KR100823187B1 - Shadow mask for cathode ray tube - Google Patents

Abstract

와

로 나타내어지며, 상기 식의 무차원 계수들(A1,A2,A3,... 및 B1,B2,B3,...)은

와

의 조건을 만족한다.It is related to the curved shape of the shadow mask which is installed on the inner surface of the panel and serves as a color-coded electrode. The axis shape, Zx is -Z axis height at any position on the X axis, Zy is -Z axis height at any position on the Y axis, the shadow shape of the shadow mask is

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Where the dimensionless coefficients A1, A2, A3, ... and B1, B2, B3, ...

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Satisfies the conditions.

Forming, aspherical, curvature, curved, impact resistant, mask

Description

Shadow mask for cathode ray tube {SHADOW MASK FOR CATHODE RAY TUBE}

1 is a perspective view showing a cathode ray tube according to the present invention in a partial cross section

Figure 2 is a perspective view showing a shadow mask of a cathode ray tube according to the present invention.

3a and 3b are simulation data comparing the initial deformation mode of the shadow mask according to the prior art and the present invention.

4A and 4B are simulation data comparing marginal impact strength and plastic strain distribution of shadow masks according to the prior art and the present invention.

The present invention relates to a shadow mask for a cathode ray tube, and more particularly, to a curved shape of a shadow mask provided on an inner surface of a panel and serving as a color-selective electrode.

Generally, a cathode ray tube has a panel having a fluorescent screen on its inner surface, an electron gun for emitting an electron beam toward the fluorescent screen, a neck portion for mounting the electron gun therein, and a trumpet shape connecting the panel and the neck portion. And a mask assembly having a funnel and a shadow mask mounted in parallel with the fluorescent screen.                         

The mask assembly is arranged to be parallel to the fluorescent screen on the inner surface and separates and lands the electron beam emitted from the electron gun to the corresponding phosphor to perform a color screening function. The mask assembly serves as a color screening electrode, and supports a shadow mask. And a plurality of spring assemblies that secure the mask frame to the panel.

The shadow mask is formed on an extremely thin thickness of aluminum-kilted (AK) steel or invar (INVAR) steel by a known photolithography process to form a plurality of beam passing apertures, and then drawing to a final shape. Is completed.

The radius of curvature of such a molding mask is set to have a ratio with respect to the radius of curvature of the inner surface of the panel for image realization, and in the case of a cathode ray tube having a flat outer surface, the radius of curvature of the shadow mask increases as the inner radius of curvature of the panel increases. It became flattened. Therefore, when a part of the curved surface of the forming mask is locally flat, the initial deformation occurs at the flat portion due to the external impact load, and the deformation propagates to the periphery as the load continues to act, thereby causing the shadow mask. Plastic deformation.

As such, when the shadow mask is plastically deformed, the quality of the cathode ray tube such as image blur and deterioration of color purity is not obtained because the electron beam emitted from the electron gun is distorted while passing through the shadow mask when the image of the cathode ray tube is reproduced. It has been a factor of deterioration.

 Accordingly, an object of the present invention is to provide a shadow mask having improved impact strength by appropriately designing a curved shape.

The object of the present invention described above,

A shadow mask mounted on an inner surface of a panel and configured to color-select an electron beam emitted from an electron gun,

Based on the center of the shadow mask, the horizontal direction is the X axis, the vertical direction is the Y axis, the direction orthogonal to the X axis and the Y axis is called the Z axis, and Zx is the -Z axis height at any position on the X axis, Zy is -Z-axis height at any position on the Y-axis,

The curved shape of the shadow mask is represented by equations (1) and (2) along the horizontal and vertical directions, and the dimensionless coefficients (A1, A2, A3, ... and B1, B2, B3,) of equations (1) and (2). ..) is achieved by a shadow mask that satisfies the conditions of equations (3) and (4).

Hereinafter, a shadow mask according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a cathode ray tube according to the present invention in a partial cross section, wherein the cathode ray tube constitutes a vacuum container with a panel 12, a funnel 14, and a neck portion 16.

The inner surface of the panel 12 is provided with a fluorescent film screen 12 ', the neck portion 16 is filled with an electron gun 18 for emitting an electron beam, and the outer surface of the neck portion 16 is deflected yoke for deflecting the electron beam. 20 is mounted.

