Patents Assigned to AT&T Ipm Corp
  • Patent number: 5462358
    Abstract: Surface temperature measurements of the tubes of operating power boilers are facilitated by using ganged and preferably scannable hollow-core sapphire probes to capture infrared radiation emanating from discrete tube surface areas. By selectively overlapping the tube surface areas scanned, the greater diameter of the scanning beam in relation to the tube diameter is compensated for and individual tubes can be assessed for surface temperature. Multiplexing the outputs of many probes to a remote signal processor which also controls the scanning regimens provides systematic automated temperature readings.
    Type: Grant
    Filed: January 3, 1994
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Walter V. Werner
  • Patent number: 5463685
    Abstract: An outbound call management capability is provided for a public switched telephone network by a network based outbound call management (NOCM) complex, which can be accessed by all subscribers to the public switched network through one or more central offices in the network. A predetermined list of telephone numbers is stored in a data base in the NOCM complex for each subscriber who uses the NOCM services. The telephone numbers are automatically dialed at one or more predetermined scheduled times. When one of the dialed telephones is answered, the NOCM complex sets up a connection through the public switched telephone network between the called party and one or more attendants at one or more telephone numbers specified by a customer of the NOCM services.
    Type: Grant
    Filed: November 9, 1994
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Barbara I. Gaechter, Paramdeep S. Sahni, I. Grace Tseng
  • Patent number: 5463659
    Abstract: A cordless telephone arranged for operation in a frequency hopping system includes multiple portable units configured for operation with a base unit and with each other by having the base unit pseudo randomly select from a plurality of communication channels available in the frequency hopping system a different starting channel for each one of the portable units. Each portable unit then provides initial communications with the base unit over the selected starting channel of the portable unit. For maintaining communications during a frequency hopping cycle between a portable unit and the base unit, the portable unit and base unit both generate a set of communication channels from the starting channel assigned to the portable unit for subsequent use in communicating over the radio frequency link. Each of the portable units is configured for operation with the base unit and with each other during a registration procedure.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventors: William J. Nealon, Heidi A. Rajan
  • Patent number: 5463670
    Abstract: Communications services and circuits are tested by a system which includes a voice response unit (VRU) operating under the control of processes performed in a workstation. The system can automate the various tasks associated with making test calls, such as by initiating one or multiple simultaneous test calls to a customer's telephone number, and then by playing a stored voice message when any of the test calls is answered by customer personnel, or by establishing a voice path that can be used to talk to the customer personnel. The circuits being tested are then monitored by the VRU, which can both detect supervisory signals as well as perform call disposition analysis by detecting ring, ring/no answer, busy, fast busy, tones, or other audible conditions that are indicative of many circuit abnormalities. A display indicates test system status to a technician, including the progress of all test calls as well as information pertaining to the test system itself.
    Type: Grant
    Filed: October 23, 1992
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Marilyn C. Chiang, R. Earl Fenley, Jr., George F. Holland, Anand K. Javvaji, Ramadevi Sreedhara
  • Patent number: 5463520
    Abstract: An integrated circuit obtains improved ESD protection by way of a shunt protection circuit having a trigger level that exhibits a hysteresis effect with respect to voltage applied to the bondpads. The hysteresis is obtained by a string of voltage dropping transistors that produce a trigger voltage level at an intermediate node, and a shorting transistor that effectively removes at least one transistor from the string. In a typical case, a PNP bipolar transistor serves as the protective device in the circuit to carry the ESD current from the bondpads. An illustrative embodiment with p-channel voltage dropping transistors and an n-channel shorting transistor is shown, along with additional capacitive boost circuitry for speeding up circuit operation. In this manner, a high peak ESD current can be carried while ensuring non-conduction of the protection circuit for normal operating voltages, and also for voltages slightly in excess of normal power supply voltages.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Dale H. Nelson
  • Patent number: 5461472
