Patents Assigned to AT&T Bell Laboratories
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Patent number: 5349743Abstract: Magnetic components are fabricated as monolithic structures using multilayer co-fired ceramic tape techniques. Fabrication of these magnetic components involves constructing multiple layers of a magnetic material and an insulating non-magnetic mataerial to form a monolithic structure with well defined magnetic and insulating non-magnetic regions. Windings are formed using screen printed conductors connected through the multilayer structure by conducting vias.Type: GrantFiled: May 2, 1991Date of Patent: September 27, 1994Assignee: AT&T Bell LaboratoriesInventors: Gideon S. Grader, David W. Johnson, Jr., Apurba Roy, John Thomson, Jr.
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Patent number: 5351236Abstract: A time-division multiplex switch (100) switches a hierarchy of data rates. It sets up higher-rate connections not as a plurality of individual lowest-rate connections but as one or more time slots in each one of a plurality of sequential frames (40, 50) that correspond to that higher rate in each superframe (30). A time-slot-interchange switching element (131, 141 ) of the switch utilizes a plurality of physically or logically distinct double-buffered data memories (301, 302, 303) each corresponding to a different one of the superframe and different-size ones of the frames. Reading and writing of each of the data memories' buffers alternates with the corresponding one of the superframe and different-size frames; reading of a data memory's buffer immediately follows writing of that buffer.Type: GrantFiled: October 20, 1992Date of Patent: September 27, 1994Assignee: AT&T Bell LaboratoriesInventor: Robert L. Pawelski
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Patent number: 5351146Abstract: There is disclosed the architecture for an all optic network which employs a three level hierarchy using wavelength vision multiplexing. At the lowest level of the hierarchy are Level-0 all optical networks. The Level-0 networks are "local" broadcast networks each of which supports a plurality of access ports and each access port can hear all the local traffic transmitted by all other access ports in the same Level-0 network. Each Level-0 network shares wavelengths internally, but there is extensive reuse of wavelengths among different Level-0 networks. The next higher level, which is the intermediate level, Level-1, is essentially a wavelength router coupled with one or more of the Level-0 networks to provide a wavelength path to one or more directly connect Level-0 networks or, in combination with a Level-2 network, a light path to one or more Level-0 network outside itself.Type: GrantFiled: March 1, 1993Date of Patent: September 27, 1994Assignees: AT&T Bell Laboratories, Digital Equipment Corporation, Massachusetts Institute of TechnologyInventors: Vincent W. S. Chan, Robert G. Gallager, Alan J. Kirby, Adel A. M. Saleh
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Patent number: 5351261Abstract: Lasing threshold for a whispering mode laser is reduced by appropriate placement of a reflector. A reflector parallel to, and within a wavelength distance of, the disk decreases radiation loss due to imperfect internal reflection. Enhancement is calculable on the basis of destructive interference between reflected and direct radiation.Type: GrantFiled: April 14, 1993Date of Patent: September 27, 1994Assignee: AT&T Bell LaboratoriesInventors: Louis D. Lanzerotti, Samuel L. McCall, Bernard Yurke
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Patent number: 5349635Abstract: A V.32 compatible modem provides a full-duplex mode of operation, while a 208B compatible modem provides a half-duplex mode of operation. The connect sequence of a V.32 compatible modem is modified so that it will automatically determine if the other modem, whether the originating modem or the answering modem, is a 208B type of modem or a V.32 type of modem. In one embodiment of the invention, the connect sequence of an originating V.32 modem is modified to detect either a 2100 Hz answer tone, which represents that the answering modem is a V.32 type of modem, or a 2021 Hz answer tone, which represents that the answering modem is a 208B type of modem. In another embodiment of the invention, the connect sequence of an answering V.32 modem is modified to transmit first a 2100 Hz answer tone and then, if no 1800 Hz V.32 signal "AA" is received from the originating modem, to transmit a 2021 Hz answer tone, thereby simulating a 208B modem has answered the data call.Type: GrantFiled: November 19, 1992Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventor: Robert E. Scott
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Patent number: 5348913Abstract: In a preferred embodiment of the invention, a substrate (11) is cleaned by immersing it in an organic solvent (17) and subjecting it to acoustic energy, immersing it in alcohol, immersing it in a surfactant, subjecting it to a cascading rinse in deionized water, baking it (FIG. 3 ), and thereafter subjecting it to ultraviolet light in an ozone ambient (FIG. 4). When the foregoing steps are followed, the contact angle is significantly reduced, and an encapsulant (14) that is thereafter applied provides more reliable protection to an encapsulated device (12) from outside contaminants.Type: GrantFiled: August 6, 1993Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventors: Richard McBride, Ching-Ping Wong
