KR100449257B1 - Formed type flat panel for use in a crt - Google Patents

Abstract

The present invention relates to a form-form flat panel for cathode ray tubes, comprising: a substantially rectangular faceplate having an effective screen area and an outer surface having a radius of curvature R and an inner surface of a curved surface; And a corner portion connecting the face plate and the skirt portion and a part of the circumference of the circumference, wherein the effective screen diameter D of the face plate is 700 mm or more, or D is 550 mm or more and less than 665 mm, and R is 10,000 mm or more. If the periphery of the face plate thickness T ₁ is _{0.03D - 5 ≤ T 1 ≤ 0.039D} + 15 / (D 0.5 - 1.5) + 2.54 , and the central portion thickness T ₂ of the face plate is 0.0185D - 6.5 ≤ T ₂ ≤ 0.0204D, and the wedge ratio (T ₁ / T ₂ ) is 1.3 ≤ T ₁ / T ₂ ≤ 2.1. Therefore, the present invention simplifies the panel manufacturing process by providing a tinted tint-formed flat panel satisfying explosion-proof characteristics according to the UL standard, and has an effect of increasing productivity by preventing a loss of color conversion of the tank.

Description

FORMED TYPE FLAT PANEL FOR USE IN A CRT}

The present invention relates to a foamed type flat panel for a cathode ray tube, and more particularly, to a foamed type flat panel for a cathode ray tube, which is made of tint glass and can satisfy explosion-proof properties.

Flat panels are widely applied to cathode ray tubes (CRTs), which are widely used in TV receivers or display devices of computers, because they have less reflection of external light and image distortion than spherical panels.

1 is a cross-sectional view schematically showing a foamed type flat panel for a color cathode ray tube. The form-type flat panel 10 has a face plate portion 12, a skirt portion 14 and a face plate portion extending rearward from the edge of the face plate portion 12 and connected to a funnel (not shown). 12 and a corner portion or blend round portion 16 connecting the skirt portion 14 to the skirt portion 14. The face plate portion 12 is a curved surface having an outer surface 12b almost flat and an inner surface 12a having a large curvature compared to the outer surface 12b. In the CRT assembly, a shaped mask (not shown) is fixed to the skirt portion 14 by stud pins (not shown).

In addition to the form-type flat panel described above, the flat panel includes a tension type flat panel in which both the outer surface and the inner surface of the faceplate are flattened and a tension type mask is used. In the case of the tension type flat panel, the tint is manufactured because the difference between the center thickness and the peripheral thickness of the faceplate, that is, the wedge rate is low.

However, in the case of the form-type flat panel, since the wedge ratio is high, the color tone is made clear to satisfy the luminance uniformity of the screen. In other words, the flat panel is made of transparent glass with high light transmittance to increase the brightness across the faceplate and to reduce the brightness of the center of the faceplate. The method is used.

However, there are the following problems when doing this. First, since a process of applying a separate coating on the outer surface of the face plate is added to the panel production process, there is a problem in that the productivity is lowered and the price of the panel is increased. Next, since the panel is made of transparent glass, tank color conversion loss occurs due to glass color tone conversion. That is, a glass bulb manufacturer produces a transparent glass gob and a tint glass product using one glass melting furnace to manufacture a transparent panel and a tint panel. A glass bulb manufacturer produces a transparent glass product, and then, in order to produce a colored glass product, a colored glass raw material to which a coloring component is added is melted in a glass melting furnace to produce a tinted glass product. As described above, it takes about 7 days to change the color tone of the glass product, and there is a problem in that the productivity of the panel is lowered because the production of the panel is stopped without producing the glass product during this period.

Therefore, since the form-type flat panel is to be manufactured in tint color tone, the tint glass has lower light transmittance than that of the transparent glass. Therefore, when manufacturing the tint panel using the tint glass product, the tint glass panel is used to satisfy the luminance requirement required by the tube maker. The thickness of the panel is inevitably thinner than that of the transparent panel made of the transparent glass product. For this reason, the foamed type flat panel manufactured in the tint color tone has a problem that the explosion-proof characteristics deteriorate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above disadvantages, and an object of the present invention is to provide a tinted color-formed flat panel satisfying the explosion-proof characteristics of UL standards while satisfying the luminance conditions of a tube maker. .

