JPH0684501A - Grid electrode of electron gun for cathode-ray tube and working method therefor - Google Patents

Abstract

PURPOSE:To enhance productivity by preforming a spherical recessed part with respect to a first prepared hole to prevent damage of a coining die, and forming a predetermined slit-like recessed part in the peripheral part of a beam passage hole to align hole centers of a first and a second members with each other. CONSTITUTION:Coining is applied sequentially to a prepared hole 2 in a second member 7, to a prepared hole 4 in a recessed part 3 of a depth L and to a hole 5 whose center is aligned with a center of the hole 4. The second member 7 is welded to a first member 6 to constitute a third grid electrode. Since the coining work is used, work pressure can be restrained to a small value, and a thin slit-like recessed part having a depth of 40-60% of material thickness and 0.4mm or more and recessed part volume of 2mm<3> or more can be formed without deformation in the peripheral part of an electron beam passage hole. Since the third electrode is formed of the members 6 and 7, centers of the holes 10, 11 can be precisely aligned with each other. With this constitution, astigmatism correction can be adequately performed and productivity is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate electrode constituting an electron gun and its processing, and more particularly to a grid electrode of an electron gun for a cathode ray tube used for a color picture tube or a monitor of a terminal device and a method of processing the same.

[0002]

2. Description of the Related Art A color cathode ray tube is still in the mainstream as a monitor of a television broadcast reception or an information processing device because of its fine image reproducibility. FIG. 4 is a cross-sectional view illustrating the structure of this type of cathode ray tube, in which 50 is a face panel, 51 is a funnel, 52 is a neck connected to the funnel, 53 is an anode terminal, and 54 is a shadow mask having many apertures. , 55 is an electron gun for emitting three electron beams, 56 is a deflecting device, and 57 is an electron beam. Further, 501 is a screen and 502 is a phosphor layer.

In FIG. 1, a vacuum container is formed by the face panel 50, the funnel 51 and the neck 52, and the electron gun 55 is housed in the neck 52.
A shadow mask 54 having a large number of apertures which are provided in the inner skirt portion so as to face the phosphor layer 502 at a predetermined interval.
Is suspended. In addition, a conductive film 511 that is evenly applied to a part of the neck 52 on the inner wall of the funnel.
And a conductive film applied to the inside of the funnel 51, a conductive film applied to the exterior, and an anode terminal 53 provided so as to penetrate a part of the funnel 51, and from the funnel 51 to the neck 52. Deflection device 56 on the outer wall of the
Is installed.

On the inner surface of the screen 501, red,
Green and blue phosphors are applied in stripes or dots, and three electron beams emitted from the electron gun are selected by the shadow mask 54 to impact each phosphor and cause it to emit light. FIG. 5 is a schematic diagram for explaining an example of the electrode configuration of an electron gun for a cathode ray tube, which includes a cathode K, which is an in-line array of three parallel electron beam generators, and a first electrode.
The grid electrode (G1) 10, the second grid electrode (G2) 20, the third grid electrode (G3) 30, the fourth grid electrode (G4) 40,
..It is composed of the anode 50, and the number of focusing grid electrodes installed differs depending on the type of electron gun.

In the figure, each grid electrode 10, 20, 3
The anodes 50 are embedded in a pair of multi-form glass 45, which are insulators, and are fixed at predetermined intervals in the tube axis xx direction. In addition, H is a heater for heating the cathode K. FIG. 6 is a front view (a) of a third grid electrode shown as a structural example of a plate grid electrode of a conventional electron gun for a cathode ray tube, and FIG. 6 (b) is a sectional view taken along line AA of (a).

In the figure, this grid electrode is composed of three layers of a first member 6, a second member 8 and a third member 9. The first member 6 is embedded in a multi-form glass 45 (FIG. 5). A support portion 61 for fixing is formed. Further, 11 is an opening provided in the first member 6, 10 is an electron beam passage hole provided in the second member 8, and 5 is an opening for forming a slit-like recess provided in the third member 9. .

