Patent ID: 7135813

Claim:
A color Braun tube apparatus, comprising: an electron gun having an electron beam generating part for generating three electron beams, including a center electron beam and a pair of side electron beams on both sides of the center electron beam, on an identical horizontal plane and a plurality of electrodes that form a main lens and have an electron beam passage aperture; and a deflection yoke for allowing the three electron beams emitted from the electron gun to scan in a horizontal direction and a vertical direction, the main lens accelerating and focusing the three electron beams generated from the electron beam generating part with respect to a screen, wherein the main lens is formed by a focus electrode to be supplied with a focus voltage, at least one intermediate electrode to be supplied with an intermediate voltage higher than the focus voltage, and an anode electrode to be supplied with an anode voltage higher than the intermediate voltage, arranged successively in a traveling direction of the three electron beams, the focus electrode and the anode electrode respectively are composed of a tubular body in which a noncircular electron beam passage aperture common to the three electron beams, having a major axis in the horizontal direction and a minor axis in the vertical direction, is formed in a portion opposed to the intermediate electrode, three electron beam passage apertures through which the three electron beams pass are formed in the respective tubular bodies constituting the focus electrode and the anode electrode, an aperture dimension in the vertical direction of the noncircular electron beam passage aperture common to the three electron beams formed in the focus electrode is smaller than an aperture dimension in the vertical direction of the electron beam passage aperture formed in a portion of the intermediate electrode opposed to the focus electrode, and an aperture dimension in the vertical direction of the noncircular electron beam passage aperture common to the three electron beams formed in the anode electrode is smaller than an aperture dimension in the vertical direction of the electron beam passage aperture formed in a portion of the intermediate electrode opposed to the anode electrode.