Right-edge differential error convergence correction
OwnerJohn Barrett Georgeinventor
Life of this patent
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Abstract
A convergence correction circuit, for a cathode ray tube projecting images having keystone, differential sinusoidal and differential right-edge curl distortions, comprises generators for horizontal-rate, generally sinusoidal, horizontal-rate sawtooth and horizontal-rate pulse waveforms. A summer combines the horizontal-rate waveforms into a horizontal-rate composite waveform. A multiplier and an amplifier generate as an output signal a product of the horizontal-rate composite waveform and a vertical-rate sawtooth waveform. A convergence correction coil is coupled for receiving the output signal and generating a dynamic magnetic field correcting the keystone, differential sinusoidal and differential right-edge curl distortions.
Claims14
A correction circuit for a cathode ray tube displaying images subject to distortion, said circuit comprising:
- means for summing three horizontal-rate waveforms to define a horizontal-rate composite waveform;
- means for generating as an output signal a product of said horizontal-rate composite waveform and a vertical rate waveform;
- means for amplifying said output signal;
- and,
- a correction coil for said cathode ray tube coupled for receiving said amplified output signal and generating a dynamic magnetic field responsive to said output signal, said output signal having a first component for correcting a keystone distortion, a second component for correcting a red/blue sinusoidal distortion and a third component for correcting a red/blue right-edge curl distortion.
A projection television receiver, comprising:
- a plurality of cathode ray tubes, each of said cathode ray tubes having a vertical yoke coil and each of said vertical yoke coils coupled to one another in series;
- a plurality of damping resistances, each of said damping resistances coupled in parallel across one of said vertical yoke coils and in series with one another;
- means for summing three horizontal-rate waveforms to define a horizontal-rate composite waveform;
- means for generating as an output signal a product of said horizontal-rate composite waveform and a vertical rate waveform;
- means for amplifying said output signal;
- and,
- a correction coil for one of said cathode ray tubes coupled for receiving said amplified output signal and generating a dynamic magnetic field responsive to said output signal, said output signal having a first component for correcting a keystone distortion, a second component for correcting a red/blue sinusoidal distortion and a third component for correcting a red/blue right-edge curl distortion.
A correction circuit for a cathode ray tube displaying images subject to distortion, said circuit comprising:
- means for generating a horizontal-rate sawtooth waveform;
- means for generating a horizontal-rate pulse waveform;
- means for generating a horizontal-rate, generally sinusoidal waveform;
- means for summing said horizontal-rate sawtooth, pulse and generally sinusoidal waveforms to define a horizontal-rate composite waveform;
- means for generating as an output signal a product of said horizontal-rate composite waveform and a vertical-rate waveform, said horizontal-rate composite waveform being DC coupled to said product generating means;
- means for amplifying said output signal;
- and,
- a correction coil for said cathode ray tube coupled for receiving said amplified output signal and generating a dynamic magnetic field responsive to said output signal, said output signal having a first component for correcting a keystone distortion, a second component for correcting a red/blue sinusoidal distortion and a third component for correcting a red/blue right-edge curl distortion.
A projection television receiver, comprising:
- a plurality of cathode ray tubes, each of said cathode ray tubes having a vertical yoke coil and each of said vertical yoke coils coupled to one another in series;
- a plurality of damping resistances, each of said damping resistances coupled in parallel with an associated one of said vertical yoke coils;
- means for generating a horizontal-rate sawtooth waveform;
- means for generating a horizontal-rate pulse waveform;
- means for generating a horizontal-rate, generally sinusoidal waveform;
- means for summing said horizontal-rate sawtooth, pulse and generally sinusoidal waveforms to define a horizontal-rate composite waveform;
- means for generating as an output signal a product of said horizontal-rate composite waveform and a vertical-rate waveform, said horizontal-rate composite waveform being DC coupled to said product generating means;
- means for amplifying said output signal;
- and,
- a correction coil for one of said cathode ray tubes coupled for receiving said amplified output signal and generating a dynamic magnetic field responsive to said output signal, said output signal having a first component for correcting a keystone distortion, a second component for correcting a red/blue sinusoidal distortion and a third component for correcting a red/blue right-edge curl distortion.
Dependencies are inferred from the claim text.