Vertical deflection circuit

Claim 2

A sawtooth generator for a deflection system, comprising: first and second active current conducting devices; a timing network coupled to an output electrode of said first device and to a control electrode of said second device for determining the trace interval of each deflection cycle; a source of deflection rate signals coupled to a control electrode of said first device for changing the conduction state of said first and second devices from a first to a second state for initiAting the retrace interval of each deflection cycle; means including first and second serially coupled capacitors coupled to an output electrode of said second device and a control electrode of said first device, said first device being responsive to the charging current of said first and second capacitors through said second device such that said retrace interval is terminated and said trace interval is initiated when said charging current reaches a predetermined amount and causes said first and second devices to change said first conduction state; a third active current conducting device having its main conduction path coupled in parallel with said means including said first and second capacitors for providing a discharge path therefor during said trace interval; and linearity correction means including a third capacitor coupled in parallel with one of said first and second capacitors for providing an additional discharge path therefor for affecting the linearity of discharge of said first and second capacitors during a first portion of said trace interval.

Claim 3

A sawtooth generator according to claim 1 wherein said linearity correction means includes a first impedance in series with said third capacitor, said impedance being large relative to the impedance of the charging path for said first and second capacitors such that when said first and second capacitors are charged through said second device relatively little charge is stored in said third capacitor.

Claim 4

A sawtooth generator according to claim 2 wherein a second impedance is coupled from the junction of said first and second capacitors to a point of reference potential for affecting the rate of discharge of said first, second and third capacitors for altering the shape of said sawtooth waveform for linearity correction.

Claim 5

A sawtooth generator according to claim 3 wherein a diode is coupled serially between said first and second capacitors and said control electrode of said first device and poled to present a low forward impedance for current charging said first and second capacitors.

Claim 6

A sawtooth generator according to claim 4 wherein a relatively large impedance is coupled from the junction of said diode and said first and second serially coupled capacitors for providing a relatively long time constant discharge path for said first and second capacitors.

Claim 7

A deflection generator comprising: a deflection winding; an amplifier coupled to said winding for supplying current thereto; a driver stage coupled to an input terminal of said amplifier, said driver stage comprising first and second active current conducting devices and a feedback path coupled from said second to said first device; oscillator and sawtooth generating means coupled to said driver stage, said means comprising third and fourth active current conducting devices; a timing network coupled to an output electrode of said third device and to a control electrode of said fourth device for determining the trace interval of each deflection cycle; a source of deflection rate signals coupled to a control electrode of said third device for changing the conduction state of said third and fourth devices from a first to a second state for initiating the retrace interval of each deflection cycle; means including first and second serially coupled capacitors coupled to an output electrode of said fourth device and a control electrode of said third device, said third device being responsive to the charging current of said first and second capacitors through said fourth device such that said retrace interval is terminated and said trace interval is initiated when said charging current reaches a predetermined amount and causes said third and fourth devices to change to said first conduction state; a fifth active current conducting device having its main conduction path coupled in parallel with said means including said first and second capacitors for providing a discharge path thereFor during said trace interval; first linearity correction means including a third capacitor coupled in parallel with one of said first and second capacitors for providing an additional discharge path therefor for affecting the linearity of discharge of said first and second capacitors during a first portion of said trace interval; the junction between said first and second capacitors being coupled to an input terminal of said driver stage for providing a sawtooth voltage waveform therefor during said trace interval; and second linearity correction means including a capacitor coupled to said deflection winding and a point in said driver feedback path for decoupling said feedback from said path for affecting the linearity of said sawtooth voltage during a second portion of said trace interval.

Claim 8

A deflection generator comprising: a deflection winding; an amplifier coupled to said winding for supplying current thereto; a driver stage coupled to an input terminal of said amplifier, said driver stage comprising first and second active current conducting devices and a feedback path coupled from said second to said first device; oscillator and sawtooth generating means coupled to said driver stage, said means comprising third and fourth active current conducting devices; a timing network coupled to an output electrode of said third device and to a control electrode of said fourth device for determining the trace interval of each deflection cycle; a source of deflection rate signals coupled to a control electrode of said third device for changing the conduction state of said third and fourth devices from a first to a second state for initiating the retrace interval of each deflection cycle; means including first and second serially coupled capacitors coupled to an output electrode of said fourth device and a control electrode of said third device, said third device being responsive to the charging current of said first and second capacitors through said fourth device such that said retrace interval is terminated and said trace interval is initiated when said charging current reaches a predetermined amount and causes said third and fourth devices to change to said first conduction state; a fifth active current conducting device having its main conduction path coupled in parallel with said means including said first and second capacitors for providing a discharge path thereFor during said trace interval; first linearity correction means including a third capacitor coupled in parallel with one of said first and second capacitors for providing an additional discharge path therefor for affecting the linearity of discharge of said first and second capacitors during a first portion of said trace interval; the junction between said first and second capacitors being coupled to an input terminal of said driver stage for providing a sawtooth voltage waveform therefor during said trace interval; and second linearity correction means including a capacitor coupled to said deflection winding and a point in said driver feedback path for decoupling said feedback from said path for affecting the linearity of said sawtooth voltage during a second portion of said trace interval.

Claim 9

A deflection generator according to claim 6 wherein said linearity correction means includes a first impedance in series with said third capacitor, said impedance being large relative to the impedance of the charging path for said first and second capacitors such that when said first and second capacitors are charged through said second device relatively little charge is stored in said third capacitor.

Claim 10

A deflection generator according to claim 7 wherein a second impedance is coupled from the junction of said first and second capacitors to a point of reference potential for affecting the rate of discharge of said first, second and third capacitors for altering the shape of said sawtooth waveform for linearity correction.

Claim 11

A deflection generator according to claim 8 wherein a diode is coupled serially between said first and second capacitors and said control electrode of said first device and poled to present a low forward impedance for current charging said first and second capacitors.

Claim 12

A deflection generator according to claim 9 wherein a relatively large impedance is coupled from the junction of said diode and said first and second serially coupled capacitors for providing a relatively long time constant discharge path for said first and second capacitors.