JP2001167711A - Color selection electrode structure, color tube and color tv receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aperture grille color selection electrode for use in a color tube, which can sufficiently reduce generation of non-uniform stripe causing deterioration in picture grade of the color tube. SOLUTION: An aperture grille 1 includes a perforated portion 101 having fine grids 12 forming fine slit holes 11, and a circumferential portion 102 extended from the perforated portion 101. In this aperture grille, numerous slot holes is formed at non-fixed portions of the circumferential portion 102. Thus, with respect to the cross section in a shorter-side direction of the fine grids 12, the following relation is realized: (cross sectional area per unit length of perforated portion)>(cross sectional area per unit length of circumferential portion).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture grill type color selection electrode assembly for a color cathode-ray tube, and more particularly to a structure for reducing the deterioration of the screen quality of a color cathode-ray tube caused by creep deformation occurring in a strip grid during a heating process. It is about.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view showing the structure of a conventional general color selection electrode assembly for a color cathode ray tube. In FIG. 3, reference numeral 1 denotes an aperture grill made of metal in which a plurality of strip grids 12 forming strip slit holes 11 are arranged, and 2 denotes an aperture grill which fixes an outer peripheral portion of the aperture grill 1 and applies a predetermined tension. A frame 3 made of metal for generating 1 is engaged with a pin (not shown) fixed at one end to the frame 2 and at the other end to a panel which is a part of a glass bulb of a color cathode ray tube. The supporting structure 4 is fixedly welded to the frame 2, and a high expansion plate 5 forming a bimetal structure with the frame 2 is arranged so as to be in contact with the surface of the aperture grill 1, and functions to attenuate the vibration of the aperture grill 1. Reference numeral 6 denotes a damper spring having a function of applying a predetermined tension to the damper wire.

[0003]

The color selection electrode structure illustrated in FIG. 3 passes through a heat treatment process called blackening in a state where the aperture grill 1 and the frame 2 are joined by welding. This heat treatment step is intended both on the surface of the aperture grill 1 and the frame 2 is a metal component, to form a triiron is a stable oxide film (FE ₃ 0 _4), in order that, Maximum temperature is about 460
The above treatment is performed in a predetermined oxidizing atmosphere at a temperature of ° C. At this time, the material of the aperture grille 1 is based on iron which can cause a creep phenomenon at the above-mentioned maximum temperature.
High stress is applied to 2 due to the tension applied by the frame 2 to the grill 1. Therefore, deformation of each strip grid 12 due to the creep phenomenon occurs. Usually, 30 is applied to the strip grid 12 of the aperture grill 1.
A stress in the range of 0 MPa to 400 MPa is applied before the heat treatment, and after the heat treatment, 200
The stress applied to the strip grid 12 decreases within a range from MPa to 300 MPa.

When the creep phenomenon occurs in the strip grid 12 of the aperture grill 1 as described above, since the grid 12 has a strip shape, the twisting phenomenon is reduced.
And a problem called a streak occurs. This twist phenomenon is shown in FIG. When the strip grid 12 is twisted as shown in FIG.
Since the transmittance of the narrow slit holes 11 formed by each other changes, the contrast becomes linear at the time of exposure in the process of forming the fluorescent screen of the color CRT. Although such a problem has been solved to some extent by providing the high expansion plate (made of stainless steel) 4 shown in FIG. 3, it can be said that it is still insufficient.

Therefore, as a further improvement measure, the material of the high expansion plate 4 shown in FIG. 3 is made of a metal which is more expensive than stainless steel, so that the thermal expansion coefficient of the plate 4 is further increased and the strip grid 12 is formed. A method for further reducing the generated stress and a method for improving the creep characteristic itself of the aperture grill material by using another material instead of iron for the aperture grill 1 are being studied. However, in the above-mentioned measures, the plate may cause a cost increase, and in the above-mentioned measures, the narrow grid 1
In addition, the etching performance when forming 2 is deteriorated, the characteristic of shielding the magnetic field is deteriorated, and the cost is increased. For this reason,
There is a need for a countermeasure that can further suppress the creep phenomenon as compared with the conventional technique shown in FIG. 3 without lowering the above characteristics and increasing the cost.

