Pulse generator for a horizontal deflection system

Claim 2

A pulse generator for producing an output pulse of a known duration in response to a command signal comprising: a charge storage device; a source of current control pulses having a fixed duration; first means, responsive to said control pulses, and coupled to said charge storage device, for maintaining a current flow of a first polarity to said charge storage device continuously during the occurrence of said control pulses to alter the charge of said device from a first charge condition to a second charge condition; second means, coupled to said charge storage device, for providing a current flow of a second polarity to said charge storage device for an interval initiated in response to said command signal and terminated in response to the attainment by said charge storage device of said first charge condition; and means, coupled to said second means, for producing an output pulse during said interval.

Claim 3

The pulse generator of claim 1, further comprising a latch circuit coupled to said second means and responsive to enabling and release signals for disabling said second means for a period commencing after said interval has terminated and ending after the initiation of the succeeding current control pulse.

Claim 4

The pulse generator of claim 2, wherein said enabling signal is developed by said second means and said release signal is developed by said source of current control pulses.

Claim 5

The pulse generator of claim 3, wherein said current control pulses are further applied to said second means to inhibit said second means during said occurrence of said control pulses.

Claim 6

The pulse generator of claim 2, further comprising a source of reference voltage and wherein said second means includes a comparator having a first input coupled to said reference voltage source and a second input coupled to said charge storage device for detecting when the voltage developed by said charge condition of said device is substantially equal to said reference voltage.

Claim 7

The pulse generator of claim 5, wherein said charge storage device comprises a capacitor having a first plate coupled to one terminal of a source of supply voltage and a second plate, and said first and second means include first and second transistors having their collector-to-emitter paths serially coupled across two terminals of said source of supply voltage, the base of said first transistor being coupled to said source of current control pulses and the base of said second transistor being coupled to said comparator and to receive said command signal, and a resistive impedance coupled between the junction of said serially coupled transistors and said second plate of said capacitor.

Claim 8

The pulse generator of claim 6, wherein said resistive impedance comprises the series combination of a diode and a first resistor, and a second resistor coupled in parallel with said series combination.

Claim 9

In a television receiver, including a source of composite video signals; first means, coupled to said source of signals, for separating horizontal synchronizing signals from said composite video signals; second means, coupled to said horizontal synchronizing signal separating means, for producing pulses related in phase and frequency to said horizontal synchronizing signals; a horizontal deflection circuit, responsive to horizontal drive signals, for producing deflection and flyback signals; and third means, coupled to said second means, and responsive to said flyback signals and pulses from said second means for producing, at an output, a horizontal drive command signal; a horizontal drive signal circuit comprising: a capacitor; a charging transistor having an input electrode coupled to said second means and an output electrode coupled to said capacitor for charging said capacitor in response to pulses from said second means; a source of reference voltage; a comparator having a first input coupled to said reference voltage source, a second input coupled to said capacitor, and an output; means, coupled to the output of said comparator and to the output of said third means, and having an output for developing a discharge signal in response to said horizontal drive command signal; a discharging transistor having an input electrode coupled to the output of said discharge signal developing means for discharging said capacitor during the occurrence of said discharge signal; and means, having an input coupled to said discharge signal developing means and an output coupled to said horizontal deflection circuit for applying a horizontal drive signal to said horizontal deflection circuit which corresponds to said discharge signal.

Claim 10

In a television receiver, including a source of composite video signals; first means, coupled to said source of signals, for separating horizontal synchronizing signals from said composite video signals; second means, coupled to said horizontal synchronizing signal separating means, for producing pulses related in phase and frequency to said horizontal synchronizing signals; a horizontal deflection circuit, responsive to horizontal drive signals, for producing deflection and flyback signals; and third means, coupled to said second means, and responsive to said flyback signals and pulses from said second means for producing, at an output, a horizontal drive command signal; a horizontal drive signal circuit comprising: a capacitor; a charging transistor having an input electrode coupled to said second means and an output electrode coupled to said capacitor for charging said capacitor in response to pulses from said second means; a source of reference voltage; a comparator having a first input coupled to said reference voltage source, a second input coupled to said capacitor, and an output; means, coupled to the output of said comparator and to the output of said third means, and having an output for developing a discharge signal in response to said horizontal drive command signal; a discharging transistor having an input electrode coupled to the output of said discharge signal developing means for discharging said capacitor during the occurrence of said discharge signal; and means, having an input coupled to said discharge signal developing means and an output coupled to said horizontal deflection circuit for applying a horizontal drive signal to said horizontal deflection circuit which corresponds to said discharge signal.

Claim 11

The television receiver of claim 8, wherein said horizontal drive signal circuit further comprises a latch circuit having a first input coupled to said third means, a second input coupled to said comparator, and an output coupled to said comparator for disabling said comparator during a period subsequent to said discharging interval and prior to the occurrence of the succeeding interval during which said capacitor is charged by said charging transistor.