JPH1186751A - Color picture tube - Google Patents

Abstract

(57) [Problem] To provide a color picture tube capable of easily improving the flatness of a panel and improving the visibility. SOLUTION: In a color picture tube in which an effective area 10 of a panel has a substantially rectangular shape and a phosphor screen is formed on an inner surface 22 of the effective area, an outer surface 21 of the effective area of the panel is substantially flat, The thickness of the effective region was increased from the center to the periphery, and the inner surface of the periphery of the effective region was coplanar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube, and more particularly to a color picture tube in which the effective area of a panel is flattened to improve the visibility without deteriorating the atmospheric pressure intensity of a vacuum envelope. .

[0002]

2. Description of the Related Art Generally, a color picture tube has a vacuum envelope consisting of a glass panel and a funnel in the form of a glass funnel, and a three-electron beam emitted from an electron gun disposed in the neck of the funnel. Is deflected by a magnetic field generated by a deflecting device mounted on the outside of the funnel, and horizontally and vertically scans a phosphor screen including a three-color phosphor layer formed on the inner surface of the effective area of the panel via a shadow mask. As a result, a structure for displaying a color image is formed.

[0003] Such a color picture tube panel is generally provided with a side wall around a substantially rectangular effective area, and has an effective area to obtain a strength capable of withstanding an atmospheric pressure load applied to a vacuum envelope. The inner and outer surfaces are formed into different curved surfaces so that the thickness of the inner and outer surfaces increases from the central portion to the peripheral portion.

The outer surface of the effective area generally has a curved surface whose height from the sealing surface with the funnel of the panel is highest at the center and lower toward the periphery. A conventional panel having such a curved surface is shown in FIGS. 9 is a panel 2 in which the outer surface of the effective area 1 is formed of a spherical curved surface, and FIG. 10 is a panel 2 which is formed of a cylindrical curved surface in which the radius of curvature in the minor axis direction of the outer surface of the effective area 1 is almost infinite.
Reference numeral 1 denotes a panel 2 having a curved surface in which the outer surface of the effective area 1 is displayed by a higher-order polynomial.

Generally, as an index indicating the flatness of a panel,
There is an R display that represents the ratio between the diagonal radius of curvature of a substantially rectangular effective area and a value obtained by multiplying the diagonal dimension by 1.7.

In recent years, the panel of a color picture tube has been flattened on the outer surface of an effective area in order to improve the visibility, and the outer surface has a shape of the above-mentioned R in consideration of the atmospheric pressure intensity of a vacuum envelope. The displayed value is about 2.0R (R display). However, even if the outer surface of the effective area is flattened in this way, the panel still has a curvature and is not enough to obtain a desired visibility.

As a method of solving the flatness of the panel, it is conceivable that the curvature of the outer surface of the effective area is made almost infinite and the inner surface has a shape having a curvature. However, even with this configuration, the flatness is not sufficient when the inner surface has a curvature, and the flatness is not sufficiently recognized when viewed from an angle, regardless of whether the screen is viewed from directly in front. .

On the other hand, the inner surface of the effective area also has various shapes. However, due to the atmospheric pressure strength of the vacuum envelope, the inner surface shape is often a curved surface similar to the outer surface shape so that the inner surface becomes thicker from the center to the periphery of the effective area.

In general, the atmospheric pressure intensity of a glass vacuum envelope decreases as the flatness of the panel increases. However, in recent years, due to improvements in panel design accuracy and reinforcement band performance, it has become possible to maintain a predetermined strength even when the panel is flattened. However, when the inner and outer surfaces of the panel are configured with similar curved surfaces as described above, in order to flatten the effective area more than the present time, the thickness of the glass is significantly increased, or a reinforcing film is attached to the outer surface of the effective area. Such reinforcement is required, resulting in a significant cost increase.

That is, at present, the color picture tube is
In some cases, the outer surface of the effective area of the panel is made substantially flat to improve visibility. However, this color picture tube panel
Since the inner surface of the effective area is curved like a known panel, in order to secure the atmospheric pressure strength of the vacuum envelope, the thickness of the effective area is increased, or a reinforcing film is applied to the outer surface of the effective area. It is necessary to reinforce by means such as sticking.

[0011]

As described above, a panel of a color picture tube is generally provided with a side wall around a substantially rectangular effective area and withstands an atmospheric pressure load applied to a vacuum envelope. In order to obtain the required strength, the inner and outer surfaces are formed to have different curved surfaces so that the thickness of the effective region increases from the center to the periphery. In recent years, flattening of an effective area of such a panel has been promoted in order to improve visibility.

However, when the effective area is flattened, the atmospheric pressure intensity of the glass vacuum envelope is reduced with the improvement of the flatness. However, there is a problem that reinforcement is required, for example, by attaching a reinforcing film to an outer surface of the effective area of the panel, which leads to a significant increase in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a color picture tube capable of easily improving the flatness of a panel and improving visibility without significantly increasing the cost. It is intended to constitute.

