Other

Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Tsutomu Tojyo

Masayoshi Misono

Hiroyuki Tamura

Masahiro Ito

Mitsuhiro Sugiyama

A color cathode ray tube including a panel section having a phosphor layer formed on an internal surface thereof, a neck portion having an electron gun assembly for emission of three electron beams therein, and a funnel section connecting the panel section and the neck portion. The electron gun assembly includes three cathodes and a plurality of grid electrodes disposed along a tube axis. The grid electrodes includes at least one plate-shaped electrode which has a fixed support structure. The plate-shaped electrode has three bulged portions along an electron beam passage, a first electron beam passage hole being formed in a respective bulged portion and a second electron beam passage being hole formed in a top face portion of a respective bulge portion. A diameter of the first electron beam passage hole is greater than a diameter of the second electron beam passage hole.

Cathode ray tube

A color cathode ray tube includes a phosphor screen, a three-beam in-line electron gun, a beam deflection device, and a convergence correction device disposed on a phosphor screen side of the electron gun. The convergence correction device includes a first pair of magnetic pieces positioned on a tube-neck wall side of side electron beams and a second pair of magnetic pieces positioned on opposite sides of a center electron beam, in the in-line direction. The first pair of magnetic pieces each have a first pair of protruding portions extending toward an adjacent one of the second pair of magnetic pieces, and the first pair of protruding portions are arranged on opposite sides of a corresponding one of the side electron beams in a direction perpendicular to the in-line direction. The second pair of magnetic pieces each have two second pairs of protruding portions, one of the second pairs of protruding portions extends toward an adjacent one of the first pair of magnetic pieces and the other of the second pairs of protruding portions extends toward an adjacent one of the second pair of magnetic pieces, each of the second pairs of protruding portions being arranged on opposite sides of a corresponding one of the electron beams in a direction perpendicular to the in-line direction. The first pair of magnetic pieces have a portion of an axial length greater than that of the second pair of magnetic pieces.

Color cathode ray tube with coma reduced

A color cathode ray tube includes a panel section having an internal surface with a phosphor layer formed thereon and a neck portion accommodating therein an electron gun assembly for emission of a plurality of electron beams plus a funnel section connecting the panel section and the neck portion together, wherein the electron gun assembly is designed to have a plate-shaped electrode with a plurality of electron beam passage holes corresponding in the number to the electron beams. The plate electrode has cylindrical bulged portions projecting in a way corresponding to the plurality of electron beams, each of which portion has its top face in which an electron beam opening or hole is formed. The present invention provides a color cathode ray tube comprising a readily manufacturable high-resolution electron gun assembly.

Color cathode ray tube

A color cathode ray tube having electron gun with a plurality of electrodes for generating and focusing three in-line electron beams toward a phosphor screen. A deflection device is mounted between a funnel portion and a neck portion for deflecting the three electron beams in horizontal and vertical directions, and a convergence correction device including a plurality of magnetic pieces positioned with respect to the three electron beams in an in-line direction of the three electron beams in magnetic deflection fields generated by the deflection device. The plurality of magnetic pieces include at least one first magnetic piece positioned on a neck wall side of side electron beams of the three electron beams in in-line direction and at least one second magnetic piece positioned with respect to a center electron beam of the three electron beams in the in-line direction, and the plurality of magnetic pieces are configured so as to locally modify the magnetic deflection fields and to make three rasters formed on the phosphor screen by the three electron beams coincident with each other. The at least one first magnetic piece has a portion of an axial length greater than an axial length of the at least one second magnetic piece, and the axial lengths are measured in a plane containing the in-line direction and a longitudinal axis of the color cathode ray tube.

A color cathode ray tube includes a vacuum envelope formed by a panel, neck and funnel portions. The cathode ray tube includes a phosphor screen, a shadow mask, an electron gun and a deflection device. The cathode ray tube further includes a convergence correction device having a plurality of magnetic pieces positioned on opposite sides of each of the three electron beams in an in-line direction of the electron beams in a magnetic deflection fields generated by the deflection device. The plurality of magnetic pieces include a first pair of magnetic pieces positioned on a neck wall side of each of side electron beams in the in-line direction and a second pair of magnetic pieces positioned on opposite sides of a center electron beam of the three electron beams in the in-line direction. The plurality of magnetic pieces are configured so as to locally modify the magnetic deflection fields to make three rasters formed on the phosphor screen by the three electron beams coincident with each other. The first pair of magnetic pieces have a portion of an axial length greater than an axial length of the second pair of magnetic pieces, where the axial lengths is measured in a plane containing the in-line direction and a longitudinal axis of the cathode ray tube.

Growing community of inventors

Mobara, Japan

Tsutomu Tojyo