One-gun two-beam cathode ray tube

A one-gun two-beam cathode ray tube comprising:

• (a) an envelope having a target screen;
• (b) an electron gun for producing an electron beam directed toward the target screen;
• (c) a first quadrupolar electron lens disposed along the path of the beam for diverging the beam in a first direction and for converging the beam in a second direction, the first and the second directions being at right angles with each other;
• (d) a second quadrupolar electron lens disposed along the path of the beam from the first electron lens for converging the beam in the first direction and for diverging the beam in the second direction;
• (e) beam separator means disposed across the path of the beam from the second electron lens and defining a pair of apertures equidistantly spaced from, and aligned in the first direction with, the geometrical center of the cross section of the incident beam, whereby two separate fractions of the incident beam are admitted through the apertures to provide first and second display beams of smaller cross sectional size;
• (f) a first pair of deflection plates for deflecting the first display beam from the beam separator means in the first direction;
• (g) a second pair of deflection plates for deflecting the second display beam from the beam separator means in the first direction;
• (h) focus corrector means disposed along the paths of the first and the second display beams from the first and the second pairs of deflection plates, the focus corrector means comprising first and second opposed pairs of electrodes which are arranged in generally boxlike configuration and which are separated from one another, the first opposed pair of electrodes being spaced from each other in the first direction and so positioned that the first and the second display beams pass the opposite sides of the midpoint between the first pair of electrodes, the second opposed pair of electrodes being spaced from each other in the second direction to an extent necessary for the passage of each display beam, the first pair of electrodes being set at a potential higher than the potential of the second pair of electrodes, whereby the first and the second display beams are diverged in the first direction to a greater extent as the display beams pass closer to the respective electrodes of the first pair;
• (i) a third quadrupolar electron lens for diverging the first and the second display beams from the focus corrector means in the first direction and for converging the first and the second display beams in the second direction;
• and
• (j) a third pair of deflection plates for deflecting the first and the second display beams from the third electron lens in the second direction.