Patent ID: 6522058
Filing Date: 2003-02-18
Classification: H01J

Abstract:
A color cathode ray tube having a vacuum envelope which comprises a panel having a phosphor screen on an inner surface thereof, a neck accommodating an electron gun which emits a plurality of electron beams in the horizontal direction and a funnel connecting said panel and said neck, andsaid color cathode ray tube externally mounting a deflection device which deflects said electron beams in the horizontal direction and the vertical direction at said neck side of said funnel, wherein said electron gun is arranged with a beam generating part which is constituted of a cathode, a control electrode and an accelerating electrode and generates the plurality of electron beams, and a main lens part which is made of a focus electrode and an anode therein and focuses the electron beams generated by said beam generating part toward said phosphor screen, in the tube axis direction, a final-stage main lens is constituted between an anode-side end portion of said focus electrode and a focus electrode side end portion of said anode, said focus electrode includes a plurality of electrode members which constitute an electrostatic quadrupole lens for changing a cross-sectional shape of the electron beams in synchronism with the deflection of said electron beams and an electron lens whose focusing force is fluctuated in synchronism with the deflection of said electron beams, said electron lens is arranged between said electrostatic quadrupole lens and said final-stage main lens, and assuming the distance from said anode-side end portion of the focus electrode to an anode-side end portion of the electrostatic quadrupole lens as L2 (mm), a following relationship is set with respect to the distance L27.55&lE;L2&lE;11.5.