Modulator Patents (Class 348/724)
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Patent number: 6633340Abstract: A video signal processor reduces the deterioration of image quality due to the superposition of noise on a sync signal included in a luminance signal. A frequency discriminator outputs a first error signal if a ratio of the frequency of a frequency-modulated signal during a sync-signal interval to the frequency of a reference frequency signal is smaller than a predetermined ratio. Alternatively, the discriminator outputs a second error signal if the ratio is greater than the predetermined ratio. If the first error signal has been input to a frequency controller a preset number of times or more during an interval before the second error signal is input thereto, the controller instructs a frequency modulator to increase the frequency of the frequency-modulated signal.Type: GrantFiled: October 23, 2000Date of Patent: October 14, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Atsushi Ohara, Takuji Yoneda
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Publication number: 20030169338Abstract: The invention relates to a method of and an apparatus for multiplexing a number of video signals.Type: ApplicationFiled: November 7, 2002Publication date: September 11, 2003Inventors: Franciscus Herman Maria Bergen, Jennifer Lynn Randall, Bruce Daniel Magid
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Publication number: 20030156228Abstract: An RF modulator includes a C/L delay compensation function of compensating for a delay of a luminance signal with respect to a chrominance signal occurring during demodulating a video signal in a TV set. The RF modulator includes a C/L delay compensation unit delaying a luminance signal by 170nsec and combining the delayed luminance signal with a chrominance signal to output a composite image signal having a C/l delay of −170nsec and a frequency modulation unit modulating the video signal received from the C/L delay compensation unit into a high frequency signal of a predetermined broadcasting channel in a single module or package. The RF modulator outputs a video signal having the luminance signal delayed by 170nsec with respect to the chrominance signal and complies with a C/L delay standard without adding any additional C/L delay compensation unit to the RF modulator.Type: ApplicationFiled: February 19, 2003Publication date: August 21, 2003Applicant: Samsung Electro-Mechanics Co., Ltd.Inventors: Jong Jin Lee, Sang Suk Kim, Chae Dong Go, Youn Joong Lee, Kyoung Soo Kwon
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Publication number: 20030151697Abstract: A wireless transmitting and receiving apparatus for wirelessly transmitting a video signal to a remote display apparatus, a transceiver therefor, and a channel determining method for determining a channel to be used in transmitting and receiving a video signal between transmitting and receiving apparatuses are provided. The video signal transmitting apparatus comprises a super heterodyne-type transmitter which selects one of a plurality of channels, modulates a video signal to be transmitted, and provides the modulated signal to an antenna; and a frequency band and channel selector which controls a modulation and demodulation frequency of the transmitter. The apparatus enables wireless transmission and reception of a video signal between a video signal processing apparatus and a remote display apparatus.Type: ApplicationFiled: September 5, 2002Publication date: August 14, 2003Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventor: Yong-jun Lim
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Patent number: 6600516Abstract: A digital radio frequency transmitter system having an input circuit for receiving digital signals to be amplified and transmitted. A digital-to-analog converter converts the digital signals into analog signals. A series circuit is provided including a radio frequency filter and a radio frequency amplifier located downstream from the converter and wherein the filter and the amplifier respectively introduce linear and non-linear distortions into the analog signals for transmission by the transmitter. A digital pre-correction circuit is located upstream from the digital-to-analog converter for pre-correcting the digital signals in a manner to compensate for at least some of the distortions. An analog pre-correction circuit is interposed between the digital-to-analog converter and the series circuit for pre-correcting the analog signals to additionally compensate for at least some of the distortions prior to application to the series circuit.Type: GrantFiled: April 21, 2000Date of Patent: July 29, 2003Assignee: Harris CorporationInventors: David Christopher Danielsons, Paul Henry Mizwicki
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Patent number: 6567132Abstract: An upconverter for converting IF television signals to VHF or UHF signals prior to broadcast is configured to process either analog or digital television signals. The upconverter identifies the type of incoming television signal and generates an appropriate reference signal depending on whether the incoming television signal is digital or analog. In an analog format, the reference signal is used by the modulator generating the IF signal to synchronize phase with the signals output by various other upconverters. In a digital format, the reference signal is used, for example, as a test signal for the upconversion circuit.Type: GrantFiled: March 10, 1999Date of Patent: May 20, 2003Assignee: General Instruments Corp.Inventors: Donald E. Groff, Marlin F. McGregor, Jr.
