Patents Assigned to American Telephone and Telegraph Company AT&T Bell Laboratories
  • Patent number: 4820376
    Abstract: Disclosed is a method of fabricating conductive polymer interconnect (CPI) material which employs chains of electrically conductive particles within an elastomeric matrix. Contact resistance is improved by removing a thin layer is elastomeric material which remains after normal processing. The surface layer is removed by plasma etching so that the conductive particles protrude at both surfaces. The protruding particles can be plated to replace any conductive material removed by the etch.
    Type: Grant
    Filed: November 5, 1987
    Date of Patent: April 11, 1989
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventors: William R. Lambert, Neng-Hsing Lu, Ray D. Rust
  • Patent number: 4819658
    Abstract: A method and apparatus for measuring the temperature profile of a surface exhibiting spatial and/or temporal variations in temperature, e.g., the surface of a machine or of a biological system, is disclosed. The inventive method involves forming a layer of fluorescent material, less than about 10 .mu.m in thickness, in thermal contact with the surface. The fluorescent material is subjected to fluorescence-inducing energy, and the resulting fluorescence, which varies as the temperature of the surface varies, is detected.
    Type: Grant
    Filed: June 30, 1987
    Date of Patent: April 11, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Paul R. Kolodner
  • Patent number: 4820007
    Abstract: A closure (20) for optical fiber cables each including at least one optical fiber (38) and a metallic shield (47) enclosed in a jacket (48) includes a splice tray (22), a bonding and gripping assembly (26) and mating cover portions (27, 29). The splice tray includes provisions (24) on one side thereof for holding an optical fiber splice such as one which may be made by a rotary splice and a raceway (51) for routing the optical fiber to the splice. Metallic conductors (45--45), if included in the cables, may be spliced on an opposite side of the splice tray. The bonding and gripping assembly is attached to the splice tray and includes opposed projecting portions (78--78) and ferrules (71--71). Each cable to be spliced is routed to the bonding and gripping assembly to cause each projecting portion to be inserted into a cable end between the shield and core thereof to establish an electrical connection with the shield and to cooperate with the associated ferrule to grip the cable end portion.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: April 11, 1989
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventors: Robert R. Ross, Ilona Vedejs
  • Patent number: 4818929
    Abstract: A novel fully differential analog comparator having cascaded gain stages powered by two buses. The two buses are powered by a current source and a variable gain current mirror responsive to the current source. The current source and the current mirror isolate the buses from external power and ground to achieve high power supply noise immunity. True and complementary outputs of the comparator are provided having an adjustable output common mode voltage to optimize the driving of subsequent logic gates responsive to the comparator.
    Type: Grant
    Filed: July 1, 1988
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Jeffrey L. Sonntag, Thayamkulangara R. Viswanathan, William B. Wilson
  • Patent number: 4818058
    Abstract: Disclosed is a connector for optical fibers and components, and a method of manufacture, which provides close alignment. Each fiber is disposed within a plug comprising two blocks placed with their major surfaces in contact. Each block has an array of grooves formed in a major surface for accommodating the fibers. A pair of deeper grooves is also formed in each major surface at opposite edges of each block and at the same time as the array of grooves to form beveled edge surfaces. Guiding rods are disposed against the beveled surfaces so that the rods are rectilinear with the fibers.
    Type: Grant
    Filed: March 3, 1988
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventor: Rocco Bonanni
  • Patent number: 4818713
    Abstract: Submicron resolution in the fabrication of transistors is obtained by using sidewall techniques. The techniques described remove the sidewalls after oxidizing the materials between the sidewalls and the openings so formed by the removal are used as a mask for subsequent substrate modification by either diffusion or ion implantation.
    Type: Grant
    Filed: October 20, 1987
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Anatoly Feygenson
  • Patent number: 4818824
    Abstract: Splices between conductors in of an aerial telephone cable are covered by a closure located within a terminal. The closure has a large central section connected via tapered joints to two end sections. A settable liquid encapsulant is received in the central section. The closure has two halves joined by a flexible hinge that runs lengthwise along a first longitudinal edge. Two rigid tabs of nonuniform thickness running lengthwise along a second longitudinal edge are secured by snaps through apertures in the tabs. The snaps have tapered sections that clamp the varying thickness rigid tabs along their lengths to prevent leakage of liquid encapsulant. The end sections have open cell foam strips fitting snugly between the cable and the end section walls which are fixed with the liquid encapsulant. The encapsulant sets within the open cell foam to form a barrier to passage of contaminants into the central section.
