Including Demodulator Patents (Class 348/507)
  • Patent number: 11088890
    Abstract: Methods and apparatus for wired communications are disclosed. A method for transmitting a data stream through a wired communications channel includes encoding the data stream to produce a first baseband modulating signal I(t) and a second baseband modulating signal Q(t) whose amplitudes together represent a time series of complex symbols (I, Q) each selected from a two-dimensional (2-D) constellation of symbols distributed on the phase plane about the origin such that at least one of the baseband modulating signals has a substantially non-zero mean amplitude, modulating the baseband signals I(t) and Q(t) to produce a modulated signal, wherein the I(t) and Q(t) components of the modulated signals are generally fixed in quadrature, and providing the modulated signal to a wired communications channel.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: August 10, 2021
    Assignee: SEESCAN, INC.
    Inventors: Stephanie M. Bench, Roger B. Shaffer
  • Patent number: 10200021
    Abstract: In accordance with an embodiment, a synchronous N pulse burst generator includes an input for an intermediate frequency trigger signal and a signal path extending from the input. The signal path includes a series of N AND gates and an OR gate. Each AND gate is arranged to receive two inputs from the signal path. The signal path introduces a time delay between the two inputs received by each AND gate. A second input of the two inputs is inverted. The signal path introduces the time delay between successive AND gates from the series of N AND gates. An OR gate receives outputs from the series of N AND gates and outputs an A/D clock signal.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: February 5, 2019
    Assignee: ANRITSU COMPANY
    Inventor: Donald Anthony Bradley
  • Patent number: 9121754
    Abstract: A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.
    Type: Grant
    Filed: May 31, 2012
    Date of Patent: September 1, 2015
    Assignee: SenSanna Incorporated
    Inventor: Jacqueline H. Hines
  • Patent number: 8856857
    Abstract: This technique relates to a receiving device, a receiving method, and a program that can demodulate transmitted signals with high accuracy. A receiving device of this disclosure includes: an amplifying unit that amplifies a received signal; an adjusting unit that adjusts gain of the amplifying unit in accordance with power of the signal; a demodulating unit that demodulates the amplified signal; and a detecting unit that detects an interval from the signal, information having the same content continuously appearing in the interval. The adjusting unit restricts the process of adjusting the gain of the amplifying unit in accordance with a result of the detection of the interval. This disclosure can be applied to receiving devices that receive broadcast signals compliant with DVB-C2 via a CATV network.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: October 7, 2014
    Assignee: Sony Corporation
    Inventors: Kenichi Kobayashi, Naoki Yoshimochi
  • Patent number: 8704952
    Abstract: A video decoder that separates and analyzes analog video signals includes a hue and saturation separator and a video signal determiner. The hue and saturation separator demodulates from a component video signal chroma signal, which includes a hue signal and a saturation signal. The video signal determiner determines at least one video signal characteristic of the component video signal dependent on the hue and saturation signal. The video signal determiner may include a mode determiner that determines the encoding standard of the video signal, and a color burst determiner that determines a location of a color burst signal with the video signal. The mode determiner may include a signal lock detector, a sequence matcher, and an encoding mode selector. The color burst determiner may include an absolute value determiner and a burst position determiner.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: April 22, 2014
    Assignee: STMicroelectronics International N.V.
