Deutsche Thomson-brandt Gmbh

Thomson Licensing S.a.

Thomson Consumer Electronics Inc.

Telefunken Electronic Gmbh

Gunter Gleim

Friedrich Heizmann

Jacques Chauvin

Friedrich Fuldner

Hermann Link

Albert Runtze

Bernd Rekla

John Barrett George

Dietmar Uhde

Hartmut Schandl

Enrique Rodriguez-Cavazos

Rolf Bohme

Peter Hoch

Rudiger Lehmann

Siegfried Quandt

Jaques Chauvin

Heinz Rinderle

Jean-Paul Louvel

Uwe Hartmann

Udo Mai

Albrecht Rothermel

Fritz Ohnemus

Rainer Schweer

Sandor Gyarmati

Fredrich Heizmann

Karin Rothermel

Elke Rosch

Vincent Humeau

Vincent De Paul Humeau

Bernd Rekia

Michael Bildl

A memory and a switchable digital filter supply different numbers of digital distortion correction values. The supplied distortion correction values are converted to an analog distortion correction signal. A passive, analog low pass filter for the analog distortion correction signal generates an analog deflection signal. The low pass filter is optimized only for those of the analog deflection signals having a given sample rate. A controller varies the different numbers of the supplied distortion correction values to maintain the given sample rate of the analog deflection signal for different horizontal scanning rates. The controller selectively implements respective operating modes for different horizontal scanning frequencies in which no interpolated distortion correction values are supplied or different numbers of interpolated distortion correction values are supplied.

Adaptable raster distortion correction system for multiple horizontal scanning frequencies

In a video display, correction data for a digital convergence arrangement are stored in a first non-volatile memory. During power turn on procedure, the correction data are read out of and stored in a volatile memory. During each deflection cycle, the data stored in the volatile memory are successively read out and applied to an auxiliary convergence winding. When a parity error is detected in the read out data, an output and/or an input of a convergence amplifier is actively disabled to prevent a disturbance of a screen of the cathode ray tube.

Auxiliary deflection winding driver disabling arrangement

A method for generating display correction waveforms for a CRT display comprises the steps of selecting one of a plurality of trace portions for forming part of a correction waveform, the trace portions having different average values. Completing each of the correction waveform by combining each selected trace portion with a respective retrace portion such that all completed correction waveforms have a predetermined average value.

Display correction waveform generator for multiple scanning

A switchable digital filter interpolates distortion correction values. The distortion correction values together with interpolated distortion correction values are supplied as an output. Proper operation of the digital filter is disturbed by transient signals occurring during horizontal retrace. The digital output is converted to an analog convergence correction signal. The digital to analog converter has an operating frequency and generates a transient signal during horizontal retrace as the operating frequency increases due to an increased horizontal scanning rate. A low pass filter receives the analog convergence correction signal and generates an analog deflection signal. An auxiliary deflection coil is driven by the analog deflection signal. The digital filter is switched off during the horizontal retrace. The digital filter is thus protected from disturbance by the transient signal and the digital to analog converter is protected from exceeding a maximum operating frequency.

Distortion correction system with switchable digital filter

A method and apparatus for obtaining correction values for convergence setting in video projection devices includes calculating the correction values for the individual video lines at least in part by interpolation between correction interpolation point values. The correction interpolation point values are in this case distributed in the form of a grid over the screen area of the video projection device. During the calculation of correction values for the video lines of a first field of the video frame, a respective set of two intermediate or final values for the interpolation is calculated, which set is applicable to neighbouring lines in different video fields, but in each case only one intermediate or final value is used for the convergence correction in the current video line. As a result, optimal convergence correction can be set for each video line without a high memory outlay and without high computing complexity.

