Patents Assigned to Telephone and Telegraph Company
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Patent number: 4861134Abstract: An opto-electronic organizer on a printed wiring card includes a plurality of opto-electronic devices each having electrical leads and at least one optical fiber extending therefrom and an optical fiber channel in the form of a closed loop for directing optical fibers. The opto-electronic devices are attached to the optical fiber closed loop channel at predetermined locations therealong and the optical fibers extending from the devices are directed into the closed loop channel wherein they are selectively interconnected. The closed loop channel has first and second portions and at least one channel joining the first and second portions so that optical fiber passing therethrough can reenter the closed loop either clockwise or counterclockwise. The organizer is affixed to the printed circuit card in predetermined alignment whereby the electrical leads extending from the opto-electronic devices are connected to prescribed electrical elements on the printed circuit card.Type: GrantFiled: June 29, 1988Date of Patent: August 29, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: George M. Alameel, Alexander Petrunia
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Patent number: 4861393Abstract: A molecular beam epitaxy method of growing Ge.sub.x Si.sub.1-x films on silicon substrate is described. Semiconductor heterostructures using Ge.sub.x Si.sub.1-x layers grown on either Ge or Si substrates are described.Type: GrantFiled: May 28, 1987Date of Patent: August 29, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: John C. Bean, Leonard C. Feldman, Anthony T. Fiory
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Patent number: 4861278Abstract: The connector comprises a plastic holder which carries two wire leads and serves as a cap for the free end of a drop wire inserted thereunto. Two metal contacts received in slots in the holder are driven in by pliers action to pierce the insulation of the leads and drop wire and to each engage both the conductor of a respective lead and a respective conductor of the drop wire to thereby electrically connect these two conductors. Next, plastic covers for the contacts, hinged to and integral with the holder, are closed to become locked thereto. The connection is then adapted to serve as a plug for an aperture in a terminal box, and to be attached thereto by snap action, and to have its leads connected to terminals in the box.Type: GrantFiled: April 26, 1988Date of Patent: August 29, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: Antoinette D. McBride, Arnold R. Smith
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Patent number: 4861136Abstract: This invention is a new type of Fabry-Perot cavity, and an optical communication system using such a cavity. The inventive Fabry-Perot cavity comprises both a waveguiding portion and a nonwaveguiding portion. In this manner, tunable cavities of desirable mid-range length, necessary to obtain required free spectral ranges, may be fabricated with minimal diffraction losses otherwise associated with cavities of such length. The cavity length may be varied using, for example, piezoelectric elements, and the various cavity elements may be aligned and connected, using fiber connector technology.Type: GrantFiled: July 15, 1987Date of Patent: August 29, 1989Assignees: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: Julian Stone, Lawrence W. Stulz
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Patent number: 4860163Abstract: In order to cool heat generating components mounted on circuit packs plugged into a backplane wiring board mounted in a compact cabinet, in which the backplane would normally prevent a stream of cooling gas entering the front of the cabinet from flowing evenly over the heat generating components, a flow control baffle is placed on each side of the backplane to direct cooling gas entering the cabinet to the rear of the circuit packs and then around the backplane to a plenum formed by the backplane and a rear surface of the cabinet where the gas is exhausted by a fan. The exhaust of the cooling gas by the fan causes the level of the cooling gas pressure in the plenum to decrease, thereby urging additional cooling gas to enter the cabinet through louvers formed in the front surface of the cabinet.Type: GrantFiled: August 5, 1988Date of Patent: August 22, 1989Assignees: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventor: Alan Sarath
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Patent number: 4859876Abstract: An electrooptic or optical parametric device comprises a noncrystalline second order optically nonlinear element and means for providing an optical input to and an optical output from said element wherein said element comprises an organic molecule having second order optical susceptibility incorporated in a directionally oriented manner in an optically clear glassy polymer. When said device is employed in an electrooptic mode it includes means for applying an electric field and/or optical input to said element for altering an optical property thereof.Type: GrantFiled: June 19, 1987Date of Patent: August 22, 1989Assignees: AT&T Bell Laboratories American Telephone and Telegraph Company, AT&T Technologies, Inc.Inventors: Carl W. Dirk, Howard E. Katz, Salvatore J. Lalama, Kenneth D. Singer, John E. Sohn
