JPS5836813B2 - color picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color picture tube in which the required facing distance between the inner surface of the panel and the aperture mask is ensured over the entire surface, and the landing characteristics are improved.

FIG. 1 is a plan view of an aperture mask used in a typical color picture tube.

In this figure, X, Y, and P are the long axis, short axis, and diagonal axis of the aperture mask 1, respectively, and 0 is the center point of the aperture mask 1, that is, the point through which the tube axis 2 of the color picture tube passes.

The aperture mask 1 is placed facing a fluorescent surface 3 formed on the inner surface of the panel 2, as shown in FIG.

The inner surface of the panel 2 and the aperture mask 1 are designed such that the distance between them (hereinafter referred to as Q value) is optimal for coating the inner surface of the panel 2 with a phosphor to create a fluorescent surface 3. and was selected.

Each is shaped like a object sphere with a specific radius of curvature.

Here, the curved shape of the aperture mask 1 in a color picture tube having a conventional dot-type fluorescent surface 3 that requires dynamic convergence will be explained with reference to FIG.

In Figure 3A, the horizontal axis is the distance r (1n1IL) from the tube axis Z of the color picture tube to an arbitrary radial position, and the vertical axis is the distance r (1n1IL) from the three-color electron gun for blue, red, and green. The Q value necessary to arrange the electron beam or the fluorescent dots on the fluorescent surface 3 to form the densest structure is taken, and the distance r(ii ) shows the required change in Q value.

As shown in the figure, the required Q value decreases from the center toward the periphery, and the degree to which it should be decreased decreases and becomes more gradual as it approaches the outermost periphery.

By satisfying such a Q value, riding characteristics are satisfied and the light output of the fluorescent surface 3 can be obtained with maximum efficiency.

Therefore, how the shape of the aperture mask 1 is determined in order to obtain such a color tube will be explained with reference to FIG. 3B.

In Figure 3B, the horizontal axis represents the distance r(-+-) from the tube axis 2 to the position in the arbitrary radial force direction, and the vertical axis represents the coordinates in the direction of the tube axis 2. 2 shows the cross-sectional shape of the aperture mask 1 in FIG.

However, in this case, it is assumed that the inner surface of the panel 2 is formed rotationally symmetrically with a single radius of curvature.

As shown in the figure, the conventional aperture mask 1 has a tube axis Z
Approximately 1/of the maximum distance rp (mm) on the diagonal axis P from
It has a radius of curvature R1 up to a distance of 2, and a radius of curvature R2 outside this, and these two parts are shaped so as to be smoothly continuous at 1/2 rp.

That is, considering the landing characteristics of conventional color picture tubes that require dynamic convergence, the inner surface of the panel 2 is formed with a single radius of curvature and rotationally symmetrical, whereas the aperture masks 1 are formed in a smooth manner. 2
A good shape is a combination of two or more parts with different curvatures and a rotationally symmetrical shape, and by satisfying the above conditions, the Q value between the aperture mask 1 and the inner surface of the panel 2 is the same. The necessary Q shown in Figure 3A throughout the entire surface
It was possible to easily form a fluorescent surface 3 with an ideal arrangement.

By the way, as is well known, the aperture mask 1 has a large number of rectangular holes arranged in a row in the short axis direction, and has blue,
A color picture tube equipped with a three-electron gun assembly (hereinafter referred to as an in-line electron gun) in which single electron guns for red and green are arranged in a row is composed of the color picture tube, a deflection yoke with an appropriate magnetic field distribution, By combining them so that their central axes coincide, dynamic convergence can be made unnecessary.

However, considering the landing characteristics of color picture tubes that do not require dynamic convergence as described above, it is necessary to optimize the alignment of the three electron beams or phosphor stripes emitted from the in-line electron gun on the phosphor surface 3. It was found that the Q value changes as shown in FIG. 4A.

In FIG. 4A, the horizontal axis represents the radial distance r (si) from the tube axis Z to the major axis X, minor axis Y, and diagonal axis P, and the vertical axis represents the required Q value, and the center point of the aperture mask 1 is 0, that is, the change in the required Q value with respect to the distance r(ii) from the tube axis 2 to the radial direction of each axis X, Y, and P.

In FIG. 4A, solid lines x, y and p represent the major axis X, respectively.
The required Q value on the short axis Y and the diagonal axis P is shown.

As shown in the figure, the required gQ value in a color picture tube that does not require dynamic convergence increases from the center toward the periphery, and the Q value at the same distance from the center point O of the aperture mask 1 is Different for each Y and P.

As is clear from a comparison with FIG. 3A, in the conventional color picture tube that requires dynamic convergence, the amount of change in the Q value is rather large at the outermost periphery of the aperture mask 1. On the other hand, in color picture tubes that do not require dynamic convergence, there is a tendency to reduce the amount of change in the Q value.

Therefore, in a color picture tube that does not require dynamic convergence, the aperture mask 1 has two or more parts with different curvatures that are clearly connected to each other, unlike the conventional aperture mask 1 that requires dynamic convergence. A complex and rotationally symmetrical shape cannot satisfy the required Q value, and has the disadvantage of deteriorating the riding characteristics.

This invention was made in consideration of these points,
It is an object of the present invention to provide a color picture tube in which the required facing interval between the inner surface of a panel and an aperture mask is ensured over the entire surface, and better riding characteristics can be obtained over the entire fluorescent surface of the inner surface of the panel.