A feature of the present invention for achieving such an object is that, in a form-type flat panel for cathode ray tube, a substantially rectangular face plate having an effective screen area and an outer surface having a radius of curvature R and an inner surface of a curved surface, and an edge of the face plate. And a skirt portion extending rearward from the edge portion and a corner portion connecting the face plate and the skirt portion and a portion of the circumference of the inner surface, wherein the effective screen diameter D of the face plate is 700 mm or more or D is 550 mm or more and 665 mm and less, when R is more than 10,000 mm, the peripheral portion of the face plate thickness T ₁ is _{0.03D - 5 ≤ T 1 ≤ 0.039D} + 15 / (D 0.5 - 1.5) + 2.54 , and the center thickness of the faceplate T ₂ is 0.0185D−6.5 ≦ T ₂ ≦ 0.0204D, and the wedge ratio (T ₁ / T ₂ ) has a relationship of 1.3 ≦ T ₁ / T ₂ ≦ 2.1.

According to another aspect of the present invention, there is provided a form-type flat panel for a cathode ray tube, comprising: a substantially rectangular faceplate having an effective screen area and an outer surface having a radius of curvature R and an inner surface of a curved surface, and a skirt extending rearward from an edge of the faceplate. And a corner portion connecting the face plate and the skirt portion and a portion of the circumference of the circumference, wherein the effective screen diameter D of the face plate is 665 mm or more and less than 700 mm and R is 10,000 mm or more. and 6.5 ≤ T ₂ ≤ 0.0204D, - T ₁ is the thickness of the peripheral portion _{0.03D - 5 ≤ T 1 ≤ 0.039D} + 15 / (D 0.5 - 1.5) + 2.54 , and the center thickness of the faceplate T ₂ is 0.0185D The wedge rate is 1.3 ≦ T ₁ / T ₂ ≦ 1.97.

In still another aspect of the present invention, there is provided a form-type flat panel for a cathode ray tube, comprising: an approximately rectangular face plate having an effective screen area and an outer surface having a radius of curvature R and an inner surface of a curved surface, and extending rearward from an edge of the face plate. And a skirt portion and a corner portion that connects the face plate and the skirt portion and a portion of the circumference is an inner surface, and the effective face diameter D of the face plate is 500 mm or more, less than 550 mm and R is 10,000 mm or more. a peripheral portion of the plate thickness T ₁ is ^{0.035D - ((0.003D) 2 -} 2.54) - 5 ≤ T 1 ≤ 0.07D - ((0.004D) 4 - 2.54) + 1.2 , and the central portion thickness T ₂ of the face plate ^{0.031D - (0.004D) 2 - 5.5} ≤ T 2 ≤ 0.056D - (0.007D) 2 - 0.254 , and the wedge rate is to have a relation that _{1.3 ≤ T 1 / T 2 ≤} 2.1.

In still another aspect of the present invention, there is provided a form-type flat panel for a cathode ray tube, comprising: an approximately rectangular face plate having an effective screen area and an outer surface having a radius of curvature R and an inner surface of a curved surface, and extending rearward from an edge of the face plate. And a skirt portion and a corner portion connecting the face plate and the skirt portion and having a portion of the circumference of the inner surface, wherein the effective screen diameter D of the face plate is less than 500 mm and R is more than 10,000 mm, the thickness of the periphery of the face plate. T ₁ is ^{0.035D - ((0.003D) 2 -} 2.54) - 5 ≤ T 1 ≤ 0.07D - ((0.004D) 4 - 2.54), and the center thickness of the faceplate T ₂ is 0.031D - (0.004D It is a (0.007D) ² + 1.5, and a wedge rate of _{1.3 ≤ T 1 / T 2 ≤} 2.1 -) 2 - 3.5 ≤ T 2 ≤ 0.056D.

