JPH09199044A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a color cathode-ray tube improving color purity during operation by preventing member compression bonding force received from a mask frame by a spring during a heating process. SOLUTION: When assuming L1 distance along a major side from a major side center of a mask frame 6 to a securing point of a spring 8, L2 for distance along a minor side from a minor side center of the frame 6 to a securing point of the spring 8, S1 for distance along the major side of the frame 6 from an engaging point with a stub pin 9 of the major side spring 8 of the frame 6 to a securing point of the spring 8, S2 for distance along the minor side of the frame 6 from an engaging point with the stub pin 9 of the minor side spring 8 of the frame 6 to a securing point of the spring 8, F1 for 1/2 external diametric dimension of the major/minor sides in the frame 6, αf for linear thermal expansion coefficent of the frame 6 equivalent to its side direction, αs for linear thermal expansion coefficient of the spring 8 and αp for linear thermal expansion coefficient of a face panel 3, the following relation is satisfied. (αf -αp ) L1 -(αs -αp )S1 }/(L1 <2> +F2 <2> )<1/2> = (αf -αp )L1 --(αs -αp )S2 }/(L2 <2> +F1 <2> )<1/2> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube used in a television receiver, an information processing device, etc., and more particularly to a mounting position and a mounting direction of a shadow mask structure supporting spring.

[0002]

2. Description of the Related Art FIG. 6 is a partially cutaway sectional view showing a schematic structure of a color cathode ray tube. As shown in FIG. 6, the color cathode ray tube is made of glass or the like, and has a funnel 2 having a neck portion 1 in which an electron gun (not shown) is provided inside the rear and a face panel 3 made of glass or the like. A bulb 12, a fluorescent screen 4 provided on the inner surface of the face panel 3, a shadow mask 5 provided at a predetermined position close to the fluorescent screen 4, and a mask frame 6 for holding and fixing the shadow mask 5. A shadow mass structure 7 composed of the above, a spring 8 provided on the outer surface of the shadow mask structure 7, and a stud pin 9 that is planted on the inner surface of the face panel 3 and one end of the spring 8 engages. . For example, the electron beam 10 corresponding to each of the RGB colors emitted from the in-line type electron gun is
Each light passes through a predetermined hole provided in the shadow mask 5 and emits each color of RGB on the fluorescent screen 4. As a result, a color image is formed on the face panel 3.

FIG. 5 is a front view of the support structure of the shadow mask structure as seen from the neck side. As shown in FIG. 5, the shadow mask structure 7 includes a shadow mask 5 close to the face panel 3, and a mask frame 6 for holding and fixing the shadow mask 5. On the outer surface of the shadow mask structure 7, four springs 8 and 8a having substantially the same shape are arranged, and one end thereof is fixed to each side of the mask frame 6. Four stud pins 9 and 9a are provided in the center of each side of the inner surface of the face panel 3.
One of the stud pins 9a on the long side is separated from the center line (a) of the side of the face panel 3 by a dimension A in order to regulate the mounting direction of the shadow mask structure 7. And the other three stud pins 9 are centered on each side of the face panel 3 (a), (b).
Planted above. That is, the two stud pins 9, 9a on the long side are planted at positions asymmetric with respect to the intersection (o) of the center line (a) and the center line (b). The shadow mask structure 7 is detachably supported on the face panel 3 by engaging the other ends of the four springs 8 and 8a with the four stud pins 9 and 9a, respectively.

Generally, the shadow mask 5 is generally made of an iron material or a low thermal expansion amber material (36% Ni-residual F).
e), the mask frame 6 is made of iron material, springs 8 and 8a
Is SUS304 material (18% Cr-8% Ni-remaining Fe)
A bimetal material composed of amber and amber is used.

