Color display tube

An electric discharge tube comprising an envelope having a main axis, a display screen and an electron gun system for producing a plurality of electron beams and converging the beams on the display screen, the electron gun system comprising first electrode means for generating the electron beams, the first electrode means being situated along axes parallel to the main axis of said tube;

• second electrode means situated along the path of the electron beams between the first electrode means and the display screen, said second electrode means comprising respective last electrodes situated on the side toward the dislay screen and an associated preceding electrode, with electrodes in use constitute a lens field which focuses the electron beams symmetrically;
• and third electrode means between the first and the second electrode means for forming an asymmetric lens field to coverge the electron beams on the display screen, characterized in that
• the axes of the electrodes of all electrode means are parallel to said axes of the first electrode means;
• and
• the last electrodes (76, 96, 106), situated on the side toward the display screen, of those second electrode means which are situated eccentrically with respect to the main axis of the tube, have axes (54) which are situated eccentrically with respect to the axes (55) of the associated preceding electrodes (75, 95, 105) and to the axes (62) of the associated first electrode means, the axes (55) of said preceding electrodes (75, 95, 105) having a smaller distance to the main axis of the tube than the axes (54) of the associated last electrodes (76, 96, 106) situated on the side toward the display screen, said axes (54) of said last electrodes in turn having a smaller distance to the main axis of the tube than the axes (62) of the associated first electrode means (71, 72, 73, 91, 92, 93).