1 is a cross-sectional view schematically showing a conventional flattened type flat panel for cathode ray tube,

2 is a plan view schematically showing a foamed type flat panel for a cathode ray tube according to the present invention;

3 is a cross-sectional view of the form-type flat panel shown in FIG. 2 taken along line A-A.

<Description of the symbols for the main parts of the drawings>

10: flat panel 12: face plate portion

14: skirt portion 16 blend round portion

22: effective screen 24: face center area

26: peripheral area D: effective screen diameter

T ₁ : Thickness around faceplate

T ₂ : Faceplate Center Thickness

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

2 is a plan view schematically showing the form-type flat panel 20 according to the present invention. As shown in FIG. 2, the form-type flat panel 20 has a rectangular shape having two long sides 18a and 18b and two short sides 20a and 20b approximately parallel to each other, and the face plate portion 12 displays an image. A face center region 24 constituting the effective screen 22 to be displayed, and a peripheral region 26 around the face center region 24. The diagonal length of the effective screen 22 is defined as the effective screen diameter D.

3 is a cross-sectional view of the form-type flat panel according to the present invention taken along line AA of FIG. 2. The same reference numerals are used for the same parts as the conventional form-type flat panel shown in FIG. 1 and the description thereof is omitted for brevity. As shown in FIG. 3, the inner surface 16a of the corner portion 16 is a portion of the circumference of the circle contacting the inner surface 12a of the faceplate portion 12 and the thickness of the faceplate peripheral area T ₁ is the corner portion 16. The inner surface 16a of) denotes the thickness of the flat panel 20 at the contact point that contacts the inner surface 12a of the face plate portion 12. The center of the face plate portion 12 is a point where a straight line extending from the neck axis (not shown) meets the face plate 12, that is, the intersection of two diagonal lines of the face plate 12, and the flat panel 20 at this point. The thickness of is defined as the faceplate center thickness T ₂ .

In addition, the foamed type flat panel according to the present invention has a tint color tone with a light transmittance of 52.5 ± 5% when its thickness is 11.43 mm.

In addition, the form-type flat panel according to the present invention satisfies the BU (brightness uniformity) standard proposed by the tube maker and at the same time satisfies the explosion-proof characteristics of the UL (Underwriters Laboratories Inc.) standard.

When the effective screen diameter (D) is 700 mm or more and the radius of curvature R of the outer surface 12b of the faceplate portion 12 is 10,000 mm or more, T ₁ and T ₂ and the wedge ratio T ₁ / T ₂ are Each of the following conditions is satisfied.

_{0.03D - 5 ≤ T 1 ≤ 0.039D} + 15 / (D 0.5 - 1.5) + 2.54

0.0185D-6.5 ≤ T ₂ ≤ 0.0204D

1.3 ≤ T ₁ / T ₂ ≤ 2.1

Formula 1 to 3 and the conditions and 32-inch form-type flat panel (Example 1) having a tint hue was manufactured to test whether the explosion-proof characteristics of the UL standard is satisfied and the results are shown in Table 1 and Table 2 shows. In addition, the experimental results of the flat panel (Comparative Examples 1 to 3) made by the conventional method with clear color tone are also shown.

division Model name (Inch) R (mm) Dimension (mm) D T ₁ T ₂ T ₁ / T ₂ Example 1 32 50,000 760 23.25 13.00 1.79 Comparative Example 1 32 100,000 760 31.69 13.00 2.44 Comparative Example 2 32 100,000 760 32.69 14.00 2.34 Comparative Example 3 32 50,000 760 30.47 12.50 2.44

division T ₁ range (mm) T ₂ range (mm) T ₁ / T ₂ range (mm) Equation hue Explosion proof properties at least maximum at least maximum at least maximum T ₁ T ₂ T ₁ / T ₂ Example 1 17.80 32.76 7.56 15.50 1.30 2.10 O O O Tint O Comparative Example 1 17.80 32.76 7.56 15.50 1.30 2.10 O O X clear O Comparative Example 2 17.80 32.76 7.56 15.50 1.30 2.10 O O X clear O Comparative Example 3 17.80 32.76 7.56 15.50 1.30 2.10 O 0 X clear O

