JP2003086114A - Electron gun of cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation and glass crack of an electrode in beading, in relation to an electron gun provided for, for instance, a neck part of a color cathode ray tube and to a structure of an electrode pin in an electrode having an electron beam passing hole. SOLUTION: Each pin part 5c of the electrode in this electron gun 1 is so formed as to reduce its cross-sectional area toward its tip part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun provided in a neck portion of a color cathode ray tube, for example, and relates to a structure of an electrode pin in an electrode having an electron beam transmitting hole.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIGS. 6 to 7, an electron gun 1 in a color cathode ray tube A directs an electron beam toward a phosphor screen based on a color signal output from a color signal output circuit. A cathode 2 for emitting an electron beam, and a plurality of grids G1, G2 for controlling, accelerating and focusing the electron beam emitted from the cathode 2.
It is generally composed of respective electrodes having G3, G4, G5, and G6.

The plurality of electrodes are arranged on a coaxial line with each other at a predetermined interval, and a pair of insulating supports 3 made of foam glass (called bead glass) such as multi-form glass,
4 are respectively supported and integrated.

The combination of the insulating supports 3 and 4 and each electrode is, as shown in FIG. 8, a certain plate thickness (for example, 0.4 m).
m, 0.6 mm, etc.) made of a metal plate (for example, made of SUS) is punched with a press die, and the electrode 5 having each hole 5a for electron beam (R, G, B) is treated by beading treatment. 7 is set on the coaxial device at a predetermined interval on a tool device (not shown).
As shown in FIG. 5, the insulating supports 3 and 4 which have been heated and softened by a heating means such as a gas burner are pushed in a direction (arrow direction) orthogonal to the coaxial line, and a bead glass implanting portion of the electrode (hereinafter referred to as a pin portion). (The same) 5b is embedded and sandwiched (this is called beading), and the insulating supports 3 and 4 are cooled and integrally fixed.

[0005]

However, if attention is paid to the implanting portion of the pin portion of the electrode and the insulating support, as shown in FIG.
As shown in, since the end portions 5b of the electrodes having a rectangular cross section bite into the insulating supports 3 and 4 that have been heated and softened by the heating means by pressing in the direction orthogonal to the coaxial line (reference numeral S in the drawing),
A load is generated on the electrode 5 itself, and the electrode is deformed or displaced. As a result, in the cathode ray tube A using such an electron gun, there is a problem that characteristics such as focus and cutoff are deteriorated.

Further, a load (reference numeral T in the figure) is also applied to the insulating supports 3 and 4 which are the bead glasses, and the glass cracks 6 may occur due to stress such as heat shrinkage when the beads are cooled. There is.

Further, when the beading process is performed, the glass is pushed away by the pin portion 5b, and the portion holding the pin portion 5b recedes to cause a gap 7 without sufficient adhesion. Therefore, the support of the pin portion 5b is not sufficiently secured,
There is a problem that the backlash of the electrodes 5 occurs and the intervals between the electrodes are deviated, resulting in deterioration of the characteristics of the cathode ray tube. The electron gun of the cathode ray tube according to the present invention has been proposed to solve such problems.

[0008]

The gist of the electron gun for a cathode ray tube according to the present invention to solve the above problems is that the pin portion of the electrode in the electron gun has a cross-sectional area that decreases toward the tip. Is being formed. Further, the pin portion is formed in a spire shape, and further, the pin portion is
It includes being formed in a taper shape that becomes thinner toward the tip.

According to the electron gun of the cathode ray tube of the present invention,
When the pin portion of the electrode is embedded in the bead glass in the beading process, the resistance force in the embedding action is reduced. As a result, the electrode is prevented from being deformed and the glass crack is prevented from occurring. The holding of the parts becomes stable.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an electron gun for a cathode ray tube according to the present invention will be described with reference to the drawings. To facilitate understanding of the invention, portions corresponding to those of the conventional example will be described with the same reference numerals as those of the conventional example. As shown in FIGS. 6 and 7, the electron gun 1 of the cathode ray tube A emits an electron beam from the cathode 2 to the phosphor screen.

The electron gun 1 has electrodes having a plurality of grids G1, G2, G3, G4, G5 and G6 for controlling, accelerating and focusing the electron beam emitted from the cathode 2. The plurality of electrodes 5 are arranged on a coaxial line at a predetermined interval, and are narrowed by a beading jig device (not shown) with insulating supports 3 and 4 which are bead glass such as multi-form glass, and integrated. Stuck to. In this way, the electron gun 1 is assembled.

As for the electrode 5, as shown in FIGS. 1A and 1B, a flat metal plate such as SUS is punched into a predetermined outer shape to form electron beam transmission holes for each color (R, G, B). 5a is provided, and a pin portion 5c which is a bead glass planting portion for fixing the insulating supports 3 and 4 is provided.

As shown in FIG. 1 (A), the pin portions 5c are provided so as to project from the upper and lower edge portions of the main body portion by at least one or more such as two or three. Then, as shown in FIG. 1B, the pin portion 5c is formed in a tapered shape that becomes thinner toward the tip end portion thereof.

