Patents Examined by M. W. Shehata
  • Patent number: 5517553
    Abstract: This invention relates to a wireless communication system, which comprises plural wireless communication units having different communication protocols, and in which a proper wireless communication unit is automatically selected from the plural wireless communication units in accordance with the operation states of the plural wireless communication units to make communication possible. Thereby, troublesome operation is not required, an optimum wireless communication method can be automatically selected, and communication cost can be reduced. In the wireless communication system of the present invention, when mobile stations are registered in a fixed station, preferential orders of the mobile stations are stored, and calling/call-reception and communication processings are controlled according to the preferential orders.
    Type: Grant
    Filed: April 5, 1993
    Date of Patent: May 14, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hideaki Sato
  • Patent number: 5457743
    Abstract: A channel unit network for interconnecting a two-wire, bidirectional signal transmitting means with a four-wire digital transmitting means in a communication system to create a precision bidirectional simulated two-wire cable pair over a transmission medium includes tip and ring switch mode drivers, a signal processing circuit, a decoupling circuit, and tip and ring balance amplifiers. The decoupling circuit is used for splitting off "voice band" frequency signals from incoming tip and ring "DC band" signals from the two-wire means. The signal processing circuit performs both analog-to-digital conversions and digital-to-analog conversions.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: October 10, 1995
    Assignee: Tollgrade Communications, Inc.
    Inventor: Frederick J. Kiko
  • Patent number: 5432835
    Abstract: This device is designed so that although voice of the opposite party will be amplified when telephone 1 on the side of the device is first placed on-hook during a telephone conversation, amplification will not occur if the opposite party places his or her phone on-hook first during a telephone conversation or if the user places telephone 1 on-hook before the opposite party picks up the telephone. The structure, which is shown in FIG. 1 such that during a telephone conversation between telephone 1 and telephone 12, when telephone 1 is placed on-hook first, the on-hook status is detected by means of the photocouplers PC-1 or PC-2, and the voice of the opposite party at telephone 12 is amplified by means of contacts y1-1 and y1-2, which are in the make position, line transformer 2, amplifier 3 and speaker 4.
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: July 11, 1995
    Assignee: Hashimoto Corporation
    Inventor: Kazuo Hashimoto
  • Patent number: 5426698
    Abstract: A transformed current sensing relay with reduced AC impedance of the operating coil is accomplished by adding a shorted secondary winding to an otherwise conventional current sensing reed relay. The shorted secondary winding is preferably implemented with a copper tube over the existing coil and inside the magnetic circuit. This transformed current sensing relay is particularly advantageous for the line current sensing function in switched network communications equipment such as high speed modems, where the transformed relay exhibits substantially lower impedance at high frequencies than the conventional current sensing relay. This transformed current sensing relay allows for the elimination of bypass capacitors and results in significant cost and space savings. Moreover, the transformer nature of the transformed current sensing relay allows for the elimination of suppression resistors from the interface resulting in additional cost and space savings.
    Type: Grant
    Filed: May 11, 1993
    Date of Patent: June 20, 1995
    Assignee: General DataComm, Inc.
    Inventor: Welles K. Reymond
  • Patent number: 5425098
    Abstract: A data transmitter-receiver device transmits a forward data to a communication channel, and receives a backward data with a returning echo noise from the communication channel. The device is provided with a first modulator for modulating the forward data into a first digital signal. A D/A converter converts the modulated first digital signal into a corresponding outgoing analog signal which is transmitted to the communication channel. A delay memory is operated to delay the forward data by a certain time delay corresponding to a return time interval of an echo noise. A second modulator modulates the delayed forward data into a second digital signal. An A/D converter receives an incoming analog signal to convert the same into a corresponding third digital signal. An echo canceler operates based on the first and second digital signals for removing an echo noise from the third digital signal. A demodulator demodulates the third digital signal after removal of the echo noise to produce a backward data.
    Type: Grant
    Filed: June 23, 1993
    Date of Patent: June 13, 1995
    Assignee: Yamaha Corporation
    Inventor: Ryo Kamiya
  • Patent number: 5425097
    Abstract: An arrangement where display control data which has been developed off-line, and which specifies the content and sequence of the display screens required to lead a customer through activation of a plurality of telephone features, is received and stored by an analog display station either at an initialization or a feature update of the station. The display control data is used by the station to communicate information relating to a particular feature to a user via the station display. The user inputs, e.g., keystrokes, received after each display screen, are stored by the station, and after the sequence has been completed, all such stored user inputs are rapidly transmitted to the switching system to effect the particular feature. Significantly, the switching system telephone feature software is not involved until after all stored user inputs are transmitted. Therefore, there is no need to modify existing software as long as the user inputs are not changed.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: June 13, 1995
    Assignee: AT&T Corp.
