US 5,703,445 A · Sawtooth generator with disturbance signal rejection for a deflection apparatus

Abstract

In a vertical sawtooth generator, an end time of a retrace portion of a vertical sawtooth signal is controlled by an output signal of a comparator. The comparator has a first input terminal that is responsive to a reference voltage and a second input terminal that is responsive to the sawtooth signal. The reference voltage is coupled to an input terminal of an amplifier of an integrator that generates the sawtooth signal. Any disturbance signal component in the reference voltage is super-imposed on the sawtooth signal. Because the same disturbance signal component is developed simultaneously in both input terminals of the comparator, a high degree of common mode rejection is provided with respect to the disturbance signal component.

Claims13

Dependent claims

A video display apparatus, comprising:

a capacitor;
a switch coupled to said capacitor and responsive to a first control signal for generating in said capacitor a sawtooth signal at a frequency that is related to a deflection frequency, an instant at which a first change in a slope of said sawtooth signal occurs being determined in accordance with said first control signal;
and
a comparator for generating said first control signal in accordance with a difference between said sawtooth signal and a reference signal, said sawtooth signal being coupled to a first input of said comparator and said reference signal being coupled to a second input of said comparator and also to said first input of said comparator, a change in said reference signal producing corresponding changes that compensate each other in said first and second inputs of said comparator.

1 more element

Dependencies are inferred from the claim text.

Sawtooth generator with disturbance signal rejection for a deflection apparatus

Life of this patent

Sawtooth generator with disturbance signal rejection for a deflection apparatus

Life of this patent

Abstract

Claims13