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Patent number: 6559898Abstract: An encoder-modulator for coupling a digital baseband television signal to a VSB digital television receiver that includes filters, equalization circuitry, and forward error correction circuitry for correcting signal impairments that are below a given threshold. The encoder-modulator processes the baseband signal for low power transmission on an RF channel with less-than-nominal bandpass characteristics. A coaxial cable or other low noise communication link directly connects the RF signal to the RF input of the television receiver. Any errors or signal impairments in the transmitted signal that are below the predetermined threshold are corrected by the filters and equalization circuitry built into the VSB digital television receiver.Type: GrantFiled: April 27, 1999Date of Patent: May 6, 2003Assignee: Zenith Electronics CorporationInventors: Richard W. Citta, Raymond C. Hauge, Thomas P. Horwitz, Paul A. Snopko
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Patent number: 6515609Abstract: A radio receiver comprises frequency translation means(20, 21, 22) for frequency down converting an input signal to an intermediate signal, digital channel selection filtering means including at least one analogue-to-digital converter(ADC)(32, 33), the ADC comprising an over-sampling quantizer(Q1, Q2) having a plurality of dynamically selectable quantization levels, and means(30, 31, 36) responsive to the characteristics of the input signal for adjusting the resolution of the ADC to the characteristics of the input signal. The ADC may comprise a Sigma-Delta ADC. The resolution may be adjusted by altering the over-sampling rate and/or selecting the number of quantization levels to handle the prevailing interference and the wanted signal.Type: GrantFiled: March 9, 2000Date of Patent: February 4, 2003Assignee: Koninklijke Philips Electronics N.V.Inventor: Timothy J. Moulsley
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Patent number: 6515712Abstract: A signal distortion compensating apparatus and method in a digital TV translator are provided that extract a reference signal from a modulator output of a digital TV translator, and conduct a pre-correction based on the extracted reference signal to compensate for a signal distortion involved in the digital TV translator. The compensating apparatus can include a modulator that modulates an input signal while conducting a distortion pre-correction controlled by a control signal applied thereto on the input signal. The modulator outputs baseband signals divided from the input signal. A signal processing unit processes the signals outputted from the modulator, and transmits the resultant signal to subscribers. An auto correction unit compares the signal, which is outputted in a distorted state from the signal processing unit, with a reference signal derived from the baseband signals output by the modulator, and generates the control signal based on the result of the comparison.Type: GrantFiled: July 18, 2000Date of Patent: February 4, 2003Assignee: LG Information & Communications, Ltd.Inventor: Chang Seop Jeong
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Patent number: 6473136Abstract: Motion information for an object and background information are broadcast-transmitted on a transmitting side. On a receiving side, the motion information and the background information are received, and one of a plurality of character models previously stored is selected. A character image is generated using the selected mode and the received motion information. The character image and the received background image are synthesized and displayed on one screen. The viewer can select a character of his or her own liking, and can view the broadcast-transmitted program as a program in which the particular character appears.Type: GrantFiled: December 8, 1999Date of Patent: October 29, 2002Assignee: Hitachi, Ltd.Inventors: Takashi Hasegawa, Yoshito Nejime
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Patent number: 6466277Abstract: A digital method and apparatus modulates a stream of digitized samples from a source, by a digital representation of a carrier to provide, for example, a 6 MHz bandwidth television signal selectively centered either at 63 MHz (Channel 3), 69 MHz (Channel 4) or 5.38 MHz IF (baseband). More particularly the method includes first resampling the stream of digitized samples and then modulating the resampled stream of samples with a repeating short sequence of complex values, which complex values represent a digitized exponential carrier.Type: GrantFiled: August 24, 1999Date of Patent: October 15, 2002Assignee: Thomson Licensing S.A.Inventor: David Lowell McNeely
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Publication number: 20020145679Abstract: A tuner of a digital television signal translator tunes to receive an RF digital television signal on a first selected television channel. A demodulator provides a baseband digital television signal from the RF digital television signal to which the tuner is tuned. The baseband television signal includes a data component identifying the first selected channel. A data replacer replaces the data component identifying the first selected channel with a data component identifying a second selected channel different from the first selected channel. The output of a modulator is modulated by the baseband television signal including the data component identifying the second selected channel for transmission as a digital television signal on the second selected channel.Type: ApplicationFiled: April 6, 2001Publication date: October 10, 2002Inventors: Ernesto C. Barreyro, Timothy V. Frahm, Michael G. White