This grid electrode includes a first member 6, a second member 8,
The third member 9 is formed with a required opening 11, an electron beam passage hole 10 and an opening for forming the slit-shaped recess 5, and these first member 6, second member 8 and third member 9 are laminated by welding. Then, they are integrated to form a grid electrode having slit-shaped recesses 5 around the electron beam passage hole 10.

However, when the grid electrode is manufactured by this method, the centers of the opening 11, the electron beam passage hole 10 and the slit-shaped recess 5 formed in the first member 6, the second member 8 and the third member 9 are aligned with each other. Is difficult to integrate.
In order to avoid this, recently, a method of forming a grid electrode by using two plate-shaped materials has been adopted as described below.

7 (a), (b) and (c) are explanatory views of the structure of a third grid electrode according to the prior art using two plate-shaped materials, where 4 is a prepared hole and 5 is a slit-shaped recess. , 6 is a first member, 7 is a second member having a slit-shaped recess processed, 10 'is an electron beam passage hole, and 11 is an opening of the first member. In this grid electrode, as shown in (a), first, a prepared hole 4 is formed in the second member, and then a slit-shaped recess 5 is formed by coining as shown in (b). The opening 1 of the first member 6
It is made to be laminated by being aligned with the center of 1 and fixed by welding.

The electron gun provided with the third grid electrode 30 of such a type can perform astigmatism correction in a large current region by providing the slit-shaped recess 5. As a disclosure of the prior art related to this type of electron gun, there is JP-A-59-215640.

[0011]

However, in the lattice electrode of the conventional electron gun for a cathode ray tube described in FIG.
In the coining step of forming the slit-shaped recess 5 in the second member 7, the prepared hole 4 is crushed during coining of the slit-shaped recess 5, and the electron beam passage hole 10 thereof is as shown in FIG. 7B. Will be transformed into.

In this grid electrode, the second member 7 is joined to the first member 6 by welding, and the electron beam passage hole 10 of the second member 7 is formed.
Since the astigmatism correction structure is formed by the slit-shaped recess 5 around the periphery of the slit, if the slit-shaped recess 5 and the electron beam passage hole 10 are misaligned, the astigmatism correction is appropriately performed. There was a problem that I could not do it.

On the other hand, the slit-shaped recess 5 formed in the second member 7 is made thinner by 40% or more with respect to the thickness of the material, the depth is 0.4 mm or more, and the volume of the recess is 2 mm ³ or more. If the recess is to be formed by coining (so-called coining) with good productivity, breakage of the coining die becomes a problem. The object of the present invention is to solve the above-mentioned problems of the prior art and to appropriately perform astigmatism correction,
It is another object of the present invention to provide an electron gun for a cathode ray tube with good productivity and a method for manufacturing the electron gun.

[0014]

To achieve the above object, the present invention has a plate-shaped first member having an opening and an electron beam passage hole having a diameter smaller than that of the opening, and the periphery of the electron beam passage hole. And a plate-shaped second member in which a thin slit-shaped concave portion having a thickness of 40% or more and 60% or less of the material thickness is formed by coining on the portion, the opening of the first member and the electron beam of the second member. The centers of the passage holes are aligned with each other, and the slit-shaped recess of the second member is bonded to the first member on a surface opposite to the surface where the slit-shaped recess is formed, and the depth of the slit-shaped recess is 0.4 mm or more, and It is characterized in that it is a grid electrode for a cathode ray tube in which the volume of the recess is 2 mm ³ or more.

Further, in the grid electrode processing method for an electron gun for a cathode ray tube according to the present invention, the first pilot hole for punching the first pilot hole at the position where the slit-shaped recess of the second member constituting the grid electrode is to be formed. A machining step, a concave portion machining step in which a spherical concave portion is preliminarily formed in the first prepared hole formed in the first prepared hole forming step by pre-forming, and a second concave portion which coincides with the center of the first prepared hole It is characterized in that it comprises a second pilot hole machining step for punching a pilot hole and a slit-shaped recess machining step for forming a slit-shaped recess coinciding with the center of the second pilot hole by coining.

