JP2003068223A - Color selecting electrode structure body for color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variations in natural frequency caused by the local deformation of a frame, while keeping a natural frequency distribution of slender grids of a color selecting electrode body used for an aperture grill type color cathode- ray tube to be a required shape. SOLUTION: A transmittance expressed by the ratio of the width of a slender slit hole to the pitch of slender grids is set so as to increase as the position of a slender hole shifts from the center of an aperture grill to its both ends, and the ratio of the second distance B between a second pressurization position and the central part of an elastic frame side 21 to the first distance A between a first pressurization position and the central part is set to be 2 or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color selection electrode assembly used in an aperture grill type color cathode ray tube.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view showing a general structure of a color selection electrode assembly 1 used in an aperture grill type color cathode ray tube. In FIG. 3, 10 is an aperture grill and 2 is a frame that supports the aperture grill 10. The aperture grille 10 has a large number of strip grids 12 that define slit-shaped holes (hereinafter, referred to as strip slit holes) 11. The frame 2 includes a pair of elastic frame sides 21 welded and fixed to the aperture grille 10.
And a pair of elastic arm portions 22 that are welded and fixed to the pair of elastic elastic frame sides 21 and connect the pair of elastic frame sides 21. Reference numeral 3 denotes a metal plate welded and fixed to the elastic frame side 21 of the frame 2, and reference numerals 4 and 5 denote metal plates welded and fixed to the elastic arm portion 22.

The aperture grille 10 is formed with a slit in a metal material by chemical etching to form a slit slit hole 11 as shown in FIG. One flat aperture grill 6 consisting of the outer peripheral portion 13 following the perforated portion
Obtained as.

FIG. 5 shows a sectional shape of the aperture grill. Aperture grille electron beam transmittance Tr
Is generally expressed as Tr (%) = (Sw / Ph) × 100, where Ph is the horizontal pitch of the strip grids 12 and Sw is the width of the strip slit holes 11.

In the conventional aperture grill, as shown in FIG. 6, the value of the transmittance is almost constant regardless of the distance X from the central portion, and the distribution is uniform over the entire perforated portion.
Note that the transmittance value of the flat aperture grille is a value that satisfies the characteristics required for a color cathode-ray tube from other color striking tolerances and color defect tolerances in consideration of the electron beam diameter, phosphor width, and black matrix width. Is set to.

Further, in order to prevent the strip grids from resonating with each other and causing a color shift of the screen, the force for pulling each strip grid in the longitudinal direction is changed according to their position, and each strip grid is changed. By making the natural frequencies of the grid different from each other, the natural frequency of the entire aperture grill has a wide range.

As described above, the conventional color selection electrode assembly is composed of an aperture grill having a uniform transmittance over the entire screen, and each strip grid is expanded so as to have different natural frequencies. It The natural frequency distribution is generally set so as to increase from the central portion toward the end portion as shown in FIGS. 7 (a), 7 (b) and 7 (c). In order to obtain such a natural frequency distribution, normally, as shown in FIG. 8, each of the pair of frame elastic frame sides is provided at four positions (two pressure positions between the central part and one end, And two pressure positions between the center and the other end). This is the frame elastic frame edge 2
Since 1 is joined to the frame elastic arm portion 22 in the vicinity of the Bessel point, if the pressure is applied to only one place on the end portion side of the elastic frame with respect to the joint portion, the desired tension cannot be obtained at the center portion, This is because if a pressure is applied to only one portion on the central side of the elastic frame with respect to the joint, a desired tension cannot be obtained on the end side.

[0008]

In the conventional aperture grill whose transmittance is uniform over the entire screen (perforated part), the cross-sectional area of the strip grid is also uniform over the entire screen, and therefore its linear density is also over the entire screen. Is uniform at.
Generally, between the tension T applied to the fine grid and the natural frequency f, the linear density ρ, the cross-sectional area S, and the specific gravity ν, T = (4 · L ² · ρ) · f ² / g = (4 ・ L ²・ ν) ・ f ²
・ S / g relationship is established. Where L is the length of the strip grid,
g is the gravitational acceleration.

Therefore, in order to provide the natural frequency distribution of the strip grid, if the linear density ρ is constant, it is necessary to change the magnitude of the force T for pulling the strip grid between the central portion and the end portion. is there. The tension applied to the strip grid is obtained by the frame reaction force by pre-pressurizing and bending the frame, welding and fixing the aperture grill, and then releasing the pressurization. large. This is because the amount of deformation at the end is smaller than that at the center, and the end is in the elastic deformation region. Further, as shown in FIG. 8, when the elastic frame side is pressed, a greater force is applied to the end side of the elastic grid so that the natural frequency distribution of the strip grid becomes higher toward the end. Since the pressure is applied by, the end portion of the frame is pressed more intensively. Therefore, in FIG. 8, the pressure position closer to the central portion is shifted to the end side, and as a result, the distance of the pressure position closer to the central portion from the central portion is A, When the distance B from the central part closer to the part is set, the pressurizing position distribution ratio B / A becomes small, the frame is locally deformed, and the variation in the natural frequency distribution becomes large.