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Publication number: 20020113905Abstract: A linear compensation system of a digital TV relay or other apparatus preferably includes a transmitting unit configured to modulate a data to an intermediate frequency (IF) signal, up convert the IF signal to an RF signal, and amplify the RF signal to a predetermined level using a high power amplifier (HPA). The system also includes a linear compensation unit to preferably directly vary a step size of an adaptive equalizer according to whether a signal-to-noise ratio (SNR) or an error vector magnitude (EVM) for an output signal of the HPA satisfies an advanced television systems committee (ATSC) or other standard. The linear compensation unit is thus configured to output an improved linear compensation coefficient to a modulator of the transmitting unit.Type: ApplicationFiled: December 26, 2001Publication date: August 22, 2002Applicant: LG Electronics Inc.Inventor: Ji Won Lee
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Patent number: 6437822Abstract: A method and apparatus are disclosed for generating an 8-level vestigial side band modulated radio frequency signal as a high definition television test signal. The invention utilizes the above in connection with a single ISA bus computer board that may be utilized in a personal computer for generating signals used to demonstrate HDTV products without the need for over the air HDTV broadcast signals.Type: GrantFiled: March 30, 2000Date of Patent: August 20, 2002Assignee: Sencore, Inc.Inventor: Michael I. Stolen
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Patent number: 6433830Abstract: The proposed phase lock technique uses various feedback loops to lock the frequency and phase of a CATV modulator output signal to that of an off-air signal without directly measuring the output frequency. One embodiment includes a tuner for receiving the off-air signal and generating an intermediate frequency signal and a phase-frequency detector for comparing the frequency and phase of the intermediate frequency signal generated by the tuner with the frequency and phase of an intermediate frequency signal generated by the modulator based on a reference input signal. The output of the phase-frequency detector is used to control the reference input signal into the modulator and the reference input signal to the tuner such that the frequency and phase of the modulator output signal is locked to the frequency and phase of the received off-air signal.Type: GrantFiled: June 14, 1999Date of Patent: August 13, 2002Assignee: General Instrument CorporationInventors: Donald Groff, Edgar Rhodes
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Publication number: 20020080285Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into, low and high, frequency band components which are designated as a first and a second data streams respectively.Type: ApplicationFiled: December 21, 2000Publication date: June 27, 2002Inventor: Mitsuaki Oshima
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Patent number: 6411342Abstract: A signal of a vestigial sideband modulated wave is generated by use of a first oscillator, an amplitude-modulator and a surface acoustic wave filter for vestigial sideband filtering at a frequency being higher than the carrier frequency of a video signal, the signal is frequency-converted to a given transmission channel by use of a first PLL frequency synthesizer, a first control circuit, a frequency converter and a filter.Type: GrantFiled: February 2, 1998Date of Patent: June 25, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Akihiro Tatsuta
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Patent number: 6388717Abstract: A digital television transmitting system is presented having a recovery circuit for recovering non-return to zero (NRZ) data pulses and transport clock pulses from a biphase-mark serial data pulse stream and wherein the recovered NRZ data pulses and the recovered transport clock pulses are applied to modulation and amplifying circuits for broadcasting by an antenna. The recovery circuit includes a first circuit for receiving the biphase-mark serial pulse stream and providing therefrom a train of first clock pulses wherein the rising edge of each the biphase-mark pulse corresponds with a rising edge of one of the first clock pulses. A second circuit receives the biphase-mark serial data pulses and the first clock pulses for providing therefrom a train of de-serialized data pulses each having a rising edge corresponding with a rising edge of one of the first clock pulses.Type: GrantFiled: January 20, 1999Date of Patent: May 14, 2002Assignee: Harris CorporationInventor: Joseph Lee Seccia
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Publication number: 20020047940Abstract: A modulation factor is kept immune from the influence of temperature variations. A modulator is provided with an operational amplifier to one of whose input ends are inputted video signals and to the other is applied a reference voltage and a video mixer into which are entered carrier wave signals and video signals amplified by the operational amplifier, wherein the reference voltage is raised or lowered as the gain of the video mixer increases or decreases, respectively, with a variation in temperature.Type: ApplicationFiled: October 16, 2001Publication date: April 25, 2002Applicant: Alps Electric Co., LtdInventors: Yasuharu Kudo, Etsuya Shibata
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Patent number: 6317167Abstract: Digital remodulation systems typically include digital to analog converters which have an inherent undesirable sin(x)/x frequency response. Digital remodulated signals are typically high frequency and thus not conducive to sin(x)/x pre-correction prior to digital to analog conversion. Described herein is apparatus and a method for pre-correcting the sin(x)/x roll off of the digital to analog converter in the digital signal path prior to the digital modulator which precedes the digital to analog converter. This apparatus corresponds to a cascading of spectrally symmetric and anti-symmetric transversal filters designed to compensate a relatively small portion of the frequency response of the resulting analog signal.Type: GrantFiled: August 24, 1999Date of Patent: November 13, 2001Assignee: Thomson Licensing S.A.Inventor: David Lowell McNeely