[0005]

However, in the above-mentioned prior art, the distance difference between the long side and the short side of the mask frame 6 at the spring fixed ends from the center of the face panel 3, the face panel 3, the spring 8, and the like. 8a and the thermal expansion difference between the mask frame 6 and the springs 8 and 8a fixed to the mask frame 6 asymmetrically with respect to the center of the face panel 3, especially on the long side, so that, for example, the funnel 2 During the heat process of manufacturing the color cathode ray tube such as adhesion with the face panel 3, the rotation amount around the center of the face panel 3 generated by the thermal expansion of the mask frame 6 is different between the long side and the short side. The springs 8 and 8a receive a non-uniform pressure force from the mask frame 6. Therefore, stress exceeding the elastic limit is locally generated in the springs 8 and 8a, which may cause plastic deformation of the springs 8 and 8a. Even when the generated stress does not exceed the elastic limit, an excessive load is applied to the fixing point between the springs 8 and 8a and the shadow mask structure 7, and the springs 8 and 8 at the fixing point.
There is a possibility that a may be displaced from the shadow mask structure 7, or welding may be displaced in the case of fixation by welding, for example. As described above, the springs 8 and 8a are plastically deformed, and the springs 8 and 8a and the shadow mask structure 7 are
If a deviation occurs at the fixing point between the shadow mask 5 and the fluorescent screen 4 on the inner surface of the face panel 3, a deviation occurs, and as a result, the electron beam 10 is landed on a predetermined phosphor. However, there is a problem that the color purity of the color cathode ray tube is deteriorated.

The present invention has been made to solve the above-mentioned problems in the prior art, and prevents uneven spring pressure from being applied to the mask frame by the spring during the thermal process of manufacturing the color cathode ray tube, and it is in operation. It is an object of the present invention to provide a color cathode ray tube capable of obtaining good color purity in the above.

[0007]

In order to achieve the above object, a first structure of a color cathode ray tube according to the present invention is a bulb having a phosphor screen made of phosphors of a plurality of colors on an inner surface of a face panel, and the bulb. A shadow mask structure that is provided inside and has a substantially rectangular shadow mask in which a large number of holes are arranged, and a substantially rectangular mask frame for holding and fixing the shadow mask, and a plant on each side of the inner surface of the face panel. It comprises four stud pins provided and four springs of which one end is fixed to the shadow mask structure and the other end is engaged with the stud pin to detachably support the shadow mask structure. a color cathode ray tube, L ₁ the distance along the long side of the mask frame from the center of the mask frame long side to fixing point of the spring, The distance along said short sides of the mask frame from the center of the serial mask frame short side until sticking point of the spring L _2, from the point of engagement with the stud pin of the mask frame length side spring to the fixing point of the spring S _{1 is} the distance along the long side of the mask frame, and S _{2 is} the distance along the short side of the mask frame from the engagement point of the spring on the short side of the mask frame with the stud pin to the fixing point of the spring. , 1/2 of the outer diameter dimension on the long side of the mask frame is F ₁ , 1/2 of the outer diameter dimension on the short side of the mask frame is F ₂ , and the mask frame equivalent in the side direction of the mask frame is the linear thermal expansion coefficient alpha _f, the coefficient of linear thermal expansion equivalent the spring-side direction of the mask frame alpha _s, equivalent the phosphate in the side direction of the mask frame When the linear thermal expansion coefficient of the panel and alpha _p, substantially satisfy the relation of the equation (1), and the four spring fixing end side, characterized in that arranged in the rotationally symmetrical direction.

A second aspect of the color cathode ray tube according to the present invention is
The configuration of, a bulb having a phosphor screen made of phosphors of a plurality of colors on the inner surface of the face panel, and provided in the bulb,
A shadow mask structure composed of a substantially rectangular shadow mask having a large number of holes and a substantially rectangular mask frame for holding and fixing the shadow mask, and four shadow mask structures implanted on each side of the inner face of the face panel. A color cathode ray tube comprising a stud pin and four springs having one end fixed to the shadow mask structure and the other end engaged with the stud pin to detachably support the shadow mask structure. L _{1 is} the distance along the long side of the mask frame from the center of the long side of the mask frame to the fixing point of the spring, and the shortness of the mask frame from the center of the short side of the mask frame to the fixing point of the spring. the spring a distance along the side L _2, from the point of engagement with the stud pin of the mask frame length side spring S ₁ the distance along the long side of the mask frame to anchoring points, the distance along said mask frame from the point of engagement with the stud pin of the short side spring to the short side of the mask frame up to the sticking point of the spring S ₂ is 1 of the outer diameter of the long side of the mask frame.
/ 2 is F ₁ , _{1 of} the outer diameter of the short side of the mask frame
When / 2 is F ₂ , the relationship of the above (Formula 2) is satisfied, and the four spring fixed end sides are arranged in rotationally symmetric directions.

