Patent ID: 6515438
Filing Date: 2003-02-04
Classification: H01J

Abstract:
An electron gun in a color CRT comprising:a controlling electrode and an accelerating electrode each having a distance S0 between a central electron beam pass through hole and an outer electron beam pass through hole for passing electron beams emitted from cathodes; a pre-focusing electrode having a distance S1 between a central electron beam pass through hole and an outer electron beam pass through hole; a focusing electrode and an anode each having a rim at an opposite part for forming single electron beam pass through hole and an electrostatic field controlling body inside of the rim, for forming a large sized main focusing electrostatic lens by a potential difference; and, diverging means for diverging the outer electron beams incident on the focusing electrode from the pre-focusing electrode outwardly with respect to the central electron beam, wherein a ratio WS/H of a sum WS of a horizontal diameter of the central electron beam pass through hole of the electrostatic field controlling body and a minimum width â€˜tâ€™ of the bridge â€˜Bâ€™ surrounding horizontal direction outsides of the central electron beam pass through hole to a horizontal width â€˜Hâ€™ of the rim is set to be 0.31&lE;WS/H&lE;0.34 for shifting positions of the outer main focusing electrostatic lenses outward in correspondence to the divergence of the outer electron beams with respect to the central main focusing electrostatic lens.