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Patent number: 6313772Abstract: A method for generating digital carrier signals for application as the carrier to a digital modulator includes providing a first repeating sequence of complex values occurring at a given sample rate and upsampling these values to a higher sample rate. A second repeating sequence of complex values is provided, wherein respective complex values in the second repeating sequence occur at the higher sample rate. The second sequence of complex values is employed to modulate the upsampled first sequence of complex values and thereby provide the complex carrier signal.Type: GrantFiled: August 24, 1999Date of Patent: November 6, 2001Assignee: Thomson Licensing S.A.Inventor: David Lowell McNeely
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Patent number: 6265949Abstract: A phase compensation apparatus and method for a digital modulator which is suitable for maintaining the optimum operating state of the modulator provided in a digital television repeater by reducing the phase distortion produced from the modulator.Type: GrantFiled: December 22, 1999Date of Patent: July 24, 2001Assignee: LG Information & Communications, Ltd.Inventor: Inn Yeal Oh
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Patent number: 6219108Abstract: Radio receivers for receiving DTV signals, in accordance with the Advanced Television Systems Committee (ATSC) standard, or analog TV, in accordance with the National Television Sub-Committee (NTSC) standard, each use a single first detector for both types of signal. This single first detector supplies its output signals to an intermediate-frequency amplifier chain for DTV signals and to another intermediate-frequency amplifier chain for analog TV signals. The response of the intermediate-frequency amplifier chain for DTV signals is synchrodyned to baseband and supplied to symbol decoding circuitry. The response of the intermediate-frequency amplifier chain for analog TV signals is supplied to a video detector. In some of the radio receivers the sound carrier of the NTSC signal has a separate, further intermediate-frequency amplifier chain. The intermediate-frequency chain for DTV signals comprises an intitial portion which has reverse AGC, a following mixer, and a final portion which also has reverse AGC.Type: GrantFiled: January 6, 1998Date of Patent: April 17, 2001Assignee: Samsung Electronics Co., Ltd.Inventor: Allen LeRoy
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Patent number: 6195797Abstract: A method and apparatus are provided for enabling multiple users to concurrently access a PC-based server in a home local area network using conventional TVs as display devices. A client system includes a TV, conventional input devices, such as a keyboard and a mouse, and a set top box for interfacing the TV to the network. The server maintains a system work area and multiple processes corresponding to user applications. The system work area is partitioned in the server into multiple independent, simultaneously active desktops, one desktop for each of the client systems. Individual processes are mapped to the appropriate desktop. Multiple frame buffers are maintained in the server, such that a different frame buffer is assigned to each client system. Each desktop is rendered within the server and stored in the corresponding frame buffer. The contents of each frame buffer are transmitted over a transmission medium to the set top box of the corresponding client system.Type: GrantFiled: February 6, 1998Date of Patent: February 27, 2001Inventor: Henry R. Williams, Jr.
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Patent number: 6177963Abstract: A video signal distribution system comprises an interface device and video signal input means for receiving TV signals on broadcast channels connected to the interface device. A plurality of video appliances and a plurality of TV sets may be connected to the interface device such that the television sets are arranged to be remote from the plurality of video appliances. A person using the system has a remote control device that may be actuated to emit signals for selecting channels for viewing and to control the video appliances. Each of the television sets includes a repeater arranged to receive the control signals from the remote control device and form corresponding electrical control signals. The interface device receives the electrical control signals corresponding to a selected TV set and directs electrical control signals to a selected one of the plurality of video appliances to provide video signals to the television sets.Type: GrantFiled: December 1, 1997Date of Patent: January 23, 2001Assignee: Multiplex Technology, Inc.Inventors: Richard T. Foye, John B. Crosby
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Patent number: 6175861Abstract: A method and apparatus are provided for enabling multiple users to concurrently access a PC-based server in a home local area network using conventional TVs as display devices. A client system includes a TV, conventional input devices, such as a keyboard and a mouse, and a set top box for interfacing the TV to the network. The server maintains a system work area and multiple processes corresponding to user applications. The system work area is partitioned in the server into multiple independent, simultaneously active desktops, one desktop for each of the client systems. Individual processes are mapped to the appropriate desktop. Multiple frame buffers are maintained in the server, such that a different frame buffer is assigned to each client system. Each desktop is rendered within the server and stored in the corresponding frame buffer. The contents of each frame buffer are transmitted over a transmission medium to the set top box of the corresponding client system.Type: GrantFiled: February 6, 1998Date of Patent: January 16, 2001Inventors: Henry R. Williams, Jr., David A. Ferris, Maurice B. Richard