In addition, a shadow mask 24 for color-selecting the electron beam 22 emitted from the electron gun 18 is installed on the frame 26 at a portion adjacent to the fluorescent screen 12 ′ on the inner surface of the panel 12. In the frame 26, a support spring (not shown) is coupled to a stud pin (not shown) fixed to the side wall of the panel 12 to maintain the fixed state. In addition, an inner shield (not shown) is fixed to one side of the frame 26 so that the electron beam emitted from the electron gun and moved to the fluorescent screen is not affected by an external magnetic field.

In FIG. 1, reference numeral 24a denotes an electron beam passing hole through which an electron beam passes.

In the cathode ray tube having such a configuration, the shadow mask 24 has a novel curved shape according to the present invention. Hereinafter, the curved shape of the shadow mask 24 will be described with reference to FIG. 2.                     

Since the shadow mask 24 varies according to the size of the cathode ray tube, it can generally be expressed by dimensionless coefficients, and the combination of these coefficients determines the curved shape.

That is, if the horizontal direction (long axis direction) is the X axis and the vertical direction (short axis direction) is the Y axis with respect to the center of the shadow mask 24, the curved shape of the shadow mask 24 is along the X axis and the Y axis. It can be represented by the following equations (1) and (2).

(Equation 1)

(Equation 2)

In the above Equations 1 and 2, Zx represents the -Z axis height at any position on the X axis, and Zy represents the -Z axis height at any position on the Y axis. And A1, A2, A3, ... and B1, B2, B3, ... represent non-dimensionalized coefficients of each polynomial.

Thus, it was found that the impact strength can be greatly improved when the coefficient of the secondary term is set within a predetermined range with respect to the sum of all coefficients among the coefficients of Equations 1 and 2 described above.

(Equation 3)

(Equation 4)

Equations 3 and 4 above show preferred coefficient ranges according to the experimental results of the present inventors.

Table 1 shows the results of the impact analysis by adjusting the coefficient ratio so that the existing shadow mask design curvature falls within the range of the coefficient ratios of Equations 3 and 4 above, and the impact strength after adjusting the coefficient ratio It can be seen that on the basis of the shock waveform of the semi-sinusoidal wave is improved from about 8G to 10G.

21inch 29 inch Conventional Invention Conventional Invention A1 11.245 11.263 12.961 8.016 A2 1.912 2.061 -0.864 4.172 A3 0 0 0 0 A1 / (A1 + A2 + A3) 85.5% 84.5% 107.1% 65.8% B1 6.006 4.368 8.365 7.428 B2 -4.045 4.052 0.501 2.705 B3 3.527 -1.731 0 0 B1 / (B1 + B2 + B3) 109.4% 65.3% 94.3% 73.3% Impact strength 22G 32G 10G 20G

3 and 4 are simulations of the impact analysis on curvature in the shadow masks of the prior art and the present invention, and FIGS. 3A and 3B compare initial deformation modes, and the shadow mask of the present invention shown in FIG. 3B is illustrated. It can be seen that the initial strain is evenly distributed. 4A and 4B compare the limit impact strength and the plastic strain distribution. When the plastic strain appearing in a predetermined region is damaged under the same condition of less than 0.1%, the shadow mask of the present invention shown in FIG. It can be seen that the impact strength improvement of about 10G was achieved.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, the shadow mask of the present invention has the effect of effectively improving the impact strength by designing the curved shape of the shadow mask so that the coefficient of the secondary term is contained within a predetermined range with respect to the sum of all coefficients.

Claims (1)

A shadow mask mounted on an inner surface of a panel and configured to color-select an electron beam emitted from an electron gun, Based on the center of the shadow mask, the horizontal direction is the X axis, the vertical direction is the Y axis, the direction orthogonal to the X axis and the Y axis is called the Z axis, and Zx is the -Z axis height at any position on the X axis, Zy is -Z-axis height at any position on the Y-axis, The curved shape of the shadow mask is represented by equations (1) and (2) along the horizontal and vertical directions, and the dimensionless coefficients (A1, A2, A3, ... and B1, B2, B3,) of equations (1) and (2). ..) is a shadow mask for a cathode ray tube satisfying the conditions of equations (3) and (4). (Equation 1)

(Equation 2)

(Equation 3)

(Equation 4)

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