[0014]

According to the present invention, there is provided a color picture tube in which an effective area of a panel constituting a vacuum envelope together with a funnel has a substantially rectangular shape, and a phosphor screen is formed on an inner surface of the effective area. The outer surface of the effective area of the panel was made substantially flat, and the thickness of the effective area was increased from the center to the periphery, and the inner surface of the periphery of the effective area was on the same plane.

The inner surface of the effective area is a curved surface represented by a higher-order polynomial.

[0016]

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

FIG. 1 shows a color picture tube which is one embodiment of the present invention. The color picture tube includes a glass panel 12 provided with a side wall 11 around a substantially rectangular effective area 10 described later, and a glass funnel shape joined to an end of the side wall 11 of the panel 12. And a glass vacuum envelope composed of the above funnel 13. Effective area 1 of the panel 12
A phosphor screen 14 made of a three-color phosphor layer that emits blue, green, and red light is provided on the inner surface. A shadow mask 15 is arranged inside the phosphor screen 14 so as to face the phosphor screen 14. On the other hand, an electron gun 18 for emitting three electron beams 17B, 17G, 17R is arranged in a neck 16 of the funnel 13. The three electron beams 17B, 17G, and 17 emitted from the electron gun 18 are used.
R is deflected by a magnetic field generated by a deflecting device 19 mounted on the outside of the funnel 13 and horizontally and vertically scans the phosphor screen 14 via a shadow mask 15 to form a structure for displaying a color image. I have.

In the panel 12, as shown in FIG. 2, the outer surface 21 of the effective area 10 is substantially flat, and the inner surface 22 is formed as a curved surface represented by a higher-order polynomial. ) Shows the cross section taken along the line BB (cross section on the short axis) and the cross section taken along the line CC (cross section on the long axis) in FIG. The thickness increases from the center to the periphery.
Further, FIG. 3 shows that the drop on the short axis is curve 23Y, the drop on the long axis is curve 23X, and the drop on the diagonal axis is curve 23.
As shown by D, the drop amount LY at the effective diameter end of each shaft
, LX, and LD are equal and are a, and FIG.
FIGS. 2E and 2E respectively show a cross section taken along the line DD (a cross section at the effective diameter end (short side) parallel to the short axis) and a cross section taken along the line EE (the effective diameter end parallel to the long axis) in FIG. As shown in section (long side), the inner surface of the effective diameter end (the inner surface around the effective area 10) is located on the same plane.

As an example, FIG. 4 shows the shape of the inner surface of the effective area 10 as a 6th-order polynomial surface expressed by the following equation 1 using a coordinate system in which the tube axis Z, the major axis X, and the minor axis Y are three orthogonal axes. Shows the amount of drop in case of

[0020]

## EQU1 ## z (x, y) = a ₁ x ² + a ₂ x ⁴ + a ₃ x ⁶ + a ₄ y ² + a ₅ x ² y ² + a ₆ x ⁴ y ² + a ₇ x ⁶ y ² + a ₈ y ⁴ + a ^{_{10 x 4 y 4 + a 11}} x 6 y 4 + a 12 y 6 + a 13 x 2 y 6 + a 14 x 4 y 6 + a 15 x 6 y 6 a 1 = 0.2090 × 10 -2 a 2 = -0.5498 × 10 ⁻⁷ a ₃ = 0.3963 × 10 ⁻¹² a ₄ = 0.2515 × 10 ⁻² a ₅ = −0.4936 × 10 ⁻⁷ a ₆ = −0.2312 × 10 ⁻¹² a ₇ = 0 .5565 × 10 ⁻¹⁷ a ₈ = −0.6352 × 10 ⁻⁷ a ₉ = −0.1430 × 10 ⁻¹⁰ a ₁₀ = 0.3085 × 10 ⁻¹⁵ a ₁₁ = −0.2614 × 10 ⁻²⁰ a ₁₂ = −0.6866 × 10 ⁻¹² a ₁₃ = 0.5904 × 10 ⁻¹⁵ a ₁₄ = −0.1480 × 10 ⁻¹⁹ a ₁₅ = 0.9382 × 10 ^{−25 In} this example, at the effective diameter end The amount of drop is uniformly 21.0mm
It has become.

Even if the inner surface of the effective area is a fourth-order polynomial surface expressed by the following equation (2), the result is as shown in FIG. 5, and almost the same result can be obtained.

[0022]

## EQU2 ## z (x, y) = a ₁ x ² + a ₂ x ⁴ + a ₃ y ² + a ₄ x ² y ² + a ₅ x ⁴ y ² + a ₆ y ⁴ + a ₇ x ² y ⁴ + a ₈ x ⁴ y ⁴ a ₁ = 0.2464 × 10 ⁻³ a ₂ = 0.9102 × 10 ⁻¹⁰ a ₃ = 0.2849 × 10 ⁻³ a ₄ = 0.7900 × 10 ⁻⁸ a ₅ = −0.1372 × 10 ⁻¹² a ₆ = 0.1976 × 10 ⁻⁷ a ₇ = −0.6612 × 10 ⁻¹² a ₈ = 0.5107 × 10 ^{−17 In} these cases, the curvature of the inner surface of the effective diameter end is infinite. However, by making this a radius of curvature of about 3000 mm or more, the drop amount on the inner surface of the panel becomes 25.5 mm at the diagonal axis end as shown in FIG. Although the panel 12 is slightly larger than the portion, the configuration of the panel 12 can improve the flatness of the panel, improve the visibility, and improve the panel performance. Without significantly increasing the thickness of the Le, it can be secured atmospheric pressure strength.