    Inventor: Ravindranath Ramalingaiah Munnan
  • Patent number: 8654873
    Abstract: In one embodiment, a Television (TV) receiver to perform a method of synchronizing a demodulator at a Viterbi decode input in the TV receiver using one or more bit de-interleaved even and odd Orthogonal Frequency Division Multiplexing (OFDM) symbols is provided. The method includes (i) performing a Viterbi decoding on the bit de-interleaved even and odd OFDM symbols when a frame boundary does not exist for the bit de-interleaved even and odd OFDM symbols, (ii) performing a convolutional encoding on an decoded data output of the Viterbi decoding, (iii) determining whether an output of the convolutional encoding of the bit de-interleaved OFDM symbols matches an input at a Viterbi decode, and (iv) determining whether the output of the convolutional encoding of the bit de-interleaved even and odd OFDM symbols matches with a SYNC pattern or a SYNC? pattern to obtain a RS packet align boundary.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: February 18, 2014
    Inventors: Gururaj Padaki, Sunil Hosur Rames, Rakesh A Joshi, Raghavendra Raichur, Rajendra Hegde
  • Patent number: 8648965
    Abstract: An image signal processor and a method for processing an image signal thereof are disclosed. When the image signal processor executes an automatic chroma gain control (ACC), the image signal processor adjusts a variable rate of ACC gain according to a size of an input color signal to reduce a time for processing the ACC. Even if a difference between the size of the input color signal and the size of a reference color signal is large, the ACC is rapidly processed. As a result, transient phenomenon disappears from a screen.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: February 11, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hye-joung Park
  • Patent number: 8279350
    Abstract: A method of composite decoding in which the input signal is converted into the frequency domain, and the symmetry of frequency components with respect to the subcarrier frequency is compared. The comparison is varied in dependence upon the frequency being processed. In this way, the separation can be adapted to suit known characteristics of different portions on the input spectrum. This is particularly useful for processing NTSC signals. The allocation of a particular component to chrominance may be biased in dependence upon a measure of the luminance information of the composite signal at a corresponding spatial frequency.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: October 2, 2012
    Assignee: Snell Limited
    Inventor: Martin Weston
  • Patent number: 7872689
    Abstract: A method of composite decoding in which the input signal is converted into the frequency domain, and the symmetry of frequency components with respect to the subcarrier frequency is compared. The comparison is varied in dependence upon the frequency being processed. In this way, the separation can be adapted to suit known characteristics of different portions on the input spectrum. This is particularly useful for processing NTSC signals. The allocation of a particular component to chrominance may be biased in dependence upon a measure of the luminance information of the composite signal at a corresponding spatial frequency.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: January 18, 2011
    Assignee: Snell Limited
    Inventor: Martin Weston
  • Patent number: 7671923
    Abstract: A digital processing system and method for tracking a subcarrier included in a video signal are provided, where a phase comparator tracks the phase of a color burst signal based on predetermined supposed phases, Y/C separation and demodulation are carried out based on a compensation phase that is updated by a phase compensator in response to the tracked phase, and the Y/C separation and demodulation are performed based on a compensation frequency determined by a frequency compensator by checking short-term and long-term variations in the updated compensation phase.
    Type: Grant
    Filed: December 19, 2005
    Date of Patent: March 2, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Heo-Jin Byeon, Kyoung-Mook Lim, Hyung-Jun Lim, Seh-Woong Jeong, Jae-Hong Park, Sung-Cheol Park
  • Patent number: 7545937
    Abstract: A video system (100) includes a chrominance processing arrangement (200). The chrominance processing arrangement (200) includes a burst accumulator (240) operative to detect a polarity inversion within a burst interval associated with a horizontal line of video information, and generate at least one output signal that compensates for the detected polarity inversion.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: June 9, 2009
    Assignee: Thomson Licensing
    Inventor: Mark Francis Rumreich
  • Patent number: 7508451
    Abstract: Phase noise mitigation in an analog video receiver implemented in an integrated circuit device. A phase correction value that indicates a phase offset between a synthesized sinusoid and a reference sinusoid conveyed in a horizontal retrace region of a composite video signal is periodically generated. A phase error that will accumulate during an interval between horizontal retrace regions of the composite video signal is estimated based, at least in part, on the phase correction value, and the phase of a chroma signal component of the composite video signal is adjusted based on the estimated phase error.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: March 24, 2009
    Assignee: Telegent Systems, Inc.