[0016]

Since the spherical concave portion is preformed in the first prepared hole, the processing pressure required for coining can be reduced.
Damage to the coining type can be prevented. In addition, a thin slit-like recess having a thickness of 40% to 60%, a depth of 0.4 mm or more, and a volume of the recess of 2 mm ³ or more can be formed around the electron beam passage hole. The center of the opening of the first member and the center of the electron beam passage hole of the second member can be precisely aligned.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a front view (a) for explaining the structure of one embodiment of a third grid electrode as a plate-shaped grid electrode of an electron gun for a cathode ray tube according to the present invention, and (b) is a sectional view taken along line AA of (a). . In the figure, 5 is a slit-shaped recess, 6 is a first member, 61 and 62 are fixing parts embedded in multi-form glass, 7 is a second member, 10 is an electron beam passage hole formed in the second member, 11 Is an opening formed in the first member.

The second member 7 is joined to the first member 6 by welding. And the thickness T2 of the second member 7 is 1.2 m.
m, the depth T1 of the slit-shaped recess 5 is 0.6 mm, the major axis l
Is 4 mm, the minor axis W is 1.5 mm, and the volume of the slit-shaped recess 5 is about 3.6 mm ³ . In the third grid electrode of the electron gun for the cathode ray tube, the electron beam passage hole 10 and the slit-shaped recess 5 are provided in the second member 7 by the following processing method. Therefore, the slit-shaped recess 5 and the beam passage hole 10 are formed.
Astigmatism correction can be appropriately performed without any positional deviation between the positions. In addition, the slit-shaped recess is formed in the above-mentioned FIG.
Since it is not formed by welding a member having an opening and a member having an electron beam passage hole as shown in (1), the productivity becomes good.

Next, a method of processing a grid electrode of an electron gun for a cathode ray tube according to the present invention will be described. 2A and 2B are process charts for explaining one embodiment of a method for processing a grid electrode of an electron gun for a cathode ray tube according to the present invention, wherein FIG. 2A is a first prepared hole processing step, and FIG. 2B is a first prepared hole processing step. A recessed portion processing step of pre-forming a spherical recessed portion in the formed first pilot hole, (c) is a second pilot hole for pulling out a second pilot hole that coincides with the center of the first pilot hole FIG. 7D is a cross-sectional view of a main part of a second member, respectively illustrating a processing step, and (d) a slit-shaped recess processing step of forming a slit-shaped recess that coincides with the center of the second prepared hole by coining.

In the figure, the first prepared hole 2 is formed in the plate-shaped material 1 which becomes the second member 7. ... First prepared hole machining step (a) Next, a spherical surface having a depth L is preformed by a spherical jig into the first prepared hole 2 machined in the first prepared hole machining step (a). The concave portion 3 is formed. ... Recessed portion processing step (b) Preformed recessed portion 3 formed in the recessed portion processing step (b)
Then, the second prepared hole 4 is processed.
...... Second prepared hole processing step (c) Then, a coining jig (coining jig) is used so as to coincide with the center of the second prepared hole 4 processed in the second prepared hole processing step (c). To form the slit-shaped recess 5.

...... Slit-shaped recess processing step (d) The second member 7 formed by the series of steps (a) → (b) → (c) → (d) is used as the first member (FIG. Welded and fixed to 6) of 1 to form the third grid electrode. According to the embodiment of the present invention described above, the processing pressure for coining can be small, and damage to the coining jig can be prevented, and
By performing the second prepared hole processing, it is possible to form the slit-shaped recess without deformation of the electron beam passage hole.

Further, since the first member 6 and the second member 7 form a third lattice electrode, the centers of the openings formed in the first member and the electron beam passage holes formed in the second member are precisely formed. Can be matched to. FIG. 3 is an explanatory view showing the result of the analysis of the relationship between the recessed portion processing amount L and the tool surface pressure in FIG. 2, wherein the horizontal axis represents the recessed portion processing amount L (m
m) is shown by taking the tool surface pressure (GPa: Giga Pascal) of the spherical jig on the vertical axis.