That is, as shown in FIGS. 7A and 8B, the viewing angle θX from the direction in which the screen is inclined with respect to the XZ plane passing through the tube axis Z and the long axis X, and the tube When viewed from a viewing angle θY from a direction inclined with respect to a YZ plane passing through the axis Z and the short axis Y, in a conventional panel in which the inner surface is formed of a spherical curved surface, the effective diameter end has a curvature. 5 (b) and 6 (b) show dashed lines 25a, 25
As shown by b, 26a, and 26b, the panel 12 of this embodiment looks bent, but in the panel 12 of this embodiment, the inner surfaces of the effective diameter ends are located on the same plane, and thus the solid lines 27a, 27b, and 2 are provided.
As shown by 8a and 28b, it looks flat.
Therefore, even if the thickness around the effective area 10 is increased so as to obtain a sufficient atmospheric pressure intensity, the visibility can be improved as compared with the conventional panel.

In the panel having the cylindrical curved surface shown in FIG. 10, when viewed from the viewing angle θY direction, the visibility in terms of flatness is good, but when viewed from the viewing angle θX direction. Visibility is poor. Further, since this panel has no curvature in the short axis direction, the atmospheric pressure intensity is inferior.

The aspect ratio of the screen of a conventional color picture tube is 4: 3, but a 16: 9 horizontally long color picture tube has recently been put to practical use. In general, the size of a color picture tube is represented by a diagonal effective diameter. Therefore, for the same size, a color picture tube having a screen aspect ratio of 16: 9 is
The short axis dimension is shorter than that of the 4: 3 color picture tube.
Therefore, in the case of a panel having a spherical inner surface, assuming that the drop amount is the same, the color picture tube having a curvature of 16: 9 at the long side effective diameter end indicated by BC and AD in FIG. : Larger than the color picture tube of No. 3, and the visibility in terms of flatness is inferior. Therefore, when the present invention is applied to such a color picture tube having a screen aspect ratio of 16: 9, a greater effect can be obtained.

[0026]

The outer surface of the effective area of the substantially rectangular panel is substantially flat, and the thickness of the effective area increases from the center to the periphery, and the inner surface of the periphery of the effective area. Are on the same plane, a color picture tube with good visibility over flatness over a wide field of view can be obtained without deteriorating the atmospheric pressure intensity.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention.

FIG. 2A is a diagram showing the shape of the panel, FIG.
2 (b) is a sectional view taken along line BB, FIG. 2 (c) is a sectional view taken along line CC, FIG. 2 (d) is a sectional view taken along line DD, and FIG.
It is E sectional drawing.

FIG. 3 is a diagram showing an inner surface shape of an effective area of the panel.

FIG. 4 is a diagram showing the amount of drop of each part from the center when the inner surface of the effective area of the panel is a sixth-order polynomial curved surface.

FIG. 5 is a diagram showing the amount of drop of each part from the center when the inner surface of the effective area of the panel is a fourth-order polynomial curved surface.

FIG. 6 is a diagram illustrating the amount of drop of each part from the center when the curvature of the inner surface of the effective area of the panel represented by a polynomial surface is corrected.

FIGS. 7 (a) and 7 (b) are views when a screen obtained on the inner surface of the effective area of the panel is viewed at a viewing angle θX inclined with respect to an XZ plane passing through a tube axis and a long axis. It is a figure for explaining how to see a long side effective diameter end.

8 (a) and 8 (b) are views when a screen obtained on the inner surface of the effective area of the panel is viewed at a viewing angle θY inclined with respect to a YZ plane passing through a tube axis and a short axis. It is a figure for explaining how to see a short side effective diameter end.

FIG. 9 is a diagram showing the shape of a conventional panel in which the outer surface of the effective area is formed of a spherical curved surface.

FIG. 10 is a diagram showing the shape of a conventional panel in which the outer surface of the effective area is a cylindrical curved surface.

FIG. 11 is a diagram showing the shape of a conventional panel in which the outer surface of the effective area is expressed by a higher-order polynomial.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Effective area 12 ... Panel 13 ... Funnel 14 ... Phosphor screen 21 ... Outer surface 22 ... Inner surface

Claims (2)

[Claims] 1. A color picture tube in which an effective area of a panel constituting a vacuum envelope together with a funnel has a substantially rectangular shape, and a phosphor screen is formed on an inner surface of the effective area. A color characterized in that the outer surface of the effective area is substantially flat, the thickness of the effective area increases from the center to the periphery, and the inner surface of the effective area is substantially coplanar. Picture tube. 2. The color picture tube according to claim 1, wherein the inner surface of the effective area is a curved surface represented by a higher-order polynomial.