Method and apparatus for obtaining correction values for video lines of

Method and circuit arrangement for commutation of a multiple winding electric motor. Particularly when they are operated with square-wave signals, multiple winding electric motors require effective interference voltage suppression for many applications. The invention specifies a method and a circuit arrangement by means of which trapezoidal waveform control signals are produced upstream of the respective output amplifiers, so that the motor is driven with low impedance, as a result of which there is no need for additional suppression means. The trapezoidal waveform control signals are composed of an operating voltage or a corresponding signal, a reference potential and a triangular waveform ramp voltage, using switching means.

Method and circuit arrangement for commutation of a multiple winding

Temperature monitoring process and device

A method of breaking a motor includes the step of applying a pulse width modulated signal to the winding of the motor. A switching voltage is used to intermittently reverse the poles of the motor for selected time periods. The time periods are separated by pauses the duration of which is dependent upon the breaking force needed to stop the motor.

Method for the control of a motor

An arrangement for monitoring an alternating signal with respect to its state as mark-to-space ratio or direct-current component, in which the alternating signal is modified so that its mark-to-space ratio or direct-current component can be detected by simple comparison with reference signals. Various information is then transmitted over a line, and the operation of the stage that generates the alternating signal can also be monitored.

Method and apparatus for monitoring an alternating signal

Power amplifier circuit for an inductive load including a supply voltage applied to the inductive load via a series circuit comprising a first transistor electronically coupled to a second transistor for conducting current from the supply voltage through the first and second transistors to the inductive load, wherein a reference potential smaller than the supply voltage is coupled at a center point of the series circuit. A circuit network is electronically coupled at a first node to a base of the first transistor and at a second node to a control voltage, the control voltage being greater than the supply voltage, wherein, when a voltage induced in the inductive load resulting from a change in current through the inductive load reaches a threshold level, the control voltage is fed via the circuit network to the base of said first transistor to block current flow between the first and second transistors to cause the second transistor to be electronically disconnected from the supply voltage and to be electronically connected to the reference potential, whereby the second transistor remains conducting while permitting the voltage at the inductive load to be greater than the supply voltage.

Power amplifier for an inductive load

Driving circuit with several sensors

When a power supply unit supplies power to a plurality of power amplifiers, an appreciable power loss is produced in the power supply unit and in the amplifiers. According to the present invention, the output voltage of the power supply unit is regulated so that it is high enough at any instant for the amplifier which at that instant has an output signal having the largest amplitude.

Circuit for the power supply of a plurality of power amplifiers

A projection television apparatus has three monochromatic picture tubes disposed in a planar orientation defining a central picture tube and two outer picture tubes. Each of the picture tubes includes a deflection unit responsive to deflection currents and raster correction signals for vertical and horizontal deflection. A control circuit, including a signal generator, supplies vertical and horizontal raster correction signals formulated for the central picture tube to all three of the picture tubes and supplies additional vertical and horizontal raster correction signals formulated for the two outer picture tubes respectively to the two outer picture tubes, respectively. Conductive paths for the formulated for the central picture tube correction signals can include variable resistors for effecting small changes in signal amplitude.

Geometry and convergence correction for projection television apparatus

A method of regulating an operational parameter of an electrical apparatus includes the steps of obtaining a signal representative of a measured value of an effect on an adjustment device of the apparatus. The measured value is compared to a desired value to provide a regulating signal during a regulating mode. A static correction value and a dynamic correction value are superimposed onto the regulating signal to generate an actuation signal. The adjustment device is adjusted with the actuation signal during an operating mode.

Deflection regulating method and device

A control circuit for maintaining the mean value of the amplitudes of control pulses having a first level and data pulses having a second level includes a detector for providing the control pulses and the data pulses. A reference voltage source provides first, second and third reference voltages having three different levels. A plurality of comparators each receive both the control pulses and the data pulses. A first comparator also receives the lowest of the reference voltages and provides regulation pulses when the control pulses reach the level of the lowest reference voltage. A second comparator receives the second highest reference voltage and provides level limiting pulses to maintain the level of the regulation pulses constant. A third of the comparators receives the highest reference voltage and provides data pulses when the third reference voltage is reached.

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Villingen-Schwenningen, Germany

Gunter Gleim