As an example of forming the pin portion 5c of the electrode 5 in a tapered shape, a case of rolling by a die will be described. The forming method by the rolling process is shown in FIG.
As shown in, the metal electrode material such as SUS (plate thickness t =
0.4 mm or the like 8 is placed on the base 9, the electrode material 8 is pressed by the stripper 10 and the outer shape is punched by the punch 11.

Then, as shown in FIG. 2B, the punched electrode material 8 is rolled by a rolling punch 12 to form a tapered pin portion.

Next, as shown in FIG. 2C, a stripper 10 is applied to the electrode material 8 on which the tapered pin portion is formed.
Then, the electron beam transmission hole is punched by the punch 11a.

Next, as shown in FIG. 2D, the tip portion 13 of the tapered pin portion is cut off by the punch 11b. Thus, the electrode 5 shown in FIG. 1 having the pin portion 5c rolled into a tapered shape is formed so that the cross-sectional area decreases toward the tip.

Since the pin portion 5c of the electrode 5 is tapered as described above, when the insulating supports 3 and 4 are beaded in the assembly of the electron gun 1, the operation thereof is as shown in FIG. Then, the pin portions 5c bite smoothly into the insulating support bodies 3 and 4 of the bead glass that have been softened by heating like wedges. Since the end surface of the pin portion 5c is thin, the resistance of the bead glass is much smaller than that of the conventional example. Therefore, due to the reduction of the load, the electrode 5 is not deformed, and the generation of glass cracks is prevented even in the insulating support.

Furthermore, since the bead glass is not strongly pushed away on the outer peripheral surface of the pin portion 5c, the pin portion 5c and the bead glass have good adhesion, and after the insulating supports 3 and 4 are cooled, Not only is there no backlash, but a sufficient bearing capacity is also secured.

As described above, the pin portion 5c of the electrode is shaped so that the cross-sectional area decreases toward the tip portion with respect to the cross-sectional area of the main body portion, so that the supporting force by beading is secured. As long as it can be ensured, the taper shape is not limited to the above-described example (see FIG. 4A). For example, as shown in FIG. As shown in FIG. 4C, it has a pointed spire shape, or as shown in FIG.
Various modifications can be made, such as by setting d to reduce the cross-sectional area. Further, not only rolling processing, but also methods such as shaving and polishing may be used.

Also, when the electrode 5e is sub-assembled to form a grid of the electron gun 1 as one component, as shown in FIG. 5B, the cross-sectional area of the pin portion 5c is reduced toward the tip. You can Note that FIG.
It is shown in order to compare the sub-assembly of the conventional electrode 5.

[0022]

As described above, in the electron gun of the cathode ray tube according to the present invention, the pin portion of the electrode in the electron gun is formed so that the cross-sectional area decreases toward the tip. Even when the pin glass bites into the bead glass when the insulating support of the bead glass is beaded, a strong resistance force is not generated, and the electrode is not deformed or displaced. Therefore, the characteristics of the cathode ray tube are prevented from being deteriorated.

Further, it is possible to prevent generation of glass cracks on the insulating support, to achieve sufficient holding around the pin portion, to prevent backlash of the electrode, and to secure a sufficient supporting force. It plays.

Further, even in the case of an electrode formed of an electrode material having a large plate thickness, by rolling the pin portion into a tapered shape or the like, it becomes possible to integrally support it by beading processing. This has an excellent effect that the electrode formed by assembly can be similarly supported.

[Brief description of drawings]

FIG. 1 is a front view (A) and a side view (B) of electrodes in an electron gun of a cathode ray tube according to the present invention.

FIG. 2 is an explanatory view (A) showing how the electrodes of the electron gun of the cathode ray tube according to the present invention are formed by rolling.
(B), (C), and (D).

3A and 3B are an explanatory view (A) and a partially enlarged explanatory view (B) of a bite portion when an insulating support is beaded to an electrode in an electron gun of a cathode ray tube according to the present invention.

FIG. 4 is a side view (A), (B), (C) showing another modification of the electrodes in the electron gun of the cathode ray tube according to the present invention.
(D).

FIG. 5 is a side view (A) showing a state where the electrodes are sub-assembled,
(B).

FIG. 6 is a front view of a cathode ray tube.

FIG. 7 is an explanatory diagram showing a manner of beading processing of an electron gun of a cathode ray tube.

FIG. 8 is a front view (A) and a side view (B) of electrodes in an electron gun of a cathode ray tube according to a conventional example.

9A and 9B are an explanatory view (A) of a biting portion and a partially enlarged explanatory view (B) when an insulating support is beaded to an electrode in an electron gun of a cathode ray tube according to the conventional example.

[Explanation of symbols]

1 electron gun, 2 cathode, 3,
4 Insulating support, 5 electrodes, 5a
Beam transmission hole, 5b, 5c pin part, 5d arc part, 6 glass crack, 7 gap, A cathode ray tube.

Claims (3)

[Claims] 1. An electron gun for a cathode ray tube, wherein the pin portion of the electrode of the electron gun is formed so that the cross-sectional area decreases toward the tip. 2. The electron gun for a cathode ray tube according to claim 2, wherein the pin portion is formed in a steeple shape. 3. The electron gun for a cathode ray tube according to claim 1, wherein the pin portion is formed in a tapered shape that becomes thinner toward the tip portion.