On the other hand, in recent years, it has been required to improve the definition of the color cathode ray tube with high definition and to improve the screen quality. However, the problem with the high definition is that the black matrix quality in the fluorescent screen coating step is high. And the screen color shift due to the vibration of the strip grid. As the horizontal pitch of the aperture grill becomes finer, the vertical stripe-like unevenness that appears on the aperture grille surface sensitively affects the quality of the black matrix, and vertical stripe-like unevenness also appears on the black matrix, degrading the quality of the fluorescent screen. . This phenomenon is more prominent at the edges or the periphery of the screen than at the center of the screen.

The vertical stripe-like unevenness appearing on the aperture grill surface tends to be alleviated when the transmittance of the aperture grill is increased, and conspicuous when the transmittance is decreased. Similarly, vertical stripe-like unevenness appearing in the black matrix tends to be improved by increasing the transmittance of the aperture grill, and deteriorated by decreasing the transmittance. Therefore, by increasing the transmittance at the edge and the periphery of the aperture grille, it is possible to improve the vertical stripe-shaped unevenness at the edge or the periphery of the screen. However, the conventional aperture grille has a uniform transmittance over its entire surface. Therefore, when increasing the transmittance at the edges or the periphery, it is necessary to increase the transmittance uniformly over the entire screen. Become.

When the value is increased while maintaining the uniformity of the transmittance on the entire screen, the line density is reduced over the entire screen, so that the pressing force applied to the frame elastic frame side is reduced, but the frame elasticity is reduced. There is no change in that the pressure is concentrated on the edge portion of the frame, and the value of the above-mentioned pressure position distribution ratio B / A does not change. That is, even in this case, since the edge portions of the frame elastic frame are intensively pressed, the problem that the natural frequency distribution varies due to local deformation of the frame still remains.

The present invention has been made in view of the above problems, and the local frequency of the frame is maintained while keeping the natural frequency distribution of the strip grid of the color selection electrode assembly used in the aperture grill type color cathode ray tube in a desired shape. It is an object to reduce variations in natural frequency due to static deformation.

[0014]

In order to solve the above-mentioned problems, the invention according to claim 1 has an aperture grill having a strip grid for defining a strip slit hole, and the above-mentioned strip grid for stretching the strip grid. A frame having a pair of elastic frame sides for supporting both ends of the aperture grille, each elastic frame side being between the central portion and its end portion so that the strip grid has a desired natural frequency distribution. In the color selection electrode assembly for the aperture grill type color cathode ray tube, which is pressurized at the first pressure position on the central side and the second pressure position on the end side, respectively, the pitch of the strip grids. To the both ends of the aperture grill from the center of the aperture grill, the transmittance represented by the ratio of the width of the narrow slit hole to the center of the elastic frame side and the first pressure position. For the first distance between the ratio of the second distance between the second pressing position and said central portion is equal to or is above a predetermined value.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the predetermined value is 2.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the invention described in (3), the first pressurization position is between the Bessel point of the elastic frame side and the central portion, and
Is located between the Bessel point and the end.

The invention according to claim 4 is the same as claims 1 to 3.
In the invention described in any one of 1 to 3, the linear density of the strip grid decreases from the center of the aperture grill toward both ends.

According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, the aperture grill is a flat aperture grill.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a graph showing the transmittance distribution of a color selection electrode assembly used in the aperture grill type color cathode ray tube of the present invention, where the horizontal axis represents the distance from the center and the vertical axis represents the transmittance (%). . As shown in the figure, in this embodiment, the pitch of the strip grid and the width of the strip slit holes are set such that the transmittance increases from the center of the aperture grille surface toward the end. Table 1 below shows transmittance Tr (X = 0 mm) at the center of the aperture grille surface and transmittance (X = 180 mm) at the end.
mm) is set to various values (specification 1 to specification 5), the standard deviation of the natural frequency variation (compared to the conventional aperture grille), the fine stripe grid in the central part, and the vertical stripe-like unevenness of the black matrix The situation and the vertical stripe-shaped unevenness of the fine grid and the black matrix in the peripheral portion are shown.

[Table 1] Specifications 1 and 2 are the transmittance Tr (X = 0 mm) at the center of the aperture grille surface and the transmittance (X = 18 mm) at the end.
(0 mm) is the same as the conventional aperture grill. In the specification 1, the transmittance at the center and the end is 23.5, and in the specification 2, the transmittance at the center and the end is 25.0. In this specification 1 and specification 2, the two pressurizing positions on the elastic frame side are 120 mm and 1 mm apart from the center, respectively.
It is located at a position of 70 mm, so the pressure distribution ratio is about 1:
It is 1.4.