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Patent number: 6169584Abstract: The depth of modulation and the absolute RF carrier level of an amplitude-modulated video signal are automatically adjusted. For adjustment of the depth of modulation, a sync tip of the video signal is sampled, corrected and normalized to a reference level, e.g., a 50% video level. A reference pulse is inserted into the video signal, e.g., in a sync pulse or in lines 22 and/or 23 of the vertical blanking interval. The reference pulse is sampled and compared to the normalized sync tip pulse to determine an error. The error is converted to an adjustment signal for a charge pump which increases or decreases the depth of modulation accordingly. For adjustment of the absolute carrier level, the insertion of a reference pulse is not required. Instead, a reference value is stored in a memory and retrieved for comparison with the corrected sync tip pulse. An error term is computed and converted to an adjustment signal for a charge pump which increases or decreases the absolute carrier level accordingly.Type: GrantFiled: December 5, 1997Date of Patent: January 2, 2001Assignees: Motorola, Inc., General Instrument CorporationInventors: Joseph B. Glaab, Alfred W. Stufflet
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Patent number: 6061101Abstract: An apparatus to modulate the digital color signal using a simple circuit that utilizes neither multiplier nor ROMs to multiplying a sine wave and cosine wave. The digital color signal modulating apparatus includes a first selector, a second selector 3, and a third selector. The first selector and the second selector provide the U signal component and the V signal component of the digital color signal to the third selector at a half cycle, rate respectively. The third selector alternately selects one of those signals, which is combined with the sub-carrier wave. For both modulations with the sine wave and with the cosine wave, the input signal is inverted and the fourth selector selects the outputs of the through path and the inversion path in turn, thus producing the modulated outputs.Type: GrantFiled: May 28, 1997Date of Patent: May 9, 2000Assignee: Oki Electric Industry Co., Ltd.Inventor: Akihiro Takei
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Patent number: 6031583Abstract: A high frequency video isolation circuit comprising: a modulating signal source for producing a modulating signal having a frequency of several hundred megahertz; an input multiplier for multiplying the modulating signal with an input video signal having frequency components in a frequency range from about several hertz to about one hundred or more megahertz, to produce a modulated video signal having frequency components in a frequency range from about one hundred megahertz to about several hundred megahertz; a first isolation transformer having an input and an output, for transforming the modulated video signal from the input to the output; and an output multiplier for multiplying the transformed modulated video signal with the modulating signal to produce an isolated output video signal having the frequency components of the input video signal.Type: GrantFiled: June 9, 1998Date of Patent: February 29, 2000Assignee: Eastman Kodak CompanyInventors: Sreeram Dhurjaty, Martin E. Trzcinski
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Patent number: 6031576Abstract: A single, common HDTV transmitter transmits a digital composite signal including station signal information of all broadcast stations in a primary market. A broadband signal of e.g., 120 MHz is established, accommodating up to 20 permanent virtual circuits (PVCs) in the broadband signal. The station signals linked to the common transmitter are packetized and digitally compressed and delivered for broadcast in a selected transmission mode such as ATM. Tuning into a broadcaster's signal will be accomplished at a receiver location by a receiver decoding the PVC address permanently assigned to the respective station. The signal is decompressed to its original HDTV format by a receiver, which may comprise a personal computer or video card, to drive the HDTV display and audio system. Each receiver is equipped with a highly directional antenna aimed at a common an antenna broadcasting the composite signal from the common transmitter.Type: GrantFiled: September 8, 1997Date of Patent: February 29, 2000Inventor: Jacob L. Kuykendall, Jr.
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Patent number: 6016169Abstract: A frequency modulation circuit which generates a frequency modulation signal responsive to a video input signal includes a programmable control circuit, an electrical flow control circuit, and an oscillation circuit. The programmable control circuit generates a plurality of electrical flow control signals responsive to an electronic data input. The electrical flow control circuit controls an electrical flow therethrough responsive to the plurality of electrical flow control signals. The oscillation circuits generates the frequency modulation signal responsive to the video input signal and responsive to the electrical flow through the electrical flow control circuit. Related methods are also disclosed.Type: GrantFiled: December 2, 1996Date of Patent: January 18, 2000Assignee: Samsung Electronics Co., Ltd.Inventor: Do-Sang Mok
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Patent number: 5946047Abstract: A network system or terminal device utilizes a unique modulation scheme that enables the transmission of digital data over a wireless, cable or direct broadcast satellite TV channel without disturbing quality of television signals. A digital data stream of the network, for example, is transparently transmitted in the television channel in a superfluous sideband segment of the frequency spectrum using a technique, herein called vestigial quadrature modulation (VQM), that entails substituting the vestigial sideband of a conventional television signal with a sideband of a data-encoded signal, preferably being QAM-modulated. A sufficient portion of the television sideband spectrum displaced by the substituted data signal, e.g., to at least the 7.sup.th harmonic, is preserved for deriving sync information that is used both for clocking the digital data from the modulated data signal and for driving vertical and horizontal sync circuits of the television.Type: GrantFiled: March 12, 1997Date of Patent: August 31, 1999Assignee: Hybrid Networks, Inc.Inventor: William C Levan
