Waveform correction for resonant recovery deflection systems

Claim 2

In a resonant recovery deflection system having switching means responsive to an input timing signal for periodically energizing the inductor of a magnetic deflection yoke from a power source and including an S-curve correction capacitor in series connection with the deflection inductor, a correction circuit responsive to the inductor current for providing a correction signal to said inductor, comprising: a correction amplifier having input and output terminals, and connected at said output terminal for applying the correction signal to said inductor of the deflection yoke, first means coupled to said inductor for producing an output voltage proportional to the derivative of the deflection current passing through said inductor, second means for producing an output voltage proportional to the derivative of a linearity corrected sweep voltage, and summing means for receiving and summing the differentiated voltage outputs of said first and second means for supply to said input terminal of said correction amplifier.

Claim 3

A correction circuit as recited in claim 1 wherein there are further provided first and second clippers for receiving and clipping the voltage outputs of said first and second means for supply to said summing means.

Claim 4

A correction circuit as recited in claim 1 wherein there is further provided a resistor connecting the input and output terminals of said correction amplifier to provide negative feedback in said amplifier.

Claim 5

A correction circuit as recited in claim 1 wherein said summing means comprises first and second resistors respectively connected at first terminals thereof with the outputs of said first and second means, and at second terminals thereof in common to said input terminal of said correction amplifier.

Claim 6

A waveform correction circuit as recited in claim 1 wherein said first means comprises: means for sensing the deflection current and producing an output voltage proportional thereto, and first differentiating means for differentiating the output voltage of said sensing and producing means.

Claim 7

A waveform correction circuit as recited in claim 5 wherein said sensing means comprises inductive pickup means connected in series between said deflection yoke circuit and said output terminal of said correction amplifier.

Claim 8

A waveform correction circuit as recited in claim 1 wherein said second means comprises: means for supplying a reference voltage comprising a linearity corrected sweep voltage, and second differentiating means for differentiating the reference voltage.

Claim 9

A waveform correction circuit as recited in claim 7, wherein said deflection yoke is utilized with a display cathode ray tube having a display surface of given curvature, said reference voltage means providing the linearity corrected sweep voltage in accordance with said given curvature.

Claim 10

A waveform correction circuit as recited in claim 7 wherein said deflection yoke is utilized with a display cathode ray tube for producing a horizontal scanning beam deflection therein and wherein said reference voltage supplying means supplies a sweep voltage having linearity correction for pincushion error in the display of the cathode ray tube.

Claim 11

A waveform correction circuit as recited in claim 1 wherein said first and second means supply the respective output voltages thereof in opposite phase to said summing means, and said summing means supplies the difference of said output voltages of said first and second means to said input terminal of said correction amplifier.

Claim 12

A waveform corrected resonant recovery deflection system comprising: a deflection current generating circuit including: in parallel connection between a common junction and a first reference potential terminal, a transistor and a diode poled for respectively opposite directions of conduction, said transistor being controlled in conduction by a periodic timing signal input, a retrace capacitor, a charging coil connected between said common junction and a second reference potential terminal, the inductor of a deflection yoke connected at one terminal thereof to said common junction, and an S-curve correction capacitor connected in series with said deflection yoke inductor, and a waveform correction circuit including: a correction amplifier, means for sensing the deflection current supplied by said generating circuit to said inductance of said deflection yoke and producing a differentiated output voltage proportional to the sensed deflection current, means for supplying a differentiated, linearity corrected sweep voltage, summing means for receiving and summing the differentiated output voltage proportional to the deflection current and the differentiated reference voltage for supplying the difference of the differentiated voltages to the input of said correction amplifier, and the output of said correction amplifier being supplied to the deflection yoke inductor.

