Raster edge correction waveform
AssigneeThomson Consumer Electronics, Inc.
InventorsRonald E. Fernsler, Kevin M. Williams
Life of this patent
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Abstract
A video display having deflection correction comprising a cathode ray tube with a deflection coil mounted on the cathode ray tube for generation of a raster having horizontal line length variations which describe a generally sinusoidally shaped raster edge. A deflection amplifier is coupled to the deflection coil for generating a deflection current therein. A modulator is coupled to the deflection coil for generating a corrective current therein responsive to a corrective signal. A corrective signal generator for generating said corrective signal having a generally sinusoidal shape is coupled to the modulator for raster edge correction.
Claims13
A video display having deflection correction comprising:
- a cathode ray tube;
- a deflection coil mounted on said cathode ray tube;
- a deflection amplifier coupled to said deflection coil to generate a deflection current therein that produces a raster having horizontal line length variations which describe a generally sinusoidally shaped raster edge;
- a diode modulator coupled to said deflection coil for generating a corrective current therein responsive to a composite corrective signal;
- and,
- a corrective signal generator generating a parabolic shaped signal coupled to an amplifier having frequency selective feedback for generating said composite corrective signal having a generally parabolic shape which includes a sinusoidal shape, said composite corrective signal being coupled to said modulator for raster correction.
A deflection waveform correction apparatus comprising:
- a source of a generally parabolic shaped correction signal;
- a side pincushion modulator for deflection current modulation responsive to a modulating signal coupled thereto;
- and
- an amplifier coupled to said source having a transfer characteristic which modifies said generally parabolic shaped correction signal to form said modulating signal, said modulating signal comprising said generally parabolic shaped correction signal and a generally sinusoidal signal component.
A video projection display having distortion correction of a projected raster comprising:
- a plurality of cathode ray tubes;
- a plurality of deflection coils, each mounted on ones of said plurality of cathode ray tubes;
- a deflection amplifier coupled to said plurality of deflection coils to generate deflection current therein that produces a projected raster having horizontal line length variations which describe a generally sinusoidally shaped raster edge;
- a waveform modulator responsive to a composite corrective signal and coupled to said amplifier for generating a corrective current;
- and
- a composite corrective signal generator generating a parabolic shaped signal, modified to include a sinusoidal shaped component, coupled to said modulator for raster correction.
Dependencies are inferred from the claim text.