    Inventors: Samuel Sheng, Weijie Yun
  • Patent number: 7489338
    Abstract: A system and method for automatically controlling color synchronization polarity during video decoding. Various aspects of the present invention may comprise at least one module that is adapted to monitor color synchronization polarity at a plurality of instances over a period of time. The at least one module may also, for example, be adapted to generate a sequence of signals indicative of the color synchronization polarity correctness at the plurality of instances. The at least one module may additionally, for example, be adapted to statistically analyze the sequence of signals. The at least one module may further, for example, be adapted to determine, based at least in part on the statistical analysis of the sequence of signals, whether color synchronization polarity is correct. The at least one module may still further, for example, be adapted to control color synchronization polarity based, at least in part, on the polarity correctness determination.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: February 10, 2009
    Assignee: Broadcom Corporation
    Inventors: Wen Huang, Brad Delanghe, Aleksandr Movshovich
  • Patent number: 7349009
    Abstract: A phase shifter (70) for correcting the phase of a sub-carrier signal input into a decoder to a burst signal has a phase shift setting (5), a correction amount setting (9?), a phase shifter (6) and a 90-degree phase shifter (7). The phase shift setting (5) holds a phase shift amount for all the scanning lines. The correction amount setting (9?) holds a correction phase shift amount for every part of all the scanning lines. The phase shifter (6) partially shifts the phase of the sub-carrier signal in a unit of part of all the scanning lines, and shifts it in a unit of all the scanning lines, based on said phase shift amount and said correction phase shift amount. The 90-degree phase shifter (7) generates a sub-carrier signal orthogonal to said phase shifted sub-carrier signal.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: March 25, 2008
    Assignee: Leader Electronics Corporation
    Inventor: Hiroyuki Tomita
  • Patent number: 7224407
    Abstract: A color demodualation device having an AD converter, a phase signal generator, a burst data generator and a multiplier. The AD converter produces digital samples of chrominance signal at a frequency four times a color subcarrier frequency, and the phase signal generator generating a phase signal for identifying phases of a burst signal and color subcarrier signals modulated by respective B-Y and R-Y signals. The burst data generator produce burst data corresponding to the burst signals modulated by respective B-Y and R-Y signals. The burst respective color subcarrier signals according to the phase signal. The multiplier produces products of the burst data and the digital samples of the chrominance signal, from which digital samples of the respective R-Y and B-Y signals are produced.
    Type: Grant
    Filed: July 5, 2002
    Date of Patent: May 29, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hideki Yoshii, Masaki Yamakawa, Jun Someya, Yoshiaki Okuno
  • Patent number: 6912258
    Abstract: A single integrated circuit multi-standard demodulator includes an adaptive inverse channel estimator for frequency domain equalization which employs a recursive least square cost function in estimating the inverse channel from the received signal and an error estimate. Utilizing a diagonal correlation matrix, the solution to may be determined utilizing fewer computational resources than required by conventional frequency domain equalizers, shifting from a computational intensive to memory intensive implementation. The memory requirement is fully satisfied by memory available within conventional OFDM decoders, and the necessary computational resources may be readily mapped to the resources available within such decoders, improving integrated circuit cost-effectiveness of the multi-standard demodulator.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: June 28, 2005
    Assignee: Koninklijke Philips Electtronics N.V.
