Patents Assigned to American Telephone and Telegraph Company
  • Patent number: 5032803
    Abstract: This disclosure describes a double-sided transmission substrate formed with striplines and end-ports in juxtaposition on either side. The transmission substrate is sandwiched between two exterior dielectric substrates, each coated on one side with a metallic layer. The three substrates are laminated together. Through-holes are drilled into the lamination and its interior substrate, at known locations to intersect the said ports. The copper exteriors of each board are etched to identify two contact pad lands on each side. Plated-thru holes are created to connect to each of the ports.
    Type: Grant
    Filed: February 2, 1990
    Date of Patent: July 16, 1991
    Assignee: American Telephone & Telegraph Company
    Inventor: Michael J. Koch
  • Patent number: 4953159
    Abstract: An audiographics conferencing arrangement for use in a business communication system allows the conferees to exchange displayed text and/or graphics stored locally in their respective data terminals. The conferees may change the displayed text and/or graphics and such changes are automatically distributed to the other data terminals so that all of the conferees view the same information. Moreover, a data terminal and its associated telephone station set may be included in an audiographics conference connection even though they are not directly served by the business communication system. In addition, one of the conferees may establish concurrent with the original audiographics conference connection a second audiographics conference connection with one or more other data terminals and transfer information obtained from one conference connection to the other conference connection.
    Type: Grant
    Filed: January 3, 1989
    Date of Patent: August 28, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: Charles C. Hayden, Frederick A. Schmidt, Mark D. Studebaker
  • Patent number: 4952226
    Abstract: A laser (20) directs a laser beam at an optical fiber (12) and the resulting forward-scattered light is detected by a detector (21). The energy of the foward-scattered laser light is monotonically inversely proportional to the thickness of a carbon coating on the optical fiber. A computer (22) generates an electrical signal for controlling carbon coating thickness by driving a valve (24) to control the flow of acetylene from a source (14) used to coat the optical fiber in a coating chamber (13).
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: August 28, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: Ralph E. Frazee, Jr., David H. Smithgall, Sr.
  • Patent number: 4953157
    Abstract: In a packet network, each data packet that is transported through the network to a destination node is assigned one of 2**N priority levels based on the type of information contained in the data packet. A data packet containing system control information is assigned the highest priority level. A data packet containing, for example, user information, is assigned a lower priority level. In addition, each priority level is associated with a respective "watermark" threshold. When a data packet arrives at a network node, the node compares the packet's associated watermark threshold with the number of data words currently stored in a common memory. The node rejects the packet if the watermark threshold is found to be less than that number to reserve space in the memory for data packets of higher priority. Otherwise, the data packet is stored in the common memory.
    Type: Grant
    Filed: April 19, 1989
    Date of Patent: August 28, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: Andrew D. Franklin, Robert J. Gallegos
  • Patent number: 4947980
    Abstract: In a facility for conveying PWBs in a path of travel, two stop/clamp devices are magnetically clamped along the path to be spaced in its length and to be within the path width occupied by the traveling board. Each of the devices has stop and clamp elements shiftable as a unit between out positions at which they are disposed in the path and in positions at which they and the rest of their device do not interfere with the travel in the path of the boards. When in the out position, the leading device is adapted to stop the travel of such a board, and both devices are then selectively operable to grip and then release the stopped board. Sensors on the leading device are used to detect the presence of a board near to and at such device. A computer is responsive to such sensors and is used to produce a desired sequence of operations of such two devices and of other units.
    Type: Grant
    Filed: March 2, 1989
    Date of Patent: August 14, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Christopher M. Helmstetter
  • Patent number: 4947134
    Abstract: A single frequency lightwave system employs semiconductor, optical amplifiers arranged in tandem with suitable nose filtering and isolation between amplifier stages. Feedback control maintains overlap between the signal frequency and one of the passbands of the amplifiers. Either direct detection or coherent detection can be used. Also described is a receiver front end which includes such an amplifier between the incoming signal and a photodetector. Both transmission systems and switching systems are described.