As can be seen from Table 1 and Table 2, it can be seen that the tinted tint-type flat panel satisfying Equations 1 to 3 and its conditions satisfies the explosion-proof characteristics of the UL standard. In addition, it can be seen that the conventional flat panel having a clear color tone does not satisfy the equations (1) to (3).

If the effective screen diameter (D) is less than 700 mm, 665 mm or more, and the radius of curvature R of the face plate 12 outer surface 12b is 10,000 mm or more, T ₁ and T ₂ , T ₁ / T ₂ are as follows. Each of the same mathematical conditions is satisfied.

_{0.03D - 5 ≤ T 1 ≤ 0.039D} + 15 / (D 0.5 - 1.5) + 2.54

0.0185D-6.5 ≤ T ₂ ≤ 0.0204D

1.3 ≤ T ₁ / T ₂ ≤ 1.97

Formed flat panel (Example 2 and Example 3) of 29 inch model satisfying Equations 4 to 6 and its conditions and having tint hue were manufactured and tested to satisfy the explosion-proof characteristics of UL standard. Are shown in Tables 3 and 4. Moreover, the experimental result of the conventional flat panel (Comparative Example 4 thru | or Comparative Example 6) whose color tone is clear was also shown.

division Model name (Inch) R (mm) Dimension (mm) D T ₁ T ₂ T ₁ / T ₂ Example 2 29 100,000 676 23.05 12.50 1.84 Example 3 29 50,000 676 23.74 12.50 1.90 Comparative Example 4 29 100,000 676 27.46 12.50 2.20 Comparative Example 5 29 100,000 676 29.46 14.50 2.03 Comparative Example 6 29 32,470 678 24.93 12.50 1.99

division T1 range (mm) T2 range (mm) T1 / T2 range (mm) Equation hue Explosion proof properties at least maximum at least maximum at least maximum T1 T2 T1 / T2 Example 2 15.28 29.52 6.01 13.79 1.30 1.97 O O O Tint O Example 3 15.28 29.52 6.01 13.79 1.30 1.97 O O O Tint O Comparative Example 4 15.28 29.52 6.01 13.79 1.30 1.97 O O X clear O Comparative Example 5 15.28 29.52 6.01 13.79 1.30 1.97 O X X clear O Comparative Example 6 15.28 29.52 6.04 13.83 1.30 1.97 0 0 X clear O

As can be seen from Table 3 and Table 4, it can be seen that the tinted tint-type flat panel satisfying the equations (4) to (6) and the conditions satisfy the explosion-proof characteristics of the UL standard. In addition, it can be seen that the conventional flat panel having a clear color tone does not satisfy the equations (4) to (6).

If the effective screen diameter (D) is less than 665 mm, more than 550 mm, and the radius of curvature R of the outer surface 12b of the faceplate portion 12 is more than 10,000 mm, T ₁ and T ₂ , T ₁ / T ₂ are Satisfies the following formula:

_{0.03D - 5 ≤ T 1 ≤ 0.039D} + 15 / (D 0.5 - 1.5) + 2.54

0.0185D-6.5 ≤ T ₂ ≤ 0.0204D

1.3 ≤ T ₁ / T ₂ ≤ 2.1

Formed type flat panels (Examples 4 to 6) satisfying Equations 7 to 9 and their conditions and having tint hue were manufactured and tested to satisfy the explosion-proof characteristics of UL standards. The results are shown in Tables 5 and 6. Indicated. Moreover, the experiment result of the conventional flat panel (Comparative Example 7 thru | or Comparative Example 11) whose color tone is clear was also shown.

