Hitachi, Ltd.

Minoru Yabe

Masaaki Yamauchi

Satoru Endo

Kenichi Noda

Shoji Shirai

Hidemasa Komoro

Mamoru Ikeda

Kenichi Matsuda

Mitsuru Igarashi

Satoru Endoh

An electrode structure for an electron gun, especially an in-line type electrode structure for an electron gun of a color picture tube. The electrode structure dispenses with auxiliary electrodes and its three cylindrical members are integrally formed by press work. After the pressing step, the inner edge of the bottom portion of each cylindrical members is beveled to provide a tapering surface having a desired circular cross section. By forming a circular groove in the bottom portion, opposite to the tapering surface, the formation of the tapering surface is made more exact.

Electrode structure for electron gun

An electron gun for a color picture tube comprises opposing cup-shaped electrodes each having a plurality of openings laterally aligned in a row, the electrodes being combined such that the openings face each other to form electron lenses. The openings are formed in flat bottom walls of said electrodes, a width of a bridge portion between adjacent openings is 0.5 to 1.5 times a thickness of the bottom wall of each electrode, and corrective plate electrodes are arranged to oppose bridge portions with a predetermined distance therefrom. The electrodes are combined such that spherical aberration of said electron lenses as a whole can be reduced when one of the electrodes is applied with a voltage which is higher than that applied to the other.

Electron gun for color picture tube

A method for producing an electrode structure for use in an electron gun, especially an in-line type electrode structure for use an electron gun of a color picture tube. The electrode structure dispenses with auxiliary electrodes by forming its three cylindrical members integrally by press work. After the pressing step, the inner edge of the bottom portion of each of the cylindrical members is beveled to provide a tapering surface having a desired circular cross section. By forming a circular groove in the bottom portion, opposite to the tapering surface, the formation of the tapering surface is made more exact.

Method of producing itegral electrode structure for electron gun

In an in-line type electron gun structure including three in-line type electron guns and a plurality of grid electrodes respectively aligned with the electron guns, each sleeve electrode has a length equal to at least 50% of an inner diameter thereof and the inner diameter is gradually increased toward a free end of the sleeve-shaped electrode from a point at about one half of the length thereof. This construction eliminates an auxiliary electrode, thus reducing the cost of manufacturing.

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Mobara, Japan

Minoru Yabe