JP2001325894A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defects in welding of composite electrodes composing an electron gun. SOLUTION: A plate-like electrode 1 and cup-like electrodes 2, 3 formed by pressing an electrode material having a hardness of 200 to 250 Hv, are welded at side edges of their outer peripheries.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to a color cathode ray tube having improved reliability by avoiding welding defects of a composite electrode constituting an electron gun.

[0002]

2. Description of the Related Art In general, a glass outer peripheral device of a color cathode ray tube comprises a panel forming a display section (phosphor screen or screen), a small-diameter neck, and a funnel-shaped funnel connecting the panel and the neck. Consisting of a vacuum envelope. The inner surface of the panel has a phosphor screen coated with phosphors of three colors, and a shadow mask as a color selection electrode is arranged close to the phosphor screen.

An electron gun for emitting three electron beams is housed in the neck, and the three electron beams emitted from the electron gun pass through a beam hole formed in a shadow mask to emit fluorescent light. A color image is reproduced by projecting on each of a plurality (generally three types) of the body screen.

The electron gun accommodated in the neck has a cathode (K) and three electron beam passage holes, a center electron beam passage hole and a side electron beam passage hole arranged in-line in close proximity to the cathode. An electron beam generating unit in which a first electrode (G1) and a second electrode (G2) each of which is arranged to face the cathode are sequentially arranged; and a focusing unit for focusing and accelerating an electron beam generated by the electron beam generating unit.・ Equipped with an acceleration lens.

This focusing / acceleration lens (including the main lens)
6, a third electrode (G3) adjacent to the second electrode (G2), and a fourth electrode (G4) arranged in order from the third electrode side (G3) to the phosphor screen side, as described later in FIG. It has a plurality of electrodes including a fifth electrode (G5), a sixth electrode (G6), and an intermediate electrode (GM) provided between the fifth electrode (G5) and the sixth electrode (G6).

FIG. 8 is a schematic diagram illustrating the structure of an intermediate electrode of an electron gun used in a conventional color cathode ray tube.
8A is a plan view, FIG. 8B is a side view in the longitudinal direction of FIG. 8A, and FIG. 8C is a side view in the lateral direction of FIG.

An intermediate electrode (GM) is welded to both sides of a plate-shaped electrode 1 which is a first electrode member having three electron beam passage holes SH, CH, SH arranged in-line in the longitudinal direction, respectively. 3 is a composite electrode composed of a cup-shaped electrode 2 and a cup-shaped electrode 3 which are electrode members. SH is a side electron beam passage hole, and CH is a center electron beam passage hole.

The plate-like electrode 1 has a bent portion BNT serving as a power supply terminal on a part of the outer periphery thereof, and a tab TB for embedding in beading glass is formed on the outer periphery in the longitudinal direction so as to project therefrom. is there.

The cup-shaped electrode 2 and the cup-shaped electrode 3 have the same shape, have a single electron beam passage opening MH, and are superposed on the plate-shaped electrode 1 and welded and integrated at the outer peripheral edges in the respective longitudinal directions. It is. That is, in a typical example, the cup-shaped electrodes 2 and 3 have rims RM2 and RM3, and this rim RM
2, RM3 are welded at two pairs of welding points WD1 and WD2 at the outer peripheral edges of the respective longitudinal edges. In addition, a welding point is not restricted to the above-mentioned location.

Further, a composite electrode in which a plate-shaped electrode serving as a first electrode member and another electrode member are combined includes a first electrode (G1), a second electrode (G2), There are three electrodes (G3) and the like. These composite electrodes are also integrated by the same welding as described above.

As a document which discloses a color cathode ray tube having this type of electron gun, for example, Japanese Patent Application Laid-Open Publication No. HEI 10-1990 can be cited.

[0012]

Conventionally, this plate-like electrode 1
Has a relatively low hardness of about 0.7 mm and a hardness (Vickers hardness) of about 150 to 160 Hv. For this reason, in the press punching process, a deformation in which the plate thickness called a so-called press sag occurs on the press punching side occurs in the inner peripheral region and the outer peripheral region of the electron beam passage hole.

FIGS. 9A and 9B are explanatory diagrams of press sag generated on a plate-like electrode. FIG. 9A is a plan view, and FIG.
(C) shows a side view in the lateral direction of (a).