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Patent number: 4860064Abstract: A previously ignored property of a degenerate 2-dimensional gas of charge carriers in a quantum well (to be termed the quantum-capacitance effect) makes possible a novel class of transistors. In these devices the collector (a quantum well having high transverse conductance) is located between gate and emitter, with a barrier layer between emitter and collector, and a relatively thin barrier layer between collector and gate, and the chemical compositions and/or thicknesses of the various layers are chosen such that application of a voltage to the gate results, as a manifestation of the quantum-capacitance effect, in an induced charge in the emitter, whereby a current between emitter and collector can be controlled by means of a voltage applied to the gate. Transistors according to the invention potentially are very fast. Exemplarily the invention is embodied in a GaAs/AlGaAs heterostructure.Type: GrantFiled: October 21, 1987Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company AT&T Bell LaboratoriesInventor: Sergey Luryi
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Patent number: 4859820Abstract: A key switch utilizing a buckling compression spring to move a switch actuator mechanism includes a cylindrical core of resilient material located within an opening formed by the coils of the compression spring to attenuate the acoustical energy generated by the buckling and unbuckling action of the spring.Type: GrantFiled: March 31, 1988Date of Patent: August 22, 1989Assignees: American Telephone and Telegraph Company, AT&T Information Systems Inc.Inventors: Casimer Gotfryd, Stephen L. Kay, Hartland P. Klotz, Robert M. Wentzel
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Patent number: 4860296Abstract: The invention is a controlled laser having an optical resonator, a laser gain medium placed inside the optical resonator, the laser gain medium being capable of emitting light and of lasing with the light, a multiple layer heterostructure placed inside the optical resonator, and means for varying an optical absorption of the multiple layer heterostructure for the light in order to control an optical gain of the optical resonator, and thereby control lasing of the laser gain medium. Passive mode locking is achieved by the light emitted by the gain medium controlling the optical absorption of the multiple layer heterostructure. Active mode locking and modulation are achieved by controlling the optical absorption of the multiple layer heterostructure by applying an electric field to the multiple layer heterostructure.Type: GrantFiled: May 14, 1987Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: Daniel S. Chemla, David A. B. Miller, Peter W. Smith
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Patent number: 4860085Abstract: A high performance bipolar transistor structure is disclosed which exhibits an extremely low extrinsic base resistance by virtue of a silicide layer which is included in the base contact portion of the structure. The silicide layer is situated to be electrically in parallel with the conventional heavily-doped polysilicon base contact region, where a vertical polysilicon runner is used to provide a self-aligned electrical contact to the base. The parallel combination of the low resistivity (0.5-4 ohm/square) silicide with the polysilicon (sheet resistance of 10-100 ohm/square) results in a low extrinsic base resistance on the order of 0.5-4 ohm/square. The disclosed device also includes a submicron emitter size, defined by vertical oxide sidewalls above the base region, which further improves the high frequency performance of the device.Type: GrantFiled: August 24, 1988Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventor: Anatoly Feygenson
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Patent number: 4859023Abstract: Optical fiber cables have an inner sheath extruded or otherwise applied to surround optical fibers. If the fibers are coupled to the sheath, substantial shrinkage of the sheath during manufacturing induces microbending losses in the optical fibers. The inventive technique involves choosing a sheath material having a low viscoelastic modulus, typically PVC, and the application of tension thereto during or after extrusion that prevents such shrinkage. This approach typically avoids the necessity of including longitudinal compressive strength members in the cable. A filled optical fiber cable having a flexible gel to prevent water entry advantageously uses the present technique.Type: GrantFiled: September 21, 1981Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: Bernard R. Eichenbaum, Manuel R. Santana
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Patent number: 4860068Abstract: Single GaAs quantum well or single GaAs active layer or single reverse interface structures with Al.sub.x Ga.sub.1-x As barrier layers have improved qualities when one or more narrow bandgap GaAs getter-smoothing layers, which are thin, are grown and are incorporated in the barrier layer before and in close proximity to the active layer.Type: GrantFiled: January 27, 1988Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: Arthur C. Gossard, Robert C. Miller, Pierre M. Petroff
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Method and apparatus for identifying location of a lost token signal in a data communication network
Patent number: 4860284Abstract: Apparatus and method for identifying the location of a lost token signal continuously transmitted on transmission paths interconnecting nodes of a network to sequentially enable the nodes to write data onto the network. The arrival of the token signal at each node is recorded in counter states of a token track counter corresponding with the node. The recorded binary counter states are compared upon the failure of the token signal to arrive at a node to detect mismatches and transitions occurring between adjacent nodes counter states identifying the network location of the lost token signal.Type: GrantFiled: April 20, 1988Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: David B. Brown, Richard E. Wallace -