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Patent number: 5349503Abstract: Applicants have discovered that a particularly efficient illuminating device for a transparent display comprises a microtextured reflecting surface formed on a major surface of a transparent substrate and a light source for directing light into the transparent substrate approximately parallel to the major surface. Preferably the substrate has two major surfaces separated by a thickness in the range 0.5 to 1.0 mm so that the substrate acts as a light guide. A substantial portion of the light passing into the substrate undergoes total internal reflection until it hits a microelement and is reflected out of the substrate. The result is an efficient illuminating device particularly useful for lighting transparent displays.Type: GrantFiled: April 23, 1993Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventors: Greg E. Blonder, Bertrand H. Johnson
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Patent number: 5349341Abstract: Disclosed is a circuit for channel units in a digital loop carrier transmission system. Two registers include information related to the health of the channel units. One of the bits of a first register is the logical "OR" of the last four bits in the second register, thus permitting a reading of a single register to determine if any problems exist.Type: GrantFiled: December 30, 1991Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventor: Mark E. Hauschild
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Patent number: 5348912Abstract: The present applicants have discovered that one can make a surface emitting laser with enhanced optical confinement and improved heat sinking characteristics by etching away portions of the growth layers peripheral to the intended laser cavity and regrowing peripheral regions of material having a lower index of refraction than the active region. Using low damage etching and either in situ regrowth or hydrogen plasma cleaning followed by regrowth, a surface emitting laser having enhanced optical isolation and heat sinking characteristics can be made.Type: GrantFiled: February 11, 1993Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventors: Kent D. Choquette, Robert S. Freund, Minghwei Hong
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Patent number: 5346855Abstract: Disclosed is a method of making InP-based DFB lasers that can reliably mitigate or substantially prevent erosion of the grating during overgrowth. The method comprises contacting, prior to overgrowth, the grating with a sulfurcontaining aqueous medium, e.g., 80 parts by weight H.sub.2 O/20 parts by weight ammonium sulfide.Type: GrantFiled: January 19, 1993Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventors: Erin K. Byrne, Utpal K. Chakrabarti, Todd R. Hayes
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Patent number: 5346655Abstract: An optical coupler using round optical fibers whose ends have been formed into a predefined shape to allow greater physical packing densities in order to achieve greater uniform illumination efficiency. The interstitial space between optical fibers is greatly reduced by thermoforming the ends of round optical fibers in a mold that makes a gradual transition from a circular shape to the predefined shape to avoid optical loss. Since the change in shape is gradual, the total cross-sectional area of the fibers remains constant; and optical loss is minimal because there is no reduction in mode volume. The predefined shape may be substantially square or rectangular. The core and cladding materials of the optical fiber are carefully chosen with respect to the glass transition state temperatures of both materials because the temperature at which the materials are formed by a mold are slightly above the glass transition state of the core or cladding, whichever is higher.Type: GrantFiled: July 26, 1993Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventors: Lee L. Blyler, Jr., Gary J. Grimes, Lawrence J. Haas
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Patent number: 5347227Abstract: Cross coupling framing signals between two timing subsystems to adjust the phase relationship between the timing subsystems. In a standby timing system, framing signal of the standby timing system is used to start a counter, and framing signal of the active timing subsystem is used to stop the counter. The delay due to drivers, receivers and interconnecting cables is made to be an integer number of counts (nominal count) of the counter. Any difference between the contents of the counter and the nominal count represents the difference in phase between the standby timing subsystem and the active timing subsystem. The standby timing subsystem is adjusted to eliminate this phase difference by eliminating the difference between the nominal count and the contents of the counter.Type: GrantFiled: December 10, 1992Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventor: James R. Bortolini
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Patent number: 5346118Abstract: Described are a process for soldering at least one component having solder bumps to a substrate and a process for forming solder bumps on metal pads of an element, such as an IC package or substrate or both. The bumps are formed by stencil printing solder paste deposits on the metal pads, heating the solder paste deposits to reflow temperature of the solder in the solder paste deposits, and allowing the molten solder in each deposit to coalesce and during subsequent cooling solidify forming the bumps on the metal pads.Type: GrantFiled: September 28, 1993Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventors: Yinon Degani, Thomas D. Dudderar, William L. Woods, Jr.
