Thomson Consumer Electronics Inc.

Thomson Licensing S.a.

Rca Inc.

Thomson Licensing

Other

Thomas Consumer Electronics, Inc.

John Barrett George

Albert Runtze

Gunter Gleim

Kevin Michael Williams

Friedrich Heizmann

William John Testin

Ronald E Fernsler

Lawrence E Smith

G&uuml;nter Gleim

Angela Renee Burnett

Fredrich Heizmann

Dal Frank Griepentrog

Walter Truskalo

Dursun Sakarya

Randy Wayne Craig

William Benjamin Aaron

Sean Patrick McPeak

Nancy Dawn Boettner

James J Wolford

Frank Albert Glad

A controllable reflecting device having an array of bi-axial mirrors that are capable of pivoting in at least four directions is described. At least three primary colored light beams are directed at each of the bi-axial mirror in three of the four pivoting directions, one for each of the primary colored light beams and a single colored beam is reflected and directed toward a projection lens. In the fourth pivoting direction, no color beam is directed to the projection lens and black is projected.

Biaxial mirror color selecting micro imager

Progressive rounding error and convergence error encountered due to multiple use of a center correction adjustment of an image of a video projection display is reduced by calculating a 3&#xd7;3 matrix for a moved color signal where the non center matrix values represent the difference between the initially measured sensor values stored at initial alignment, and stored most recently measured sensor values. The matrix center value is the sum of the averaged values calculated from the edge center errors, the stored sum of previous moves and the current move. Rerun of the sensor finding routine resets the stored move sum to zero.

Center convergence optimization in a projection display apparatus

A dynamic focus amplifier for generating a dynamic focus voltage for a focus electrode for a cathode ray tube at a capacitive load includes a source of a periodic signal at a horizontal deflection frequency. A pull-down transistor is responsive to the periodic signal and coupled to the capacitive load for producing, in accordance with the periodic signal, a first portion of the dynamic focus voltage that decreases, during a first portion of a period of the periodic signal. A storage capacitor is coupled to the capacitive load for replenishing a charge stored in the storage capacitor from a charge stored in the capacitive load to develop a control voltage in the storage capacitor. A pull-up transistor is responsive to the control voltage and coupled to a source of a high voltage and to the capacitive load for producing from the high voltage a current that is coupled to the capacitive load. The current develops a second portion of the dynamic focus voltage that increases, during a second portion of the period of the periodic signal, and stores the charge in the capacitive load.

Focus voltage amplifier

A method for setting opto-sensor detection sensitivity in a projection video display comprising the steps of sequentially generating video signals of different colors for illuminating a sensor with video images of the video signals. In responsive to the video signals automatically selecting respective detection thresholds. Sequentially detecting sensor signals in excess of the respective detection thresholds. Coupling the detected sensor signals for automated adjustment of the projection video display.

Video controlled detector sensitivity

In a projection television receiver, a common switch mode power supply energizes the convergence circuits, and other load circuits of the projection television receiver. In normal operation, a switch couples a supply voltage produces in the common switch mode power supply to the convergence circuits. When, as a result of a fault, a supply current in the convergence circuits is excessive, the common switch mode power supply is decoupled from the convergence circuits and other load circuits remain energized and operative.

Power supply protection arrangement

A parabola generator for providing dynamic correction includes a capacitor source of a parabolic input signal at a frequency related to a horizontal deflection frequency coupled to a first terminal of the capacitor. A diode switch is coupled to a voltage at a reference level and to a second terminal of the capacitor for periodically clamping a peak level of a signal developed at the second terminal. A transistor switch is responsive to a periodic switch control signal and coupled to the second terminal of the capacitor for periodically clamping a signal applied from the second terminal, during retrace, for removing a parasitic parabolic voltage portion to generate a dynamic correction signal. The dynamic correction signal is coupled to the cathode ray tube to vary a field in a beam path of an electron beam of the cathode ray tube for providing dynamic correction.