    Inventor: Michael K. Pula
  • Patent number: 5414764
    Abstract: A communication unit connectable in parallel with other communication equipment to a two-wire telephone line communicates through the telephone line and a detector detects a voltage across the two-wire telephone line. A command unit commands communication by the communication unit and a controller controls the communication by the communication unit according to the detection by the detector and the command by the command unit.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: May 9, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsunehiro Watanabe, Hisao Terajima, Teruyuki Nishii
  • Patent number: 5412716
    Abstract: A system of impedance matching is provided to match the total impedance of the cable system to the total impedance of the powered elements such as the repeaters. The source impedance of the power supplies may be considered as part of the cable impedance. By matching impedances, the source voltage for driving the electronics is advantageously minimized.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: May 2, 1995
    Assignee: AT&T Bell Laboratories
    Inventor: Matthew S. Blaha
  • Patent number: 5408529
    Abstract: A dual tone detector (100) for a single dual tone, a dual tone multi-frequency (DTMF), or similar system processes an input signal through both bandpass (103) and band reject (104) tone detectors. If both the bandpass (103) and band reject (104) tone detectors detect a tone, then the dual tone detector (100) provides a tone detect output signal. If only the bandpass tone detector (103), which is susceptible to false tones, detects a tone, then a voice input signal is muted and the tone detector (100) activates the tone detect output signal only if both the bandpass (103) and band reject (104) tone detectors subsequently detect a tone. In one embodiment, a dual bandpass/band reject tone detector (120) processes the input signal through shared front-end band reject filters (121, 122), limiters (124), resonators (127, 128), and a processing section (130) in order to save circuit area. Limiter and peak detector functions are also implemented in shared circuitry to further reduce circuit area.
    Type: Grant
    Filed: June 2, 1993
    Date of Patent: April 18, 1995
    Assignee: Motorola, Inc.
    Inventor: Carlos A. Greaves
  • Patent number: 5394466
    Abstract: Combination apparatus for connecting one or more incoming telephone company lines to one or more telephone subscriber premises lines and for connecting incoming cable television signals to a television set, and a cable television module for being mounted to telephone network interface apparatus and for connecting incoming cable television signals to a television set.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: February 28, 1995
    Assignee: Keptel, Inc.
    Inventors: Pina Schneider, Eric J. Hermsen, Frank S. Siano
  • Patent number: 5381472
    Abstract: A power source control circuit for a telephone set, includes a power source switch, a detecting circuit, a power hold circuit, and a control circuit. The power source switch supplies an external power to the telephone set. The detecting circuit detects an off-hook operation of the telephone set or an incoming signal arriving at a line. The power hold circuit holds the power source switch in an ON state for a predetermined time period on the basis of an output from the detecting circuit. The control circuit is activated by supply of the external power and transmits an extension signal for extending the ON state of the power source switch within the predetermine time period.
    Type: Grant
    Filed: August 9, 1991
    Date of Patent: January 10, 1995
    Assignee: Tamura Electric Works, Ltd.
    Inventors: Kazuhide Kobayashi, Takehiko Ishii, Osamu Kai
  • Patent number: 5373554
    Abstract: A telephone includes a speech network for transmitting an outgoing voice signal and receiving an incoming voice signal from a remote telephone. The speech network is not supplied with power from a telephone exchange through a telephone line but supplied with a separate power supply. To interrupt the power supply from the telephone exchange, a transformer is interposed between the speech network and the telephone line. A ringer circuit and a dialer circuit are connected to the primary side of the transformer. Because the power supplied to the speech network does not fluctuate, the circuit design of the speech network can be readily performed using inexpensive circuit components.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: December 13, 1994
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Tatsuya Sato
  • Patent number: 5369697
    Abstract: Dual tone multifrequency (DTMF) signals are automatically generated by a telecommunications device after a telephone number is called. The signals generated to call the telephone number are determined by a manually operated switch indicating pulse code signal generation or dual tone multifrequency signal generation. It is determined that the telephone number has been dialed by detecting a ring-back signal, voice frequency signals, DTMF signals, or data stream signals. Alternatively, if a predetermined period of time, such as ten seconds, passes without the user pressing a number on the keypad, it may be assumed that the telephone number has been dialed. Upon detecting one of these signals or the passage of time, the telecommunications device is controlled to generate only dual tone multifrequency signals for communication with automated services, such as voicemail, telephone banking, reservation systems, etc.
    Type: Grant
    Filed: April 30, 1993
    Date of Patent: November 29, 1994
    Assignee: Boston Technology, Inc.
