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| Number | Title | Issue Date |
| 5479505 | Telephone network enclosure containing protected termination device This invention discloses a telephone network interface enclosure comprising a telephone company compartment having a cover therefor and a telephone subscriber compartment having a cover therefor. A network termination module containing a protector element... | 12/26/1995 |
| 5452352 | Automatic dialing system The invention relates to a credit card dialing apparatus for use in automatically dialing account numbers, security codes and phone numbers into telephones. The apparatus includes a credit card size device having a memory, encoder, speaker, microphone and... | 09/19/1995 |
| 5442696 | Method and apparatus for detecting control signals The present invention provides a method and apparatus for detecting control signal information for an element of a communication system. The control signal information is included in one or more segments of a signal communicated over a communication syste... | 08/15/1995 |
| 5442698 | Ringing generator for telephones A ringing generator includes a binary signal source generating a waveform with eight degrees of freedom controlled to suppress or cancel certain harmonics to produce a binary low frequency signal substantially free of low frequency components other than t... | 08/15/1995 |
| 5436968 | Digital data-dependent ac impedance termination of telephone line The potential impedance mismatch of digital terminal equipment and a line test unit that has been equipped to conform with the Bellcore standard of terminating the line with a 600-900 ohm impedance during data reception is addressed by modifying the craft... | 07/25/1995 |
| 5430796 | Auxiliary attenuator arrangement for use in voice-switched speakerphone and method of selectively inserting communication loss in speakerphone paths Speech signals appearing at the receiving and transmitting paths of a speakerphone which operates under voice switching, are received at a control circuit. The control circuit issues a control signal which assumes a first level in the event that a signal ... | 07/04/1995 |
| 5428681 | Apparatus and method for reducing the risk of undesirable parameter drift of an adaptive filter used for echo cancellation Apparatus for reducing the risk of undesirable drifting of the parameters, so-called bursting, of an adaptive echo filter which is coupled between a receiving branch and a transmitting branch included in a four-wire loop. A difference signal (E) which con... | 06/27/1995 |
| 5422948 | Subscriber line interface for improving the frequency characteristics of the transmitted and received signals A subscriber line interface circuit, coupled between a telephone unit terminal and a switching system, includes a coding and decoding circuit for controlling analog voltages inputted thereinto and outputted therefrom, using a direct current bias voltage, ... | 06/06/1995 |
| 5422929 | Telephone line repeater and method of testing same A telephone line repeater (28) includes a pattern decoder/recognizer (100) which recognizes, inter alia, an input interrogating signal transmitted on a telephone network (20). The interrogating signal includes an address field (302) having at least one su... | 06/06/1995 |
| 5420921 | Method for the detection of a disable tone signal of an echo canceller A disable tone detection method for an echo canceller, in which the disable tone signal is within a predetermined tolerance range from a nominal frequency and includes phase inversions occurring at predetermined intervals. The method includes the steps of... | 05/30/1995 |
| 5420918 | Telephone apparatus for invalidating incoming call signals during dialing Provided is an exchange system accommodating an ISDN circuit as a line wire, in which a channel of the line wire is capable of being selected by an operation performed at a connected telephone. If, in a state where the ISDN circuit has been selected by th... | 05/30/1995 |
| 5418849 | Procedure and device for adaptive digital cancellation of the echo generated in telephone connections with time-variant characteristics A procedure and device are described for cancellation of the echo produced in telephone connections with electrical time-variant characteristics such as for example those affected by phase roll. The echo canceller obtained in accordance with the procedure... | 05/23/1995 |
| 5416837 | Telephone network interface enclosure This invention discloses a telephone network interface enclosure comprising a telephone company compartment and a telephone subscriber compartment. Disposed within the telephone company compartment is a metal grounding strip. There is a network terminatio... | 05/16/1995 |
| 5408332 | Focusing apparatus for video camera or the like A focusing apparatus for a video camera or the like in which a change-over between automatic focusing and manual focusing is possible includes an endlessly rotatable and hand-worked manipulator, a detector for detecting the direction and amount of manipul... | 04/18/1995 |
| 5402483 | Digital telephone system with terminals connected to a digital exchange unit providing all functions of the terminals A telephone apparatus includes a digital exchange unit and at least one digital telephone terminal connected to the digital exchange unit. The at least one digital telephone terminal generates monitoring signals and has multiple functions. All of the moni... | 03/28/1995 |
| 5371789 | Multi-channel echo cancellation with adaptive filters having selectable coefficient vectors A multi-channel echo canceller comprises a set of subtractors connected respectively in communication channels for respectively receiving a signal from a respective microphone and cancelling an echo contained in it with a cancelling signal, and a set of a... | 12/06/1994 |
| 5363436 | Remotely programmable, vandal-resistant voice communications unit A vandal resistant, remotely programmable voice communications unit is capable of being programmed for automatically calling predetermined telephone numbers. The unit is programmed remotely from any touch-tone telephone. A vandal-resistant push-button act... | 11/08/1994 |
| 5361300 | Balancing resistor and thermistor network for telephone circuits, and combination thereof with relay A balancing resistor and thermistor network for telephone circuits, and combination with an external relay, which reliably handles all three levels of adverse conditions, automatically resets under certain conditions, is physically small in size, and is s... | 11/01/1994 |
| 5347576 | Line interface unit retrofit circuit A retrofit circuit for communication one of three conditions from a line interface unit (LIU) to a receiver unit (RU), using only one external connection between the LIU and the RU. The LIU has a detection circuit and two resistors. The RU has a voltage c... | 09/13/1994 |