    Abstract: The parallelism of two nominally parallel surfaces is determined by placing a planar reflector (50) on one surface and a cube beam splitter (52) on the other surface. The reflector is placed to reflect light in a direction normal to the plane of the reflector. The cube beam splitter is placed to reflect part of the light striking a first face (54) back in the opposite direction. The cube beam splitter also reflects part of the incident light towards the reflector so that the reflector reflects the light back to the cube beam splitter, causing the light to exit the first cube beam splitter face. An autocollimator (10) is provided to direct a beam of light (24) into the first face (54) of the cube beam splitter (52) and to display the divergence between the first and second reflected beam portions, the divergence corresponding to the degree of non-parallelism between the two surfaces.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventors: George T. Harvey, Joseph S. Kovalchick, Ralph A. Treder
  • Patent number: 5461005
    Abstract: Electrical discontinuities in a silicide formed on a patterned surface are prevented by forming metal fillets in the recesses of the patterned polysilicon covered surface, and then depositing a metal layer and reacting with silicon to form the silicide. The fillet provides extra metal at a place where there is typically a deficiency in conventional deposition techniques.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Ajit Manocha, Sailesh M. Merchant, Ranbir Singh
  • Patent number: 5461690
    Abstract: A bend-limiting apparatus 20 for attachment to an optical connector 10 has a generally cylindrical shape and includes an axial bore 28 along its central axis for holding an optical cable 30. The front end 22 of the bend-limiting apparatus attaches to the optical connector and has an outside diameter which is comparable in size to the connector. The back end of the bend-limiting apparatus has an outside diameter which is comparable in size to the optical cable. The bend-limiting apparatus is made from a flexible material which is sufficiently stiff to accommodate heavy side loads, but includes a number of grooves 23 that are exclusively positioned on its back half to accommodate light side loads. These grooves preferably extend from an outside surface 29 of the apparatus into the axial bore, and also extend in a circumferential direction at least part way around the apparatus. Such a design effectively limits the minimum bend radius of an optical cable over a wide range of side loads.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Norman R. Lampert
  • Patent number: 5461217
    Abstract: Systems and methods for providing secure electronic financial transactions are disclosed. Money is electronically stored on a plurality of smart cards. At least one smart card is equipped with an electronic security wall having a closed state and an open state. In the closed state, the smart card is disabled from participating in at least one financial transaction, and in the open state, the smart card may participate in at least one financial transaction. At least one smart card is equipped with at least one of a first security key for changing the state of the electronic security wall from the open state to the closed state, and a second security key for changing the state of the electronic security wall from the closed state to the open state.
    Type: Grant
    Filed: February 8, 1994
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: David M. Claus
  • Patent number: 5461610
    Abstract: A technique for reducing multiple access interference (MAI) experienced by receivers of transmissions from a transmitter, e.g., a base station, in a direct-sequence code division multiple access communication system, e.g., a cellular radio system, is disclosed. The technique provides for the precoding of user signature sequences for use in spreading information signals to be transmitted. The use of precoded signature sequences significantly reduces the average level of MAI experienced by the receivers. Despreading of received signals by receivers may be accomplished with the original (i.e., non-precoded) signature sequences. Thus, no changes to receivers are required. The technique includes a feature for determining a set of sequences for both transmitter and receiver from a smaller set of orthogonal sequences.
    Type: Grant
    Filed: August 31, 1992
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Vijitha Weerackody
  • Patent number: 5461413
    Abstract: A monolithic array of surface emitting lasers is used in a printer engine to illuminate a photosensitive surface.
    Type: Grant
    Filed: December 30, 1993
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Martin Askinazi, Herbert O. Burton
  • Patent number: 5461308
    Abstract: The present inventors have discovered that a compact, highly sensitive current sensor can be made for any inductive component having an air gap in its magnetic path by disposing a layer of magnetoresistive material in the path of the fringing magnetic field. In the preferred embodiment, a thin magnetoresistive film of La.sub.w Ca.sub.x Mn.sub.y O.sub.z on a LaAlO.sub.3 /Al.sub.2 O.sub.3 substrate provides a high sensitivity in the range of 1-100 mV/ampere of DC current in the inductive component. The current sensor consumes a very small amount of power and provides the desirable electrical isolation between the sensor and the active device circuit.