    Type: Grant
    Filed: August 19, 1987
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Mayankkumar M. Dixit, Charles Tanzola
  • Patent number: 4818721
    Abstract: Implantation of a Group V ion species (e.g., phosphorus or arsenic) into an In-based Group III-V compound semiconductor (e.g., InP, InGaAs) followed by implantation of Be ions produces a shallow p-type surface layer and avoids significant in-diffusion of the dopant species. High carrier concentrations and activation efficiencies are attained. The technique has application in the fabrication of FETs, APDs and ohmic contacts.
    Type: Grant
    Filed: July 29, 1987
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Kou-Wei Wang
  • Patent number: 4818060
    Abstract: A flame and smoke resistant optical fiber cable (20) having a relatively small diameter includes a core comprising a ribbon array or a plurality of individual fibers and a sheath system. The sheath system includes an impregnated fiber glass tape (35) which has been wrapped about the core. The tape is impregnated with a solution system which comprises a micaceous constituent, a fluoropolymer constituent and a lubricant such as silicone. The impregnated system provides the tape and hence the cable with unexpectedly superior fire retardant and smoke resistance properties so that the cable is suitable for plenum and riser use. Advantageously, the thickness of the tape impregnated with such a system is relatively thin which is helpful in maintaining a relatively small diameter for the cable. An all dielectric strength member system is disposed between the tape and a plastic jacket (37).
    Type: Grant
    Filed: March 31, 1987
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Candido J. Arroyo
  • Patent number: 4818984
    Abstract: A method and apparatus for transmitting messages from one processor to a plurality of other processors in a distributed processing system having no hardware message broadcast facilities. The transmitting processor includes a broadcast program process for controlling the transmission of any messages destined for a plurality of other processors. Different client processes in the transmitting processor request the broadcast process to transmit a broadcast message. The single broadcast process controls the number of individual messages which are sent out sequentially to each of the receiving processors in such a way as to ensure that the broadcast messages do not interfere with other message traffic that frequently has tighter delivery time requirements. The broadcast process transmits the broadcast messages to each of the plurality of recipient processors without waiting for acknowledgment response messages from any of these processors.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Shih-Jeh Chang, Richard T. Emery, Shafik J. Hakim, Jen-Lie Ho, Paul E. Janssen, Carol M. McCullagh
  • Patent number: 4816846
    Abstract: A color printing system employing a large area pattern of controllable light sources, where the pattern includes rows that are aligned substantially with the movement of a print medium in relation to the light sources. All of the light sources in each row contribute to the exposure of each pixel in a corresponding row of the resulting color print. The large area pattern of light sources can be realized with a range of approaches, from the use of a plurality of light sources to the use of a single light source coupled with an appropriate light modulator. In one embodiment, a liquid crystal light modulator was employed for each of the three primary colors.
    Type: Grant
    Filed: December 17, 1987
    Date of Patent: March 28, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Richard V. Kollarits
  • Patent number: 4816421
    Abstract: Disclosed is a technique, termed "mesotaxy", for producing a heteroepitaxial structure comprising a layer of single crystal second material embedded in, and epitaxial with, a single crystal first material matrix. Mesotaxy comprises implantation of at least one chemical species (e.g., Co, Ni, Cr, Y or Mg) into a single crystal body (typically a semiconductor, e.g., Si or Ge) such that a buried layer rich in the implanted species is formed, and heat treating the implanted body such that a buried stoichiometric compound layer (e.g., CoSi.sub.2) is formed. Exemplarily, 3.multidot.10.sup.17 /cm.sup.2 200 keV Co ions are implanted into (100) Si nominally at 350.degree. C., followed by a heat treatment that consists of 1 hour at 600.degree. C. and 30 minutes at 1000.degree. C. The resulting buried CoSi.sub.2 layer is epitaxial with the Si matrix, has high conductivity and is of good crystalline quality. The Si overlayer is of device quality.
    Type: Grant
    Filed: November 24, 1986
    Date of Patent: March 28, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Robert C. Dynes, Kenneth T. Short, Alice E. White
  • Patent number: 4817082
    Abstract: A switching arrangement comprising a crossbar array of crosspoint elements where each column of crosspoint elements, is associated with its own control ring mechanism. The enabling of the individual crosspoint elements of a column and the subsequent transmission of packets are effected rapidly in response to a token, e.g., a single enable bit, that is circulated on the associated control ring. Contention delays between packets are eliminated by passing the token during, rather than after, packet transmission. Upon receipt of a token bit at a crosspoint element, the crosspoint element is enabled while concurrently the token is passed to the next crosspoint element.
