Patents Assigned to American Telephone and Telegraph Company
  • Patent number: 5450249
    Abstract: A demodulator circuit receives an input signal read from a track of a magnetic medium and generates a control signal to maintain alignment of a read-write head with the track. The demodulator circuit includes at least one transistor. The at least one transistor has an electrode switchable between first and second voltage sources. The electrode is coupled to the second voltage source to block processing of the input signal. The electrode is coupled to the first voltage source to process the input signal. The at least one transistor provides an effective resistance when coupled to the first voltage source that is dependent on the voltage level of the first voltage source. The at least one transistor half-wave rectifies the input signal when the electrode is coupled to the first voltage source.
    Type: Grant
    Filed: May 19, 1993
    Date of Patent: September 12, 1995
    Assignee: American Telephone and Telegraph Company
    Inventors: Krishnaswamy Nagaraj, Reza S. Shariatdoust
  • Patent number: 5421930
    Abstract: A winding tool (14) is provided on a manipulator (18) of a type used to route the optical fiber. A hook (22) extends from the winding tool to capture optical fiber (10) extending from a device (11), and the hook is retracted to secure the fiber. A routing wheel (17) is positioned between the device (11 ) to which the optical fiber is connected and the reel such that the wheel can press the optical fiber (10) against an adhesive-coated substrate. The winding tool then winds the optical fiber around a reel (16). The optical fiber next feeds from the reel (16) to the routing wheel (17) as the manipulator (18) is moved to route the optical fiber on the coated substrate. Preferably, prior to the winding and wheel positioning step, the optical fiber between the reel and the routing wheel is engaged with an alignment tool (27).
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: June 6, 1995
    Assignee: American Telephone and Telegraph Company
    Inventor: William R. Holland
  • Patent number: 5413884
    Abstract: A technique is disclosed for utilizing direct-write electron-beam photolithography and holographic optical exposure to form gratings in optoelectronic structures. The direct-write e-beam process is used to form rectangular grating teeth in a mask substrate, where the mask is then used as a phase mask to transfer the pattern to the optoelectronic device. Advantageously, the utilization of a direct write e-beam technique to form the grating pattern on the photomask allows for the formation of any desired number and location of abrupt phase shifts, multiple grating pitches, alignment fiducials, and any other desired features. Therefore, a single exposure of the direct write e-beam mask allows for a plurality of different grating patterns to be simultaneously printed.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: May 9, 1995
    Assignee: American Telephone and Telegraph Company
    Inventors: Thomas L. Koch, Frederick W. Ostermayer, Jr., Donald M. Tennant, Jean-Marc Verdiell
  • Patent number: 5361259
    Abstract: A WAN is formed using Frame Relay Protocol and a telephone network interface unit. An originating LAN sends a message to a router which communicates with a telephone network interface unit using Frame Relay Protocol. The telephone network interface unit determines the destination of a packet received from the router by interpreting the Frame Relay Protocol, and it associates a phone number with that destination. The interface unit uses the phone number to establish at least one DSO connection over a digital telephone network to a destination network interface. A destination network interface unit receives the packet from the digital telephone network and provides the packet to a router which interfaces to the destination LAN. The network interface units add or drop additional DSO channels as required by the traffic load and thereby provide variable bandwidth.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: November 1, 1994
    Assignee: American Telephone and Telegraph Company
    Inventors: Steven D. Hunt, Edward W. Landis
  • Patent number: 5230010
    Abstract: Fractional rate modulation is accomplished by separating incoming data into frames of bits. Each frame is partitioned into bit words of unequal lengths. The words are divided by a modulus to obtain remainders. The remainders are transmitted using for example QAM modulation. At the receiving end the process is reversed. The ratio of the baud rate of the system to the incoming bit rate defines the modulus as well as the number of QAM modulation points.