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Patent number: 5896182Abstract: Amplitude modulator comprising a differential input pair receiving a modulating input signal, and a Gilbert cell multiplying a carrier signal by the modulating input signal; anda second differential pair of transistors receiving the carrier signal, and the output signal of which is added to the output signal of the Gilbert cell.Type: GrantFiled: June 11, 1996Date of Patent: April 20, 1999Assignee: U.S. Philips CorporationInventor: Philippe Klaeyle
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Patent number: 5886752Abstract: A wideband phase and frequency modulator using a direct digital synthesis alias frequency band is described. The modulator is spurious free by the utilization of a fixed frequency at the output of the direct digital synthesizer wherein only certain submultiples of the clock frequency are used. Known frequency ratios relative to the clock frequency of the direct digital synthesizer (DDS) cause the DDS to function as a simple divider resulting in extremely low spurious levels when additional conditions are met. An additional frequency synthesizer may be utilized to achieve a tuning range since the DDS output is preferably held at a fixed frequency. At least one additional mixing operation is utilized for upconversion to a microwave frequency. Since fixed frequency ratios are used, implementation simpler than a full DDS may also be constructed consisting of digital modulators, multiplexers, digital to analog convertors, and filters.Type: GrantFiled: December 22, 1997Date of Patent: March 23, 1999Assignee: Rockwell InternationalInventor: Ray L. Cross
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Patent number: 5877821Abstract: An apparatus (300, 400) and method are provided for multimedia communications, such as for video conferencing. One of the embodiments of the apparatus for multimedia input and control (300) includes a video input (310) to produce an input video signal; an audio input (320) to produce an input audio signal; a radio frequency modulator (350); a data/control input (330) to produce an input data signal; and a processor arrangement (360) responsive when operably coupled, through a set of program instructions, to produce a first processor signal to the radio frequency modulator to combine the input video signal with the input audio signal to form a composite audio/video signal, and the processor arrangement (360) further responsive to modulate the input data signal to form a modulated input data signal and produce a second processor signal to the radio frequency modulator to combine the input video signal with the modulated input data signal to form a combined video/data signal.Type: GrantFiled: January 30, 1997Date of Patent: March 2, 1999Assignee: Motorola, Inc.Inventors: Douglas J. Newlin, Timothy M. Burke
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Patent number: 5877820Abstract: In optically transmitting a video signal comprised of luminance and chrominance signals which are frequency modulated to provide an FM luminance signal and an FM chrominance signal in respective adjacent frequency bands, such as, 6 to 20 MHz and 20 to 30 MHz, respectively, whereupon, infrared signals corresponding to the FM luminance and chrominance signals are output by respective emitting diodes, a carrier frequency for the FM chrominance signal is set, for example, between 25.93 and 26.08 MHz, so that the lower sideband wave of the FM chrominance signal is spaced by a substantial frequency from a frequency band in which a secondary distortion of the FM luminance signal is substantially generated. Further, the upper sideband wave of the FM chrominance signal is removed, as in a trap circuit, for ensuring that the transmitted FM chrominance signal will be accommodated in the respective frequency band therefor when its carrier frequency is set, as above.Type: GrantFiled: December 13, 1996Date of Patent: March 2, 1999Assignee: Sony CorporationInventors: Toshikatsu Yamamuro, Tadashi Ezaki, Hiroshi Moriuchi
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Patent number: 5875005Abstract: The method for generating a modulated television signal involves performing a first filtering and a second filtering to obtain two signals, one having a passband that is equal to complete passband and the other one having a passband that is equal to the sideband to be suppressed. The signal having a complete passband is amplitude-modulated with a video carrier, obtaining a first signal. The signal having a passband equal to the sideband to be suppressed is then divided into a first component and a second component, and the first component is phase-shifting by 90.degree. with respect to the second component. The first component is modulated with a video carrier that is phase shifted by 90.degree., obtaining a second signal. The second component of the signal having a passband equal to the sideband to be suppressed is modulated with the video carrier, obtaining a third signal. The second and third signals are then subjected to an algebraic sum, obtaining a fourth signal.Type: GrantFiled: March 6, 1996Date of Patent: February 23, 1999Assignee: M.B. International S.r.l.Inventor: Michele Bargauan