Waveform generator for controlling an electron beam in a cathode ray tube

A projection display comprises three cathode ray tubes each having a deflection yoke and convergence yoke and each tube generating a raster for projection. One of the three cathode ray tubes has the convergence yoke coupled for current flow in a direction opposite to that of the other two convergence yokes. An amplifier is respectively coupled to each convergence yoke for convergence correction of each raster. A convergence circuit supplies correction signal values that are coupled to each respective amplifier such that convergence correction by the other two convergence yokes is responsive to a difference between the correction signal value coupled to the one convergence yoke and the correction signal values coupled to the other two convergence yokes.

Convergence optimization in a projection display

A projection display uses a matrix of digital correction factors defining deflection correction factors between which linear interpolation is used for intermediate points on the display. A circuit for generating a correction signal to correct image distortion on a display screen, comprises a memory storing displacement values corresponding to spaced points on the screen in a grid of rows and columns. The displacement values of the grid generally define correction curves for correcting the image distortion without introducing significant banded regions on the display screen. An interpolator is coupled to the memory for interpolating intermediate values between adjacent ones of the stored displacement values, and a digital to analog converter is coupled to the interpolator for providing the correction signal.

Digital raster correction

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. The correction waveforms may have vertical and/or horizontal rates.

Display correction waveform generator for multiple scanning frequencies

A method for determining raster positioning in a video projection display apparatus comprises the steps of detecting illumination by a first edge of a measurement image moving in a first direction. Detecting illumination by a second edge of the measurement image moving in a second direction, and averaging movement values related to the first and second edge illuminations of the detecting steps.

Projection video display with photo transistor sensors

A video imaging apparatus comprises first and second cathode-ray tubes, each having an ultor electrode and a focus electrode. A power supply generates an ultor voltage, which may have a fluctuating voltage component produced by beam current variations, and which is coupled to first and second ultor electrodes of the first and second cathode-ray tubes. A high voltage amplifier generates a dynamic focus voltage component at a frequency related to a deflection frequency. A combining network combines the fluctuating voltage component and the dynamic focus voltage component to develop a combined, dynamic focus voltage. The combined, dynamic focus voltage is coupled to each of the first and second focus electrodes for developing from the combined, dynamic focus voltage each of a first dynamic focus voltage at the first focus electrode and a second dynamic focus voltage at the second focus electrode.

Focus voltage control arrangement

A method of operating a photo sensor in a projection display device comprises the steps of, illuminating the sensor with a projected image. Detecting a signal from the sensor responsive to the illumination by the projected image. Changing a threshold value of the detector until the signal detection ceases. Storing a value representative of the threshold value which terminated detection of the signal from the sensor.

Automated calibration in a projection display apparatus

A horizontal deflection winding centering circuit includes a Darlington transistor and a diode. The Darlington transistor and diode form a non-linear network that is coupled in series with an inductor. The series arrangement of inductor and non-linear network is coupled in parallel with a horizontal deflection winding. The base voltage of the Darlington transistor is produced by a voltage divider coupled in a current path of the inductor current.

Centering circuit

A projection television display apparatus comprises a display device with an image formed for projection and a display screen for receiving the projected image. A plurality of photo sensors are located adjacent to edges of the display screen and each generates an output signal responsive to an intensity of illumination by the projected image. A detector with controllable detection threshold is coupled to the photo sensors for generating a signal having a first state when the output signal generated by each of the plurality photo sensors is greater than the detection threshold, and a second state when the output signal generated by each of said plurality photo sensors is less than the detection threshold. A controller is coupled to the display device and to the detector for setting the detection threshold for the output signal generated by each one of the plurality of photo sensors. In response to the signal having the first state, the controller moves the image on the display device to sequentially illuminate another one of the plurality of photo sensors.

Projection video display with multiple photo sensors

For control and correction of deflection parameters especially of convergence, a grid pattern is displayed on the picture screen of a television device. For control of the convergence parameters and the evaluation of the correction values the crossing points of the grid pattern are marked by a cursor. The cursor is formed by at least one irregularity in the grid pattern being, regular otherwise. The irregularity may consist in an omission within the grid pattern like an interruption within one horizontal or vertical grid line. An image signal generator for the grid pattern with position cursor includes a raster generator, a grid generator, a cursor generator, and means for combining a grid signal from the grid generator and a cursor signal from the cursor generator so as to inhibit the grid signal corresponding to locations on the grid pattern where the position cursor is visible by an absence of display of portions of the grid pattern.

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Carmel, IN, United States of America

John Barrett George