The third aspect of the color cathode ray tube according to the present invention is
In the first or second configuration of the present invention, the configuration of
It is preferred that the face panel and shadow mask be substantially flat.

The fourth color cathode ray tube according to the present invention is also provided.
With respect to the above configuration, in any one of the first to third configurations of the present invention, it is preferable that a reinforcing panel is fixed to the front surface of the face panel.

A fifth aspect of the color cathode ray tube according to the present invention.
In the above configuration, in any one of the first to fourth configurations of the present invention, it is preferable that tension is applied to the shadow mask in at least one direction substantially parallel to the face panel.

According to the first aspect of the present invention, the distance from the center of the long side of the mask frame to the fixing point of the spring along the long side of the mask frame is L ₁ , and from the center of the short side of the mask frame. The distance along the short side of the mask frame to the fixing point of the spring is L ₂ , and the long side of the mask frame from the engagement point of the spring on the long side of the mask frame with the stud pin to the fixing point of the spring. the along distance S _1, the mask frame short side S ₂ of the distance along the short side of the mask frame from the point of engagement with the stud pin of the spring to the fixing point of the spring, the long side of the mask frame 1/2 of the outer diameter F _1, 1/2 and F ₂ on the short side outer diameter of the mask frame, equivalent the Masukufu the side direction of the mask frame The linear thermal expansion coefficient of the over arm alpha _f, linear thermal expansion coefficient alpha _s equivalent the spring-side direction of the mask frame, the linear thermal expansion coefficient equivalent the face panel side direction of the mask frame alpha _{When p} is set, the relation of (Equation 1) is substantially satisfied, and the four spring fixing end sides are arranged in a rotationally symmetric direction. Since the amount of rotation around the center of the face panel at the long side side and the short side side fixed end can be made equal, the uneven pressure force that the spring receives from the mask frame is prevented, and the color purity is good during operation. It is possible to realize various color cathode ray tubes.

According to the second configuration of the present invention,
The distance along the long side of the mask frame from the center of the long side of the mask frame to the fixing point of the spring is L ₁ , and along the short side of the mask frame from the center of the short side of the mask frame to the fixing point of the spring. The distance is L ₂ ,
The distance along the long side of the mask frame from the engagement point of the spring on the long side of the mask frame with the stud pin to the fixing point of the spring is S ₁ , the engagement point of the spring on the short side of the mask frame with the stud pin. To the fixed point of the spring along the short side of the mask frame is S ₂ , half of the outer diameter of the long side of the mask frame is F ₁ , and the outer diameter of the short side of the mask frame is F ₁ . If (1/2) of the above is F ₂ , then (Equation 2)
And the four spring fixing end sides are arranged in a rotationally symmetric direction, so that the crimping force received by the four springs is reduced during the thermal process of manufacturing the color cathode ray tube. Since the amount of rotation around the center of the face panel at the long side side and the short side side fixed ends can be made substantially equal, uneven pressure force that the spring receives from the mask frame is prevented, and color purity during operation is improved. It is possible to realize a good color cathode ray tube.

Further, in the first or second structure of the present invention, according to a preferable example in which the face panel and the shadow mask are substantially flat, it is possible to reduce the reflection of external light and to display an image. Distortion can be reduced.

Further, in the first to third structures of the present invention, according to the preferable example in which the reinforcing panel is fixed to the front surface of the face panel, explosion proof measures and surface treatment such as antistatic and coloring are possible. Become.

