Abstract: A color cathode ray tube has a phosphor screen and an electron gun. The electron gun includes an electron beam generating section for emitting three in-line electron beams toward the phosphor screen and an electron beam focusing section for focusing the electron beams onto the phosphor screen. The electron beam focusing section includes at least one cup-shaped electrode having a tubular portion and a flange formed continuously from the tubular portion. The tubular portion has a generally rectangular cross section having an outwardly curved portion at each side thereof in a direction of arrangement of the three in-line electron beams in a plane perpendicular to the color cathode ray tube axis, the flange has a generally rectangular cross section having an outwardly curved portion at each side thereof in the direction of arrangement of the electron beams in the plane perpendicular to the color cathode ray tube axis, and the flange is formed with a locally thinned-down portion.

Abstract: The profile lines of plate-like grid electrodes are formed by a first punching step and separation lines of the plate-like grid electrodes are formed by a subsequent punching step. The angle of a crossing portion formed by the profile line and the separation line is set to not less than 70 degrees and not more than 110 degrees. Due to such a constitution, burrs on the plate-like grid electrode which constitutes an electron gun of a color cathode ray tube can be reduced so that the quality of the cathode ray tube can be enhanced and the manufacturing time of the cathode ray tube can be shortened.

Abstract: A cathode-ray tube includes a plate having a first hole on a first surface of the plate and a second hole on a second surface of the plate. The first and second holes coupled together to allow electron beams to pass therethrough. The plate is a unitary structure. The first hole is formed by initiating a first hole formation from the first surface, and the second hole is formed by initiating a second hole formation from the second surface. The first surface is on an opposing side of the second surface.

Abstract: A cathode ray tube has a phosphor screen and an electron gun. The electron gun includes an electron beam generating section and an electron beam focusing section for focusing an electron beam from the electron beam generating section onto the phosphor screen. The electron beam generating section and the electron beam focusing section are mounted in predetermined spaced relationship on plural insulator support rods. The electron beam focusing section includes at least one compound electrode formed of a first electrode member, a second electrode member and a plate-like electrode member sandwiched therebetween. The plate-like electrode member is fabricated from a material thicker than materials from which the first and second electrode members are fabricated. The plate-like electrode member is laser-welded to the first and second electrode members at points of edges of the first and second electrode members.

Abstract: A cathode-ray tube includes a plate having a first hole on a first surface of the plate and a second hole on a second surface of the plate. The first and second holes are coupled together to allow electron beams to pass therethrough. The first hole has a first diameter, and the second hole has a second diameter.

Abstract: The present invention provides a color cathode ray tube which can make the focusing of a center electron beam and side electron beams uniform by reducing the non-uniformity of the spot shape of electron beams depending on a deflection quantity.

Abstract: A color cathode ray tube has a phosphor screen and an electron gun. The electron gun includes an electron beam generating section for emitting three in-line electron beams toward the phosphor screen and an electron beam focusing section for focusing the electron beams onto the phosphor screen. The electron beam focusing section includes at least one cup-shaped electrode having a tubular portion and a flange formed continuously from the tubular portion. The tubular portion has a generally rectangular cross section having an outwardly curved portion at each side thereof in a direction of arrangement of the three in-line electron beams in a plane perpendicular to the color cathode ray tube axis, the flange has a generally rectangular cross section having an outwardly curved portion at each side thereof in the direction of arrangement of the electron beams in the plane perpendicular to the color cathode ray tube axis, and the flange is formed with a locally thinned-down portion.

Abstract: A color cathode ray tube having an electron gun which includes a one piece electrode plate. The one piece electrode plate has three beam passage holes in an in-line arrangement and bead supports. The one piece electrode plate has two portions including a portion having the beam passage holes and a portion having the bead supports which are formed as a one piece structure. The portion having the beam passage holes has a thickness larger than a thickness of the bead supports portion and the one piece structure has steps and continuous walls between the two portions.

Abstract: A cathode-ray tube having an electron gun which includes an electrode plate (E) in which a portion having three beam passage holes (H) and a portion having bead supports (S) are formed as a unitary or one piece structure, the two portions having different thicknesses (T.sub.1, T.sub.2), and the steps being inclinedly formed along the boundaries of the two portions. Since the portion having beam passage holes and the portion having bead supports are formed as a unitary or one piece structure easily and highly precisely in the electrode plate, the conventionally employed process of welding can be omitted, and thereby the productivity is raised and the manufacturing cost is decreased. Moreover, use of the material having the steps formed in advance contributes to increasing the productivity and preventing the machining tools from being damaged during the press-forming.

Abstract: In an electron gun for a cathode ray tube in which a focus electrode group includes a single platelike electrode having three apertures arrayed in one plane and a thickness equal to a depth of each of the three apertures, a tapered surface is formed on the entrance side and/or exit side of each of the three apertures, the tapered surface having a diameter larger than the aperture diameter and having a linear or curved shape in cross section, and a step which extends in the direction of the depth is formed around an aperture periphery of the tapered surface. With this constitution, the concentricity between each of the tapered surfaces and a respective one of the apertures can be measured with high precision on the basis of the boundary between each of the tapered surfaces and the corresponding one of the steps, thereby improving the precision of measurement of the concentricity between each of the apertures formed in the platelike electrode and the tapered surface formed around the aperture periphery.

Abstract: An electron gun which has an assembly precision improved by the reduction of deformation of an electrode during assembly as well as good focusing performance due to the elimination of positional deviation of electron beams. The electron gun comprises a composite electrode including at least two electrode elements united together and a plurality of electrodes sequentially arrayed along a single axis at predetermined intervals. In the electron gun, opposed faces of the electrode elements of the composite electrode are perpendicular to the axis and the opposed faces are provided with projections which serve to constitute the composite electrode when the projections are united together in opposed relationship to each other.

Abstract: There is provided an electron gun which has an assembly precision improved by the reduction of deformation of an electrode during assembly as well as good focusing performance due to the elimination of positional deviation of electron beams. There is also provided a method of assembling such an electron gun. The electron gun comprises a composite electrode including at least two electrode elements united together and a plurality of electrodes sequentially arrayed along a single axis at predetermined intervals. In the electron gun, opposed faces of the electrode elements of the composite electrode are perpendicular to the axis and the opposed faces are provided with projections 1a and 1b which serve to constitute the composite electrode when the projections are united together in opposed relationship to each other.

Abstract: A cathode-ray tube having an electron gun which includes an electrode plate (E) in which a portion having three beam passage holes (H) and a portion having bead supports (S) are formed as a unitary structure, the two portions having different thicknesses (T.sub.1, T.sub.2), and the steps being inclinedly formed along the boundaries of the two portions. Since the portion having beam passage holes and the portion having bead supports are formed as a unitary structure easily and highly precisely in the electrode plate, the conventionally employed process of welding can be omitted, and thereby the productivity is raised and the manufacturing cost is decreased. Moreover, use of the material having the steps formed in advance contributes to increasing the productivity and preventing the machining tools from being damaged during the press-forming.