COLOR CATHODE-RAY TUBE APPARATUS

摘要

A color cathode ray tube apparatus of this invention includes an electron gun. In the electron gun, an intermediate electrode (GM2) is arranged at the mechanical center between a focus electrode (G3) and anode electrode (G4) that form a rotationally symmetric bi-potential lens. A disk-like intermediate electrode (GM1) is arranged at the mechanical center between the focus electrode (G3) and intermediate electrode (G4). The disk-like intermediate electrode (GM1) has an electron beam hole with a diameter larger in the vertical direction than in the horizontal direction. The intermediate electrode (GM2) has a circular electron beam hole. Voltages are applied to the disk-like intermediate electrode (GM1) and intermediate electrode (GM2) such that they form an electron lens similar to that formed when the disk-like intermediate electrode (GM1) 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. <IMAGE>