Patents Examined by Robert Hearn
  • Patent number: 3982187
    Abstract: A mechanism for driving a television tuner channel indicator located behind a panel and mounted concentrically with a selector shaft and a concentric fine tuning shaft. The driving mechanism includes a two-piece gear housing mounted on the selector shaft for rotation therewith, a driving gear affixed to the fine tuning shaft, a driven gear, and three planetary gears mounted within the housing and engaging the driving and driven gears. The selector shaft passes through the gear housing and engages the coarse tuning mechanism of the tuner. The driven gear engages the fine tuning mechanism of the tuner, and the indicator is attached to the gear housing. The driving mechanism may be provided with apparatus for actuating an AFC defeat switch when the television tuner is being fine tuned or tuned between channels.
    Type: Grant
    Filed: March 31, 1975
    Date of Patent: September 21, 1976
    Assignee: Sarkes Tarzian, Inc.
    Inventors: Joe G. Badger, Alarico A. Valdettaro
  • Patent number: 3980957
    Abstract: A television tuner features a switching voltage generator that resets the voltage across the varicap tuning diodes to about zero voltage when a new tuning range is switched on. This allows the full steepness of the capacitance-voltage characteristics of the diodes to be used in each range. This in turn allows more ranges to be tuned and reduces the effects of stray capacitances.
    Type: Grant
    Filed: March 14, 1975
    Date of Patent: September 14, 1976
    Assignee: U.S. Philips Corporation
    Inventor: Walter Putzer
  • Patent number: 3979676
    Abstract: Disclosed is a digital modem using continuously variable sloped delta modulation and adapted for digitizing voice signals in a telephone system. In the analog to digital direction (A/D), an analog input signal is converted into a digital output, the output logic condition being indicative of the direction of change in amplitude from the last signal input. The signal pulse indicating positive change or absence of pulse indicating negative change is passed to a shift register for transmission of the first pulse signal and storage of a plurality of bits. A feedback network receives the pulse bits from the shift register, and the bits are converted to a summed signal for resolution into a reconstructed or simulated signal against which the incoming signal is checked. For the receiving or D/A direction, a somewhat similar circuit in reverse is used to reconstruct an analog signal from the received data bits.
    Type: Grant
    Filed: October 21, 1974
    Date of Patent: September 7, 1976
    Assignee: International Standard Electric Corporation
    Inventor: Mario Poma
  • Patent number: 3979677
    Abstract: Equalizing system arranged for pulse transmission, adaptive equalization being achieved without the use of an additional periodic adjusting pulse pattern. For this purpose in a control voltage generator the sub-bands and the associated additional sub-bands of an equalized pulse signal processed by the phase and amplitude control circuits are used after pulse regeneration directly as a local reference signal and an adjusting signal respectively. The sub-bands and additional sub-bands are applied to the cascade connection of a comparator and a mean-value device for generating the control voltage which controls the phase and amplitude control circuits in a feedback mode.
    Type: Grant
    Filed: April 3, 1975
    Date of Patent: September 7, 1976
    Assignee: U.S. Philips Corporation
    Inventor: Felix Bagdasarjanz
  • Patent number: 3979678
    Abstract: Pulse radar apparatus comprising at least an error voltage generator, a dither-tuned magnetron, a frequency control circuit, a conditional circuit and an angular position indicator connected to the magnetron tuning shaft for turning the local oscillator frequency f.sub.l to a frequency f.sub.lo, showing a fixed difference f.sub.o with the magnetron frequency, where f.sub.o = f.sub.z - f.sub.lo. When, by means of the indicator, the conditional circuit determines that the magnetron is being tuned in a defined frequency range comprising the frequency f.sub.l, the frequency control circuit is alternatively supplied with an error voltage and a voltage proportional to ##EQU1## TO DELIVER A FINE AND A COARSE TUNING VOLTAGE, RESPECTIVELY.
    Type: Grant
    Filed: September 18, 1974
    Date of Patent: September 7, 1976
    Assignee: Hollandse Signaalapparaten B.V.