    Inventor: Dagnachew Birru
  • Patent number: 6839092
    Abstract: In accordance with an embodiment of the present invention a microprocessor in the horizontal phased lock loop reads the horizontal timing with respect to the sync input and provides an increment inch to the horizontal discrete time oscillator to make corrections in its timing to maintain lock to the sync input. The horizontal discrete time oscillator output is used to produce a pixel clock which drives the color discrete time oscillator in a color phased locked loop. A microprocessor reads a phase error between the color burst input and the color local oscillator frequency and writes an increment incsc to the color discrete time oscillator to maintain lock to the color burst. The horizontal phase locked loop adjusts inch that varies about nominal increment (nom_inch) by ?h. The feed forward error correction for the adjustment to the color discrete time oscillator is the nomimal increment (nom_incsc) and a feed forwarded scaled version of ?h.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: January 4, 2005
    Assignee: Texas Instruments Incorporated
    Inventor: Karl Renner
  • Patent number: 6765621
    Abstract: A color system discriminator is provided with a frequency detector, a vertical-synchronizing frequency detector, a plurality of color demodulators, a demodulating switch, and a controller. The type of the color system of a received signal is determined with reference not only to the burst lock frequency indicated in the tuner detection signal and the phase of the R-Y color difference signal of the image signal, but also to the frequency of the sound carrier signal and the vertical synchronizing frequency.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: July 20, 2004
    Assignee: NEC Corporation
    Inventor: Masao Okada
  • Patent number: 6760076
    Abstract: There is disclosed a system and method for recovering a recurring data segment synchronization pattern in the presence of an arbitrary phase rotation of a pilot carrier by detecting and compensating for the amount of the phase rotation. The system comprises a first synchronization pattern detector capable of receiving a real component of a complex signal and detecting a data segment synchronization pattern on the real component, and a second synchronization pattern detector capable of receiving an imaginary component of a complex signal and detecting a data segment synchronization pattern on the imaginary component. There is also disclosed a method for compensating a pilot carrier phase rotation comprising the steps of determining the angle of pilot carrier phase rotation present in a complex signal and rotating the pilot carrier signal through the same angle in the opposite direction.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: July 6, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Karl R. Wittig
  • Patent number: 6753924
    Abstract: In a conventional construction to obtain a reference signal for a tuner and a subcarrier for color difference signal demodulation by only one quartz oscillator, the reference signal is unstable due to a PLL operation for oscillation of the subcarrier, which causes tuning error or tuning shift. To realize stable tuning operation, in an oscillation signal processing apparatus having a construction to use one quartz oscillator to obtain a reference signal for a tuner and a subcarrier to demodulate a color difference signal, a PLL operation is performed with the quartz oscillator and a color burst signal when the tuning operation is not performed, while a phase comparison operation is stopped and oscillation is fixed to 3.58 MHz when the tuning operation is performed.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: June 22, 2004
    Assignee: Funai Electric Co., Ltd.
    Inventors: Hirotsugu Suzuki, Kazuhiko Yamamoto
  • Patent number: 6567129
    Abstract: A color demodulation apparatus having color demodulation capabilities as the conventional ones, with its size reduced by sharing part of processing circuit therein is provided. An adder circuit 10 and a SW circuit 11 shift the phase of a ramp wave generated by a VCO circuit 9 alternately 90 degrees and 180 degrees for each clock. A SIN data generator circuit 12 generates a phase alternate SIN wave signal from the shifted ramp wave. A multiplier circuit 3 performs R-Y and B-Y demodulation through multiplexing based on the phase alternate SIN wave signal. An accumulator circuit 6 accumulates burst signals of each of R-Y and B-Y signals of the demodulated, multiplexed signal. A second load hold circuit 8 separately outputs an R-Y burst signal to the VCO circuit 9, and a B-Y burst signal to a comparator circuit 13, constituting two feedback loops. A first load hold circuit 5 separates R-Y and B-Y signals from the multiplexed signal, and outputs these two signals.
    Type: Grant
    Filed: November 7, 2000
    Date of Patent: May 20, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Nobuo Taketani, Hiroshi Moribe, Hisao Morita, Hiroshi Ando, Ryuichi Shibutani
  • Patent number: 6330034
    Abstract: A microprocessor controlled color phase locked loop is provided which provides flexibility and adaptability for different television standards and sampling rates. Color burst phase error and color burst amplitude information are stored in data registers located at the output of the phase locked loop's low pass filter rather than at the output of the color demodulator.