It can be seen from the figure that the tool surface pressure in the recessed portion machining step, that is, the slit coining step can be reduced by increasing the recessed portion machining amount, that is, the pre-forming processing amount. However, if the preforming amount L is too large,
Since the tool surface pressure in the pre-forming step becomes high, the pre-forming processing amount L is 60% to 70% of the depth T1 of the slit-shaped recess.
In the above embodiment, the pre-forming amount L was 0.4 mm and 67% of the depth T1 of the slit-shaped recess.

As a result, it is possible to perform a precise third process that is easy to process.
A grid electrode can be manufactured, and an electron gun for a cathode ray tube having good focusing characteristics can be assembled.

[0025]

As described above, according to the present invention,
It is possible to manufacture a grid electrode in which the positions of the slit-shaped recess and the electron beam passage hole are exactly matched, and it is possible to provide a grid electrode of an electron gun for a cathode ray tube that can appropriately perform astigmatism correction. . Further, since it is not necessary to form the slit-shaped recess by welding the two members, it is possible to improve productivity.

[Brief description of drawings]

FIG. 1A is a front view for explaining the structure of one embodiment of a third grid electrode as a plate-shaped grid electrode of an electron gun for a cathode ray tube according to the present invention, and FIG. 1B is a sectional view taken along the line AA of FIG. is there.

FIG. 2 is a process drawing for explaining one embodiment of a method for processing a grid electrode of an electron gun for a cathode ray tube according to the present invention.

FIG. 3 is an explanatory diagram showing a result obtained by analyzing a relationship between a recessed portion processing amount L and a tool surface pressure in FIG. 2.

FIG. 4 is a cross-sectional view illustrating the structure of a cathode ray tube.

FIG. 5 is a schematic diagram illustrating an example of an electrode configuration of an electron gun for a cathode ray tube.

FIG. 6 is a front view (a) of a third grid electrode shown as a structural example of a plate grid electrode of a conventional electron gun for a cathode ray tube, (b).
It is an AA sectional view of (a).

FIG. 7 is an explanatory diagram of a configuration of a third grid electrode using two plate-shaped materials according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate-shaped material 2 1st prepared hole 3 Recessed part 4 2nd prepared hole 5 Slit-shaped recessed part 6 1st member 61,62 Embedded fixing part in multiform glass 7 2nd member 10 It was formed in the 2nd member. Electron beam passage hole 11 Aperture formed in the first member

Claims (2)

[Claims] 1. A plate-shaped first member having an opening, and an electron beam passage hole having a diameter smaller than that of the opening, and 40% or more and 60% or more of the material thickness by coining around the electron beam passage hole. % Or less of a plate-shaped second member having a thin slit-shaped recess formed therein, the center of the opening of the first member coincides with the center of the electron beam passage hole of the second member, and the slit-shaped recess is formed. A cathode ray, characterized in that the slit-shaped recess of the second member has a depth of 0.4 mm or more and the volume of the recess is 2 mm ³ or more, which is bonded to the first member on the surface opposite to the surface. Lattice electrode for tube electron gun. 2. A plate-shaped first member having an opening, and an electron beam passage hole having a diameter smaller than that of the opening, and 40% or more and 60% or more of the material thickness by coining around the electron beam passage hole. % Or less of a plate-shaped second member having a thin slit-shaped recess formed therein, the opening of the first member is aligned with the center of the electron beam passage hole of the second member, and the slit-shaped recess is formed. A method for processing a grid electrode of an electron gun for a cathode ray tube, wherein the slit-shaped concave portion of the second member has a depth of 0.4 mm or more and a volume of 2 mm ³ or more, which is bonded to the first member on the surface opposite to the surface. In the first step, a first prepared hole forming step of forming a first prepared hole at a position where a slit-shaped recess of the second member forming the grid electrode is to be formed,
A recessed portion machining step in which a spherical recessed portion is preliminarily formed in the first prepared hole formed in the first prepared hole machining step by preforming;
From a second prepared hole processing step of removing a second prepared hole that coincides with the center of the prepared hole, and a slit-shaped recess processing step of forming a slit-shaped recess that coincides with the center of the second prepared hole by coining. A method of processing a grid electrode of an electron gun for a cathode ray tube, comprising: