Color cathode ray tube having a small neck diameter

A cathode ray tube comprising at least an evacuated envelope comprising a panel portion having a phosphor screen on an inner surface thereof, a neck portion, a funnel portion connecting said panel portion and said neck portion,

• a deflection device mounted in a vicinity of a transition region between said funnel portion and said neck portion, and
• an in-line electron gun housed in said neck portion, said in-line electron gun including an electron beam generating section comprising at least a cathode, a control electrode and an accelerating electrode and for generating and directing three electron beams in a horizontal plane toward said phosphor screen,
• a main lens section comprising
• a focus electrode including a first sub-electrode and a second sub-electrode adjacent to but spaced from said first sub-electrode, said second sub-electrode having a single opening at one end thereof for passing the three electron beams, said single opening having a diameter larger in a horizontal direction than a diameter thereof in a vertical direction, and a plate electrode placed inside said second sub-electrode and forming apertures for passing the three electron beams respectively,
• an anode facing said one end of said second sub-electrode, said second-sub-electrode and said anode forming a main lens therebetween, and
• an electrostatic quadrupole lens formed between said electron beam apertures in one of said first sub-electrode and said second sub-electrode and parallel plates attached to another of said first sub-electrode and said second sub-electrode so as to face said electron beam apertures and to sandwich the three electron beams, a lens strength thereof being varied with application thereon of a voltage varying with an increase in a deflection angle of the three electron beams,
• wherein a distance from said main lens to said phosphor screen is not larger than 300 mm, an outer diameter T of said neck portion housing said in-line electron gun satisfies a following inequality:
• 23.2 mm.ltoreq.T.ltoreq.25.9 mm,
• and
• a value D of twice a distance from a center of a trajectory of a side electron beam of the three electron beams to a vertical edge of said single opening satisfies a following inequality:
• 5.0 mm.ltoreq.D.ltoreq.6.5 mm.
• 2.