Patent number: 4860358Abstract: An arrangement and a method for recognizing a speech pattern employs a quick initial processing based upon subpatterns of speech features from which time-sequence information has been removed is followed by more conventional processing of a plurality of the best candidates. The initial processing, or pre-selection, eliminates large numbers of unlikely candidates, the best candidates being retained by setting an empirically determined threshold for similarity, as measured by a suitable distance measurement. To facilitate retrieving the complete speech feature patterns including time-sequence information for the subsequent processing, the code books of the subpatterns also contain associated indices pointing to the corresponding complete patterns.Type: GrantFiled: December 18, 1987Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventor: Lawrence R. Rabiner
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Patent number: 4859827Abstract: Laser welding of an outer sleeve 14 to an inner fiber ferrule 12 is expedited by, first, machining a thinned region 18 in the outer diameter of the sleeve. After the ferrule has been inserted in the sleeve, the thinned region permits the laser to fuse through the sleeve and melt part of the ferrule, as is required for laser welding of ferrule for the sleeve. The thinned region is preferably made by using a rotary cutter to cut an axially extending slot in the outer sleeve, which permits a succession of laser welds 21 in the axial direction in the slot. In a preferred embodiment, thinned regions 18,19 are made on opposite sides of the outer sleeve, and laser welding is performed simultaneously on both sides of the sleeve so as to avoid distortions caused by thermal stress asymmetries.Type: GrantFiled: October 17, 1988Date of Patent: August 22, 1989Assignee: American Telephone and Telegraph CompanyInventors: Richard J. Coyle, Jr., Jaroslav Mracek
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Patent number: 4858168Abstract: A 32-bit adder utilizes an optimal partitioning scheme for improving the 32-bit carry look-ahead. Instead of relying on the powers-of-four partitioning scheme used in prior art adders, the inventive technique uses "double generate" and "double propagate" terms. These represent the generate and propagate functions for two bits. In addition, "double group geneate" and "double group propagate" terms are produced, which represent the generate and propagate terms for a 8-bit groups. In this manner, a partition of 1-bit/8-bit is obtained, rather than the prior art 1-bit/4-bit/16-bit. The critical path is typically shortened from 7 logic levels to 5 logic levels, resulting in faster operation. The double functions are advantageously implemented using logic circuitry having two (or more) outputs per gate.Type: GrantFiled: February 16, 1988Date of Patent: August 15, 1989Assignee: American Telephone and Telegraph CompanyInventor: InSeok S. Hwang
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Patent number: 4856866Abstract: Disclosed are aligned plug optical fiber connectors that can accommodate larger differences in plug diameter and/or a wider range of plug diameters than is possible in prior art connectors, resulting inter alia in increased economy. The first of these advantages is attained through the use of bilaterally decoupled plug alignment means, i.e., means in which radial deformation of one half of the alignment means does not result in analogous deformation of the other half. A simple example of bilaterally decoupled alignment means is an alignment sleeve with a centrally located lateral slit. The second of the above advantages is attained through use of limited contact bilaterally decoupled alignment means, i.e., bilaterally decoupled alignment means shaped such that only a limited portion of the plug surface is in contact with the alignment means. A simple example of such alignment means is a transversely split alignment sleeve whose bore has roughly ellipsoidal cross-section.Type: GrantFiled: August 15, 1988Date of Patent: August 15, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventors: Lucius J. Freeman, Paul F. Gagen
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Patent number: 4855996Abstract: Modems, data service units, application modules and other data communication devices, installed in a common equipment cabinet, are interconnected by way of a time division multiplexed bus. Time slots assigned to the various devices recur at a number of regularly-spaced access periods across each time division multiplex frame. The rate at which the access periods occur and the total number of access periods that make up each frame are chosen in such a way as to accommodate a mix of devices having respective bus access rates wherein there is at least one pair of rates for which neither rate of the pair is a whole number multiple of the other. The process of allocating access periods to the time slots is carried out using a known lemma to identify linear Diophantine equation solutions.Type: GrantFiled: August 3, 1988Date of Patent: August 8, 1989Assignees: American Telephone and Telegraph Company, AT&T Information Systems Inc.Inventor: William Douskalis
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Patent number: D303111Type: GrantFiled: November 18, 1985Date of Patent: August 29, 1989Assignee: American Telephone and Telegraph Company, AT&T Bell LaboratoriesInventor: Steven J. Paley
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Patent number: D303115Type: GrantFiled: March 28, 1988Date of Patent: August 29, 1989Assignee: American Telephone and Telegraph Company, AT&T Information SystemsInventors: Norman K. Hart, Lynnet Koh, Eugene A. Mills