As described above, in the conventional aperture grill type color CRT color selection electrode assembly,
There is a problem that a creep phenomenon occurs in the strip grid in a heat process called blackening, and a phenomenon called uneven streaks that lowers the screen quality of a color CRT cannot be sufficiently overcome.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not reduce the characteristic of shielding a magnetic field and does not increase the cost.
An object of the present invention is to provide a color selection electrode assembly for a color cathode-ray tube in which the deformation of the strip grid due to the creep phenomenon is sufficiently and easily reduced, and the screen quality is not degraded due to uneven streaks.

[0008]

The invention according to claim 1 is
A perforated portion in which a plurality of strip grids forming a plurality of strip slit holes for transmitting an electron beam are formed, and an outer peripheral portion extending in the longitudinal direction of the strip grid following the perforated portion. An aperture grill comprising: a frame that fixes a peripheral edge of the outer peripheral portion extending in a short direction of the strip grid to apply tension to the strip grid; Regarding the cross section in the direction, the cross-sectional area per unit length of the non-fixed portion of the outer peripheral portion between the peripheral portion and the perforated portion is smaller than the cross-sectional area per unit length of the perforated portion. Features.

According to a second aspect of the present invention, there is provided the color selecting electrode assembly according to the first aspect, wherein the non-fixed portion of the outer peripheral portion has a plurality of holes along the short direction of the strip grid. It is characterized by being formed.

According to a third aspect of the present invention, in the color selection electrode assembly according to the second aspect, the hole in the non-fixed portion is a slot hole, and the hole is formed in the short direction of the strip grid. The minimum opening dimension of the slot hole is 80% of the minimum opening dimension of the narrow slit hole in the short direction.
It is characterized by the following.

According to a fourth aspect of the present invention, there is provided the color selecting electrode assembly according to any one of the first to third aspects.

According to a fifth aspect of the present invention, there is provided the color cathode ray tube according to the fourth aspect.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) A feature of a color selection electrode structure for a color cathode-ray tube according to the present embodiment is that a perforated portion composed of a plurality of strip grids forming a plurality of strip slits. An outer peripheral portion (strictly speaking, an unfixed portion of the outer peripheral portion) extending in the longitudinal direction of the strip grid following the perforated portion, rather than a cross-sectional area per unit length (for example, 1 mm) in the short direction of the strip grid. ) In that the cross-sectional area per unit length in the short direction of the strip grid is reduced. As a result, the stress generated in the aperture grill due to the tension applied by the frame is higher at the outer peripheral portion than at the perforated portion. As a result, the creep phenomenon generated in the heat process called blackening is concentrated on the outer peripheral portion, and the occurrence of creep phenomenon in the perforated portion is suppressed. As a result, it is possible to reduce the uneven streaks due to the twisting phenomenon of the strip grid. . An aperture grill having such a structure can be easily realized, for example, by providing a plurality of holes (through holes or non-through holes) such as slot holes by etching in a non-fixed portion of the outer peripheral portion.

Hereinafter, a color selection electrode structure for a color cathode ray tube according to the present embodiment will be specifically described with reference to the perspective view of FIG.

In FIG. 1, the aperture grill 1 is
A plurality of strip grids 12 forming strip slits 11 through which electron beams pass are formed by etching from one end 1E1 parallel to the longitudinal direction of the grid 12 to the other end 1E2 in the transverse direction of the grid 12 by etching. It comprises a perforated portion 101 formed and an outer peripheral portion 102 extending in the longitudinal direction of the strip grid 12 following the perforated portion 101. In the outer peripheral portion 102, both peripheral portions 1E3 and 1E4 extending along the lateral direction of the strip grid 12 are welded to the upper surface portion 2TS of the frame 2 which has been subjected to stress in advance and curved in a convex shape. Fixed. In other words,
The frame 2 fixes the aperture grill 1 to the upper surface portion 2S of the frame 2 while curving the aperture grill 1 in a convex shape, and generates a predetermined tension in the aperture grill 1. One end of the support structure 3 is fixed to a corresponding portion of the frame 2.
The other end of the support structure 3 has a pin (not shown) embedded in a panel which is a part of a glass bulb of a color CRT.
Is engaged. The damper wire 5 is supported by the other end of a damper spring 6 having one end fixed to the frame 2 and arranged so as to be in contact with the aperture grill 1. As a result, the damper wire 5 functions to attenuate the vibration of the aperture grill 1. In addition, damper spring 6
Has a function of applying a predetermined tension to the damper wire 5.
Further, a high expansion plate 4 (same as the plate 4 in FIG. 3) made of stainless steel is welded and fixed to the bottom of the frame 2 to form a bimetal structure with the frame 2.