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Patent number: 5822020Abstract: The method envisages performing a first filtering and a second filtering of a video signal to obtain two signals, one signal having a passband that is equal to the complete band and a bandwidth that is a function of the frequency, and another signal whose passband is equal to the side band to be suppressed, and amplitude-modulating the signal having a complete passband with a video carrier, obtaining a first signal. The signal whose sideband is equal to the band to be suppressed is phase-shifted by 90.degree. and modulated with the video carrier phase-shifted by 90.degree., obtaining a second signal. The algebraic sum of the first signal and of the second signal obtains a third signal that represents the television signal having the desired side band.Type: GrantFiled: March 6, 1996Date of Patent: October 13, 1998Assignee: M.B. International S.r.l.Inventor: Michele Bargauan
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Patent number: 5815218Abstract: A circuit device provided in a video signal processing apparatus. The circuit device includes a tuner for tuning a television signal, an IF amplifier for demodulating the television signal, and an RF converter having an RF oscillator for modulating video and audio signals into a television signal in a VHF band. The tuner, IF amplifier and RF converter are accommodated in a shield case. Further, the circuit device includes a circuit including a resonance circuit having a coil and a capacitor for controlling an oscillation frequency of the RF oscillator and a switch for switching a parameter of the resonance circuit to vary the oscillation frequency.Type: GrantFiled: January 4, 1996Date of Patent: September 29, 1998Assignee: Funai Electric., LtdInventor: Osamu Maeda
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Patent number: 5812221Abstract: A UHF transmitter for digital TV signals includes, for example, twelve silicon carbide transistor RF output power amplifier panels driven in parallel by two silicon carbide amplifier driver panels and where each panel is comprised of two modules each further including a 180.degree. signal splitter, a pair of quadraphase signal splitters and combiners, a 180.degree. signal combiner, and five RF amplifier pallets which themselves are comprised of two silicon carbide transistors located on a common flange and operated in push-pull relationship so as to suppress even order distortion products and reduce sensitivity to ground currents. A monitoring system, including a touch screen control display and control panel senses the status of all assemblies so as to allow an operator to control the transmitter and inquire about the status of the various components and power supplies, and to replace one or more units as required without the need for turning the transmitter off.Type: GrantFiled: February 14, 1997Date of Patent: September 22, 1998Assignee: Northrop Grumman CorporationInventors: Carlton Daniel Davis, Robert Kent Long, Jack Jerome Hawkins
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Patent number: 5805240Abstract: A radio frequency transmitter includes a video signal input terminal, an audio signal input terminal, a variable frequency modulation degree circuit, a band pass filter, a sound intensity regulation circuit, a voltage controlled oscillator, a modulation mixer, and an amplifying circuit. The transmitter is arranged to eliminate high frequency abnormalities, prevent interference of audio signals with video signals, stabilize the audio frequency response of the transmitter, and improve circuit stability.Type: GrantFiled: December 27, 1995Date of Patent: September 8, 1998Assignee: Forward Electronics Co., Ltd.Inventors: Yee-Cheng Lo, Venson Liaw
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Patent number: 5801595Abstract: A digital signal processing device and method for vestigial sideband (VSB) modulation of a digital signal. A 2.sup.n -ary digital signal d.sub.i is provided to a baseband shaping filter which samples the signal to provide a baseband signal which has real and imaginary portions Re(S.sub.bb (kT)) and Im(S.sub.bb (kT)), where ##EQU1## The VSB signal is provided with perfect sideband suppression without using analog filters. The digital signal processing device and method is characterized by requiring minimal bandwidth in the shaping filter.Type: GrantFiled: January 10, 1997Date of Patent: September 1, 1998Assignee: Harris CorporationInventors: Robert C. Davis, Edwin R. Twitchell
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Patent number: 5748261Abstract: A satellite video receiver (12) for providing output signals to a television signal receiver (52) includes apparatus (10, 15, 16, 20, 45, 60, 65, 70) for operator selection of the modulator output channel frequency of the satellite receiver. The operator may select a modulator main channel, or an alternative manufacturer pre-set modulator default channel. In a first recovery mode, the operator may automatically replace an existing modulator channel with a manufacturer pre-set default channel, e.g., if a chosen main channel is forgotten. In another recovery mode, the operator may automatically re-establish a previously selected modulator main channel recalled from memory.Type: GrantFiled: March 20, 1996Date of Patent: May 5, 1998Assignee: Thomson Consumer Electronics, Inc.Inventor: Michael Anthony Pugel
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Patent number: 5737025Abstract: In the present invention, an ancillary code is added to a composite video signal in its active video portion. The ancillary code may be spread over several frequencies and summed at the output of a decoder to enhance the legibility of the ancillary code at the output of the decoder. Frequency-stepping may be used to add the ancillary code at ones of a plurality of selected frequencies within the bandwidth of the composite video signal. The ancillary code may be hierarchically apportioned between respective uniquely specified sequential segments corresponding to many distribution points of the composite television signal. This hierarchical ancillary code may be frequency-interleaved between harmonics of the horizontal sync frequency of the composite video signal. The ancillary code may be redundantly added above and below the roll-off frequency of a VCR.Type: GrantFiled: February 28, 1995Date of Patent: April 7, 1998Assignee: Nielsen Media Research, Inc.Inventors: Robert A. Dougherty, David A. Kiewit, Daozheng Lu, Henry B. Wheeler
