between at least one first information containing terminal and a second terminal. The system and method includes generating a random number within the first terminal in response to receipt of a begin signal from the second terminal, and comparing the random number to a count incremented and maintained by a digital counter within the first terminal. When the random number is equal to the count, the first terminal transmits a request to transmit signal to the second terminal. If the second terminal responds with a first acknowledgment, the first terminal then sends an information containing signal to the second terminal. If the information containing signal is correctly received, the second terminal responds by transmitting a second acknowledgment which is received by the first terminal.

Abstract: A self defense missile, for bombers in particular, wherein the slower flying bomber is being overtaken by a faster flying hostile aircraft in the rear quadrant. The self defense missile is an unpowered missile having wings to provide lift, a guidance system to control the direction of flight of the missile, and a homing detection in the tail of the missile to cause the missile to fly into the path of the hostile aircraft. In operation, the self defense missile is launched parallel to the direction of flight of the bomber. As the missile slows down, the wings give it lift to keep it at the appropriate altitude. The homing detector in the tail guides on the approaching hostile aircraft and the guidance system keeps the self defense missile on a collision course.

Abstract: An assembly of fiber optic couplers of substantially identical form in an integrated array comprising two sets of optical fibers arranged side by side across an arcuate surface, epoxied in place, and lapped to develop mating planar surfaces which expose at least partially lapped portions of the respective optical fibers. Preferably, a launch coupler array is provided in which one set of optical fibers is of smaller diameter than those of the other set and is lapped to a depth sufficient to sever the fiber cores. The two lapped faces are then aligned so that one set of severed ends of the smaller fibers is joined with the exposed core portions of the other set of fibers. Selection of fiber size and lapping of the second set of fibers is performed to develop opposed mating portions of individual fibers which are substantially equal in extent and dimensions.

Abstract: A matrix multiplier system incorporating an integrated fiber optic coupling array in combination with an arrangement for individually modulating the signals on the respective optical fiber transmission lines to develop the matrix multiplication. Each of the individual couplers accomplishes the coupling of an input signal into a bi-directional fiber optic transmission line with high efficiency and unilateral coupling effect. The signal thus coupled into the bi-directional transmission line is reflected back to the coupler output after multiplication by the modulating vector component for the individual coupler element. Because of the fabrication of a large number of identical fiber optic couplers in a compact, integral array and the manner in which the light signals can be modulated, the matrix multiplier system is extremely effective in pattern recognition, signal discrimination, selected signal enhancement, and the like.

Abstract: An optical image scanner utilizing an integral array of fiber optic launch couplers to direct an input light image to a selectively reflective termination and then to an output termination. The selectively reflective termination is sequenced to scan the bidirectional fibers of the launch coupler array to direct, in turn, the light transmitted through the launch coupler to the output. Thus, an input light image, applied in parallel, is scanned to develop a serial output for the respective pixels of the image. In one particular arrangement in accordance with the invention, the selectively reflective termination comprises an array of binary driven Faraday rotators. In an alternative arrangement, the reflective scanner comprises a rotating disc with a single reflective spot positioned near the periphery and facing the terminal ends of the bidirectional fibers of the launch coupler array.

Abstract: A threaded member has an external helical thread 18a presenting a crest 24 of spiral outline whose trailing end is in the form of an abutment 26 for resisting withdrawal from a resiliently deformable workpiece. In a preferred application, the threaded member is a die-cast grub screw S and locates within a hinged plastics furniture fastener F. Advancing the grub screw S by 1/2-turn from its initial position in the fastener F breaks a frangible locating web 28 and allows the abutment 26 to pass an abrupt shoulder 64. This gives a tangible warning to the user that a ridge 12b on the grub screw S is correctly located beneath a head H of an anchor A.

Abstract: A low-loss bidirectional optical coupler is provided by mounting together and joining with epoxy resin two like fiber optic elements in face-to-face relationship along a common plane. Each of the elements is fabricated by affixing a portion of an optical fiber with epoxy resin along the curved surface of a solid support form. After the epoxy securing the fiber to the form is cured and hardened, a planar surface extending partially into and along the fiber is established by lapping and polishing the element to a carefully controlled depth. The techniques employed and the resulting devices permit coupling between pairs of individual fibers joined in the manner described.