KR950012697B1 - Color crt of shadow mask type - Google Patents

Abstract

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Description

Shadow Mask Type CRT

1 is a front view of a face plate panel of a shadow mask type color tube according to the present invention.

2 is a cross-sectional view of the face plate panel shown in FIG.

A cross section taken along line 2 (a) or X-X, a cross section taken along line 2 (b) or Y-Y.

3 is a cross-sectional view of an effective screen boundary of a face plate panel of a shadow mask type color brown tube according to the present invention, and FIG. 3 (a) is a cross-sectional view along a long side effective screen boundary parallel to the long axis XX, and FIG. Sectional view along a short side effective screen boundary parallel to YY.

4 is a cross-sectional view of the face plate panel and shadow mask of the shadow mask type color brown tube according to the present invention in the diagonal direction of the screen.

5 illustrates the relationship between the characteristics of the deflection yoke and the curved surface of the shadow mask.

6 is a cross-sectional view for explaining the structure of a shadow mask type color tube according to the present invention.

* Explanation of symbols for main parts of the drawings

1: face plate panel 2: effective screen part

3: Peripheral 4: Effective Screen Boundary

5 panel skirt 6 fluorescent surface

7: shadow mask 8: neck

31: short edge portion 32: long edge portion

41: short side effective screen boundary 42: long side effective screen boundary

X-X: Long axis (X axis) Y-Y: Short axis (Y axis)

V: diagonal diameter Z: tube axis

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shadow mask type color tube, and more particularly to a shadow mask type color tube having a so-called flat face having the shape of the face plate panel close to a plane.

The color cathode ray tube (hereinafter referred to as "color-brown tube") used for color image display is composed of a panel portion which is an image screen, a neck portion for receiving an electron gun, and a funnel portion for connecting a panel portion (face plate panel) to the neck portion. The kernel portion is equipped with a deflection device for deflecting the electron beam emitted from the electron gun to scan the fluorescent surface formed on the inner surface of the panel.

The inner face of the face plate panel is provided with a shadow mask, which is a color selective electrode having a curvature almost conforming to the curvature of the inner face, to regulate the position at which a plurality of electron beams emitted from the electron gun collide on the fluorescent surface.

The electron gun accommodated in the neck part has various electrodes such as a cathode electrode, a control electrode, a convergence electrode, and an acceleration electrode, and modulates an electron beam from the cathode into a signal applied to the control electrode, through the convergence electrode and the acceleration electrode. A predetermined cross-sectional shape and energy are applied to impinge on the fluorescent surface. The electron beam is polarized in the horizontal direction and the vertical direction by the deflection device provided in the funnel portion in the course of reaching the fluorescent surface from the electron gun to form an image on the fluorescent surface (see, for example, Japanese Patent Laid-Open No. 59-215640). ).

By the way, there exists a tendency to make the shape of the said faceplate panel which forms the image of the color-brown tube of recent years into the small flat face which became close to the plane.

The plan view of the faceplate panel of the shadow mask type color CRT is greatly influenced by the curvature of the periphery (periphery of the faceplay panel). Therefore, reducing the curvature of the periphery increases the feeling of the flatness of the faceplate panel, but the shadow mask also becomes flat along the curvature of the faceplate panel, so landing errors caused by thermal expansion of the shadow mask ( = Doming phenomenon) increases, and the image (outside reflection) reflected on the outer surface of the face plate panel is deformed, making it difficult to perform high quality image display.

As a color-brown tube which achieves two tasks of flattening the faceplate panel and improving the ming phenomenon, there is one disclosed in Japanese Patent Laid-Open No. 63-232247.

In the invention disclosed in the above publication, the shape of the inner surface and the outer surface of the face plate panel is expressed by a three-dimensional spatial equation in which the major axis (horizontal axis) is the X axis, the minor axis (vertical axis) is the Y axis, and the tube axis is the Z axis. And approximates the curved shapes Z _x and Z _Y on the Y axis to Z _x = A _l X ² + A ₂ X ⁴ and Z _Y = A ₃ Y ² + A ₄ Y ⁴ , respectively, Curved image P _x , P _Y at the point (X = X ₁ , Y = Y _l ) of the boundary of the effective screen boundary of P _x = A _l X ₁ ² / (A _l X ₁ ² + A ₂ X ₁ ⁴ ), P _Y = A ₃ Y ₁ ² / (A ₃ Y ₁ ² + A ₄ Y ₁ ⁴ ) and the integers A _l , A ₂ , A ₃ and A ₄ are 0.3 P _x (X = X ₁ ) 0.6, 0.95 P _Y (Y = Y _l ) Set to satisfy 1.0. In addition, the shape of the effective screen boundary of the short side (short side) axis and the long side (long side) axis of the face plate panel is formed to be an arc having almost the same curvature, and the radius of curvature R (mm) is the effective diagonal diameter V ( 1.5 inches (42.5 V + 45.0) R By forming so as to satisfy 2.0 (42.5 V + 45.0), it is possible to reduce the dominance of the shadow mask, the strength, the surface reflection, and the planarization of the face plate panel.