Further, in any one of the first to fourth aspects of the present invention, according to a preferable example in which the shadow mask is applied with tension in at least one direction substantially parallel to the face panel, during operation. The thermal expansion of the generated shadow mask can be suppressed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to examples. <First Embodiment> FIG. 2 is a partially cutaway sectional view showing a schematic structure of a first embodiment of a color cathode ray tube according to the present invention. As shown in FIG. 2, the color cathode ray tube is made of glass or the like, and includes a funnel 2 having a neck portion 1 in which an electron gun (not shown) is provided inside the rear and a face panel 3 made of glass or the like. A bulb 12, a fluorescent screen 4 provided on the inner surface of the face panel 3, a shadow mask 5 provided at a predetermined position close to the fluorescent screen 4, and a mask frame 6 for holding and fixing the shadow mask 5. A shadow mass structure 7, which is composed of the following components, four springs 8 provided on the outer surface of the shadow mask structure 7, and a stud pin 9 which is planted on the inner surface of the face panel 3 and is engaged with the other end of the spring 8. doing. For example, RG emitted from an in-line type electron gun
The electron beam 10 corresponding to each color B passes through a predetermined hole provided in the shadow mask 5, and emits each color RGB on the fluorescent screen 4. As a result, a color image is formed on the face panel 3.

The face panel 3 and the shadow mask 5 are formed substantially flat. As a result, the reflection of external light can be reduced and the distortion of the image can be reduced. Also, on the front surface of the face panel 3,
The reinforcing panel 11 is adhered using resin or the like. As a result, explosion-proof measures and surface treatments such as antistatic and coloring are possible. Further, the shadow mask 5 has at least about 10 kg / mm in one direction substantially parallel to the face panel 3.
Tension of ² or more is applied. Thereby, the thermal expansion of the shadow mask 5 during operation can be suppressed. Further, a reinforcing plate 6 a is attached inside the mask frame 6 so as to withstand the tension of the shadow mask 5.

FIG. 1 shows a first color cathode ray tube according to the present invention.
FIG. 7 is a front view of the support structure for the shadow mask structure in the embodiment of FIG. As shown in FIG. 1, the shadow mask structure 7 is composed of a shadow mask 5 close to the face panel 3 and a mask frame 6 for holding and fixing the shadow mask 5. On the outer surface of the shadow mask structure 7, four springs 8 having substantially the same shape are arranged, and one end thereof is fixed to each side of the mask frame 6. Here, the fixed end sides of the four springs 8 are arranged in a rotationally symmetrical direction. That is,
When the spring 8 moves from the fixed end side to the other end side, the directions of rotation around the center of the mask frame 6 are the same for all the four springs 8. Further, four stud pins 9 are planted at substantially the center of each side of the inner surface of the face panel 3.

The two stud pins 9 that engage with the short side springs 8 are planted on the center line (b) of the face panel 3 on the short side. Further, the two stud pins 9 that engage with the long side spring 8 are slightly separated from the center line (a) of the face panel 3 on the long side and the center line (a) and the center line (b) are separated from each other. It is planted in a symmetrical position with respect to the intersection (center) (o). The shadow mask structure 7 is detachably supported on the face panel 3 by engaging the other ends of the four springs 8 with the four stud pins 9.

The shadow mask 5 is made of iron material, the mask frame 6 is made of 13 chromium steel (13% Cr-remaining Fe), and the spring 8 is made of SUS304 material (18% Cr-8% Ni).
A bimetallic material consisting of residual Fe) and amber material is used.

Further, in FIG. 1, L₁Is the center line (a)
From the long side spring 8 fixed point, L_TwoIs medium
Distance from the core wire (b) to the fixed point of the short side spring 8
Away, S ₁Is the relationship between the long side spring 8 and the stud pin 9
Along the long side of the mask frame 6 from the meeting point to the fixing point
Length, S_TwoWith the stud pin 9 of the short side spring 8
Along the short side of the mask frame 6 from the engagement point to the fixation point
Length, F₁Is 1 of the outer diameter of the mask frame 6 on the long side.
/ 2, F_TwoIs 1 / the outer diameter of the short side of the mask frame 6.
2 are shown respectively.

