Hitachi, Ltd.

Akio Yamaguchi

Shoji Shirai

Sachio Koizumi

Kazuo Majima

Yukihiro Izumida

Hidemasa Komoro

An electron gun for a color picture tube has at least a cathode, a control grid, an accelerating grid, a focus grid and an anode, each of which has three apertures aligned in line. The focus grid and the anode made of elongated plates serves as main lens electrodes, and the apertures of the focus grid and the anode constitute a main lens assembly. The three apertures of each of the elongated plates has a central aperture defined by two first curves arcuated outward, two side apertures each of which is defined by a second curve as an inner half arcuated inward and a third curve as an outer half arcuated outward, the first and second curves being less arcuated than the third curve. The three apertures are aligned such that the major axes thereof are parallel to a shorter axis of the elongated plate and are located at equal intervals. The three apertures are spaced apart from each other through corresponding bridge portions. The third curve of each of the two side apertures is apart from a corresponding end of the elongated plate along the longitudinal direction.

Electron gun for color picture tubes having uniquely formed lens

A color cathode ray tube wherein spring-back of a skirt of a shadow mask which causes the distortion of apertures of the shadow mask is prevented. The shadow mask is formed to exhibit a radius of curvature on an opposing pair of edges thereof. The shadow mask may be formed to exhibit a radius of curvature on four opposing edges. The radius of curvature is substantially equal to a radius of curvature of an apertured area of the shadow mask.

Growing community of inventors

Mobara, Japan

Akio Yamaguchi