    Inventors: Bernhardus Walter Antonius Burgers, Wilhelmus Antonius Teulings
  • Patent number: 3974449
    Abstract: An adaptive feedforward transversal equalizer acting jointly with a data decision-directed demodulating carrier recovery system to achieve substantially jitter-free passband equalization of a suppressed-carrier coherent data signal without the use of pilot tones is improved by adding a feedback transversal filter section operating on past demodulated data symbols. The weighted output of the feedback section is subtracted from the demodulated output output of the feedforward section to provide signals from which data decisions are made and common error signals are derived. Tap-gain coefficients for both feedforward and feedback filter sections and phase angle for the demodulating carrier recovery system are adaptively updated in accordance with the common error signal. Severe frequency offset and phase jitter are simultaneously compensated.
    Type: Grant
    Filed: March 21, 1975
    Date of Patent: August 10, 1976
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: David Duncan Falconer
  • Patent number: 3974452
    Abstract: A receiver is disclosed for signal-seeking operation on a plurality of channels. The receiver uses power cycling of the RF amplifier stage, mixers, local oscillators and intermediate frequency amplifiers which is in synchrony with the electronic stepping switch used to sequence among the channels. The power which is cycled to these portions of the receiver passes in series through light emitting diode channel indicators.
    Type: Grant
    Filed: September 6, 1974
    Date of Patent: August 10, 1976
    Assignee: Regency Electronics, Inc.
    Inventor: Charles Cunningham
  • Patent number: 3973204
    Abstract: A microwave mixer is integrated with an yttrium-iron-garnet (YIG) tuning element to provide a YIG tuned heterodyne conveter or mixer. An input signal is provided to the YIG tuning element by an input coupling loop and local oscillator power is provided to an output coupling loop. A mixing diode is connected in series with the output coupling loop close to the YIG tuning element, and the mixing products appear on the output coupling loop. The output coupling loop is connected to a circuit which separates the local oscillator input signal from the intermediate frequency output signal.
    Type: Grant
    Filed: February 25, 1975
    Date of Patent: August 3, 1976
    Assignee: Hewlett-Packard Company
    Inventor: Richard C. Keiter
  • Patent number: 3973201
    Abstract: A premodulation filter is used to slow the transitions of a digital data signal to reduce spectrum occupancy. Carrier signal generator means provides in-phase and quadrature-phase carrier signals. A first modulation means receives the in-phase carrier signal for modulation by the filtered digital data signal. A second modulation means receives the quadrature-phase carrier signal and a control signal for modulation of the quadrature-phase carrier signal by the control signal. A combining means receives the modulated signals from the first and the second modulation means for providing a combined output signal. An amplitude limiter receives the combined output signal for limiting the amplitude variations in the combined signal. A circuit means receives the filtered digital data signal, and provides the control signal which adjusts the amplitude of the quadrature-phase carrier signal to complement the amplitude of the modulated in-phase carrier signal.
    Type: Grant
    Filed: August 16, 1974
    Date of Patent: August 3, 1976
    Assignee: NCR Corporation
    Inventor: Carl F. Andren
  • Patent number: 3971990
    Abstract: A pulse transmitter-receiver system for detecting the presence and proximity of objects employs transmission of short base-band or subnanosecond electromagnetic signals and reception thereof by a dispersionless, broad band transmission line antenna system with a receiver circuit cooperating with a biased semiconductor diode located within the transmission line antenna system for instantaneously detecting substantially the total energy of each reflected base-band pulse and for providing corresponding outputs suitable for indication of the presence or of the range of such proximate objects.