The operation of the color cathode ray tube constructed as above will be described below. For example, during the thermal process of manufacturing the color cathode ray tube such as the adhesion of the funnel 2 and the face panel 3, the mask frame 6, the spring 8 and the face panel 3 undergo thermal expansion. Due to this thermal expansion
On the long side of the mask frame 6, arrow B shown in FIG.
1, a moment is generated on the short side of the mask frame 6 in the direction of arrow C shown in FIG. 1, that is, in the clockwise direction around the center point (o) in FIG. To do. The rotation amount at this time is represented by the ratio of the distance from the center point (o) to the fixing point of the spring 8 and the thermal expansion difference between the spring 8 and the face panel 3 and the mask frame 6. That is, the linear thermal expansion coefficient of the mask frame 6 equivalent to the side direction of the mask frame 6 is α _f , and the spring 8 equivalent to the side direction of the mask frame 6 is equal to.
Where α _{s is} the coefficient of linear thermal expansion and α _p is the coefficient of linear thermal expansion of the face panel 3 equivalent to the side direction of the mask frame 6, on the long side, {(α _f −α _p ) L ₁ − (α _s
−α _p ) S ₁ } / (L ₁ ² + F ₂ ² ) ^1/2 , and on the short side, {(α _f −α _p ) L ₂ − (α _s −α _p ) S ₂ } /
It is represented by (L ₂ ² + F ₁ ² ) ^1/2 , and when these are equal, that is, when the relationship of the above (Equation 1) is satisfied, the crimping force received by the spring 8 is most relaxed. Α _{s at} this time
Is a linear thermal expansion coefficient equivalent to the long side direction of the mask frame 6 for the long side spring 8, and a linear thermal expansion coefficient equivalent to the short side direction of the mask frame 6 for the short side spring 8.

In this embodiment, in the case of a 17-inch color cathode ray, α _f = 11.6 × 10 ⁻⁶ (1 / ° C.), α _s = 11.9 ×
10 ⁻⁶ (1 / ° C.), α _p = 10.0 × 10 ⁻⁶ (1 / ° C.), F ₁ = 160.3 (mm), F ₂ = 122.3 (m
m), S ₁ = S ₂ = 56.1 (mm), and when L ₂ is L ₂ = S ₂ = 56.1 (mm), that is, the short side stud pin 9 has a center line (b). ), L ₁ is L ₁ = 58.3 (mm), and the crimping force received by the spring 8 is most relaxed when the long side stud pin 9 is slightly displaced from the center line (a).

As described above, according to the configuration of this embodiment, L
₁ , L ₂ , α _f , α _s , α _p , S ₁ , S ₂ , F ₁ , F ₂
In the heat process of manufacturing the color cathode ray tube, the long side and the short side are provided by providing the relationship of the above (Formula 1) and arranging the four spring fixed end sides in a rotationally symmetric direction. Since the amount of rotation around the center of the face panel 3 at the side fixed ends can be made equal, the uneven pressure force that the spring 8 receives from the mask frame 6 can be prevented,
It is possible to realize a color cathode ray tube having good color purity during operation.

<Second Embodiment> FIG. 3 is a front view of a support structure for a shadow mask structure in a second embodiment of a color cathode ray tube according to the present invention, as viewed from the neck side. The difference from the first embodiment is that all four stud pins 9 on the long side and the short side are planted on the center lines (a) and (b). The rest of the configuration is the same as that of the first embodiment, so its explanation is omitted here.

The operation of the color cathode ray tube having the above structure will be described below. For example, during the thermal process of manufacturing the color cathode ray tube such as the adhesion of the funnel 2 and the face panel 3, the mask frame 6, the spring 8 and the face panel 3 undergo thermal expansion. Due to this thermal expansion
Similar to the first embodiment, the mask frame 6 generates a moment that tries to rotate in the clockwise direction around the center point (o) in FIG.

FIG. 4 is an experimentally obtained relation between the pressure force applied to the spring during the heating process and the ratio of the distance from the center point to the fixed ends on the long side and the short side. As shown in FIG. 4, the crimping force received by the spring 8 is the ratio (L ₁ ² + F ₂ ² ) of the distances from the central point (o) to the fixed ends on the long side and the short side.
^It changes depending on ^1/2 / (L ₂ ² + F ₁ ² ) ^1/2 . If this ratio is in the range of 0.77 or more and 0.84 or less, that is,
When the pressure applied by the spring 8 is 10 kgf or less, there is no practical problem and a color cathode ray tube with good color purity can be realized.