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: August 7, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Nils A. Olsson
  • Patent number: 4942574
    Abstract: A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module. The data switching modules chain groups of incoming packets destined for a common outlet of the space division switch so that only one connection in that switch is required for transmitting each group of chained packets from a data switching module to a concentrator.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: July 17, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Bruce R. Zelle
  • Patent number: 4942442
    Abstract: Radiation-induced effects discovered in layered structures of conductor and semiconductor materials are utilized in radiation-sensitive devices such as, e.g., highly linear as well as highly nonlinear position sensors. Such devices includes a structure of alternating layers of conductor and semiconductor materials, and electrical contacts are provided between which a radiation-induced voltage appears. Among suitable layer materials are silicon and titanium, and resulting devices are sensitive to electromagnetic as well as to particle radiation.
    Type: Grant
    Filed: April 27, 1989
    Date of Patent: July 17, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Clyde G. Bethea, Daniel Brasen, Barry F. Levine, Ronald H. Willens
  • Patent number: 4941738
    Abstract: A polarization independent semiconductor amplifier is used in a double-pass configuration; that is, the output of the amplifier is passed through a 45.degree. Faraday rotator to a mirror and then through the rotator and the amplifier again. Polarization independent gain is thus achieved.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: July 17, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Nils A. Olsson
  • Patent number: 4941905
    Abstract: An optical preform is prepared first by depositing soot about a glass subate rod (22) to form a boule. Then the soot boule is sintered to consolidate the material and provide a preform from which optical fiber is drawn. The boule is relatively large so that the resulting preform is capable of providing more optical fiber than those used in the past. In order to be able to sinter successfully the enlarged boule, microwave energy from a furnace (60) is coupled to the glass rod so that the sintering proceeds from the rod radially outwardly thereby allowing gases readily to escape and rendering the process highly efficient.
    Type: Grant
    Filed: March 4, 1988
    Date of Patent: July 17, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Technologies, Inc.
    Inventor: Pundi L. Narasimham
  • Patent number: 4940381
    Abstract: A mobile hoist for loading and unloading heavy objects onto and from shelves in space limited quarters includes a hydraulic cylinder piston combination for elevating and lowering the objects utilizing a platform or a boom which may be attached to the piston. The piston moves up and down in response to a flow of hydraulic fluid to and from the hydraulic cylinder. The flow of the hydraulic fluid is controlled by a metering valve which is opened and closed by a cam driven arrangement designed to ensure that the fluid flow through the metering valve is nonlinear enabling soft, no shock stops regardless of the weight of the objects being elevated or lowered. The boom includes a sling lock mechanism which allows for placement of objects in locations with limited clearances.
    Type: Grant
    Filed: August 26, 1988
    Date of Patent: July 10, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Ambrose L. Rysewyk
  • Patent number: 4939102
    Abstract: 36 We have discovered the III-V semiconductor layers with previously unattainably high effective hole concentrations can be produced by molecular growth processes (e.g. MBE) if an amphoteric dopant such as Be is used and if, during the growth of the highly doped III-V layer, the substrate is maintained at a temperature T.sub.g that is substantially lower than customarily used. For instance, a InGaAs layer with effective hole concentration 1.0.times.10.sup.20 cm.sup.-3 was grown at T.sub.g =450.degree. C., and a GaAs layer with effective hole concentration of 1.0.times.10.sup.20 cm.sup.-3 was grown at T.sub.g of 475.degree. C. The heavily doped III-V layers can be of device grade and can usefully be part of electronic devices such as high speed bipolar transistors.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: July 3, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: Robert A. Hamm, Roger J. Malik, Morton B. Panish, John F. Walker
  • Patent number: 4938847
    Abstract: Disclosed is a method of semiconductor device fabrication involving the detection of water in a dielectric layer that is part of the body of such device. At relatively high values of a voltage applied across the dielectric layer, water that is present in the dielectric decomposes and releases protons. Varying the applied voltage gives rise to a displacement current. The released protons contribute an ionic component to the displacement current. The ionic component is detected.
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: July 3, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: John M. Andrews, Jr., Nadia Lifshitz, Gerald Smolinsky
  • Patent number: 4937872
    Abstract: Apparatus that solves the problem of pattern recognition in a temporal signal that is subject to distortions and time warp. The arrangement embodying the invention comprises a neural network, an input interconnection network, and a plurality of signal modification circuits. A plurality of input leads delivers a preselected characteristic stimulus to associated signal modification units, and in response to an applied stimulus, each signal modification unit develops a plurality of output signals that begins at the time of stimulus application, rises to a peak, and decays thereafter. The mean time delay of each output (time to reach the peak) is different for each of the modification unit output signals. The outputs of the signal modification units are applied to the input interconnection unit wherein connections are made in accordance with the sequences that are to be recognized.