However, in the conventional color CRT having the curved shape, the flattening of the face plate panel is further improved, and when the radius of curvature of the periphery is out of the R (mm) range, the outer reflection is greatly distorted, especially local distortion. This increases. Furthermore, there has been a problem that the number of the radiators due to the domming of the shadow mask increases, which greatly impairs the quality of the displayed image.

Accordingly, an object of the present invention is to solve the problems of the prior art, and to provide a shadow mask type color brown tube which can improve the distortion of the external reflection of the faceplate panel and reduce the shadowing of the shadow mask to obtain a high quality image display. To provide.

In order to achieve the above object, the present invention is a color-brown tube having a rectangular face plate panel having an effective screen portion and a peripheral portion surrounding the effective screen portion and having a long axis and a short axis, wherein at least the long axis of the paste panel of the rectangular shape of the curved surface shape of the outer surface of the X-axis, the speed-Y axis, and tube when expressed axis in a three-dimensional expression in the Z-axis, the long axis curved surface shape on the phase and speed-Z _X and Z _Y Each

Z _x = Z ₁ X ² + A ₂ X ² + A ₃ X ⁶

Z _Y = Z ₄ X ² + A ₅ X ⁴ + A ₅ Y ⁶

And approximate the curves P _x , P _Y of at least the outer surface of the faceplate panel at points (X = X ₁ , Y = Y _l ) of the effective screen boundary, which is a boundary between the effective screen and the peripheral portion, respectively.

P _x = A _l X ₁ ² / (A ₁ X ₁ ² + A ₂ X ₁ ⁴ + A ₃ X ₁ ⁶ )

P _Y = A ₄ X _l ² / (A ₄ Y ₁ ² + A ₅ Y ₁ ⁴ + A ₆ Y ₁ ⁶ )

Once, the integers A _l , A ₂ , A ₃ , A ₄ , A ₅ and A ₆

0.5 P _x (X = X _l ) 0.9

0.6 P _Y (Y = Y _l ) 1.0

Characterized in that set to satisfy.

Further, the shape of the short side effective screen boundary and the long side effective screen boundary on the outer surface of the face plate panel have an arc shape with almost the same curvature, and the radius of curvature R (mm) of the arc is the effective diagonal of the face plate panel. When the diameter is V (inch),

2.0 (42.5V +45.0) R 4.0 (42.5V +45.0)

It is characterized by satisfying.

By setting the curved surface P _X , P _Y and the radius of curvature R at the points of the inner surface and the outer surface of the faceplate panel Z _X , Z _Y and the effective screen boundary within the above range, the distortion of the surface reflection of the peripheral portion is reduced, It is possible to obtain the flat cathode color cathode ray tube with high quality image display performance by improving the domming resistance of the shadow mask having a curved surface that mimics the curved surface of the face plate panel.

EMBODIMENT OF THE INVENTION Hereinafter, the shadow mask type color brown tube of this invention is demonstrated concretely by an Example.

1 is a front view of a face plate panel for explaining an embodiment of a shadow mask type color tube according to the present invention, a cross-sectional view taken along the line XX of FIG. 2 (a) or FIG. 1, and FIG. 2 (b) (1) is a face plate panel, (2) an effective screen portion, (3) a peripheral portion, (31) a short side peripheral portion, (32) a long side peripheral portion, (4) ) Is an effective screen boundary, 41 is a short side effective screen boundary, 42 is a long side effective screen boundary, XX is a long axis (X axis), YY is a short axis (Y axis), and V is a diagonal diameter (inch).

1 and 2, the face plate panel 1 has a rectangular shape with the long axis of the X axis and the short axis of the Y axis YY, and a fluorescent surface made of three phosphors is formed on the inner surface thereof. The effective screen portion 2 has an outer surface and an inner surface substantially the same shape, and the effective screen portion 2 displays an image due to the collision of an electron beam.

The periphery 3, which is not displayed, is formed around the effective display unit 2, and the short side periphery 31 and the long side periphery 32 are formed, and a continuous surface is formed in the skirt portion connected to the funnel portion (not shown). Doing.

The outer surface of the face plate panel according to the present invention is generally represented by the following formula.