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Patent number: 5638135Abstract: A digital encoder includes a matrix circuit for synthesizing chrominance signals R-Y and B-Y based on RGB signals sampled at a predetermined sampling frequency which is an integral multiple of a chrominance subcarrier; low-pass filters; a delay circuit; a switch circuit for reducing a frequency of an output from the low-pass filters; a digital modulator for subjecting a chrominance subcarrier to quadrature two-phase balanced modulation using an output signal from the switch circuit so as to output a chrominance signal having a sampling frequency 1/m that of the predetermined sampling frequency; a sampling frequency conversion circuit for multiplying the sampling frequency of the chrominance signal by a factor of m so as to output a chrominance signal having the predetermined sampling frequency; and an adder for computing a sum of the luminance signal delayed by the delay circuit, the chrominance signals output by the sampling frequency conversion circuit and a composite synchronizing signal so as to synthesizType: GrantFiled: April 4, 1996Date of Patent: June 10, 1997Assignee: Ricoh Company, Ltd.Inventor: Takuo Mukai
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Patent number: 5635995Abstract: A dual chrominance signal processor is disclosed which may be used in a combination television and video cassette recorder system, for example. Such a chrominance signal processor includes first and second modulated chrominance signal sources, and first and second demodulating carrier signal sources, corresponding to the first and second modulated chrominance signal sources, respectively. A demodulator is responsive to a chrominance signal and a demodulating carrier signal, for demodulating the chrominance signal. A signal selector is coupled between the signal sources and the demodulator, and selectively couples one of the first and second chrominance signal sources, and the corresponding one of the first and second demodulating carrier signal sources, to the demodulator in response to a selection signal.Type: GrantFiled: June 7, 1995Date of Patent: June 3, 1997Assignee: David Sarnoff Research Center, Inc.Inventors: Christopher H. Strolle, Steven T. Jaffe
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Patent number: 5596319Abstract: A vehicle remote control system includes at least one remote controlled vehicle and a remote control station for each of the at least one remotely controlled vehicles. Each control station allows a user to control the operation of one of the remote control vehicles. Each remote controlled vehicle includes a camera having a lens with a field of view in a direction toward a forward path of travel for that vehicle. In a preferred embodiment, the vehicle is a car and includes various sensors for monitoring the operation of various parameters of the vehicle, such as speed. Each car is equipped with an instrument panel located in the field of view of the lens as well as two side rear view mirrors, one attached to a left fender and the other to a right fender, which are also located in the field of view of the lens.Type: GrantFiled: October 31, 1994Date of Patent: January 21, 1997Inventor: Willie L. Spry
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Patent number: 5585837Abstract: A video signal processing and distribution apparatus receives a cable television signal which includes a plurality of television channels. The cable television signal is transferred through one or more band block filters, each of which can block a particular channel from the cable television signal. An oscillator is provided for each local video signal that is desired to be added into the cable television signal. Each oscillator produces a carrier signal within the band of a removed television channel. The local video signal modulates the carrier signal to produce a new channel signal that is combined with the cable signal, which has had at least one selected channel removed. The resulting modified cable signal is distributed to one or more television sets wherein each set can view a plurality of new locally generated channels which have been added to the cable television signal in place of previously existing channels.Type: GrantFiled: March 15, 1995Date of Patent: December 17, 1996Inventor: Dale B. Nixon
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Patent number: 5555275Abstract: At the transmitter side of a signal transmission system, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between the first and second data streams is developed by shifting the signal points to other positions in the space diagram. At the receiver side of a signal transmission, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into two, low and high, frequency band components which are designated as a first and a second data stream respectively.Type: GrantFiled: April 5, 1995Date of Patent: September 10, 1996Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Mitsuaki Oshima
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Patent number: 5541671Abstract: A satellite video receiver (12) for providing output signals to a television signal receiver (52) includes apparatus (10, 15, 16, 20, 45, 60, 65, 70) for operator selection of the modulator output channel frequency of the satellite receiver. The operator may select a modulator main channel, or an alternative manufacturer pre-set modulator default channel. In a first recovery mode, the operator may automatically replace an existing modulator channel with a manufacturer pre-set default channel, e.g., if a chosen main channel is forgotten. In another recovery mode, the operator may automatically re-establish a previously selected modulator main channel recalled from memory.Type: GrantFiled: February 6, 1995Date of Patent: July 30, 1996Assignee: Thomson Consumer Electronics Inc.Inventor: Michael A. Pugel