The structural features of this embodiment are as follows. That is, in the non-fixed portion of the outer peripheral portion 102 located between the perforated portion 101 and the welded portion of the outer peripheral portion 102 with the frame 2 or the perimeter portion 1E3, 1E4, a plurality of slot holes 1021 They are arranged along the short direction. Moreover, the slot holes 1021 are formed by etching in the non-fixed portions of the outer peripheral portion 102 at the same pitch as the narrow slit holes 11.

Here, FIG. 2 shows both cross-sectional shapes of the strip grid 12 forming the strip slit holes 11 and the slot hole forming portion 1022 forming the slot holes 1021.
FIG. 2A shows a strip slit hole 11 and a strip grid 1.
2 is a longitudinal sectional view showing an upper part T of the strip grid 12. FIG.
1 has a width of 0.070 mm, and the lower side B1 has a width of 0.190.
mm, and the plate thickness is 0.100 mm. On the other hand, FIG. 2B shows the slot hole 1021 and the slot hole forming portion 10.
22 is a longitudinal sectional view showing a slot hole forming portion 1022.
The width of the upper part T2 is 0.020 mm, the width of the lower part B2 is 0.210 mm, and the plate thickness is 0.100 mm. The pitch between the centers of the narrow slit holes 11 and the pitch between the centers of the slot holes 1021 are both set to the same pitch of 0.25 mm. As a result, the cross-sectional area of the strip grid 12 is 0.0
1 mm ² , the slot hole forming portion 1022
Has a cross-sectional area of 0.008 mm ² . Thereby, regarding the longitudinal cross section of the thin grid 12 in the short direction,
The relationship of (cross-sectional area per unit length of the non-fixed portion of the outer peripheral portion 102) <(cross-sectional area per unit length of the perforated portion 101) is established.

The tension applied from the frame 2 to the aperture grill 1 generates a stress of 320 MPa in the strip grid 12, and when converted from the above-mentioned cross-sectional area relationship, a stress of 400 MPa is applied to the slot hole forming portion 1022. Has occurred. When the above-described heat treatment for blackening is performed in this state, the stress in the strip grid 12 becomes 30%.
0 MPa, and the stress change before and after the heat treatment for blackening was 20 MPa.
MPa. On the other hand, in the case where no slot hole is provided in the non-fixed portion of the outer peripheral portion as shown in FIG. 3, in order to generate a stress of 300 MPa in the strip grid after the heat treatment, the strip grid before the heat treatment is required. As the internal stress, a value of 380 MPa is required.
A change in stress of MPa will occur. As is apparent from this comparison, when the present color selection electrode assembly shown in FIGS. 1 and 2 is used, the change in the stress of the strip grid 12 before and after the heat treatment for the blackening can be performed without deteriorating the characteristics and increasing the cost as described above. It has become possible to greatly reduce.

The minimum opening width of the slot grid 1021 in the short direction of the narrow grid 12 is 0.040 mm, which is the minimum opening width 0 of the narrow slit hole 11 in the short direction. This corresponds to a size of about 67% of 0.060 mm. As a result, there was no problem that the phosphor was exposed to portions other than the perforated portions of the phosphor screen during the exposure for producing the phosphor screen of the color cathode ray tube. It has been confirmed by the inventor of the present invention that this advantage can be obtained even when the minimum opening width or the minimum opening size of the slot hole 1021 is set to 80% of that of the narrow slit hole 11. Conversely, when the minimum opening dimension of the slot hole 1021 is set to 90% of that of the narrow slit hole 11, the result that the above advantage cannot be obtained is obtained. Therefore, in the present color selection electrode assembly, the outer peripheral portion 10
2 is 80% or less of the minimum opening dimension of the narrow slit hole 11 in the short direction of the narrow grid 12 of the slot grid 1021 (0, %), Even if the light emitted from the exposure device during the phosphor screen forming step passes through the slot hole 1021, it does not reach the required exposure amount on the phosphor screen.
No fluorescent screen is formed other than the perforated portions on the fluorescent screen formed by the narrow slit holes 11.