Claim 13

A waveform corrected resonant recovery deflection system comprising: a deflection current generating circuit including: in parallel connection between a common junction and a first reference potential terminal, a transistor and a diode poled for respectively opposite directions of conduction, said transistor being controlled in conduction by a periodic timing signal input, a retrace capacitor, a charging coil connected between said common junction and a second reference potential terminal, the inductor of a deflection yoke connected at one terminal thereof to said common junction, and an S-curve correction capacitor connected in series with said deflection yoke inductor, and a waveform correction circuit including: a correction amplifier, means for sensing the deflection current supplied by said generating circuit to said inductance of said deflection yoke and producing a differentiated output voltage proportional to the sensed deflection current, means for supplying a differentiated, linearity corrected sweep voltage, summing means for receiving and summing the differentiated output voltage proportional to the deflection current and the differentiated reference voltage for supplying the difference of the differentiated voltages to the input of said correction amplifier, and the output of said correction amplifier being supplied to the deflection yoke inductor.

Claim 14

A waveform corrected resonant recovery deflection system as recited in claim 11 wherein there is further provided first and second clipper means respectively receiving the differentiated output voltage proportional to the deflection current and the differentiated, linearity corrected sweep voltage, for clipping the differentiated voltages prior to supply thereof to said summing means.

Claim 15

In a resonant recovery deflection system having switching means responsive to an input timing signal for periodically energizing an inductor of a magnetic deflection yoke from a power source and including an S-curve capacitor connected in series with said deflection inductor, a correction circuit for correcting the waveform of the deflection current in said in-ductor, comprising: first means responsive to the current flowing through said inductor for producing an output signal proportional to the derivative of the deflection current, second means for producing an output voltage proportional to the derivative of a linearity corrected sweep voltage, summing means for receiving and summing the differ-entiated voltage outputs of said first and second means for providing a summed output, and a correction, class A amplifier having an input coupled to receive the summed output of said summing means and an output connected for applying a correction signal to said inductor of said defleCtion yoke, said class A amplifier including a feedback resistive element connected in parallel thereto.

Claim 16

In a resonant recovery deflection system having switching means responsive to an input timing signal for periodically energizing an inductor of a magnetic deflection yoke from a power source and including an S-curve capacitor connected in series with said deflection inductor, a correction circuit for correcting the waveform of the deflection current in said in-ductor, comprising: first means responsive to the current flowing through said inductor for producing an output signal proportional to the derivative of the deflection current, second means for producing an output voltage proportional to the derivative of a linearity corrected sweep voltage, summing means for receiving and summing the differ-entiated voltage outputs of said first and second means for providing a summed output, and a correction, class A amplifier having an input coupled to receive the summed output of said summing means and an output connected for applying a correction signal to said inductor of said defleCtion yoke, said class A amplifier including a feedback resistive element connected in parallel thereto.

Claim 17

In a resonant recovery deflection system having switching means responsive to an input timing signal for periodically energizing an inductor of a magnetic deflection yoke from a power source and including an S-curve correction capacitor in series connection with said deflection inductor, a correction circuit responsive to the inductor current for providing a correction signal to said inductor, comprising: a correction amplifier having input and output terminals, and connected at said output terminal for applying the correction signal to said inductor of said deflection yoke, a current transformer having a first winding connected in series with said deflection inductor and said output terminal of said correction amplifier, and a second winding inductively coupled to said first winding, a resistor connected in parallel with said second winding for producing an output voltage proportional to the deflection inductor current, differentiating means for differentiating the output voltage derived from said resistor, reference means for producing an output voltage proportional to the derivative of a linearity corrected sweep voltage, and summing means for receiving and summing the output of said differentiating means and said reference means for supply to said input terminal of said correction amplifier.

Claim 18

In a resonant recovery deflection system having switching means responsive to an input timing signal for periodically energizing an inductor of a magnetic deflection yoke from a power source and including an S-curve correction capacitor in series connection with said deflection inductor, a correction circuit responsive to the inductor current for providing a correction signal to said inductor, comprising: a correction amplifier having input and output terminals, and connected at said output terminal for applying the correction signal to said inductor of said deflection yoke, a current transformer having a first winding connected in series with said deflection inductor and said output terminal of said correction amplifier, and a second winding inductively coupled to said first winding, a resistor connected in parallel with said second winding for producing an output voltage proportional to the deflection inductor current, differentiating means for differentiating the output voltage derived from said resistor, reference means for producing an output voltage proportional to the derivative of a linearity corrected sweep voltage, and summing means for receiving and summing the output of said differentiating means and said reference means for supply to said input terminal of said correction amplifier.