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US 5,345,151 AGranted
Automatic calibration in a waveform generator for deflection
AssigneeThomson Consumer Electronics, Inc.
InventorJohn B. George
Life of this patent
Estimating the term…
Abstract
An analog multiplier is used for generating an output signal that is coupled to a convergence winding of a projection television. The analog multiplier multiplies a horizontal rate sawtooth signal with a vertical rate parabola signal. To prevent temperature related drift, tolerances and component aging from affecting the output signal, the multiplier is calibrated during each vertical blanking interval.
Claims8
A video display deflection apparatus, comprising:
- a source of a modulation signal at a frequency that is related to a vertical deflection frequency;
- a source of a second signal at a frequency that is related to a horizontal deflection frequency;
- a modulator responsive to said modulation and second signals for generating an output signal at a frequency that is related to said horizontal deflection frequency, modulated in accordance with said modulation signal;
- an amplifier responsive to said output signal and coupled to a winding for generating a magnetic field that corrects for a beam landing error in a cathode ray tube;
- and
- means responsive to said output signal for sampling said output signal, during a predetermined portion of a period of said modulation signal, remote from a peak amplitude of said output signal to generate an adjustment signal that is coupled to an input of said modulator to reduce an amplitude of said output signal in a negative feedback manner.
3 more elements
Dependencies are inferred from the claim text.