Z = A _l X ² + A ₂ X ⁴ + A ₃ X ⁶ + A ₄ Y ² + A ₅ Y ⁴ + A ₆ Y ⁶ + A ₁₀ X ² Y ⁴ + A ₁₁ X ⁴ Y ⁴ + A _{l 2} X ⁶ Y ⁴ + A ₁₃ X ² Y ⁶ + A _l ⁴ X ⁴ Y ⁶ + A ₁₅ X ⁶ Y ⁶

Here, Z is an amount indicating how far the outer surface is from the center when the center of the panel is zero, as it is moved away from the center. As indicated by the above formula, the curved surface Z is determined by 15 coefficients of A _{1 to} A _l5 . Fifteen coefficients means that there are fifteen degrees of freedom, which means that selecting the optimal coefficients requires a large amount of evaluation and is extremely difficult in reality.

The present invention finds that the equivalent curvature of the periphery, as well as the coefficient of the curvature on the X-axis and the Y-axis, play an important role for the reduction of the flattening of the face panel. With the proper choice, it has been reached that the flattening and the reduced dominance of the panel can be obtained.

In the present invention, when the effective diagonal diameter is V (inch), the radius of curvature R (mm) of the short side and long side effective screen boundary of the outer surface of the face plate panel is 2.0 (42.5 V + 45.0). R It can be set within the range of 4.0 (42.5V + 45.0). Here, Z _x , Z _Y are the surface shapes of the faceplate tunnel (1) expressed in three-dimensional space along the major axis XX and minor axis YY axis, that is, Z _x = A _l X ² + A ₂ X ⁴ + A ₃ X ⁶ , Z _Y = A ₄ Y ² + A ₅ Y ⁴ + A ₆ Y ⁶ .

Here, R can be defined as follows. That is, in FIG. 3 (a), the long axis R is R = (d _X ² + _x1 ² ) / 2d _x , and in FIG. 3 (b), the short axis R is R = (d _y ² + y ₁ ² ) / 2dy.

When the curved shape substantially parallel to the major axis XX and the minor axis YY of the effective screen boundary unit 4 is represented by the three-dimensional spatial equations P _x and P _Y , the same curvature and the effective diagonal diameter are used. At the point (4 = X _l , Y = Y _l ) of 4), the curved shapes P _x , P _y , are each P _x = A _l X _l ² / (A _l X ₁ ² + A ₂ X _l ⁴ + A ₃ X ₁ ⁶ ), P _Y = A ₄ Y ₁ ² / (A ₄ Y ₁ ¹ + A ₅ Y ₁ ⁴ + A ₆ Y _l ⁶ ), and the integers A _l , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ are 0.5 Px (X = X ₁ ) 0.9, 0.6 P _Y (Y = Y _l ) It is set to be in the range of 1.0. When the constants A _{1 to} A ₆ are set to satisfy the above conditions, even if the equivalent curvature radius of the peripheral portion is set large, it is possible to prevent the deterioration of the dominant characteristic and the reflection image remarkably.

3 is a cross-sectional view of the effective screen boundary portion of FIG. 1, which is a cross-sectional view along the long side effective screen boundary portion 42 substantially parallel to the third (a) or the long axis XX, and the third (b) or the short axis (YY). It is sectional drawing along the parallel short side effective screen boundary part 41. FIG.

3, the effective screen boundary portion 42 substantially parallel to the XX axis has a curved surface continuous to the short edge portion 31, and the effective screen boundary portion 41 substantially parallel to the YY axis is formed on the long edge portion 32. As shown in FIG. It has a continuous curved surface.

Thereby, the curved surface including the effective screen boundary portion 42 substantially parallel to the XX axis and the curvature R ₁ and R ₂ each having substantially the same curvature R ₁ and R ₂ including the effective screen boundary portion 41 substantially parallel to the YY axis, (XX side axis) and the periphery of the short side (YY side axis) are planarized and it is possible to improve distortion of surface reflection. In addition, it is possible to reduce the doming phenomenon of the shadow mask mounted inside the faceplate panel and to reduce the landing error.

On the other hand, when the curved surface of the panel is set as described above, the cross section in the diagonal direction of the panel causes a so-called reverse bending phenomenon in which the sign of the second derivative of the curved surface of the outer surface is changed once, as shown in FIG. . However, if the shape of the shadow mask is reversed, the shadow mask has a weak strength because a large number of holes are formed in a thin metal plate, and a so-called howling phenomenon in which the shadow mask vibrates due to the vibration of the shadow mask caused by the sound of the TV receiver. Occurs. Therefore, an important point in the present invention is that even if the sign of the second derivative on the outer surface of the panel is changed, the sign of the second derivative does not change at least in the perforated portion of the shadow mask. Here, the reason for limiting to at least the perforated part is that the periphery where the perforated part is not formed is made of a metal plate having a relatively high strength and the influence of howling is small. However, it is of course most desirable for the second derivative not to change throughout the shadow mask.

