Deflection waveform generator
AssigneeUnited Technologies Corporation
InventorGlenn C. Waehner
Life of this patent
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Abstract
A deflection waveform generator uses a low voltage accurate capacitor to integrate the yoke deflection current and derive a parabolic waveform for "S" correcting the basic sawtooth deflection waveform. This parabolic waveform is fed back to the inverting input of a balanced operational integrating amplifier, the inverting input also having the integrating network coupled thereto. The polarities of the signal waveforms at the inverting input are such that the combined signal fed through the integrating network creates a "S" corrected sawtooth yoke deflection current which drives the electron beam in a manner which compensates geometric distortion inherent in the CRT.
Claims4
A waveform generator to be used in conjunction with a CRT having a deflection yoke, comprising:
- an operational amplifier means having an inverting and a non-inverting inputs in which the input time constants are substantially equal, and an output from which a signal waveform suitable for driving a CRT deflection yoke can be derived, and further including integrating means coupled to said inverting input for creating a basic sawtooth;
- means coupled to said deflection yoke of said CRT for integrating the current waveform driving said deflection yoke;
- and
- feedback means having a first path which is connected to said inverting input of said operational amplifier and a second path which is connected to said non-inverting input of said operational amplifier, both paths having substantially equivalent time constants whereby a pair of similarly shaped parabolic waveforms are presented to said inputs of said operational amplifier so that said yoke deflection current waveform is "S" corrected.
Dependencies are inferred from the claim text.