Patents Assigned to American Telephone and Telegraph Company AT&T Bell Laboratories
  • Patent number: 4894689
    Abstract: A transferred electron device is described in which the charge of the drifting packets is imaged perpendicular to the charge-packet direction so that essentially all of the packet-averaged, space-charge field is normal to the drift direction. This permits continuous formation of contiguous charge packets.
    Type: Grant
    Filed: December 28, 1984
    Date of Patent: January 16, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: James A. Cooper, Jr., Karvel K. Thornber
  • Patent number: 4894824
    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.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: January 16, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Jayant G. Hemmady, Michael J. Knudsen, Robert K. Nichols, Gaylord W. Richards, Gary A. Roediger
  • Patent number: 4894583
    Abstract: Certain yttrium orthosillicate phosphors doped with various rare-earths are particularly suitable for use in various display devices including cathode ray tubes. Included are single crystal phosphors which exhibit high brightness and long life under high energy excitation and conventional powder phosphors with great sensitivity.
    Type: Grant
    Filed: September 2, 1988
    Date of Patent: January 16, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: George W. Berkstresser, Charles D. Brandle, Jr., Joseph Shmulovich, Alejandro J. Valentino
  • Patent number: 4893336
    Abstract: An improved call forwarding arrangement where forwarded calls receive different terminating treatment from non-forwarded calls, for example providing a readily detectable, distinctive alerting signal for forwarded calls or completing only forwarded calls to a station and denying or forwarding other calls without requiring any customer involvement. The arrangement provides an improved call forwarding service for customers with advanced station display capabilities and, in addition, allows selective answering of only forwarded calls by customers that have conventional, analog station equipment. Both switch-based and station-based implements are disclosed.
    Type: Grant
    Filed: December 17, 1987
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Mark S. Wuthnow
  • Patent number: 4892374
    Abstract: A method for aligning an opto-electronic device such as a semiconductor laser to a waveguide on a substrate is disclosed. The method comprises placing the device onto the substrate such that it is in rough alignment with the waveguide, optically pumping the device such that the device emits electromagnetic radiation, with some of the emitted radiation being coupled into the waveguide and detected by appropriate means. If indicated by the detector signal, the position of the device is then adjusted until the desired degree of coupling is attained, whereupon the device is mechanically secured to the substrate and appropriate electrical connections made between device and substrate. Devices useful in the practice of the method typically comprise a window in their top metallization layer.
    Type: Grant
    Filed: March 3, 1988
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: David A. Ackerman, Louis A. Koszi
  • Patent number: 4893071
    Abstract: A capacitance based, high resolution, incrementally encoding, position measuring system employs an array of identical replicated electrodes that are driven in unison from an RF source and mounted in proximity to a patterned monolithic reference ground plane of arbitrary size. Motion of such position-sensing arrays is monitored by measuring both the sums and the differences of the electrode displacement currents in such a way as to provide incrementally encoding position signals in both one and two dimensions together with a continuous measurement of the height of the sensor array above the patterned ground plane. In various modifications, the system and methods are applied both to one dimensional linear, as well as to two dimensional planar and two dimensional cylindrical motion measurement and control. Various techniques for eliminating the effects of spurious capacitances are also disclosed.
    Type: Grant
    Filed: May 24, 1988
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Gabriel L. Miller
  • Patent number: 4892617
    Abstract: Extremely useful compositions for delineation of materials utilized in device applications have been found. These compositions include a polymer having segments that are at least 10 monomer units long of a first entity and segments again at least 10 monomer units long of a second entity. The monomer units are chosen so that each segment type provides a specific chemical characteristic to the polymer.