As shown in FIG. 9 (a), the electrode material near the cut portion by the shearing force of the press die in the inner peripheral area of the electron beam passage holes SH, CH, SH to be pressed and also in the outer peripheral area. Are easily deformed to cause press dripping DR. As shown by the oblique lines in the drawing, the press sag DR tends to occur remarkably in a region where the press blanking portion is close. When the press sag DR occurs, as shown in FIGS. 9B and 9C, the plate pressure at the part of the press sag DR partially decreases.

A bent portion BNT serving as a power supply terminal in FIG.
Is carried out at the same time as this press blanking. If the hardness of the plate-like electrode 1 is high, cracks are likely to occur at the bending corners during the processing of the bent portion BNT, and partial chipping of the press die, that is, so-called chipping is likely to occur.

FIG. 10 is a partial view of a welded portion of the intermediate electrode GM, in which the portion B in FIG. 8B is enlarged. As shown in FIG. 10, a gap is formed between the cup-shaped electrode 2 and the rim RM2 of the cup-shaped electrode 2 to be welded to the press punching side due to the press dripping DR generated by the press punching process. Since welding of this type of electrode is performed with reference to the center of contact between the two, the welding mark WD1 at the welding point may not reach the plate-like electrode 1, and the welding failure indicated by C in the figure may occur. More frequently. Since the flatness is maintained on the rim RM3 side of the cup-shaped electrode 3, welding marks WD2 in this portion are formed so as to bridge the rim RM3 of the plate-shaped electrode 1 and the cup-shaped electrode 3, and a good welding state is obtained. To maintain.

If the above-mentioned welding defect occurs, the accuracy of the composite electrode is reduced, and the composite electrode is peeled off during operation, thereby lowering the reliability of the electron gun. The reliability of the color cathode ray tube incorporating the electron gun is also lowered. I do. It is practically impossible to control the above-mentioned press sagging by press working. It is also conceivable to increase welding energy (laser light intensity) to increase welding marks. However, if the welding marks are increased, the electrodes themselves may be damaged, and deformation or perforation may occur. It is naturally limited. Solving this has been one of the issues.

The occurrence of defective welding due to the above-described press sagging is not limited to the intermediate electrode, but may be a type in which a plate-shaped electrode, which is the first electrode member that has been pressed, and another electrode member are welded and integrated. The same occurs in various composite electrodes.

An object of the present invention is to provide a color cathode ray tube with improved reliability by solving the above-mentioned problems of the prior art.

[0020]

In order to achieve the above-mentioned object, the present invention optimizes the hardness of the material of the plate electrode. As a result, the occurrence of the above-mentioned press sag is reduced, the occurrence of cracks in the bent portion and the occurrence of chipping in the press die are avoided, and the reliability of the composite electrode obtained by welding two or more electrode members including the intermediate electrode is improved. I do. A typical configuration of the present invention is described as follows.

(1) A panel in which a phosphor screen is provided on the inner surface and a color selection electrode is provided adjacent to the phosphor screen, a neck accommodating an electron gun, and a funnel connecting the panel and the neck. The electron gun has a cathode and a center electron beam passage hole and a side electron beam passage hole which are arranged in-line in close proximity to the cathode. An electron beam generation unit in which a first electrode and a second electrode held in opposition are sequentially arranged, and a focusing unit and an acceleration unit including a plurality of electrodes for focusing and accelerating an electron beam generated by the electron beam generation unit are provided. The at least one electrode constituting the focusing / acceleration unit is configured such that the plate-shaped electrode and the cup-shaped electrode are in contact with each other at their outer peripheral edges, and a side edge of the abutted outer peripheral edge. A welded composite electrode, and the hardness of the above plate-shaped electrode is formed above the electrode material 200 Hv.

By using such an electrode material having a hardness of 200 Hv or more, the occurrence of press sag at the time of press punching is reduced, and the occurrence of defective welding points with other electrode members is prevented.

(2) The electrode material constituting the plate-like electrode is a stainless steel material having a hardness of 250 Hv or less.

When the upper limit hardness is 250 Hv or more, the frequency of occurrence of cracks in the bent portion and chipping of the press die increases. Therefore, the hardness of the stainless steel constituting the plate electrode is set to 250 Hv or less.

(3) The plate-shaped electrode has three electron beam passage holes, and when the cup-shaped electrode has a single electron beam passage opening, the plate-shaped electrode has a plurality of electron beam passage holes. Due to the small width of the electrode material between or at the outer edges, the occurrence of press sag increases. Also in this case, the use of the stainless material (1) or (2) can reduce the occurrence of the press sag and increase the hardness to 250 Hv.
By setting it as follows, it is possible to suppress the occurrence of cracks in the bent portion and chipping of the press die.

