Kabushiki Kaisha Toshiba

Tustomu Takekawa

Hirofumi Ueno

Noriyuki Miyamoto

A color cathode ray tube apparatus of this invention includes an electron gun. In the electron gun, an intermediate electrode is arranged at the mechanical center between a focus electrode and anode electrode that form a rotationally symmetric bi-potential lens. A disk-like intermediate electrode is arranged at the mechanical center between the focus electrode and intermediate electrode. The disk-like intermediate electrode has an electron beam hole with a diameter larger in the vertical direction than in the horizontal direction. The intermediate electrode has a circular electron beam hole. Voltages are applied to the disk-like intermediate electrode and intermediate electrode such that they form an electron lens similar to that formed when the disk-like intermediate electrode does not exist. Therefore, an electron beam spot is focused in an optimal manner on the entire surface of a phosphor screen, and elliptic distortion is decreased. A good image is displayed on the entire surface of the phosphor screen.

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Fukaya, Japan

Tustomu Takekawa