Patent ID: 7323813

Claim:
A cathode ray tube having an electron gun which includes at least three cathodes which are disposed in an in-line arrangement, a first grid electrode, a second grid electrode, a third grid electrode, a fourth grid electrode, a focusing electrode having an inner electrode, a final electrode, and a shield cup which is arranged on a face plate side of the final electrode, and an antenna getter mounted on the shield cup, the electron gun emitting a center electron beam and two side electron beams which are arranged to sandwich the center electron beam therebetween, assuming an aperture diameter of the center electron beam aperture formed in the shield cup as Vscc, an aperture diameter of the center electron beam aperture formed in an inner electrode as V 5 c , and a distance between the electron beam aperture formed in the shield cup and the inner electrode as L, a relationship tan θc=(V 5 c −Vscc)/2L≧0.08 is established, and assuming an aperture diameter of a side electron beam aperture formed in a shield cup as Vscs, an aperture diameter of side electron beam aperture formed in an inner electrode as V 5 s , and a distance between the electron beam aperture formed in the shield cup and the inner electrode as L, a relationship tan θ=(V 5 s −Vscs)/2L≧0.11 is established.