Specifications 3 to 5 are according to this embodiment in which the transmittance Tr (X = 180 mm) at the end of the aperture grille surface is larger than the transmittance (X = 0 mm) at the center. In the specification 3, the transmittance at the center is 20.0, the transmittance at the end is 23.6, and in the specification 4, the transmittance at the center is 21.
5, the transmittance at the end is 25.1, and in the specification 5, the transmittance at the center is 22.9 and the transmittance at the end is 26.5. In this specification 3 to specification 5, the two pressure positions on the elastic frame side are 80 mm and 170 m from the center, respectively.
Therefore, the pressure distribution ratio is about 1: 2.1.
Is. As shown in Table 1, in the specifications 3 to 5, the concentrated pressurization to the end portion of the frame is relaxed, and the variation of the natural frequency is reduced by 50% as compared with the conventional one. Also, specifications 5
In, the vertical stripe-shaped unevenness in the peripheral portion is also significantly improved.

In Table 2 below, in the flat aperture grill of specification 5, as shown in FIG. 2, of the two pressure positions on the frame elastic frame side, the pressure position on the end side is constant (B = 170 mm). ), The pressurizing position on the central side is changed in four ways (specification 5-1: A = 80 mm, specification 5-2: A =
100 mm, specification 5-3: A = 120 mm, specification 5-
4: A = 140 mm) shows the standard deviation of the natural frequency variation (compared with the conventional aperture grille).

[Table 2] As can be seen from Table 2, when the pressurizing position distribution ratio of the frame elastic frame side becomes about 1: 2, the variation of the natural frequency is suddenly improved (compared to the conventional one). This is because when the pressurization position distribution ratio is 1: 2 or less, the pressing force concentrated on the end portion of the frame elastic frame side and the joint with the frame elastic arm portion is distributed at a ratio of 1: 2.
It is shown that after it exceeds the value, it suddenly becomes dispersed over the entire elastic frame side, and local deformation is reduced.

That is, in the above embodiment, since the linear density of the strip grid is higher in the central portion than in the end portions of the aperture grille, the natural frequency distribution of the strip grid is desired. As described above, when the frame is pressed, the force that should be applied to the central portion of the frame is larger than in the conventional case. Therefore, the pressing position of the frame does not gather on the end side of the elastic frame side unlike the conventional case, but it moves to the center side, local deformation of the frame is reduced, and the variation of the natural frequency distribution of the strip grid is reduced. Is reduced.

Further, in the above-described embodiment, since the transmittance is large at the edges and the periphery of the aperture grille, the vertical stripe unevenness at the edges or the periphery of the screen is improved. Vertical stripes that deteriorate the quality of the black matrix are conspicuous at the peripheral portion or the edge portion of the screen, but are not conspicuous at the central portion, so even if the transmittance at the central portion of the screen is small, the image quality does not deteriorate. .

[0024]

According to the present invention, the natural frequency distribution due to the local deformation of the frame is maintained while keeping the natural frequency distribution of the strip grid of the color selection electrode assembly used in the aperture grill type color cathode ray tube in a desired shape. It becomes possible to reduce variations.

[Brief description of drawings]

FIG. 1 is a graph showing a transmittance distribution of a color selection electrode assembly used in an aperture grill type color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining pressure position distribution on the frame elastic frame side of the color selection electrode structure according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a general configuration of a flat aperture grill type color selection electrode assembly.

FIG. 4 is a perspective view showing a configuration of a flat aperture grill.

FIG. 5 is a horizontal sectional view of the flat aperture grill.

FIG. 6 is a graph showing a transmittance distribution of a conventional flat aperture grill.

FIG. 7 is a diagram showing a shape of natural frequency distribution of a general flat aperture grill.

FIG. 8 is an explanatory diagram of general frame pressurization in a conventional flat aperture grill.

[Explanation of symbols]

1 color selection electrode structure, 2 frames, 3,4,5
Metal plate, 6 flat aperture grille, 1
0 aperture grill, 11 narrow slit holes,
12 strip grids, 13 outer peripheral portion, 21 frame elastic frame sides, 22 frame elastic arm portions, Sw strip slit hole width, Ph horizontal pitch.

Claims (5)

[Claims] 1. An aperture grill having a strip grid defining a strip slit hole, and a frame having a pair of elastic frame sides for supporting both ends of the aperture grill so as to stretch the strip grid. In order that the strip grid has a desired natural frequency distribution, each elastic frame side has a first pressing position on the central portion side and a first pressing position on the end portion side between the central portion and the end portion. In the color selection electrode assembly for the aperture grill type color cathode ray tube which is respectively pressed at two pressing positions, the transmittance represented by the ratio of the width of the narrow slit holes to the pitch of the narrow grid is The pressure increases from the center of the aperture grill toward the both ends, and the center portion and the second pressure position with respect to a first distance between the center portion of the elastic frame side and the first pressure position. Color selection electrode structure the ratio of the second distance is equal to or is above a predetermined value between. 2. The color selection electrode assembly according to claim 1, wherein the predetermined value is 2. 3. The first pressure position is between the vessel point and the center portion of the elastic frame side, and the second pressure position is between the vessel point and the end portion. The color selection electrode structure according to claim 1 or 2, characterized in that. 4. The color selection electrode structure according to claim 1, wherein the linear density of the strip grid decreases from the center of the aperture grill toward both ends. 5. The aperture grill is a flat aperture grill, and the aperture grill is a flat aperture grill.
The color selection electrode structure according to any one of 1.