The hardness of the above-mentioned stainless steel material is determined by the so-called pressing rate or rolling rate (the thickness of the base material plate) from the thickness of the base material plate to the thickness at the time of processing the electrode product. When the plate thickness is D and the plate pressure at the time of processing the electrode product is d, (D−
d) / D is a pressing rate or a rolling rate). It is also determined by the annealing conditions before press working.

With the above configuration, the reliability of the electron gun is improved, and as a result, a highly reliable color cathode ray tube with good image quality can be obtained.

The operation and effect of the configuration of the present invention described above will be described in detail in the embodiments, but the present invention is not limited to this, and departs from the technical idea of the present invention. Needless to say, various modifications are possible.

[0029]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view for explaining the structure of an intermediate electrode which is one of the composite electrodes constituting an electron gun used in a color cathode ray tube according to the present invention. 1A is a plan view, FIG. 1B is a side view in the longitudinal direction of FIG. 1A, and FIG. 1C is a side view in the lateral direction of FIG. 2 (a) is a plan view, FIG. 2 (b) is a side view in the longitudinal direction of FIG. 2 (a), and FIG. 2 (c) is a view of the same. (A) is a side view in the short direction.

FIG. 3 is an explanatory view of the cup-shaped electrode constituting the intermediate electrode. FIG. 3 (a) is a plan view and FIG.
3A is a side view in the longitudinal direction of FIG. 3A, and FIG. 3C is a side view in the lateral direction of FIG. The intermediate electrode (GM) will be described later with reference to FIG.

In FIG. 1 to FIG. 3, in this embodiment, as in the description of FIG. 8, the intermediate electrode (GM) has three electron beam passage holes SH, CH,
This is a composite electrode including a cup-shaped electrode 2 and a cup-shaped electrode 3 as second and third electrode members welded to both sides of a plate-shaped electrode 1 as a first electrode member having SH. SH is a side electron beam passage hole, and CH is a center electron beam passage hole.

The plate-like electrode 1 has a bent portion BNT serving as a power supply terminal at a part of the outer periphery thereof, and tabs TB for embedding in beading glass are protrudingly provided at a plurality of places on the outer periphery in each longitudinal direction. It is.

The cup-shaped electrode 2 and the cup-shaped electrode 3 have the same shape, have a single electron beam passage opening MH, and are superposed on the plate-shaped electrode 1 and welded at the outer peripheral edge in each longitudinal direction to be integrated. It is. That is, in a typical example, the outer periphery of the cup-shaped electrode 2 and the cup-shaped electrode 3 in contact with the plate-shaped electrode 1 is
Each has a rim RM2, RM3, and this rim RM2,
RM3 is welded at two pairs of welding points WD1 and WD2 at the side edges of the outer peripheral edges in the longitudinal direction. The welding point is
It is not limited to the above location.

Further, a composite electrode in which a plate-shaped electrode, which is a first electrode member, and another electrode member are combined includes a first electrode (G1), a second electrode (G2), And a third electrode (G3). These composite electrodes are also integrated by the same welding as described above.

FIG. 4 is a partial view of the welded portion of the intermediate electrode GM, in which the portion A in FIG. 1B is enlarged. In this embodiment, since the plate-like electrode 1 constituting the intermediate electrode GM is formed of a stainless steel material having a hardness of 200 Hv or more, the press dripping DR hardly occurs by the press-punching process unlike the conventional plate-like electrode.

Therefore, since there is almost no gap between the rim RM2 and the cup-shaped electrode 2 to be welded to the press punching side, the welding mark WD1 at the welding point WD1 is
Is formed as a bridge between

At the same time as the press-cutting of the electron beam passage holes SH, CH, SH and the outer shape of the plate-like electrode 1, a bent portion BNT serving as a power supply terminal is formed. When the bending of the bent portion is performed, if the hardness of the material of the plate-like electrode 1 is too large, cracks may occur in the bending angle or chipping (chipping) may occur in the press die. Therefore, in the present embodiment, the hardness of the material of the plate electrode 1 is set to 250 Hv or less.

FIG. 5 is a diagram for explaining the hardness of the electrode material of the plate electrode, the occurrence of poor welding due to press dripping, the occurrence of cracks in the bent portion, and the occurrence of chipping in the press die. The horizontal axis shows the Vickers hardness (Hv) of the stainless steel, and the vertical axis shows the amount of press sag (relative value).