    Type: Grant
    Filed: July 24, 1989
    Date of Patent: June 26, 1990
    Assignee: American Telephone and Telegraph Company
    Inventors: John J. Hopfield, David W. Tank
  • Patent number: 4937814
    Abstract: The invention relates to a switching module for asynchronous time multiplex comprising at least one junction switch for transmitting packet-switched information from one bus (14) to another bus (16). The junction switch comprises a translation memory (9) for translating packet addresses into new addresses, a comparator (10) for selecting the packets that are to be routed to another bus, a queue memory (12) for storing selected packets until an insertion circuit places the selected packets into the queue memory (12) on the other bus (16). With the aid of a such junction switch, a flexible network structure can be realized, the traffic of packets on the different buses can be mutually asynchronous and virtual circuits can be realized with the aid of the translation memory (9).
    Type: Grant
    Filed: April 21, 1989
    Date of Patent: June 26, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Eric Weldink
  • Patent number: 4937817
    Abstract: A packet distribution network including a distributed arrangement for selecting packets based on the availability or unavailability of packet destinations is disclosed. A plurality of input units receive and store packets before distribution. Each input unit also receives a sequence of addresses representing packet destinations and a sequence of usage indicators each describing the availability or unavailability of an associated one of the destination addresses. The sequence of addresses and the associated usage indicators are provided to the input units such that the address of each packet destination is contemporaneously received by only one input unit. Each input unit selects a stored packet based on the received destination addresses and associated usage indicators and marks previously available destinations unavailable to other input units by modifying the usage indicator associated with a packet destination for which a packet is selected.
    Type: Grant
    Filed: December 29, 1988
    Date of Patent: June 26, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Sheng L. Lin
  • Patent number: D308965
    Type: Grant
    Filed: September 2, 1987
    Date of Patent: July 3, 1990
    Assignee: American Telephone and Telegraph Company
    Inventor: Dale C. Bina
  • Patent number: RE33266
    Abstract: A folded bit line configured DRAM, with standard even and odd rows of memory cells, also includes spare even and odd rows of memory cells which can be substituted for standard rows found to have defective cells or interconnections. Each of the decoders associated with a standard row includes provision for being disconnected if found to be associated with a defective row. One common spare decoder is associated with one spare even and one spare odd row of memory cells. Each spare decoder is designed normally to be deselected for any address but to be able to assume the address of any disconnected standard row. Disconnection of a standard decoder and substitution of a spare decoder with the appropriate even or odd row are made possible by appropriate inclusion of fusible links which are selectively opened by laser irradiation. The use of one spare decoder with both an even and odd row serves to reduce the number of needed spare decoders and thus reduces overall chip size.
    Type: Grant
    Filed: January 15, 1987
    Date of Patent: July 17, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Austin C. Dumbri
  • Patent number: H842
    Abstract: A technique for providing high current carrying metal conductors for coupling to transistors or the like to increase the current carrying capacity of the transistor without substantial increase in size. The conductors are tapered along the axis of current flow with current being conducted to or from the tapered portion of the conductors, such that the current density therein is substantially constant.
    Type: Grant
    Filed: June 30, 1989
    Date of Patent: November 6, 1990
    Assignee: American Telephone And Telegraph Company
    Inventor: Christopher D. Ochs
  • Patent number: H965
    Abstract: Differential amplifier having multiple stages, each stage having the gain thereof set by digital control. The gain of each stage is individually controlled, thereby allowing wide dynamic range and gain. Each stage has a differential pair with multiple sets of gain-setting resistors in the emitters of the pair. By selecting which resistor set, or combination of resistor sets, is used, the gain of the stage is controlled. The result is a 4 stage, 0-45 dB gain amplifier for RF or IF applications, with the gain adjustable in 3 dB increments.
    Type: Grant
    Filed: January 26, 1990
    Date of Patent: September 3, 1991
    Assignee: American Telephone and Telegraph Company
    Inventors: Paul C. Davis, Scott L. Forgues, Iconomos A. Koullias