    Type: Grant
    Filed: October 19, 1987
    Date of Patent: January 9, 1990
    Assignee: American Telephone & Telegraph Company, AT&T Bell Laboratories
    Inventors: Frank S. Bates, Mark A. Hartney, Anthony E. Novembre
  • Patent number: 4892635
    Abstract: Reactive ion etching of the planarizing layer of a multilevel resist structure utilized to make integrated-circuit devices is carried out employing a plasma derived from carbon dioxide. The etching step is characterized by high throughput, good linewidth control, negligible radiation damage and low sensitivity to process parameter variations.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventor: Avinoam Kornblit
  • Patent number: 4893270
    Abstract: A medical information system (1) for use in a hospital environment. The system comprises clinic and department computer terminals (1000) of the hospital interconnected with a message network (19). A computer terminal (10010, 10011, 10022) is arranged to enter record and medical data into the system. The record and medical data is formatted (10017, 10018) into a data message and transmitted over the message network to each of the other computer terminals. Each computer terminal modifies (10015, 10017, 10018) the received record and medical data in accordance with clinic and departmental station requirements file data (10015) assigned the receiving computer terminal and records (10011, 10018, 10022) the modified record and medical data in forms files and medical data dictionary data bases (100112, 100222).
    Type: Grant
    Filed: May 12, 1986
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Roger P. Beck, Daniel L. Castagno, Robert B. Craig, Jr., Timothy S. Davidheiser, Allen W. Haley, Jr., Stanley M. Huff, Russell P. Radigan
  • Patent number: 4893302
    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.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Jayant G. Hemmady, Michael J. Knudsen, William P. Lidinsky, Robert K. Nichols, Gaylord W. Richards, Gary A. Roediger, Scott B. Steele, Ronald C. Weddige, Bruce R. Zelle
  • Patent number: 4893330
    Abstract: A method and an apparatus are disclosed to enable a public switching network to limit the geographical calling area of calls charged to a credit card. When a credit card call is originated, the called party number is included as part of the credit card validation request. The called party number is compared against numbers stored in a call restriction table previously entered by the owner of the credit card. The network accepts or denies credit card calls as a result of this comparison.
    Type: Grant
    Filed: June 1, 1989
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Victor A. Franco
  • Patent number: 4892795
    Abstract: A process of making a lithium cell with a positive electrode that comprises a niobium chalcogenide (e.g., NbSe.sub.3) active material. The process comprises forming the active material by a procedure that comprises forming a layer of Nb powder on an inert substrate (e.g., an alumina plate), and reacting the powder with selenium or sulfur vapor such that the desired (fibrous) chalcogenide is formed. The powder layer typically is formed by depositing (e.g., by spraying) a layer of slurry on the substrate, with the slurry comprising a liquid such as propylene glycol and Nb powder, and removing the liquid from the deposited slurry. The resulting layer of Nb powder can be of uniform thickness, advantageously is less than 0.1 mm thick, and adheres relatively well to the substrate. In preferred embodiments reacting the Nb powder with Se vapor comprises a two-stage heat treatment, the first stage comprising maintaining the powder in contact with Se vapor for at least four hours at a temperature in the range 520.
    Type: Grant
    Filed: September 14, 1988
    Date of Patent: January 9, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wei-Chou Fang, Brijesh Vyas
  • Patent number: 4891480
    Abstract: An electrical device is provided which has contacts having regions with a conductive matte-finish metal surface. The matte-finish surface is characterized by having a Knoop hardness number of at least 300, a diffuse reflectance of less than about 20 percent, and a specular reflectance of less than about 2 percent. These contacts have a contact resistance of less than about 50 milliohms, under a 50-gram load, even after exposure to 50.degree. C. and 95% relative humidity for a period of 20 days. Reflection electron microscopy shows that particularly advantageous matte-finish surfaces have sharply peaked asperities with average peak angles of less than about 90 degrees. In one embodiment, the surface is formed of hardened nickel electroplated from an electrolytic bath with a pH above about 7.0.
    Type: Grant
    Filed: February 1, 1989
    Date of Patent: January 2, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Clarence A. Holden, Jr., Henry H. Law
  • Patent number: 4891840
    Abstract: A system for communicating a wide band signal across a plurlaity of narrow band channels by separating the wide band signal into two or more narrower sub-bands and modulating the developed narrower sub-bands down to baseband. The baseband channels are algebraically combined to form unique combination signals, and the combination signals are transmitted over the narrowband channels. On the receiving end, the combination signals are algebraically combined to recreate the original baseband channels. The channels are modulated up to their original frequency bands, and arithmetically combined to recreate the desired broadband signal.
    Type: Grant
    Filed: March 10, 1986
    Date of Patent: January 2, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Douglas O. Reudink
  • Patent number: 4891746
    Abstract: A power inverter efficiency is optimized at high frequency in a fully resonant inverter operating with a range of load impedance that takes into consideration switching loss and conducting loss as a combined overall effect. Within this range of load impedance the inverter is constrained to operate with switching loss which is generally considered unacceptable in a conventional high frequency high efficiency power inverter, but the overall combined high efficiency of the disclosed power inverter has a wider range of load impedances than has been previously achieved in such a resonant power inverter. Non-linear capacitance across switching the device is positively utilized in achieving this goal.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: January 2, 1990
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wayne C. Bowman, William A. Nitz, Norman G. Ziesse
  • Patent number: 4889402
    Abstract: A rib waveguide polarization modulator is described that permits easy application to monolithic optical circuits. The device comprises a rib waveguide having two polarization modulation sections with a phasing section between the two modulation section. The phasing section adjusts the phase of the optical radiation in the waveguide before it enters the second modulation section.
    Type: Grant
    Filed: April 21, 1989
    Date of Patent: December 26, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Franz K. Reinhart
  • Patent number: 4888624
    Abstract: High resistivity In-based compound Group III-V epitaxial layers are used to prevent substantial current flow through a region of a semiconductor device, such as a CSBH, DCPBH, EMBH or CMBH laser, a LED, a photodiode, a HBT, or a FET. Also described is a hydride VPE process for making the high resistivity material doped with Fe. The Fe is supplied by a volatile halogenated Fe compound, and the extend of pyrolysis of the hydride is limited to allow transport of sufficient dopant to the growth area.
    Type: Grant
    Filed: April 20, 1988
    Date of Patent: December 19, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wilbur D. Johnston, Jr., Robert F. Karlicek, Jr., Judith A. Long, Daniel P. Wilt
  • Patent number: 4886765
    Abstract: Silicides are important for submicron VLSIC technology. Problems have been found in forming silicides by known techniques involving simply depositing a metal film and heating that metal to form a silicide layer. This invention solves the problems through recognition that polymeric contamination can be left on the surface from commonly-used previous reactive ion etch steps, and removes any such contamination to metal deposition by the additional step of heating in dry oxygen at a low temperature, such as 800 degrees Centigrade, before the contamination has been significantly hardened.
    Type: Grant
    Filed: October 26, 1988
    Date of Patent: December 12, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Min-Liang Chen, Chung W. Leung, Chih-Yuan Lu, Nun-Sian Tsai
  • Patent number: 4887233
    Abstract: A fast pipeline adder comprising a plurality of registered adder rows. In one embodiment, additions in the pipeline are realized in reclocked half adders. In another embodiment, modified adders are employed which accept two carry inputs and develop two carry outputs. The resulting number of individual cells is reduced to approximately half of those in the prior embodiment. In still another embodiment, switch means are included in each cell to delete the reclocking and in still another embodiment, the adders in the diagonal of the pipeline adder are provided with additional inputs to permit use of the pipeline adder in recursive addition applications. In still another embodiment, the cells are permitted to output the inverse of the intended signal, reducing thereby the physical realization of the cells and increasing the speed of the cells.
    Type: Grant
    Filed: March 31, 1986
    Date of Patent: December 12, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Glenn L. Cash, Mehdi Hatamian, Adrianus Ligtenberg
  • Patent number: 4887135
    Abstract: A self-aligned one transistor-capacitor memory cell is provided which uses an n-channel MOS transistor having separate drain and source regions with a first level polysilicon conductor coupled to the top plate of the capacitor and separate second level polysilicon conductors coupled to the gate and drain of the transistor. A reduction in a dimension of the memory cell is acheived compared to a similar memory cell which uses only one level of conductors.
    Type: Grant
    Filed: January 24, 1985
    Date of Patent: December 12, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Glen T. Cheney, Howard C. Kirsch, James T. Nelson, James H. Stefany