The amount of press sag depends on the thickness of the electrode material and the thickness of the rim of the cup electrode.

As shown in FIG. 5, the hardness of the plate electrode is 2
If it is less than 00 Hv, the amount of press sag becomes large, and 250 Hv
It can be seen that cracking of the bent portion and chipping of the press die occur when the ratio exceeds.

Therefore, the hardness of the plate electrode is 200 Hv
As described above, within the range of 250 Hv or less, good welding can be obtained, and cracking of the bent portion and chipping of the press die can be suppressed.

FIG. 6 is a side view for explaining an example of the configuration of an electron gun using the composite electrode of this embodiment. This electron gun has a first electrode having a cathode K and three electron beam passage holes, a center electron beam passage hole and a side electron beam passage hole, which are arranged in-line in proximity to the cathode K, respectively, facing the cathode. An electron beam generation unit in which an electrode (G1) 20 and a second electrode (G2) 21 are sequentially arranged;
It has a focusing section and an acceleration section including a plurality of electrodes for focusing and accelerating the electron beam generated by the electron beam generation section.

The focusing section / acceleration section includes a third electrode (G3) 2
2, a fourth electrode (G4) 23, a fifth electrode (G5) 24, a sixth electrode (G6) 25, and an intermediate electrode (5) disposed between the fifth electrode (G5) 24 and the sixth electrode (G6) 25; GM) 2
8.

A shield cup 26 is attached to the electron beam emission side of the sixth electrode (G6) 25.

A fixing tab (not shown) is formed on each of these electrodes, and this tab is embedded in the beading glass 27 and fixed in a predetermined arrangement. A built-in resistor 29 is attached to the beading glass 27, and the anode voltage is divided by a resistor and applied to an intermediate electrode (GM) 28.

Among the various electrodes constituting the electron gun shown in the figure, the intermediate electrode (GM) 28 is a composite electrode in which a cup-shaped electrode is welded before and after the plate-shaped electrode, and the first electrode (G1) 2
0, the second electrode (G2) 21, and the third electrode (G3) 22 are composite electrodes obtained by welding a cup-shaped electrode to one side of a plate-shaped electrode.

In this embodiment, in particular, the intermediate electrode (G
Regarding M) 28, its problems and solutions have been described, but the first electrode (G1) 20, the second
The same applies to other composite electrodes such as the third electrode (G3) 22.

By applying the embodiment described with reference to FIGS. 1 to 5 to the electron gun shown in FIG. 6, a highly reliable electron gun can be obtained.

FIG. 7 is a schematic sectional view for explaining the overall structure of a color cathode ray tube according to the present invention. Here, a flat panel type color cathode ray tube is shown as an example. In the figure, a panel 30 is joined to a large-diameter edge which is one end of a funnel 31, and the other end of the funnel 31 having a funnel-shaped gradually smaller diameter is connected to a neck 32.

The outer surface of the panel 30, which is formed by applying a plurality of phosphors having different coloring characteristics to the inner surface to form the phosphor screen 33, has an equivalent radius of curvature of, for example, 8000 mm to 10,000.
mm, and the equivalent radius of curvature of the inner curved surface is made smaller than the equivalent radius of curvature of the outer surface to maintain the mechanical strength of the glass envelope.

The phosphor screen 33 on the inner surface of the panel 30
, A shadow mask structure 34 is installed.
The shadow mask structure 34 includes a shadow mask 36 having a number of beam holes attached to a mask frame 35. The shadow mask structure 34 is a mask frame 35
A suspension mechanism 37 welded to the outer wall of the panel 30 engages with and supports a stud 38 erected on the inner surface of the side wall of the panel 30.

On the electron gun side of the mask frame 35, a magnetic shield 39 for shielding the electron beam flux B from external magnetism such as terrestrial magnetism is attached.

On the side wall of the funnel 31, an anode button 42 for introducing a high voltage (anode voltage) from the outside is provided. An inner conductive film 43 electrically connected to the anode button 42 is applied to the skirt portion of the panel 30, the inner surface of the funnel 31, and the inner surface of the neck 32 at the front end of the electron gun housing portion. The high voltage applied from the anode button 42 by the internal conductive film 43 is applied to the phosphor screen 33.
To the anode of the electron gun 40.

A deflection yoke 41 is provided on the neck side of the funnel 31 to deflect the electron beam B in two directions, horizontal and vertical, so as to reproduce a two-dimensional image on the phosphor screen 33. I do.

