Thomson Consumer Electronics Inc.

Thomson Licensing S.a.

Thomson Licensing

Rca Licensing Corporation

Rca Licensing Corportion

Robert D Altmanshofer

Enrique Rodriguez-Cavazos

David J Duffield

Michael Evan Crabb

Donald Henry Willis

Robert Preston Parker

William A Lagoni

Barth Alan Canfield

Nathaniel H Ersoz

Enrique R Cavazos

Estill T Hall, Jr

A color television receiver system processes color difference signals for providing tint control while maintaining uniform color amplitude with respect to changes in hue shift angle. The color difference signals are modified as a function of each other and as a function of a hue shift angle to produce modified color difference signals. A color difference signal [B-Y] is supplied as a first input to multipliers Mand M. Another color difference signal [R-Y] is supplied as a first input to another pair of multipliers Mand M. A control signal generator produces output signals sin &#x3b8; and cos &#x3b8; where &#x3b8; is the hue shift angle. The sin &#x3b8; signal is supplied as a second input to multipliers Mand Mwhile the cos &#x3b8; signal is supplied as a second input to multipliers Mand M. The outputs of Mand Mare added in an adder Ato produce a modified output [R-Y]'. Similarly, the output of multiplier Mis provided as a positive input to adder Awhereas the output of multiplier Mis provided as a negative input to adder Ato produce a modified color difference signal [B-Y]&#x2032;. The modified color difference signals [R-Y]&#x2032; and [B-Y]&#x2032; represent a color vector having an amplitude A that remains substantially constant over a relatively wide range of hue shift angles &#x3b8;.

Color difference hue control system

A horizontal synchronizing system, comprising: a source of a horizontal synchronizing signal; a source of first and second higher frequency horizontal drive signals; a phase detector for generating a first control voltage responsive to the horizontal synchronizing signal and the first horizontal drive signal; a source of a second control signal; and, a switch for selectively supplying the first control signal to the source of the drive signals for a phase-locked mode of operation at the first higher frequency and supplying the second control signal to the source of the drive signals for a phase-unlocked mode of operation at the second higher frequency.

Horizontal synchronization for digital television receiver

A phase locked loop, comprising: a controllable oscillator requiring a control signal having a given bias voltage for generating a clock signal; an integrator for developing the control signal; a source of an external synchronizing signal; first and second voltage sources defining a voltage potential related to the given bias voltage; a first switch coupled to the first and second voltage sources and responsive to the clock signal for developing a regenerated clock signal having a peak to peak voltage determined by the voltage potential; and, a second switch responsive to the external synchronizing signal for periodically sampling portions of the regenerated clock signal and coupling the sampled portions to the integrator, the sampled portions charging and discharging the integrator to generate the control signal with a large enough magnitude to provide the given bias voltage, said first and second switches forming a phase detector.

Phase control for oscillators

A television receiver system includes an HDTV tuner, and an NTSC tuner. In response to the entering of a channel number, a CHANNEL UP or CHANNEL DOWN command, or a channel label, in a channel selection mode, a controller searches a 'paired channel' table for associated HDTV and NTSC channels. If an HDTV channel is associated with that channel number or channel label, the HDTV tuner is controlled to select the HDTV channel. If no HDTV channel is associated with that channel number or channel label, the NTSC tuner is controlled to select the corresponding NTSC channel. In another embodiment, the controller determines if HDTV signals are actually being received. If not, the controller causes the NTSC tuner to select the corresponding NTSC channel. In yet another embodiment, the 'paired channel' data is sent via an Extended Data Services (EDS) transmission and automatically loaded into memory.

Television receiver having the capability to associate any HDTV and any

A television receiver system having PIP capability includes two NTSC tuners and signal processing arrangements, and an HDTV tuner and signal processing arrangement. In order to accomplish a CHANNEL SWAP function, a controller searches a table for data indicative of pairing of NTSC channels and HDTV channels, the NTSC channel associated with the main channel HDTV source is tuned by the PIP NTSC tuner, and the HDTV channel associated with the PIP NTSC source is tuned by the HDTV tuner. If the inset image has no paired HDTV channel then the second NTSC tuner is controlled to select the channel formerly tuned by the PIP NTSC tuner.

Signal swap apparatus for a television receiver having an HDTV main

Wide screen television

An automatic kinescope bias (AKB) arrangement embodied in an integrated circuit (IC) includes circuitry for generating a timing signal during an AKB test interval, circuitry for generating a test signal in response to the timing signal, and circuitry including an output terminal for coupling the test signal to the kinescope. The AKB IC also includes an input terminal and a switching element coupled between the input terminal and the output terminal and responsive to the timing signal for selectively decoupling the input terminal from the output terminal. In a television system which includes a bias network which is coupled to the output of the video signal source and which inhibits the kinescope from being cutoff during the AKB test interval, the input terminal of the AKB IC is coupled to the output terminal of the video signal source. This allows the bias network to be decoupled from the display device during the AKB test interval, thereby preventing the bias network from affecting AKB operation. Alternatively, in a television system which does not include a bias network which inhibits the kinescope from being cutoff during the AKB test interval, the output terminal of the AKB IC is directly coupled to the output terminal of the video signal source.

Automatic kinescope bias arrangement

Vertical zoom and panning for television

In beam scan velocity modulation (SVM) system for a television receiver, a video signal is applied to a differentiator followed by a limiting differential amplifier. A driver amplifier coupled to the limiting amplifier drives an output stage that supplies current to an SVM coil. Certain video signals with large high frequency content may tend to produce excessive dissipation in the devices of the output stage. To prevent this, a current source for the differential amplifier is controlled by a voltage which is a measure of the average current through the output stage. The magnitude of the current source is varied to thereby vary the peak-to-peak signal output from the limiting amplifier to prevent overdissipation of the output devices. The presence of random noise in the video signal can produce unwanted SVM operation which can impair the viewed image. The unwanted noise component in the video signal can be reduced in amplitude by coring. The coring is unaffected by the variable limiting.

Beam scan velocity modulation apparatus

In a beam scan velocity modulation (SVM) system for a television receiver, a video signal is applied to a differentiator followed by a limiting differential amplifier. A driver amplifier coupled to the limiting amplifier drives an output stage that supplies current to an SVM coil. Certain video signals with large high frequency content may tend to produce excessive dissipation in the devices of the output stage. To prevent this, a current source for the differential amplifier is controlled by a voltage which is a measure of the average current through the output stage. The magnitude of the current source is varied to thereby vary the peak-to-peak signal output from the limiting amplifier to prevent overdissipation of the output devices. The driver amplifier performs a coring operation that is unaffected by the variable limiting.

A convergence control system for a television apparatus, for example a projection television, comprises: a plurality of channels, each channel having a digital memory for storing a set of grid coordinate values defining a convergence correction grid; and, a pair of multiplying digital to analog converters for the grid coordinate values. A single circuit for generating sequential digital addresses is coupled to each of the channels for outputting the grid coordinate values from each of the digital memories to respective multiplying digital to analog converters of the channel. The values of respective horizontal grid lines are supplied to only one of the multiplying digital to analog coverters. A single waveform generator develops a pair of analog waveforms of complementary phase for modulating respective multiplying digital to analog converters of each pair in each channel. The sum of the modulating waveforms is constant. The succession of modulated analog values define the convergence correction signal for each channel.

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Carmel, IN, United States of America

Robert D Altmanshofer