Dynamic focusing circuit having a pseudo horizontal output circuit to eliminate phase deviation in a focus signal

A dynamic focusing circuit generating a dynamic focus signal by use of a sawtooth wave signal generated from a vertical output circuit and a rectangular wave signal generated from a horizontal oscillating circuit, said dynamic focusing circuit comprising:

• a vertical parabola wave output circuit for generating a vertical parabola wave signal after integrating and amplifying said sawtooth wave signal and eliminating a DC component from said sawtooth wave signal;
• a first amplifying circuit for amplifying said vertical parabola wave signal;
• a vertical-modulating and horizontal-size-adjusting circuit for modulating amplitude of said vertical parabola wave signal by comparing said vertical parabola wave signal with a predetermined variable reference voltage;
• a pseudo horizontal output circuit for generating a pseudo horizontal wave signal whose amplitude is determined by a level of said variable reference voltage, wherein a wave signal formed by said rectangular wave signal is mixed with a wave signal supplied by said vertical-modulating and horizontal-size-adjusting circuit and thereby said rectangular wave signal is combined with said vertical parabola wave signal;
• a second amplifying circuit for amplifying said pseudo horizontal wave signal;
• a focus signal output circuit for varying DC voltage level of a dynamic focus signal consisting of a vertical frequency component generated from said first amplifying circuit and a horizontal frequency component generated from said second amplifying circuit;
• a horizontal phase control circuit for controlling phase of said rectangular wave signal;
• and
• a duty adjusting circuit coupled to said horizontal phase control circuit for varying duty of said rectangular wave signal.