    Type: Grant
    Filed: March 9, 1987
    Date of Patent: March 28, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Milo Orsic
  • Patent number: 4817083
    Abstract: A switching network including both space division and time division switching stages where a permanent connection arrangement, interposed between the network input channels and a larger number of internal, time division channels at the input side of the space division stage, provides permanent rather than switched connections between each input channel and multiple internal channels. The pattern of permanent connections to multiple internal channels is designed such that the network is rearrangeable to avoid blocking to connect any idle output channel of the network to any busy or idle input channel.
    Type: Grant
    Filed: March 6, 1987
    Date of Patent: March 28, 1989
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventor: Gaylord W. Richards
  • Patent number: 4814974
    Abstract: A digital system has a resource, such as a communication bus, adapted for access by a plurality of devices, a plurality of devices adapted to access the resource, and an arbitrator for arbitrating access to the resource by the devices. The arbitrator includes a programmable memory comprising a plurality of addressable words and an address generator for cyclically sequentially addressing each of the memory words. Each word stores information defining a priority order of the devices for accessing the resource. In particular, each word is divided into a plurality of segments, and each segment corresponds with a priority level in the order of priority. Each segment holds information identifying the device currently having the corresponding priority level. The priority order is changeable by reprogramming the contents of the memory. The priority order so implemented may be any conceivable order, and in particular may include a constant decreasing priority, a round-robin priority, or a combination of the two.
    Type: Grant
    Filed: March 28, 1986
    Date of Patent: March 21, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: C. Murali Narayanan, Benjamin Zee
  • Patent number: 4814291
    Abstract: Certain devices require a high quality thin (<25 nanometer) dielectric layer formed on a deposited silicon layer. Applications include capacitor dielectrics in dynamic memories and linear devices. In another application, an electrically erasable programmable read only memory (EEPROM) uses an SiO.sub.2 layer between the write gate and the floating gate. The present technique oxidizes amorphous silicon under conditions that suppress grain growth to produce a higher quality oxide than that achieved with conventional furnace oxidation of polysilicon. Rapid thermal oxidation is one method of practicing the technique.
    Type: Grant
    Filed: February 25, 1986
    Date of Patent: March 21, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Sea-Chung Kim, Alvaro Maury, William H. Stinebaugh, Jr.
  • Patent number: 4814962
    Abstract: A DC to DC converter combines a half-bridge inverter with a resonant rectifier through a series LC circuit which conducts power at substantially a single frequency. Energy stored in the parasitic capacitors of the two power switches are transferred from one parasitic capacitor to the other in order to enhance efficiency of operation. The transfer is controlled by controlling the relative phase between the voltage and current in the inverter section.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: March 21, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Frank M. Magalhaes, Roman Ostapiak, Ralph Walk, Norman G. Ziesse
  • Patent number: 4812101
    Abstract: Disclosed is a method and apparatus for continuous introduction and exit of workpieces into and out of a vacuum. A first seal is provided between the atmosphere and a first pumping station. This seal comprises compliant members positioned within cavities in a plate so that the pressure differential causes the members to push against the workpiece and the cavity wall to establish a rotating seal. A second seal may also be provided between the first pumping station and the vacuum chabmer. This seal includes compliant members mounted within a series of differentially pumped cavities and providing a low friction seal with the workpiece.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: March 14, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Carroll H. George, Guy W. Lynott, Andrew N. Pargellis
  • Patent number: RE32893
    Abstract: The invention is a nonlinear or bistable optical device having a low switching energy. The invention uses a means responsive to light for generating a photocurrent, a structure having a semiconductor quantum well region, and means responsive to the photocurrent for electrically controlling an optical absorption of the semiconductor quantum well region. The optical absorption of the semiconductor quantum well region varies in response to variations in the photocurrent. A photodiode or phototransistor may be used as the means responsive to light, and may be made integral with the structure having the semiconductor quantum well region. An array of devices may be fabricated on a single chip for parallel logic processing.
    Type: Grant
    Filed: October 6, 1987
    Date of Patent: March 21, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: David A. B. Miller
  • Patent number: RE32900
    Abstract: A fast circuit switching system that establishes a circuit for each packet-sized data communication. Information is conveyed from a number of communications modules in source channels to a number of port controllers and to a network. Information is conveyed from the network to destination channels. Each communications module includes a transmitter that transmits in an associated source channel, circuit setup request signals defining destination channels and also transmits data. Each port controller stores one of a number of status words defining the availability of the destination channels and each of these status words is cycled to each port controller. A port controller responds to one of the circuit setup request signals and to subsequent data, when one of the status words cycled thereto defines as available, a destination channel defined by the circuit setup request signal, by transmitting the circuit setup request signal and the subsequent data to the network.
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: April 4, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Milo Orsic