    Type: Grant
    Filed: December 30, 1993
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Sungho Jin, Mark T. McCormack, Apurba Roy, James C. Wadlington
  • Patent number: 5461379
    Abstract: Loss of synchronization, due to a digital data signal having the same signal value for an extended number of bit or symbol periods, is overcome through the use of a coding scheme which assures transitions after each such period despite the absence of transitions in the signal to be encoded. Broadly, within the encoder, a digital input signal having m signal levels is transformed into a coded digital output signal having n possible signal values, where m<n. The transformation alters the current digital input signal value as a function of the previous coded digital output signal value and the current digital input signal value performed in a number system whose modulus is n. In a disclosed embodiment, a binary input signal is coded into an output signal having three signal levels.
    Type: Grant
    Filed: December 14, 1993
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Joseph B. Weinman, Jr.
  • Patent number: 5461685
    Abstract: An optical passband filter having a frequency transition that is several of orders of magnitude narrower than prior optical filters includes two frequency routing devices. The first frequency routing device has one input for receiving the input signal and at least N outputs, where N corresponds to the number of frequencies that compose the input signal. The N outputs of the first frequency routing device are each coupled to inputs of a second frequency routing device. The outputs of the second frequency device each correspond to one of the selected output frequency bands into which the input signal is to be divided. A multiplexed input signal containing several different frequency channels is divided into bands that are each directed to respective outputs of the second frequency routing device. The frequency transition between the various bands may be as small as the frequency resolution between adjacent outputs of the first frequency routing device.
    Type: Grant
    Filed: October 18, 1993
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Bernard Glance, Robert W. Wilson
  • Patent number: 5461333
    Abstract: A multi-chip module is composed of two or more integrated-circuit chips located on a substrate such as a dielectrically coated silicon substrate. The chips are interconnected by means of transmission wiring lines. At least some of the chips contain one or more input buffer circuits, each composed of two branches ("legs"). Each such branch contains, in one embodiment, an n-channel MOS transistor connected in series with a pair of series-connected p-channel MOS transistors--whereby, in each such branch, one of the p-channel MOS transistors is located between (intermediate) the other of the p-channel MOS transistors and the n-channel MOS transistor of that same branch. On the other hand, in each buffer circuit, the intermediate p-channel MOS transistors of both branches are cross-coupled.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Joseph H. Condon, Robert C. Frye, Thaddeus J. Gabara, King L. Tai, Scott C. Knauer, deceased, Carroll H. Knauer, executor
  • Patent number: 5461707
    Abstract: A method of reducing the size of an image of a document page selected rows and columns are eliminated from an image of a document page. The image is made up of a plurality of pixels which form rows and columns. Low information areas in the image are identified. An overall percentage of size reduction of the image is determined. Up to a predetermined maximum percentage of each low information area corresponding to the overall percentage of reduction is selectively removed so that the overall formatting of the document page is maintained.
    Type: Grant
    Filed: October 15, 1993
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Lawrence P. O'Gorman
  • Patent number: 5461693
    Abstract: Disclosed is an optical fiber distribution frame which provides means for testing the patch connections. Optoelectronic circuits are inserted into each module and are optically connected to the incoming optical fiber cable. The circuit includes a light source for launching a test signal into the patch fiber, a detector for monitoring a test signal from the patch fiber, and a microprocessor for controlling the launching and for monitoring the received signals.
    Type: Grant
    Filed: July 14, 1994
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Richard J. Pimpinella
  • Patent number: 5461390
    Abstract: A locator device for monitoring the location of subjects, usable in conjunction with a database system connected to a wireless network, wherein the database system causes a polling signal to be sent periodically to each of the subject's locator devices in the area. The locator device includes a wireless transceiver to receive the polling message and, in response, query a location determination device for the current location of the device. This location is then sent back through the wireless network to the database. The database determines from a record on that particular subject where that subject is supposed to be at that time. If the subject being monitored is not within the area where he or she is supposed to be, then the database may automatically contact law enforcement officials.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: October 24, 1995
    Assignee: AT&T IPM Corp.
    Inventor: Joseph Hoshen
  • Patent number: D363721
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Michael W. Lum, Jeffrey P. McAteer, Robert B. Wills
  • Patent number: D363731
    Type: Grant
    Filed: July 21, 1994
    Date of Patent: October 31, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Tor A. Alden, Marc J. Beacken, Robert L. Doran, John E. Nordman, James G. Turner