    Inventors: John P. Murray, David F. Hemmings, David S. Gergacz
  • Patent number: 5363438
    Abstract: A selective ringing receiving circuit comprises a timing generating circuit for generating a timing signal for bit length comparison, a bit length comparison circuit for comparing, in terms of the timing signal, the respective bit lengths of `1` and `0` of a received digital signal outputted in a direct conversion system when a selective ringing signal is received from a base station, thereby producing a changing point detection/selection signal, a changing point detection circuit for selecting the rising and falling changing points of the received signal using the changing point detection/selection signal to produce a detected rising or falling changing point signal of the received digital signal, and a bit synchronization circuit for performing bit synchronization in response to the detected changing point inputted.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: November 8, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Yasunari Tanaka
  • Patent number: 5359650
    Abstract: The invention relates to remotely powered circuitry, and in particular to telephones. The circuit of the invention uses a counter to measure or compare the duration of power supply interruptions on the remote power supplying line to cause the remotely powered circuitry to be initialized whenever the duration of such an interruption becomes greater than or less than a specified duration. Advantageously, comparators are used so as to be able to take a plurality of durations into consideration. Thus, each time the power supply on the remote power line is interrupted, if the interruption is not of an acceptable duration, then the remotely powered circuitry is initialized.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: October 25, 1994
    Assignee: SGS-Thomson Microelectronics, S.A.
    Inventor: Christian Tournier
  • Patent number: 5357569
    Abstract: A two to four wire hybrid converter for use in a telephone system that allows other telephone equipment, such as a caller identification device, to more readily decipher signals. The converter controls noise by using a digital to analog converter, hybrid circuit, interface circuit, and controller. The digital to analog converter accepts a receive digital data signal from a transmission line and converts it to a receive analog signal. The hybrid circuit accepts the receive analog signal and provides it to the customer telephone line, as well as accepting a transmit telephone analog signal from the customer telephone line. Such transmit telephone analog signals are then converted to digital signals and provided to the carrier transmission lines. The hybrid circuit includes an inverter, variable amplifiers, and summing circuit. The inverter inverts the transmit telephone analog signal with respect to the receive analog signal.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: October 18, 1994
    Assignee: Teltrend Inc.
    Inventors: Frank X. Garcia, Bruce R. Miller
  • Patent number: 5311587
    Abstract: A sensor circuit for telephone line includes a detection coil (52) inserted in a telephone line (22). The coil generates a magnetic flux according to a line current which flows in the telephone line. A magnetic sensor (54) such as a Hall element generates a voltage signal in response to the magnetic flux. An output of the magnetic sensor is applied to a comparing circuit (58) and a tone deriving circuit (60) via an amplifier (56). The comparing circuit includes two comparators one of which compares the voltage signal from the magnetic sensor with a first reference voltage (V1) and the other of which compares the output signal with a second reference voltage (V2), so that a line current supervisory signal is outputted from the comparing circuit. The tone deriving circuit includes a band-pass filter and derives a tone signal from the voltage signal of the magnetic sensor.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: May 10, 1994
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroyuki Ohta, Masaaki Sugiyama
  • Patent number: 5267307
    Abstract: A communication apparatus includes a memory for storing extension number information or transfer destination information in association with calling party number information, a unit for receiving calling party number information sent from a calling party at a called party, a unit for comparing the calling party number information received by the receiving unit with the calling party number information stored in the memory; and a unit for notifying a call reception to an extension terminal equipment identified by the extension number information associated with the calling party number information received by the receiving unit, or transferring a call reception to the transfer destination associated with the calling party number information received by the receiving unit, respectively, in accordance with the comparison result by the comparing unit.
    Type: Grant
    Filed: June 13, 1991
    Date of Patent: November 30, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Michihiro Izumi, Shoichi Takashima
  • Patent number: 5237607
    Abstract: A dial illuminating assembly allows for minimum power operation while maintaining uniformity of illumination in a telephone dial. The dial illumination assembly includes a plurality of fiber optic light guides for receiving light rays emanating from a light source and for directing these light rays to a plurality of translucent buttons. Illumination of the translucent buttons is achieved by creating multiple abraded surfaces on the light guides for dispersing the light rays in the vicinity of each translucent button. The light guides are routed along opposed sides of the translucent buttons with abraded surfaces on the light guides being positioned next to each button for providing the desired illumination. The dial illuminating assembly directs light rays so efficiently that only one light source is needed to provide uniform illumination in standard telephone dials.
    Type: Grant
    Filed: January 3, 1992
    Date of Patent: August 17, 1993
    Assignee: AT&T Bell Laboratories
    Inventor: Perry W. Diamantis
  • Patent number: 5195132
    Abstract: 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 energy attenuated by the transmitting set, in which such restoration is performed at a point along a telephone connection between the transmitting and receiving telephone stations, for example, at a point within a telecommunications system which establishes the connection.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: March 16, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Duane O. Bowker, John T. Ganley, J. H. James