| 5333192 | Line interface circuit A line interface circuit for coupling signals between a telephone line and a hybrid circuit includes a loop driver circuit for supplying energizing current to the telephone line and for driving the telephone line with alternating current signals. A loop c... | 07/26/1994 |
| 5333194 | Autoequalizing bidirectional-to-unidirectional hybrid network An autoequalizing hybrid circuit for providing a cancelation path to minimize the two-wire receive path signals that are reflected onto a two-wire transmit path from a subscriber line interface circuit is disclosed. The hybrid circuit includes a variable ... | 07/26/1994 |
| 5333195 | Telephone network speech signal enhancement The quality of voice signals transmitted by a telephone station set, or similar device, are enhanced in accordance with the steps of the instant method before such signals are delivered to a receiving telephone station set by restoring the level of speech... | 07/26/1994 |
| 5329588 | Telecommunication line circuit Each line wire is separately biassed by DC potentials feeding Inputs of the respective line wire driver amplifiers, the first potential (BA) being nearer ground and the second at an equal distance from the negative supply used to power the amplifiers so a... | 07/12/1994 |
| 5323457 | Circuit for suppressing white noise in received voice A white noise suppressing circuit for suppressing white noise contained in a received voice of a speaker telephone apparatus includes a filter for suppressing white noise contained in an aural input signal input to an aural signal line, a switch for short... | 06/21/1994 |
| 5315644 | Telephone interface circuit A circuit for interfacing a host telephone system having a trunk line pair with a central office line pair and an additional circuit line pair includes a loop current monitor circuit for monitoring the host telephone system trunk line pair which is normal... | 05/24/1994 |
| 5313519 | Protected telephone network interface device A telephone network interface device comprises a base structure, a protector assembly disposed within the base structure and a cover on the base structure. The device also includes a telephone jack and terminals to which a telephone subscriber's wiring ca... | 05/17/1994 |
| 5311588 | Call progress detection circuitry and method There is disclosed a method and system for determining the progress of a calling connection. The system measures the peak voltage of the signals on the line and derives a ratio of these peak signals to the average value of the signal. From this ratio a de... | 05/10/1994 |
| 5307404 | Signal detecting device A signal detecting device capable of determining whether automatically dialling transmission is to be carried out by detecting an identification signal sent from an exchange system via a telephone line. The frequency variation of the identification signal... | 04/26/1994 |
| 5305377 | Apparatus for providing an ISDN to analog interface An interface for translating signals from a ISDN terminal to an analog telephone terminal including apparatus for separating ISDN signals into control and data signals, apparatus for utilizing the control signals to generate tone signals for transfer to a... | 04/19/1994 |
| 5289538 | Circuit arrangement for signal and information conversion between analog junction lines and digital terminal devices in communications exchanges A circuit arrangement converts signals and information between analog junction lines and digital terminal devices in communications exchanges. A decentralized control device is provided in order to process and pass on switching criteria and codes received... | 02/22/1994 |
| 5287404 | Telephone subscriber line voltage change detection Changes in a telephone subscriber line voltage are detected in a telephone set by supplying a voltage dependent upon the subscriber line voltage to a potential divider having first, second, and third tapping points, the second tapping point being between ... | 02/15/1994 |
| 5285495 | Push-button telephone dialing device with telephone hold function circuit A push-button telephone dialing device for a telephone set has a push-button keypad with a plurality of keys which include a hold function key, and a telephone dialing integrated circuit including a key input signal generator wired to the push-button keyp... | 02/08/1994 |
| 5283827 | Digital line card for interfacing a remotely located digital telephone to a central office system A digital line card for interfacing a remotely located digital telephone to a central office system by a two-wire connection is disclosed. The digital line card consists of a line interface connected to the two-wire connection. The line interface provides... | 02/01/1994 |
| 5280521 | Portable telephone system A portable telephone system is disclosed in which a plurality of i-th class exchanges, which accommodate key service units of a plurality of portable telephone sets present in each service area, and at least one (i+1)th class exchange which accommodates t... | 01/18/1994 |
| 5280524 | Bone conductive ear microphone and method An ear piece device configured for being supported in the ear and providing a microphone which is sensitive only to sounds conducted within the skull of the user is contained within a housing which is configured at one end to fit snugly at the ear canal o... | 01/18/1994 |
| 5274701 | Telephone alerter In a telephone alerter a transducer disc is held onto a printed circuit board by an annular housing which is detachable from the board. The housing has spaced feet which are received through apertures in the board and the housing is then rotated to engage... | 12/28/1993 |
| 5271059 | Method and configuration for forming a line termination of a telephone line In a method and configuration for forming a line termination at two line terminals of a telephone line, alternating signals are separated from direct signals applied to line terminals, referred to a reference variable and added to a transmission signal fr... | 12/14/1993 |
| 5271060 | Circuitry for interfacing telecommunications equipment to a communication channel Measuring the programming resistor in a data jack by placing the resistor in an AC voltage divider circuit via a transformer. An AC voltage (preferably generated by the modem's own transmitter circuitry) is applied to the voltage divider circuit, and an A... | 12/14/1993 |
| 5267309 | Telephone line unit having programmable read-only memory A line unit, used in a line shelf having a line shelf processor and common logic, is provided with an EEPROM device for storing information relative to the line unit. The stored information includes line unit type identification codes, auto provisioning d... | 11/30/1993 |
| 5255316 | Hands-free telephone apparatus Digital-type hands-free telephone apparatus is provided including a microcontroller, an audio board and a COFIDEC circuit, in which the microcontroller permanently calculates the average values of 16 successive samples on each one of the send and receive ... | 10/19/1993 |