    Type: Grant
    Filed: February 26, 1975
    Date of Patent: July 27, 1976
    Assignee: Sperry Rand Corporation
    Inventor: Gerald F. Ross
  • Patent number: 3970937
    Abstract: A modem having a transmitter portion including a first modulator connected to receive audio frequency signals and supplying an output signal through a single sideband filter to a second modulator providing an output signal at a unique channel frequency, a receiver portion including a first demodulator connected to receive transmitted signals and supplying an output signal to a second demodulator through a single sideband filter with the second demodulator providing audio frequency output signals, a carrier switch supplying a small amount of the carrier to the second modulator during operation of the transmitter and a carrier level switch associated with the carrier switch for supplying the carrier at high and low levels, and a crystal controlled channel oscillator connected to the second modulator of the transmitter portion and the first demodulator of the receiver portion with removable, plugin crystals connected thereto for controlling the channel frequency of the modem.
    Type: Grant
    Filed: December 19, 1974
    Date of Patent: July 20, 1976
    Assignee: Motorola, Inc.
    Inventors: Wayne J. Bates, Walter L. Berenson, William H. Euchner, Jr., James H. Grigg, Morton Stern, Ronald W. Taylor
  • Patent number: 3970936
    Abstract: Telecommunication is effected by generating a beam of mu mesons or muons, varying a property of the beam at a modulating rate to generate a modulated beam of muons, and detecting the information in the modulated beam at a remote location.
    Type: Grant
    Filed: May 29, 1973
    Date of Patent: July 20, 1976
    Assignee: The United States of America as represented by the United States Energy Research and Development Administration
    Inventor: Richard C. Arnold
  • Patent number: 3970939
    Abstract: A self-contained alarm signal apparatus is disclosed which comprises an electrical signal generator, and encoder connected to receive the output of the generator and to encode a message to be delivered to a transmitter, a source of stored mechanical energy, and connector means for intermittently applying energy from the energy source to the generator for production of an electrical signal. Also provided are first and second input devices for delivering mechanical inputs to the connector means, each of the mechanical inputs operative to cause the connector means to apply energy to the generator. The first input device comprises manually actuable means and the second input device is automatically operable and comprises a timer and means to deliver a mechanical input to the connector means at predetermined time intervals.
    Type: Grant
    Filed: October 22, 1974
    Date of Patent: July 20, 1976
    Assignee: Solid State Technology, Inc.
    Inventor: John G. Willis
  • Patent number: 3967061
    Abstract: A method and apparatus is described for receiving a data stream incorporating a self-clocking Manchester code. The data stream is applied to monostable multivibrators which produce pulses at each positive-going and negative-going transition in the voltage level of the data stream. Output pulses from the monostable multivibrators are applied to a third monostable multivibrator which is responsive to only the positive-going pulses applied thereto; the third multivibrator produces an output pulse having a period greater than one-half the bit period, but less than the whole bit period, of the data stream. The positive-going voltage transition of the output of the third multivibrator is used to trigger a clock pulse which is applied to a pair of gates. The gates enable a pair of latches to which the data stream is applied to recover data from the stream and apply the data to a shift register.
    Type: Grant
    Filed: March 5, 1975
    Date of Patent: June 29, 1976
    Assignee: NCR Corporation
    Inventor: Joseph J. Dobias
  • Patent number: 3967062
    Abstract: A method and apparatus is described for generating a data stream incorporating a self-clocking Manchester type code. The data, originally stored in a shift register, is shifted out of the register in bi-level form with a first voltage level representing one binary value and a second voltage level representing a second binary value. The output voltage levels from the shift register are applied simultaneously to two AND gates with an inverter interposed between the shift register and one of the AND gates. Two clock pulse trains are utilized, one having a clock rate twice the clock rate of the other. The clock pulses are respectively applied to the AND gates, the outputs of which are OR'ed and applied to a flip-flop. The output pulses from the OR-gate clocks the flip-flop which toggles to provide a suitably encoded self-clocking data stream at the true and the not true outputs thereof.