    Type: Grant
    Filed: September 26, 1990
    Date of Patent: July 20, 1993
    Assignee: American Telephone & Telegraph Company
    Inventors: William L. Betts, Gordon F. Bremer
  • Patent number: 5206317
    Abstract: Excellent resolution and sensitivity in the patterning of resists utilized in device and mask manufacture is obtained with a specific composition. In particular this composition involves polymers having recurring pendant acid labile .alpha.-alkoxyalkyl carboxylic acid ester moieties in the presence of an acid generator activated by actinic radiation such as UV-visible, deep ultraviolet, e-beam and x-ray radiation.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: April 27, 1993
    Assignees: E. I. du Pont de Nemours and Company, American Telephone and Telegraph Company
    Inventors: Walter R. Hertler, Dotsevi Y. Sogah, Gary N. Taylor
  • Patent number: 5194105
    Abstract: Apparatus (11) is robotically operated to pick up an optical element such as a ball lens (12) or an optical fiber, place it in a groove or depression (13) of a substrate (14), and apply pressure to it so that it is bonded to the substrate. The tool comprises a retracting element holder (17) surrounding a bonding tool (16). A vacuum channel (18) communicates with the element holder so that, by the application of a vacuum, it can pick up an optical element. The tool then moves the element to place it, for example, in a depression (13) of a substrate, whereupon the vacuum is released, thereby to allow the element to nest between opposing sidewalls of the depression. The retracting holder element is simultaneously retracted vertically upwardly so as to expose a bonding surface of the bonding tool. After the element has nested in the groove, the bonding tool contacts the element and forces it against opposite sidewalls to effect a thermo-compression bond of the optical element with the sidewalls.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: March 16, 1993
    Assignee: American Telephone and Telegraph Company
    Inventor: Hung N. Nguyen
  • Patent number: 5187763
    Abstract: An optical fiber cable (20) includes a core which (22) is filled with a filling material (26) comprising a composition of matter which passes industry wide drip tests, which substantially has no oil separation and which has excellent thermal oxidative stability. The filling composition includes a relatively high molecular weight aliphatic hydrocarbon which may be a polyalphaolefin, for example, or a relatively high molecular weight mineral oil. Also included in the composition of the filling material is a fumed silica, a block copolymer and a relatively high amount of an antioxidant system. Swelling of coating materials for optical fibers (25,25) which are relatively soft and which are in contact with the filling material is substantially less than that experienced with prior art filling materials. Because of the inclusion of a low pour point aliphatic hydrocarbon in the filling material, the cable provides excellent optical performance at low temperatures.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: February 16, 1993
    Assignee: American Telephone & Telegraph Company
    Inventor: Ching-Fang Tu
  • Patent number: 5164983
    Abstract: A telemarketing complex is managed by a system that compiles and processes traffic analysis data obtained from customer premises-based information sources as well as public switched telecommunications network-based information sources, such that service levels are automatically and dynamically balanced among telecommunications centers (TCs) in the complex. Typically, the telemarketing complex is comprised of a plurality of ACDs and a plurality of data centers that may be selectively linked to the (TCs) where the telemarketer receives calls. The system includes: (1) an interface to network-based services that report the origin and destination of each of a plurality of calls received by the telemarketer at all locations; (2) an interface to network-based services that enables the telemarketer to affect changes in call processing logic; and (3) a traffic control center processor (TCCP) that accepts input data from all other elements in the system.
    Type: Grant
    Filed: January 28, 1991
    Date of Patent: November 17, 1992
    Assignee: American Telephone & Telegraph Company
    Inventors: Percy B. Brown, Brenda Casselman, Gerard Conn, Robert A. Malmi, Valentine C. Matula, Margaret H. Redberg, Dimitri T. Stein, Bernadette M. Strout
  • Patent number: 5162792
    Abstract: An arrangement is provided to correlate random connections made at one end of a multiwire cable with connections that are to made at the opposite end of the cable, in which the different leads of the cable are usually separated, for example, by a distinctive color pattern. The arrangement includes identifying the respective leads by a distinguishing marking, connecting a first end of the leads to a first connector, sensing the distinguishing marking of the lead connected to each contact of the first connector, and, responsive to the first end distinguishing marking, generating a first order identifying signal.
