Patent ID: 6847159

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 and has a first outer diameter of the neck portion, and a second neck portion which accomodates an electron gun which emits a single electron beam toward the phosphor screen 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, the electron gun includes a main lens which is constituted of a final electrode and a focus electrode which has portion thereof inserted into the inside of the final electrode, the final electrode has a large-diameter portion and a portion whose diameter is gradually decreased toward the phosphor screen, and a high voltage is applied to the final electrode is set to equal to or more than 25 KV.