    Type: Grant
    Filed: October 30, 1998
    Date of Patent: December 11, 2001
    Assignee: Texas Instruments Incorporated
    Inventors: Karl Renner, Peter Chang
  • Patent number: 6215528
    Abstract: The key component of a digital PAL or NTSC color decoder is a quadrature demodulator for these AM modulated signals. For a SECAM color decoder, however, an FM demodulation is required which is conventionally implemented using a Hilbert filter which is followed by a CORDIC processor and a differentiation stage. It would be advantageous if for multi-standard applications a general-purpose color demodulator for PAL, NTSC and SECAM systems could be implemented on one chip having as much as possible common demodulation processing stages. According to the invention a single common quadrature mixer is used for all three color systems. A resulting bias effect caused by the use of a single mixing frequency is corrected in a clamping stage. The bias effect can also be used for line identification.
    Type: Grant
    Filed: February 18, 1999
    Date of Patent: April 10, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Jinan Lin, Maximilian Erbar
  • Patent number: 6172713
    Abstract: A color system determination circuit for use with an input video signal having a frequency component is disclosed. The circuit includes a color trap filter for attenuating the frequency component in the input video signal with the color trap filter providing a color burst output signal, a comparator for comparing the color burst output signal of the color trap filter and the frequency component of the input video signal, a maximum value detector which receives the color burst output signal of the color trap filter and a color burst sampling signal and detects a maximum value of the color burst output signal of the color trap filter during a period of the color burst sampling signal, and another maximum value detector which receives the video signal and the color burst sampling signal and detects a maximum value of the video signal during the period of the color burst sampling signal.
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: January 9, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Hisao Morita
  • Patent number: 6064442
    Abstract: A color video signal demodulating apparatus is provided. The apparatus includes a color subcarrier signal generator for generating a color subcarrier signal synchronously with a color burst, an abnormal burst detector for detecting an abnormal color burst included in a color video signal, such as a signal for the DVD, and a color subcarrier signal generation controller for controlling the color subcarrier signal generator such that no color subcarrier signal corresponding to the abnormal color burst is generated in response.
    Type: Grant
    Filed: July 22, 1998
    Date of Patent: May 16, 2000
    Assignee: Pioneer Electronic Corporation
    Inventor: Tsuneo Aihara
  • Patent number: 6038276
    Abstract: A phase lock loop which locks a numerically controlled oscillator (NCO) to a non-continuous reference signal. The phase of the reference signal is ascertained by detecting the zero crossings of the signal. The zero crossing is provided to a phase detector which compares the phase of the NCO with that of the reference signal. The phase detector generates a phase error which is provided to a loop filter. The loop filter filters the phase error and provides a control signal to the NCO. The phase detector is enabled for the duration corresponding to the time when the reference signal contains valid phase information. A mechanism detects bad reference cycles and removes the phase error corresponding to these bad reference cycles from consideration. Another mechanism detects phase locked by the phase lock loop by measuring the width of the reference cycles within the duration when the reference signal is valid.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: March 14, 2000
    Inventor: Truong T. Dinh
  • Patent number: 5995168
    Abstract: A video receiver includes a tuner, a QAM demodulator including a selective gated PLL carrier recovery circuit, and a digital equalizer. The selective gated PLL carrier recovery circuit has a normal operation mode and a selection control mode. The channel changing of the tuner is performed after the selective gated PLL carrier recovery circuit is set to the selection control mode and the digital equalizer is held at its current state.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: November 30, 1999
    Assignee: NEC Corporation
    Inventor: Manabu Yagi
  • Patent number: 5831680
    Abstract: In a color signal processing circuit capable of processing a PAL/NTSC color television signal, in order to prevent an image deterioration caused by chromatization when a PAL signal is received in an NTSC signal receiving mode, there is provided a gate control signal generating circuit for alternately generating gate control signals "GA" and "GK", one for one horizontal period and the other for a next one horizontal period, in response to application of a phase inverting pulse "R" which inverts in polarity every one horizontal period.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: November 3, 1998
    Assignee: NEC Corporation
    Inventors: Kunihiko Azuma, Kenji Mori
  • Patent number: 5703660
    Abstract: A video signal decoder using a sample clock tied to a frequency that is an integer multiple of four times the color subcarrier (4*Fsc). By using a 4*Fsc rate on a given input wave, the decoder determines the phase shift between the sample clock and the original wave being sampled. Then, the decoder calculates the color based upon that shift. Circuitry for implementing the decoder contains two major circuit paths. The decoding process consists of two main phases and each path performs a different function during each phase. During the first phase, the first path calculates constants based upon a user's hue and saturation adjustments used for chroma demodulation. Also during the first phase, the second path examines the color burst signal and from that signal finds the black level of the incoming video signal. During the second phase, the first path decodes the color in the TV signal using the constants calculated during the first phase.