4 illustrates one embodiment of the present invention. 4 is a cross-sectional view in a diagonal direction of the CRT of the present invention. However, when the rib 71 is formed along the periphery to improve the strength of the shadow mask, the curved surface of the rib does not change.

In addition to the shape of the inner curved surface of the panel, the characteristics of the fun yang yoke play an important role in determining the curved shape of the shadow mask. This is shown in FIG. 5, where (DP) is the deflection surface of the deflection yoke. The optimal spacing between the shadow mask and the inner surface of the panel is determined by a value S that is approximately given by the spacing of the electron guns. However, the effective value S varies depending on the characteristics of the deflection yoke. Therefore, by selecting the characteristics of the deflection yoke, it is possible to change the curved surface of the shadow mask.

6 is a cross-sectional view illustrating the structure of a shadow mask type color tube according to the present invention, where (1) a ferrite play panel, (2) an effective screen portion, (3) a peripheral portion, and (5) a panel skirt portion. , (6) fluorescent surface, (7) shadow mask, (8) neck, (9) funnel, (10) magnetic shield, (11) deflection yoke, (12) electron gun, (13) The silver purity adjustment magnet, (14) eye center beam point concentration adjustment magnet, (15) the side focusing adjustment magnet, and (16) the electron beam.

The outer surface and the inner surface of the face plate panel 1 are formed in a curved shape as described above, and on the outer surface of the face plate panel 1, a thin film containing SnO ₂ and InO ₃ for antireflection and antistatic, if necessary. This single layer or multilayer is formed. In addition, a conductive thin film made of graphite, titanium dioxide, or the like is attached to the inner surface of the funnel 9.

The shadow mask 7 is formed in a shape that follows the curved shape of the face plate panel 1, that is, has the same curved surface as the face plate panel 1. That is, since the curvature of the periphery of this shadow mask 7 is larger than the conventional one, rigidity is increased, springback at the time of press working is small, and the doming phenomenon at the time of operation is reduced.

Here, the magnetic shield 10 has a function of mainly blocking the influence of geomagnetic.

As described above, according to the present invention, it is possible to planarize the face plate panel, to reduce distortion of surface reflection mainly caused by the curved surface of the periphery thereof, and to reduce the dominant phenomenon of the shadow mask to display a high quality image. A shadow mask type color tube with excellent function can be provided.

Claims (4)

A shadow mask type color brown tube comprising an effective screen portion and a peripheral portion surrounding the effective screen portion, and having a rectangular face plate panel having a long axis and a short axis, wherein the rectangular shape of the curved surface of at least an outer surface of the face plate panel is provided. The surface phenomena Z _X and Z _Y on the long axis and the short axis are respectively expressed when the long axis of the shape faceplate panel is represented by the X axis, the Y axis, and the tube axis Z. Z _x = Z ₁ X ² + A ₂ X ⁴ + A ₃ X ⁶ Z _Y = Z ₄ Y ² + A ₅ Y ⁴ + A ₆ Y ⁶ The curved surfaces R _x and P _Y of at least the outer surface of the face plate panel at points (X = X ₁ , Y = Y _l ) of the effective screen boundary, which is a boundary between the effective screen portion and the peripheral portion, are respectively approximated. Px = A _l X ₁ ² / (A _l X ₁ ² + A ₂ X ₁ ⁴ + A ₃ X ₁ ⁶ ) P _Y = A ₄ Y ₁ ² / (A ₄ Y ₁ ² + A ₅ Y ₁ ⁴ + A ₆ Y ₁ ⁶ ) Once, the integers A _l , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ 0.5 Px (X = X ₁ ) 0 .9 0.6 P _Y (Y = Y _l ) 1.0 Shadow mask type color tube, characterized in that set to satisfy. The curved surface of the short side effective screen boundary portion and the curved surface of the long side effective screen boundary portion of the outer surface of the face plate panel have an arc shape with almost the same curvature, wherein the radius of curvature R (mm) of the arc is When the effective diagonal diameter of the faceplate panel is V (inch), 2.0 (42.5V +45.0) R 4.0 (42.5V +45.0) Shadow mask type color tube, characterized in that to satisfy. The shadow mask type color-brown tube according to claim 2, wherein the curved expression of the cross-section in the diagonal direction of the shadow mask does not change at least the second derivative at the effective portion. The shadow mask type color-brown tube according to claim 2, wherein the curved expression of the cross-section in the diagonal direction of the shadow mask does not change to the periphery.