Hereinafter, this invention will be explained in detail using FIGS. 4A and 4B.

As mentioned above, in a color picture tube that does not require dynamic convergence, it is necessary to make the required Q value different for each axis X, Y, and P. When considering the respective cross-sectional shapes for each, this means that the radius of curvature needs to be different for each.

The required Q value tends to be small at the outermost periphery of the aperture mask 1, and the fact that this tendency is small means that each cross-sectional shape can be formed with a single radius of curvature.

Therefore, how the shape of the aperture mask 1 that satisfies these conditions is determined will be explained with reference to FIG. 4B.

In Figure 4B, the horizontal axis represents the distance r (mi) in the radial direction from the tube axis Z to the long axis X, short axis Y, and diagonal axis P, and the vertical axis represents the coordinates in the two directions of the tube axis. 2 shows a cross-sectional shape of the aperture mask 1 along each axis X, Y, and P including the axes X, Y, and P.

However, in this case, it is assumed that the inner surface of the panel 2 is formed rotationally symmetrically with a single radius of curvature.

In this Figure 4B, RX y RY and RP are the respective axes X and Y obtained from the required Q value shown in Figure 4A.
and the optimal radius of curvature at P.

Now, as shown in FIG. 5, the center coordinates of the aperture mask 1, that is, the coordinates through which the tube axis Z passes, are set to
R is the radius of curvature of a cross section that passes through 0.0) and is inclined at an angle θ with the X axis, and R is the optimal radius of curvature of a cross section with major axis X and minor axis Y.
If X and RY, then the following formula. However, when ■ = 0 and θ = 9o゜, 0 = 9o゜A. It has been found that by determining n and A, it is possible to provide the necessary optimum values over the entire aperture mask 1.

In the embodiment of this invention, for example, the optimum radii of curvature Rx, RY and RP in a 26"/110° deflection tube are
62R, 1044R, and 979R, but when applied to the above formula, a curved surface satisfying n=1.25 and A=3.08 was obtained.

In addition, although the 90' deflection tube and the 110° deflection tube each have their own characteristics, the curved surface of the aperture mask 1 also has 90' deflection tubes.
It has also been found that n is suitably 0.9 to 1 for a 0° deflection tube, and 1.2 to 1.4 for a 1,110° deflection tube.

In this way, in a color picture tube that does not require dynamic convergence, the major axis X1 the minor axis Y and the diagonal axis P
By obtaining the respective optimal curvature radii determined from the required Q values for the three axes and applying them to equation (1),
The radius of curvature R of the cross section in the arbitrary radial direction of the aperture mask 1 is determined and the optimal curved surface shape is obtained, so that the required Q value is satisfied over the entire surface, and the fluorescent surface 3 is ideally arranged.
format can be easily achieved.

Furthermore, the mold used for press molding to obtain the aperture mask 1 having the shape described above is obtained by NC processing, but since an arbitrary cross section is represented by a single R, the input program for processing is also difficult. It has the advantage of being very short and easy to process.

In the above-mentioned embodiment, the inner surface of the panel 2 was formed rotationally symmetrically with a single radius of curvature, and the aperture mask 1 was formed so as to satisfy the relationship of equation (1) above, but conversely, the aperture mask 1 It goes without saying that the panel 2 may be formed rotationally symmetrically with a single radius of curvature, and the inner surface of the panel 2 may be formed so as to satisfy the relationship of equation (1) above.

As described above, according to the present invention, even in a color picture tube that does not require dynamic convergence, the necessary facing distance between the inner surface of the panel and the aperture mask can be ensured over the entire surface, and even more excellent Since a landing characteristic is obtained, there is an advantage that the light output of the fluorescent surface can be obtained with maximum efficiency.

[Brief explanation of the drawing]

Figure 1 is a plan view of an aperture mask used in a normal color picture tube, Figure 2 is a diagram for explaining the arrangement relationship between the panel and the aperture mask, and Figure 3A is a diagram that requires dynamic convergence. FIG. 3B is a diagram for explaining the required facing distance between the panel and the aperture mask in a color picture tube, and FIG. 4 is a diagram for explaining the cross-sectional shape of the aperture mask in a color picture tube that requires dynamic convergence. Figure 4A is a diagram for explaining the required spacing between the panel and aperture mask in a color picture tube that does not require dynamic convergence, and Figure 4B is for explaining the cross-sectional shape of the aperture mask in a color picture tube that does not require dynamic convergence. FIG. 5 is a plan view of an aperture mask for explaining an embodiment of the present invention. In the figure, 1 is an aperture mask, 2 is a panel, 3 is a fluorescent surface, X is a long axis, Y is a short axis, Z is a tube axis, and P is a diagonal axis. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In a color picture tube in which an aperture mask is disposed facing a fluorescent surface formed on the inner surface of a panel at a predetermined interval, the X-axis includes the tube axis which is the center of the aperture mask. When the radius of curvature of the cross section forming an angle θ with is R, and the radius of curvature of the cross section along the 1, when θ=900 ■-900A n is formed so as to satisfy the following relationship: 0.9 to 1.4, and the other is formed rotationally symmetrically with a single radius of curvature. Picture tube.