    Type: Grant
    Filed: February 8, 1996
    Date of Patent: December 30, 1997
    Assignee: Cirrus Logic, Inc.
    Inventors: Robert J. Hankinson, Otto Sponring
  • Patent number: 5654767
    Abstract: In a digital chrominance signal demodulating device receiving a carrier chrominance signal obtained by digitizing an analog composite video signal, a frequency component near the horizontal frequency of the color subcarrier is extracted, and color-difference signals are output. An identifying circuit forms a selection signal for identifying one of the color-difference signals contained in the carrier chrominance signal, within a color burst signal period, on the basis of a system clock and a horizontal sync signal. A selecting circuit selects the color-difference signals on the basis of the selection signal. The color-difference signals obtained by sampling in accordance with the system clock are kept in phase with the color burst signal. Accordingly, the digital chrominance signal can be demodulated by the use of less expensive digital circuits.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: August 5, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomoaki Ikeda, Kazuhiko Yawata
  • Patent number: 5459524
    Abstract: This invention is for a reference generator and demodulator for recovering information which has been phase, modulated on (or encoded on) a carrier. The inventive concepts described herein include a novel reference measurement circuit including a sampler and phase measurement circuit to measure the carrier reference's phase and/or frequency relative to a discrete time sampling phase and frequency, and a demodulator reference signal generator to generate properly phased reference signals for use by the phase demodulator circuit. The invention is particularly useful for decoding chroma difference signals of PAL and NTSC television video signals. It is suited to be implemented in digital form, operating on digitized signals thereby deriving all of the benefits normally expected of digital signal processing, including precision, freedom from drift and freedom from alignment. The invention is also particularly well suited to implementation by integrated circuit.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: October 17, 1995
    Inventor: J. Carl Cooper
  • Patent number: 5450136
    Abstract: A decoder circuit for receiving a video input signal which includes Manchester coded data bits and a range tone component having a frequency of about 102.6 kilohertz. A phase lock loop circuit detects the presence of the 102.6 kilohertz range tone component and then generates a system clock signal which is phase locked to the range tone component of the video input signal. The system clock signal is provided to a clock generating circuit which generates a clock signal having four phases. The phase lock loop circuit also provides a logic signal which is supplied to a data detecting circuit allowing the data detecting circuit to convert the Manchester coded data bits to digital data bits.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: September 12, 1995
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Anthony Cirineo
  • Patent number: 5396294
    Abstract: Different from typical signal processing which employs a feedback control, by adopting a demodulating circuit employing AFC, which is not affected by a comb filter, the response characteristic against jitter is improved and a down converted chrominance signal can be demodulated with a good accuracy. Therefore, the noise rejection effect by a comb filter is improved, the detecting accuracy of the residual phase error is also improved, and the S/N ratio of the phase is improved by combining feedforward APC compensation with a velocity error, and this results in a much improved picture quality.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: March 7, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kunihiko Fujii, Naoshi Usuki
  • Patent number: 5355226
