Abstract: A locking system for a security door comprises a lock mounted on an inner surface of a door and an operating system located outside of the door. The lock has a bolt movable between locking and unlocking positions and a releasable blocking mechanism controlling and preventing movement of the bolt to its unlocking position. A mechanism for actuating the blocking mechanism is operatively coupled to the operating system. The operating system is independent of and spaced from the lock position to mask the blocking mechanism position.

Abstract: A low cost, low power consumption pager of approximate credit card size which can serve as both a pager and a credit card or telephone calling card. The pager is powered by a flat, flexible battery, and is comprised of low power consumption pager circuitry. The circuit is turned on and off at regular intervals to converse energy. The pager holder is altered to incoming messages by a combination of audio and visual signals. The pager can be activated or deactivated by itself or in concert with other pager devices by a single cell. The pager includes a magnetic strip, or the like, for encoding identification and security data and for performing account verification. The audio circuit on the pager can emit audio signals of varying pitch and amplitude, each combination representing a distinct class of messages. Each pager can emit a unique sound distinguishing that pager from all others in a group.

Abstract: Real time synchronization of radio signal data is achieved by a feedback loop between a clearinghouse generating data and a radio station transmitting data. Transmission time is adjusted in response to detected timing errors by selectively inserting padding data between certain data packets to shift data packet position within a data stream transmitted at a predetermined transmission rate. Data flow control is achieved by use of variable length flags delimiting data packets whereby longer flags result in less data flow and shorter flags result in greater data flow.

Abstract: A method and apparatus of this invention changes a frequency at which a control circuit (signal processing circuit) operates in accordance with an operational load of a circuit. More specifically, a pager comprises a signal processing circuit for detecting a first signal sequence within received signals by comparing the received signals with codes originated in the pager and for identifying a second signal sequence received in association with the first signal sequence within the received signals, the signal processing circuit being supplied with a first clock signal having a first frequency when the signal processing circuit detects the first signal sequence and being supplied with a second clock signal having a second frequency when the signal processing circuit identifies the second signal sequence. Still, the frequency applied to the signal processing circuit may be changed in accordance with the operational load of the circuit.

Abstract: A paging system where messages are numbered before they are transmitted. The paging receivers in the system compare both the number and the text information in each message which is received to the message number and the text information in the most recently received previous message. The comparison is used to determine if the same message was previously received and if the any messages were missed. The receiver includes an icon which is turned on to indicate if a message has been received. The icon is set to a blinking state if a message is received and if there is a break is the sequence of message numbers indicating that a message has been missed.

Abstract: A audio system may be monitored and controlled from one of many remote locations. The audio sources are located at a central location, however, the signals monitored at a remote location may originate from the same or a different source as the signal being monitored at the central location or any other location. The sources are selected and routed to speakers by at least two independent selectors, and the volume is controlled by associated volume controllers, either in the speakers or at the central location. Control of the system is simplified through the use of one or more radio frequency remote controls. Commands issued to the system from a remote control are verified by a verification signal added to the output signal on the appropriate output channels. To alleviate confusion, remote controls retain exclusive control over the source and output they most recently controlled.

Abstract: A communication receiver (12) comprises a receiver (54) for receiving selective call signals including messages and further for receiving a receiver operating instruction, a control (82) for controlling a receiver function, a memory (67) for storing the received receiver operating instruction describing the operation of the receiver function being controlled, a retrieval circuit (58) for recalling the stored receiver operating instruction, and a display (84) for presenting the received messages, and further for presenting the recalled operating instruction. The memory (67) can also store information enabling the controllable receiver function, and both the enabling information and the receiver operating instruction can be reprogrammed to reconfigure the operation of the communication receiver.

Abstract: A terminal unit of a mobile communication system of the type using a vibrating device for alerting the user of the terminal unit to an incoming call by vibration. The terminal unit has a flat belt clip which is the single member of the terminal unit positioned closest to the user's body when the unit is put on the user's body. A piezoelectric element or similar vibration source included in the vibrating device is securely received in a recess which is formed in the body of the belt clip.

Abstract: Interconnecting network for simultaneous selective connecting of each of N inputs to one of N outputs has an input section which includes the inputs and contains at least the consecutive stages 1 to n-1 of a n-stage baseline network and has N outputs, and an output section which has N inputs which are connected to the N outputs of the input section, includes a n-stage baseline network and has N outputs which form the outputs of the interconnecting network. The order of the n-1 stages following the inputs is the same in both baseline networks.

Abstract: A broadband space tree-switch matrix establishes a desired switching path by sensitizing only the sequence of logic gates defined by the desired path such that only these sensitized logic gates are operable to undergo switching and thereby permit transmission of only the corresponding input signal. The tree-switch includes a plurality of cascaded stages wherein the first stage consists of dual-input NAND gates each receiving a corresponding input signal at one input and a control signal at another input. The remaining stages include a plurality of switching nodes each having a first NAND gate cascaded to a second NAND gate wherein the second NAND gate has a HIGH steady-state logic signal present at one of its inputs. An appropriate combination of control signals are applied to the NAND gates in the first stage to effect a selected switching path. A second broadband space switch matrix comprises a plurality of NAND gates arranged into a series of cascaded stages to form a tree-switch configuration.