The electron gun 4 for emitting three electron beams in the direction of the phosphor screen 33 is provided inside the neck 32.
0 is stored. An example of the structure of the electron gun 40 housed inside the neck 32 is as described with reference to FIG.

As described above, according to the present embodiment, it is possible to obtain a color cathode ray tube having improved reliability by avoiding poor welding of the composite electrode constituting the electron gun.

In this embodiment, an austenitic stainless steel, for example, SUS305 or SUS304 is used to apply to the plate electrode 1 constituting the intermediate electrode GM, but another material is used for other electrode parts. May be.

[0059]

As described above, according to the present invention,
Of the electrodes of the electron gun, by setting the hardness of the electrode material of the plate-shaped electrode of the composite electrode obtained by welding the plate-shaped electrode and the cup-shaped electrode to a specific range, the occurrence of press sag is suppressed and the cup-shaped electrode is formed. To prevent the occurrence of cracks at the corners of the bent part during press bending of the power supply terminal of the plate-shaped electrode and to prevent chipping of the press die, and to provide a highly reliable color cathode ray tube. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an intermediate electrode which is one of composite electrodes constituting an electron gun used in a color cathode ray tube according to the present invention.

FIG. 2 is an explanatory view of a plate-like electrode constituting the intermediate electrode of FIG.

FIG. 3 is an explanatory view of a cup-shaped electrode constituting the intermediate electrode of FIG. 1;

FIG. 4 is a partial view of a welded portion of the intermediate electrode GM, in which a portion A in FIG. 1B is enlarged.

FIG. 5 is an explanatory diagram of hardness of an electrode material of a plate-like electrode, occurrence of welding failure due to press dripping, cracking of a curved portion, and occurrence of chipping of a press die.

FIG. 6 is a side view illustrating a configuration example of an electron gun using the composite electrode according to the present embodiment.

FIG. 7 is a schematic sectional view illustrating the overall structure of a color cathode ray tube according to the present invention.

FIG. 8 is a schematic diagram illustrating a configuration of an intermediate electrode of an electron gun used in a conventional color cathode ray tube.

FIG. 9 is an explanatory diagram of press sag generated on a plate-like electrode.

10 is an intermediate electrode GM obtained by enlarging a portion B in FIG. 8B.
3 is a partial view of a welded portion of FIG.

[Explanation of symbols]

1 ··· Plate electrode, 2, 3 ··· Cup electrode, S
H: Side electron beam passage hole, CH: Center electron beam passage hole, MH: Electron beam passage opening, TB: Tab, BNT: Bent part, RM
2, RM3... Rim, WD1, WD2.

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[Procedure amendment]

[Submission date] May 26, 2000 (2005.2.
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

As a document which discloses a color cathode ray tube having this type of electron gun, for example, JP-A-2-79339 can be cited.

Continuing on the front page (72) Inventor Takeshi Yonera 3350 Hayano, Mobara-shi, Chiba Prefecture Within Hitachi Electron Devices, Ltd. F term (reference) 5C041 AA03 AB07 AC02 AC26 AC28 AC46 AC48 AD07 AE01

Claims (3)

[Claims] 1. A panel provided with a phosphor screen on the inner surface and having a color selection electrode provided adjacent to the phosphor screen, a neck accommodating an electron gun, and a funnel connecting the panel and the neck. A color cathode ray tube having a vacuum envelope, wherein the electron gun comprises a cathode, and three electron beam passage holes, a center electron beam passage hole and a side electron beam passage hole arranged in-line in close proximity to the cathode. A first electrode and a second electrode each having
An electron beam generating unit in which electrodes are sequentially arranged; and a focusing unit and an accelerating unit including a plurality of electrodes that focus and accelerate the electron beam generated by the electron beam generating unit, and constitute the focusing and accelerating unit. At least one electrode is
A composite electrode in which a plate-shaped electrode and a cup-shaped electrode are brought into contact with each other at an outer peripheral edge thereof and welded at a side edge of the abutted outer peripheral edge, and the plate-shaped electrode is pressed with an electrode material having a hardness of 200 Hv or more. A color cathode ray tube characterized by being formed by processing. 2. The color cathode ray tube according to claim 1, wherein an electrode material constituting said plate-shaped electrode is a stainless steel material having a hardness of 250 Hv or less. 3. The plate-like electrode according to claim 1, wherein the plate-like electrode has three electron beam passage holes arranged in-line, and the cup-like electrode has a single electron beam passage opening. Color cathode ray tube.