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: November 10, 1992
    Assignee: American Telephone and Telegraph Company
    Inventor: Robert J. T. Morris
  • Patent number: 5155788
    Abstract: A sheathed optical fiber (15) which may be used in a package (20) in guidance systems for tethered vehicles includes a carrier (21) on which are wrapped a plurality of convolutions of the sheathed optical fiber. The sheathed optical fiber in a preferred embodiment includes a metallic tubular member (40) with optical fiber (30) being disposed in a longitudinally extending passageway (42) of the tubular member and secured therein against unintended lateral disassociation with the tubular member in a manner which minimize microbending losses. The reinforced optical fiber has mechanical ruggedness and tensile load capability which render it ideal for use in tethered vehicles.
    Type: Grant
    Filed: August 29, 1990
    Date of Patent: October 13, 1992
    Assignee: American Telephone & Telegraph Company
    Inventors: J. Thomas Chapin, Carl R. Taylor, Peter A. Woog
  • Patent number: 5134480
    Abstract: Deinterlacing systems and methods useful with television and other interlaced data signals derive values for pixels on missing lines using best matching values for blocks of pixels through time-recursive comparison of current pixels block values with such values for prior frames of data and also with later frames. Noise propagation is attenuated by mixing of current interpolated pixel data and memory size efficiency is achieved by comparisons based on blocks of pixels, with the block size adjustable for data accuracy. Use of chrominance signal comparisons and reduced data rate coding techniques provide added capabilities to the deinterlacing systems and methods.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: July 28, 1992
    Assignees: The Trustees of Columbia University in the City of New York, American Telephone and Telegraph Company
    Inventors: Feng-Ming Wang, Dimitris Anastassiou, Arun N. Netravali
  • Patent number: 5081647
    Abstract: A method and apparatus for communicating a voice conversation over a single telephone channel using continuously variable level quadrature amplitude modulation establishes and maintains two totally independent communication paths, each near perfect in amplitude and phase with respect to frequency over a bandwidth suitable for communication of continuously variable amplitude pulses. These pulses may be representations of any suitable bandlimited analog signal. The method establishes almost flawless QAM channels (real, imaginary), then allows switching to continuously variable amplitude analog transmissions.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: January 14, 1992
    Assignee: American Telephone & Telegraph Company
    Inventor: Gordon Bremer
  • Patent number: 5076096
    Abstract: Various methods have been proposed for measuring the viscosity of thermosetting polymers. It has been found that these method are generally inaccurate. A test which avoids the inaccuracies of previous techniques is proposed. In this test the heated thermosetting resin is forced at a known flow rate through a runner and through a capillary tube at the end of the runner. By measuring the pressure differential across the capillary a meaningful measure of viscosity is obtained.
    Type: Grant
    Filed: January 25, 1989
    Date of Patent: December 31, 1991
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Lee L. Blyler, Jr., Philip Hubbauer, Gerhard W. Poelzing, Richard C. Progelhof
  • Patent number: 5064051
    Abstract: An apparatus (20) is provided for transferring articles (40--40) from a pickup position to a pickoff position and then to a dropoff position. The apparatus includes a pair of pickup arms (60--60) which are spaced apart to engage lugs (42--42) oppositely extending from an article to be transferred. As the transfer arms are caused to be moved rotatably, the article is transferred to the pickoff position whereat the lugs are adjacent to stepped end portions (88--88) of a pair of pickoff arms (80--80). Further movement of the transfer arms causes the article to engage surfaces (92--92) of the stepped free ends of the pickoff arms and to be supported by engagement of the lugs with surfaces (94--94) of the stepped end portions of the pickoff arms. Afterwards, the pickoff arms are turned to allow the article to descend until, at a predetermined position, the lugs of the article become engaged with a conveyor (100) and become disengaged from the pickoff arms.