Abstract: A multiple transmitter wide area communication system comprises a central station having a plurality of acknowledge back receivers, each receiving acknowledge back responses on one of a plurality of acknowledge back channels, and a plurality of transmitters each transmitting on an individual channel. The system further comprises a plurality of remote stations each having an acknowledge back receiver which is capable of selectably receiving acknowledge back responses on each of the individual channels, and a transmitter which is capable of selectably transmitting on each of the individual channels. Each central station transmitter substantially simultaneously transmits at a high data bit rate on each individual channel the addresses for acknowledge back pagers for which messages are intended, and further transmits at a high data bit rate the associated messages intended only for those acknowledge back pagers which responded with an acknowledge back response.

Abstract: A paging receiver is provided which digitizes and stores received analog voice messages. The stored voice message may be retrieved by using a first switch for a normal playback mode, or by using a second switch for a fast forward and fast reverse playback mode. The fast forward and fast reverse playback modes are achieved by sequentially retrieving every N(th) message bit stored in memory.

Abstract: A paging terminal for transmitting address and variable length message signals to a plurality of remotely located acknowledge back and non-acknowledge back pagers, each having a unique address, includes an input for accepting variable length messages to be sent to a group of M pagers within the plurality of pagers, wherein M is an integer number. A controller orders the acknowledge back pager addresses for transmisison prior to the transmission of addresses for the non-acknowledge back pagers. A transmitter sequentially transmits the ordered addresses corresponding to the group of M pagers as an address batch during a first time period, and sequentially transmits the variable length messages for the group of pagers in a message batch including end of message markers delimiting an associated variable length message during a second time period subsequent to the first time period.

Abstract: A pager has a TV receiver for receiving a TV radio wave which causes the display to display a TV image. The pager has a color designation circuit for designating a display color of a message. The color designation circuit designates the display color of the message in accordance with a predetermined method for emphasizing the message. The display then displays the message in the designated color.

Abstract: A keyless entry system for operating a vehicular door lock device between a first door locking position and a second door unlocking position. The system has an electrically drivable actuator associated with the vehicular device for operating the latter between the first and second positions, a radio signal transmitter of a size equivalent to a credit-card, and being triggerrable by a trigger command and generating a radio code signal containing a preset identification code, the radio signal transmitter having a first antenna.

Abstract: An interface and protocol for linking devices (18) with a control unit (10). The interface includes a dedicated request line (30) per device, a dot-ORed acknowledge line (32), at least one clock line (38) transmitting sets of N clock pulses from the control unit to a device during each data exchange, two data line (34, 36) for serial duplex data transmission and a pair of shift registers one being positioned in the control unit and another being positioned in each of the devices. The protocol is such that for either a read or a write operation the control unit issues two request signals in spaced relationship on the request line and the selected device responds with two acknowledge signals is spaced relationship on the acknowledge line with each one of the acknowledge signals falling after the fall of its associated request signal.

Abstract: A data communication system includes an external unit, such as a card reader/writer, with the ability of reading and writing data for a recording medium. The recording medium, such as an IC card, transacts signals with the external unit by being coupled electromagnetically in non-contact fashion with the external unit and is supplied power from the external unit. The external unit includes a first data processor, a first electromagnetic transducing coil for the electromagnetic coupling with the medium, a carrier wave generator connected to the first coil for generating a carrier for transmitting a signal to the recording medium, and a received signal discriminator. The recording medium includes a second data processor, a second electromagnetic transducing coil for the electromagnetic coupling with the external unit, a switching circuit connected to the second coil for varying the load impedance of the second coil in response to a signal to be sent to the first coil, and a received signal detecting circuit.

Abstract: A switching matrix network provide switching of digital signals of different sampling frequencies by sampling the digital signals at a sampling frequency greater than any digital input signal and generating an interference signal as a measure of the phase difference or the frequency difference between the sampling frequency and the digital input signal using an input intermediate memory chain. The interference signals are transmitted in coded form through the switching matrix during sampling periods not occupied by data. The original input signal is regenerated at the output of the switching matrix from the interference signal using an output intermediate memory chain and clock regenerating circuits.

Abstract: A transponder system including a transponder and an interrogator having a transmission coil for producing a high-intensity electromagnetic field for inductively powering the transponder and two receiver coils for receiving a low-intensity electromagnetic field reradiated by the transponder. The transmission coil includes one or more conductive windings circumscribing a substantially polygonal volume of space. The receiver coils are diametrically disposed opposite one another within the volume space of the transmitter and are electrically connected to each other in a differential circuit relationship, the output of which is at a minimum when the two receiver coils receive approximately equal quantities of energy and is at a maximum when one of the receiver coils receives more electromagnetic energy from the transponder than the other receiver coil. The transponder uses a coil to derive both a power source and a clock pulse from the high-intensity field for powering and driving an identification circuit.

Abstract: A portable receiver has a time of day clock and receives a signal indicative of the location of the portable receiver. The portable receiver has a memory which has a plurality of locations with corresponding time zones. Upon reception of the location signal, the receiver determines the time zone of the location and the time zone of the time of day clock. The time of day clock is then adjusted to correspond to the time zone of the location. The location signal may also be used to adjust the operating frequency of the receiver.