    Type: Grant
    Filed: March 5, 1975
    Date of Patent: June 29, 1976
    Assignee: NCR Corporation
    Inventor: Joseph J. Dobias
  • Patent number: 3962641
    Abstract: In a tuning apparatus for a broadcast receiver having a voltage controlled variable frequency oscillator for generating a local frequency signal corresponding to a selected broadcasting station, and being provided with a phase locked loop including a reference signal oscillator, a variable frequency divider which receives the local frequency signal, usually through a prescaler, for further dividing the local frequency signal with a variable dividing ratio, and a frequency and phase comparator for comparing outputs of the reference signal oscillator and the variable frequency divider, respectively, and producing a corresponding control voltage which is applied through a low pass filter to the voltage controlled oscillator for determining the local frequency signal in dependence on the dividing ratio of the variable frequency divider; a dial member is provided with a scale calibrated to represent broadcast frequencies over a predetermined frequency band and cooperating with an indicator movable along the scale
    Type: Grant
    Filed: December 20, 1974
    Date of Patent: June 8, 1976
    Assignee: Sony Corporation
    Inventor: Hisashi Suwa
  • Patent number: 3962642
    Abstract: A channel indicator device is disclosed in which a tuner for achieving station selection between VHF and UHF band television broadcastings is provided in association with a single channel selection shaft of the tuner, a switch for band selection is also provided in connection with the channel selection shaft, and an indicator in the type of a plural-unit indication is provided, the indicator having a numeral corresponding to a selected channel in response to the channel selection and a code corresponding to a selected one of the VHF and UHF bands. The indicator has provided with a plural-unit indication member consisting of a plurality of indication elements to form a numeral "8".
    Type: Grant
    Filed: June 14, 1974
    Date of Patent: June 8, 1976
    Assignee: Sony Corporation
    Inventors: Nobuo Kitamura, Takao Mogi
  • Patent number: 3962640
    Abstract: An automatic oscillator frequency control is provided for operations such as employed in channel selection in radio and television receiver systems. A code is stored representative of a selected frequency band within which a selected channel is located. The frequency of an oscillator is varied monotonically from a reference frequency at one extremity of a selected frequency range successively to traverse a plurality of such frequency bands. A frequency marker is generated at the margin of each band and the markers are counted. The number of counted markers is compared with the stored code to generate a control state. In response to the control state, a pattern control causes it to dither between limits of the selected band until a signal is encountered at the selected frequency within the selected band. At that point, the oscillator is locked to the frequency of the received signal.
    Type: Grant
    Filed: September 9, 1974
    Date of Patent: June 8, 1976
    Assignee: Texas Instruments Incorporated
    Inventor: Steven J. Bomba
  • Patent number: 3961266
    Abstract: A television tuning system employing a varactor tuner in which the local oscillator frequency is time sampled by an asynchronously gated counting system to provide tuning information for a channel number computer. The computer has a presettable modular scaler and presettable units and tens counters to derive the corresponding channel number and a fractional portion of the intrachannel spacing. A comparator is coupled to the channel number computer for comparing the derived channel number information with the desired or input channel number information. A keyboard-selected channel number is encoded and stored in a memory which supplies the information to the comparator and to a decoder display unit for visually displaying the selected channel number. The memory also supplies information to a band decoder which provides band preset information to the channel computer and selectively activates the VHF and UHF tuners.
    Type: Grant
    Filed: January 3, 1974
    Date of Patent: June 1, 1976
    Assignee: Zenith Radio Corporation
    Inventor: Akio Tanaka
  • Patent number: 3961264
    Abstract: A frequency converter circuit includes an input voltage-to-current converter which delivers signal current to a tuned IF circuit via a current steering circuit controlled by a local oscillator. In a preferred embodiment voltage-to-current conversion is effected without introducing unwanted harmonics by a double-gate MOSFET. Current steering is performed by a pair of push-pull connected transistors alternately driven into saturation by the local oscillator so that they alternately deliver signal current to the tank circuit in opposite senses. A current-limited diode clamps the output signal level in response to high input current levels to prevent over-driving an output filter.
    Type: Grant
    Filed: May 2, 1974
    Date of Patent: June 1, 1976
    Assignee: Hekimian Laboratories, Inc.
    Inventors: Norris C. Hekimian, Walter Mack