(Modification) In the first embodiment, a plurality of slot holes 1021 are arranged in the non-fixed portion of the outer peripheral portion 102 of the aperture grill 1 so that the narrow grid 1
2 easily reduced the cross-sectional area in the lateral direction.
However, the same effect can be easily realized by forming through holes of various shapes such as round holes and elliptical holes in the non-fixed portion of the outer peripheral portion by etching, instead of the slot holes. The same effect can be obtained by arranging a non-through hole formed by half-etching in a non-fixed portion of the outer peripheral portion instead of a through hole such as a slot hole. In other words, when “holes” are defined as a general concept of through holes and non-through holes, by forming “a plurality of holes” along the short direction of the strip grid in the non-fixed portion of the outer peripheral portion, The relationship of (cross-sectional area per unit length of the non-fixed portion of the portion) <(cross-sectional area per unit length of the perforated portion) can be easily realized.

(Supplementary Note) The color cathode-ray tube can be formed by incorporating the color selection electrode assembly described in the first embodiment or its modification into a glass bulb. Further, it is possible to constitute, for example, a color television receiver by using the CRT.

[0022]

According to the first, fourth, and fifth aspects of the present invention, the etching property at the time of forming the aperture grill is deteriorated without increasing the cost and without deteriorating the characteristic of magnetic field shielding. Without causing the creep phenomenon occurring in the heat step in the blackening to concentrate on the outer peripheral portion, the occurrence of the creep phenomenon on the strip grid of the perforated portion can be remarkably suppressed. As a result, the twist of the strip grid normally caused by the creep of the strip grid in the perforated portion is sufficiently reduced, and as a result, it is possible to sufficiently eliminate the uneven streaks appearing on the screen of the color cathode ray tube. .

According to the second, fourth and fifth aspects of the present invention, the cross-sectional area per unit length of the non-fixed portion of the outer peripheral portion is defined as the cross-sectional area of the perforated portion with respect to the cross section in the short direction of the strip grid. This has the effect that the structure of reducing the size can be easily secured.

According to the third, fourth, and fifth aspects of the present invention, it is possible to secure a desired cross-sectional area of the outer peripheral portion without forming unnecessary fluorescent screens other than the perforated portions. can get.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a color selection electrode structure for a color CRT according to a first embodiment.

FIG. 2 is a longitudinal sectional view showing a sectional shape of a perforated portion and a non-fixed portion of an outer peripheral portion of the aperture grill according to the first embodiment.

FIG. 3 is a perspective view showing a conventional color selection electrode assembly for a color cathode ray tube.

FIG. 4 is a longitudinal sectional view showing a state in which a thin grid of the aperture grill is twisted by thermal deformation.

[Explanation of symbols]

1 aperture grill, 11 narrow slit holes, 12
Fine grid, 101 Perforated part, 102 Outer part, 1
E3, 1E4 peripheral part, 1021 slot hole, 102
2 slot hole forming section, 2 frame, 3 support structure,
4 High expansion plate, 5 damper wire, 6 damper spring.

Claims (5)

[Claims] An aperture having a plurality of strip grids forming a plurality of strip slits for transmitting an electron beam, and extending in the longitudinal direction of the strip grid following the aperture. An aperture grill comprising an existing outer peripheral portion; and a frame for fixing a peripheral portion of the outer peripheral portion extending in a short direction of the narrow grid and applying tension to the narrow grid, Regarding the cross section in the short direction of the grid, the cross-sectional area per unit length of the non-fixed portion of the outer peripheral portion between the peripheral portion and the perforated portion is the cross-sectional area per unit length of the perforated portion. A color selection electrode assembly characterized by being smaller than 2. The color selection electrode assembly according to claim 1, wherein a plurality of holes are formed in the non-fixed portion of the outer peripheral portion along the short direction of the strip grid. Characteristic electrode structure for color selection. 3. The color selection electrode assembly according to claim 2, wherein the holes in the non-fixed portion are slot holes, and the minimum of the slot holes in the short direction of the strip grid. The color selecting electrode assembly, wherein an opening size is 80% or less of a minimum opening size of the narrow slit hole in the short direction. 4. A color cathode ray tube comprising the color selection electrode assembly according to claim 1. Description: 5. A color television receiver comprising the color cathode ray tube according to claim 4.