division Model name (Inch) R (mm) Dimension (mm) D T ₁ T ₂ T ₁ / T ₂ Example 4 25 30,000 590 23.66 12.00 1.97 Example 5 25 50,000 590 24.28 12.00 2.02 Example 6 28 100,000 660 22.93 12.50 1.83 Comparative Example 7 25 30,000 590 25.16 13.50 1.86 Comparative Example 8 25 100,000 590 25.71 13.00 1.98 Comparative Example 9 25 53,570 598.9 24.57 12.50 1.97 Comparative Example 10 28 100,000 660 28.12 13.50 2.08 Comparative Example 11 28 100,000 660 23.93 13.50 1.77

division T ₁ range (mm) T ₂ range (mm) T ₁ / T ₂ range (mm) Equation hue Explosion proof properties at least maximum at least maximum at least maximum T ₁ T ₂ T ₁ / T ₂ Example 4 12.70 26.21 4.42 12.04 1.30 2.10 O O O Tint O Example 5 12.70 26.21 4.42 12.04 1.30 2.10 O O O Tint O Example 6 14.80 28.90 5.71 13.46 1.30 2.10 O O O Tint O Comparative Example 7 12.70 26.21 4.42 12.04 1.30 2.10 O X O clear O Comparative Example 8 12.70 26.21 4.42 12.04 1.30 2.10 0 X O clear O Comparative Example 9 12.97 26.55 4.58 12.22 1.30 2.10 0 X 0 clear O Comparative Example 10 14.80 28.90 5.71 13.46 1.30 2.10 0 X 0 clear O Comparative Example 11 14.80 28.90 5.71 13.46 1.30 2.10 0 X 0 clear O

As can be seen from Table 5 and Table 6, it can be seen that the tinted tint-type flat panel satisfying the equations (7) to (9) and the conditions satisfy the explosion-proof characteristics of the UL standard. In addition, it can be seen that the conventional flat panel having a clear color tone does not satisfy the equations (7) to (9).

If the effective screen diameter (D) is 500 mm or more, less than 550 mm, and the radius of curvature R of the outer surface 12b of the faceplate portion 12 is 10,000 mm or more, T ₁ and T ₂ , T ₁ / T ₂ are Satisfies the following formula:

^{0.035D - ((0.003D) 2 -} 2.54) - 5 ≤ T 1 ≤ 0.07D - ((0.004D) 4 + 2.54) + 1.2

^{0.031D - (0.004D) 2 - 5.5} ≤ T 2 ≤ 0.056D - (0.007D) 2 - 0.254

1.3 ≤ T ₁ / T ₂ ≤ 2.1

Formed type flat panel (Example 7) that satisfies Equations 10 to 12 and its conditions and has a tint tint was manufactured and tested to satisfy the explosion-proof characteristics of the UL standard. In addition, the experimental results of conventional flat panels (Comparative Example 12 and Comparative Example 13) in which the color tone is clear are also shown.

division Model name (Inch) R (mm) Dimension (mm) D T ₁ T ₂ T ₁ / T ₂ Example 7 21 50,000 508 21.08 11.00 1.92 Comparative Example 12 21 100,000 505.3 23.32 12.00 1.94 Comparative Example 13 21 100,000 508 23.30 13.00 1.79

division T ₁ range (mm) T ₂ range (mm) T ₁ / T ₂ range (mm) Equation hue Explosion proof properties at least maximum at least maximum at least maximum T ₁ T ₂ T ₁ / T ₂ Example 7 13.00 22.25 6.12 15.55 1.30 2.10 O O O Tint O Comparative Example 12 12.93 22.42 6.08 15.53 1.30 2.10 X O O clear O Comparative Example 13 13.00 22.25 6.12 15.55 1.30 2.10 X O O clear O

As can be seen from Table 7 and Table 8, it can be seen that the tint-colored form-type flat panel satisfying the equations (10) to (12) and the conditions satisfy the explosion-proof characteristics of the UL standard. In addition, it can be seen that the conventional flat panel having a clear color tone does not satisfy the equations (10) to (12).