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Patent number: 5346583Abstract: A substrate (10) is formed having first and second opposite flat surfaces. Photolithographic masking and etching is used to form on the first surface of the substrate at least one lens (25) having a central axis. Photolithographic masking and etching is also used to form on the second surface of the substrate an optical fiber guide (23). The fiber guide is then used to mount an optical fiber(27) on the second surface of the substrate such that the central axis of the optical fiber is substantially coincident with the central axis of the lens, thereby giving the desired alignment.Type: GrantFiled: September 2, 1993Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventor: Nagesh R. Basavanhally
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Patent number: 5346581Abstract: In a preferred embodiment, the disclosed method of making a compound semiconductor (e.g., InP, GaAs) device comprises etching of a semiconductor body by exposure of the body to a chemical beam or beams that comprise an etching medium (e.g., PCl.sub.3, AsCl.sub.3) and a precursor chemical (e.g., trimethylindium, trimethylgallium), followed by chemical beam epitaxy (CBE) growth of semiconductor material on the etched surface without exposure of the semiconductor body to the ambient atmosphere. Presence of the precursor chemical in the etching beam can result in significantly improved surface morphology, with attendant high quality re-growth. Multiple etching/growth sequences are facilitated by the almost instantaneous (e.g., about 1s) switching between the etching and growth modes that is possible in a reactor according to the invention.Type: GrantFiled: April 1, 1993Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventor: Won-Tien Tsang
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Patent number: 5345670Abstract: A magnetic device (10), suitable for attachment to a substrate, includes at least one sheet winding (24) having a pair of spaced-apart terminations (26), each receiving an upwardly rising portion (28) of a lead (12). The sheet winding terminations and upwardly-rising lead portions, together with at least a portion of the sheet windings, are then encapsulated with masses of insulative material (18, 19 and 34). A ferromagnetic core (20,22) surrounds at least a portion of the sheet windings to impart a desired magnetic property to the device.Type: GrantFiled: December 11, 1992Date of Patent: September 13, 1994Assignee: AT&T Bell LaboratoriesInventors: Lennart D. Pitzele, Matthew A. Wilkowski
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Patent number: 5345529Abstract: An optical fiber connective device enables one or more optical fiber(s) to be precisely mounted, essentially perpendicular, to a substrate. The connective device includes a support plate having holes with optical fiber(s) precisely mounted there through. The support plate, with mounted optical fiber(s), is then inserted into aligned holes in the substrate and attached to the substrate. The precise mounting of the connective device to the substrate enables optional coupling of optical signals from the optical fiber(s) to optoelectronic chips mounted over holes of the substrate.Type: GrantFiled: July 6, 1993Date of Patent: September 6, 1994Assignee: AT&T Bell LaboratoriesInventors: Theodore Sizer, II, James A. Walker
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Patent number: 5345542Abstract: A high speed data display routine used in imaging of displays of geographic or other detail depicting, for example, the depth of an ocean, acoustic prediction plots, photographs and logos. The speed is achieved by a process for efficiently mapping the data values to the display matrix. The information processing uses proportional mapping, but only on the two edges of the data matrix. The processing performs substantially fewer calculations during the mapping process, by rely in accordance with certain conventions on straight raw data copying operations using pre-determined counts.Type: GrantFiled: October 15, 1993Date of Patent: September 6, 1994Assignee: AT&T Bell LaboratoriesInventor: Curtis C. Wye
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Patent number: D350743Type: GrantFiled: March 30, 1993Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventors: John A. Hicks, III, Stephen G. Miggels
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Patent number: RE34735Abstract: An improved call waiting arrangement where a caller is free to exercise discretion in interrupting ongoing telephone calls because the caller is prompted, for example via an audible announcement, that the called party is busy on another call but that the caller may request interruption of the call by remaining off-hook. If the caller believes that his call is sufficiently important, he requests call interruption by remaining off-hook. If the caller chooses not to interrupt, he may make subsequent call attempts promptly because he knows that the called party is busy on another call rather than being away from home. Alternatively, the caller may activate auto-callback such that a call is completed between the two parties as soon as the status of the called station returns to on-hook.Type: GrantFiled: June 11, 1992Date of Patent: September 20, 1994Assignee: AT&T Bell LaboratoriesInventors: Tsaul Kuabe T,, Wing N. Toy, deceased