    Abstract: A magnetic recording-reproduction apparatus records and reproduces a wide-band video signal without a color burst signal. For this purpose, a two-step phase resetting operation is conducted on the FM carrier at the front porch and the horizontal sync pulse of the video signal so as to permit those phases to coincide with reference phases. A synchronizing panel clock generator generates the first reference signal with the first FM frequency corresponding to a peak level of the horizontal sync pulse and the second reference signal with the second FM frequency corresponding to a front porch level. In this case, the reference signals are phase-synchronous with each other at the leading edge of the horizontal sync pulse, and each of the FM frequencies is set to be an integer multiple of the horizontal scanning frequency.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: October 11, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroaki Nogami, Soichi Iwamura
  • Patent number: 5351089
    Abstract: A video signal processing device comprises: a unit for extracting a first color burst signal from a first video signal; a unit for generating a first subcarrier in synchronism with the first color burst signal extracted from the first video signal; a unit for extracting a second chrominance signal and a second color burst signal from a second video signal; a unit for demodulating the second chrominance signal and the second color burst signal on the basis of the first subcarrier to obtain a demodulated second color signal and a demodulated second color burst signal; and an operating unit for performing operation process of the demodulated second color signal on the basis of the demodulated second color burst signal in a manner such that the demodulated second color signal is converted into a corrected color signal which is substantially the same as an imaginal second color signal which is obtained on the assumption that the second chrominance signal is demodulated on the basis of a second subcarrier synchroni
    Type: Grant
    Filed: February 4, 1993
    Date of Patent: September 27, 1994
    Inventors: Yoshiyuki Matsumoto, Makoto Furihata
  • Patent number: 5325184
    Abstract: A method of and apparatus for regulating color in a color broadcasting receiver is disclosed and is composed of a tuner, a demodulator, and a burst level detector for detecting the color burst level of a video signal output from the demodulator and outputting the color burst level as a corresponding control voltage signal. A color controller is disclosed for controlling the color by emphasizing or attenuating the high band components of the video signal output from the demodulator in accordance with the control voltage level from the burst level detector, so that it is possible to receive video signals without much change in color regardless of the variation of the voltage standing wave ratio (VSWR) that varies according to changes in the connection between the broadcast antenna and RF cable.
    Type: Grant
    Filed: April 28, 1992
    Date of Patent: June 28, 1994
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sung-kyu Choi
  • Patent number: 5317410
    Abstract: An I-axis phase pulse is allowed to be detected at the sampling point of a chrominance signal with a digitally-implemented circuit. A chrominance signal (sampling frequency f.sub.1) is subsampled by a frequency f.sub.2 (f.sub.1 /N) and subsampling pulses generated in N subsampling pulse generators 10 for N phases, the adjacent ones of the pulses being shifted by one clock (1/f.sub.1) with respect to one another. The subsampled chrominance signal is input to an I-axis determining circuit 17. The I-axis determining circuit operates to detect a maximum value M.sub.1 of a color burst signal (sampling frequency f.sub.1) and the data M.sub.2 after one clock and compare both of the values with each other. Based on the compared result, a selecting signal S.sub.4 is detected for selecting an I-axis phase pulse at the sampling point of the chrominance signal. A selecting circuit 18 selects, as an I-axis phase pulse S.sub.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: May 31, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroki Monta, Toshiaki Tsuji, Kiyoshi Imai
  • Patent number: 4944917
    Abstract: Disclosed is a method for inhibiting corrosion of metal surfaces in contact with H.sub.2 S-containing acid gases streams and aqueous amine scrubbing solutions, which method comprises: contacting the H.sub.2 S-containing stream with amine scrubbing solution in the presence of an effective amount of an ammonium or alkali-metal thiosulfate salt and an effective amount of sulfide and/or hydrosulfide ions.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: July 31, 1990
    Assignee: Exxon Research and Engineering Company
    Inventors: Patrick C. Madden, II, Z. Andrew Foroulis