Further, when the effective screen diameter D is less than 500 mm and the radius of curvature R of the outer surface 12b of the faceplate portion 12 is 10,000 mm or more, T ₁ and T ₂ , T ₁ / T ₂ are as follows. Satisfies the formula.

^{0.035D - ((0.003D) 2 -} 2.54) - 5 ≤ T1 ≤ 0.07D - ((0.004D) 4 - 2.54)

^{0.031D - (0.004D) 2 - 3.5} ≤ T2 ≤ 0.056D - (0.007D) 2 + 1.5

1.3 ≤ T1 / T2 ≤ 2.1

Formed type flat panel (Examples 8 to 12) satisfying Equations 13 to 15 and its conditions and having a tint tint were prepared and tested to satisfy explosion-proof characteristics of UL standards. The results are shown in Tables 9 and 10. Indicated. Moreover, the conventional flat panel (comparative example 14 and comparative example 16) which color tone is clear also shown together.

division Model name (Inch) R (mm) Dimension (mm) D T ₁ T ₂ T ₁ / T ₂ Example 8 10 57,260 230.8 15.22 8.80 1.73 Example 9 15 50,000 355.6 17.69 10.00 1.77 Example 10 15 50,000 355.6 17.19 9.50 1.81 Example 11 17 57,260 406.7 20.38 11.00 1.85 Example 12 17 57,260 406.7 21.56 10.50 2.05 Comparative Example 14 17 57,260 406.7 23.70 11.00 2.15 Comparative Example 15 17 57,260 406.7 23.20 10.50 2.21 Comparative Example 16 19 57,260 457.2 25.60 11.00 2.33

division T ₁ range (mm) T ₂ range (mm) T ₁ / T ₂ range (mm) Equation hue Explosion proof properties at least maximum at least maximum at least maximum T ₁ T ₂ T ₁ / T ₂ Example 8 5.14 17.97 2.80 11.81 1.30 2.10 O O O Tint O Example 9 8.85 23.34 5.50 15.22 1.30 2.10 O O O Tint O Example 10 8.85 23.34 5.50 15.22 1.30 2.10 O O O Tint O Example 11 10.29 24.01 6.46 16.17 1.30 2.10 O 0 O Tint O Example 12 10.29 24.01 6.46 16.17 1.30 2.10 0 0 O Tint O Comparative Example 14 10.29 24.01 6.46 16.17 1.30 2.10 0 0 X clear O Comparative Example 15 10.29 24.01 6.46 16.17 1.30 2.10 0 0 X clear O Comparative Example 16 11.66 23.36 7.33 16.86 1.30 2.10 X 0 X clear O

As can be seen from Table 9 and Table 10, it can be seen that the tinted tint-type flat panel satisfying the equations (13) to (15) and the conditions satisfy the explosion-proof characteristics of the UL standard. In addition, it can be seen that the conventional flat panel having a clear color tone does not satisfy the condition of Equations 10 to 12.

As described above, since the flat panel according to the present invention is a flat panel having a tint tint that satisfies the explosion-proof characteristics according to the UL standard, the coating process required when producing the flat panel of the clear tint is omitted, so-called tank color conversion loss. Has the effect of preventing.

What has been described above is merely an embodiment of the flat panel according to the present invention, the present invention is not limited to the above-described embodiment, the invention without departing from the gist of the invention as claimed in the claims below Anyone with ordinary knowledge in the field will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (8)