    Type: Grant
    Filed: July 24, 1990
    Date of Patent: November 12, 1991
    Assignee: American Telephone and Telegraph Company
    Inventor: Robert F. Blundy
  • Patent number: 5049721
    Abstract: A laser marking apparatus provides markings of enhanced readability in an outer jacket of repetitively spaced sections along the length of a moving cable which is delivered from a supply source. The cable is advanced under tension and is wound onto a take-up spool. The outer jacket is of a specified color and has an outer surface. The laser marking apparatus includes a first guide roller, a laser marker, an applicator, a coarse brush roller with a first driving mechanism, a fine brush roller with a second driving mechanism and a second guide roller. The first and second guide rollers are disposed adjacent to the supply source before the laser marker and before the take-up spool after the fine brush roller, respectively, in order to guide the cable along a path of travel so that the outer jacket passes adjacent to the laser marker. The laser marker inscribes in the outer jacket markings opening to the outer surface thereof.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: September 17, 1991
    Assignees: American Telephone and Telegraph Company, Directed Energy, Inc.
    Inventors: Stanley J. Parnas, Leroy V. Sutter, Jr., Randy C. Horne, Robert A. Wessels, Jr., Celestino Rey, Jack E. Andrews
  • Patent number: H1137
    Abstract: A process for forming a dielectrically isolated wafer is disclosed. In particular, the conventional process is altered to replace the step of growing the thick polysilicon handle layer with the steps of growing a relatively thin conformal coating layer and bonding a single crystal wafer thereto. The wafer will become the substrate of the final device structure. The process of bonding is considered to be more efficient and economical than the prior art polysilicon growth process. Additionally, the tub structures of the wafer bonding process may be exposed to a somewhat lower temperature (for bonding) for shorter period of time than the tub regions of the conventional thick polysilicon DI structures. Therefore, the tub regions will exhibit superior qualities (e.g., less stress, fewer crystal defects) when compared with those formed with the conventional polysilicon growth technique.
    Type: Grant
    Filed: November 5, 1990
    Date of Patent: February 2, 1993
    Assignee: American Telephone and Telegraph Company
    Inventors: William G. Easter, Richard H. Shanaman, III
  • Patent number: H1155
    Abstract: An optical isolator is disclosed which comprises a Faraday rotator disposed between a pair of polarization selective elements (e.g., linear polarizers, birefringent wedges, birefringent plates, etc.). Improvement in isolation stability as a function of variations in temperature and/or signal wavelength are achieved in accordance with the teachings of the present invention by utilizing a Faraday device with a rotation .theta. less than the conventional 45.degree.. A linear reduction in .theta., while resulting in a some signal loss, provides a linear increase in both temperature and wavelength stability.
    Type: Grant
    Filed: June 8, 1992
    Date of Patent: March 2, 1993
    Assignee: American Telephone and Telegraph Company
    Inventors: Vincent J. Fratello, Ralph S. Jameson, Steven J. Licht
  • Patent number: H1174
    Abstract: A process for forming a dielectrically isolated wafer is disclosed. In particular, the conventional process is altered to replace the step of growing the thick polysilicon handle layer with the steps of growing a relatively thin conformal coating layer and bonding a single crystal wafer thereto. The wafer will become the substrate of the final device structure. The process of bonding is considered to be more efficient and economical than the prior art polysilicon growth process. Additionally, the tub structures of the wafer bonding process may be exposed to a somewhat lower temperature (for bonding) for shorter period of time than the tub regions of the conventional thick polysilicon DI structures. Therefore, the tub regions will exhibit superior qualities (e.g., less stress, fewer crystal defects) when compared with those formed with the conventional polysilicon growth technique.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: April 6, 1993
    Assignee: American Telephone and Telegraph Company
    Inventors: William G. Easter, Richard H. Shanaman, III
  • Patent number: H1373
    Abstract: Apparatus and method are disclosed for providing the transfer of a semiconductor wafer from a first to a second location. The apparatus includes a transfer arm including a plurality of apertures to facilitate the attachment of a bowed wafer, without breakage or frontside contact, to the transfer arm. The size, number and location of the apertures may be determined in accordance with the size of the wafer, the amount of bow, as well as the type of bow (i.e., simple or complex). A plurality of flexible members may be disposed in a one-to-one relationship with the apertures and utilized to achieve a secure vacuum seal of the wafer to the transfer arm.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: November 1, 1994
    Assignee: American Telephone and Telegraph Company
    Inventors: Christopher E. Durham, William J. Malriat, Allen R. Melcher, Randy J. Penn