Patent ID: 7075221

Claim:
A projection tube comprising a panel having a phosphor screen on an inner surface thereof, a funnel, a neck portion, and a stem portion which seals the neck portion, wherein: the neck portion includes a first neck portion which constitutes a portion connected to the funnel portion and has a first outer diameter of the neck portion, and a second neck portion which constitutes a portion which accommodates an electron gun having a focus electrode and an anode electrode and has a second outer diameter of the neck portion; the first outer diameter of the neck portion is set smaller than the second outer diameter of the neck portion; a deflection yoke which deflects the electron beam is mounted on the first neck portion having the first outer diameter; a velocity modulation coil is mounted on the second neck portion having the second outer diameter; the electron gun emits a single electron beam to the phosphor screen; the focus electrode is divided into a first focus electrode and a second focus electrode having a gap therebetween, and a focus voltage is applied to both the first focus electrode and the second focus electrode; the focus electrode and the anode electrode are disposed in the second neck portion; and a maximum operating voltage of the electron gun is set to equal to or more than 25 kV.