Formed flat panel for cathode ray tube, A substantially rectangular faceplate having an effective screen area, an outer surface with a radius of curvature R, and an inner surface with a curved surface, A skirt portion extending rearward from an edge of the faceplate, A corner portion connecting the face plate and the skirt portion and the portion of the circumference being inner; If the effective screen diameter D of the face plate is 700 mm or more, or D is 550 mm or more and less than 665 mm, and R is 10,000 mm or more, the peripheral thickness T ₁ of the face plate is 0.03D-5 ≦ T ₁ ≦ 0.039 and + 2.54, the center thickness of the faceplate T ₂ is 0.0185D - D + 15 / (1.5 D 0.5) - and 6.5 ≤ T ₂ ≤ 0.0204D, the wedge ratio (T ₁ / T ₂₎ is 1.3 ≤ T ₁ / Formed type flat panel for cathode ray tube, characterized in that the relationship T ₂ ≤ 2.1. The form-type flat panel for cathode ray tube according to claim 1, wherein the form-type flat panel for cathode ray tube is made of tinted glass having a light transmittance of 52.5 ± 5% based on 11.43 mm. Formed flat panel for cathode ray tube, A substantially rectangular faceplate having an effective screen area, an outer surface with a radius of curvature R, and an inner surface with a curved surface, A skirt portion extending rearward from an edge of the faceplate, A corner portion connecting the face plate and the skirt portion and the portion of the circumference being inner; If the effective screen diameter D of the face plate is 665 mm or more, less than 700 mm and R is 10,000 mm or more, the peripheral thickness T ₁ of the face plate is 0.03D-5 ≤ T ₁ ≤ 0.039D + 15 / (D ^0.5- 1.5) + 2.54, the center thickness of the face plate T ₂ is 0.0185D-6.5 ≤ T ₂ ≤ 0.0204D, the wedge ratio is 1.3 ≤ T ₁ / T ₂ ≤ 1.97 . 4. The foamed type flat panel for cathode ray tube according to claim 3, wherein the foamed type flat panel for cathode ray tube is made of tinted glass having a light transmittance of 52.5 ± 5% based on 11.43 mm. Formed flat panel for cathode ray tube, A substantially rectangular faceplate having an effective screen area, an outer surface with a radius of curvature R, and an inner surface with a curved surface, A skirt portion extending rearward from an edge of the faceplate, A corner portion connecting the face plate and the skirt portion and the portion of the circumference being inner; If the effective diameter of the screen D is at least 500 mm of the face plate is less than 550 mm, and R is more than 10,000 mm, thickness T ₁ the periphery of the face plate is ^{0.035D - ((0.003D) 2 -} 2.54) - 5 ≤ T 1 ^{≤ 0.07D - ((0.004D) 4} - 2.54) + 1.2, and the center thickness of the faceplate T ₂ is ^{0.031D - (0.004D) 2 - 5.5} ≤ T 2 ≤ 0.056D - (0.007D) 2 - 0.254 The wedge ratio is 1.3 ≤ T ₁ / T ₂ ≤ 2.1, characterized in that the foamed type flat panel for cathode ray tubes. The flat panel for cathode ray tube of claim 5, wherein the cathode ray tube flat panel is made of tint glass having a light transmittance of 52.5 ± 5% based on 11.43 mm. Formed flat panel for cathode ray tube, A substantially rectangular faceplate having an effective screen area, an outer surface with a radius of curvature R, and an inner surface with a curved surface, A skirt portion extending rearward from an edge of the faceplate, A corner portion connecting the face plate and the skirt portion and the portion of the circumference being inner; The effective diameter D of the screen face plate is less than 500 mm and when R is more than 10,000 mm, thickness T ₁ the periphery of the face plate is ^{0.035D - ((0.003D) 2 -} 2.54) - 5 ≤ T 1 ≤ 0.07D - ((0.004D) ⁴ - 2.54), and the central portion thickness T ₂ of the face plate is 0.031D ^{- (0.004D) 2 - 3.5 ≤} T 2 ≤ 0.056D - (0.007D) 2 + 1.5 , and a wedge rate of 1.3 Formed type flat panel for cathode ray tube, characterized in that the relationship ≤ T ₁ / T ₂ ≤ 2.1. 8. The form-form flat panel for cathode ray tube according to claim 7, wherein the form-type flat panel for cathode ray tube is made of tinted glass having a light transmittance of 52.5 ± 5% based on 11.43 mm.