In this embodiment, in the case of a 17-inch color cathode ray, α _f = 11.6 × 10 ⁻⁶ (1 / ° C.), α _s = 11.9 ×
10 ⁻⁶ (1 / ° C.), α _p = 10.0 × 10 ⁻⁶ (1 / ° C.), F ₁ = 160.3 (mm), F ₂ = 122.3 (m
m), S ₁ = S ₂ = 56.1 (mm), and L ₁ = L ₂ = 56.1 (mm). That is, when all the four stud pins 9 on the long side and the short side are on the center lines (a) and (b), the distance from the center point (o) to the fixed ends on the long side and the short side is The ratio (L ₁ ² + F ₂ ² ) ^1/2 / (L ₂ ² + F ₁ ² ) ^1/2 is 0.79, and as shown in FIG. 4, four springs are used during the thermal process of manufacturing the color cathode ray tube. All crimping force of 8 is 10k
Since it is less than or equal to gf, the same effect as the first embodiment can be obtained in practical use.

As described above, according to the configuration of this embodiment, L
₁ , L ₂ , α _f , α _s , α _p , S ₁ , S ₂ , F ₁ , F ₂
In the heat process of manufacturing the color cathode-ray tube, the long side and the short side are provided because the relationship of the above (Formula 2) is provided and the four spring fixed end sides are arranged in a rotationally symmetric direction. Since the amount of rotation around the center of the face panel 3 at the side fixing end can be made substantially equal, the uneven pressure force applied to the spring 8 from the mask frame 6 can be prevented, and the color cathode line having good color purity during operation. A tube can be realized.

In the first and second embodiments, the shadow mask 5 is made of an iron material, and the mask frame 6 is made of an iron material.
Chrome steel (13% Cr-remaining Fe), SU for spring 8
The case where a bimetal material composed of an S304 material (18% Cr-8% Ni-remaining Fe) and an amber material is used as an example for description, but the material is not limited to these.

In the first and second embodiments, the case where the stud pin 9 is planted on the center lines (b) and (a) and (b) is described as an example. However, the position of the stud pin 9 is not limited to these positions.

[0033]

As described above, according to the present invention,
It is possible to prevent a non-uniform pressure contact force of the spring from the mask frame during the thermal process of manufacturing the color cathode ray tube, and to realize a color cathode ray tube having good color purity during operation.

[Brief description of drawings]

FIG. 1 is a front view of a support structure for a shadow mask structure in a first embodiment of a color cathode ray tube according to the present invention, viewed from a neck side.

FIG. 2 is a partially cutaway sectional view showing a schematic configuration of a first embodiment of a color cathode ray tube according to the present invention.

FIG. 3 is a front view of a support structure for a shadow mask structure in a second embodiment of a color cathode ray tube according to the present invention, as viewed from the neck side.

FIG. 4 is a diagram showing a relationship between a compression force received by a spring during a heating process of a color cathode-ray tube according to the present invention and a ratio of a distance from a center point to a long side side and a short side side fixed end.

FIG. 5 is a front view of a support structure for a shadow mask structure of a color cathode ray tube according to a conventional technique as viewed from a neck portion side.

FIG. 6 is a partially cutaway sectional view showing a schematic configuration of a color cathode ray tube in a conventional technique.

[Explanation of symbols]

 3 Face panel 5 Shadow mask 6 Mask frame 7 Shadow mask structure 8 Spring 9 Stud pin 12 Valve

Claims (5)

[Claims] 1. A bulb having a phosphor screen made of phosphors of a plurality of colors on an inner surface of a face panel, a substantially rectangular shadow mask provided in the bulb and having a large number of holes, and holding and fixing the shadow mask. Shadow mask structure consisting of a substantially rectangular mask frame, four stud pins implanted on each side of the face panel inner surface, one end fixed to the shadow mask structure, and the other end fixed to the stud pin. A color cathode ray tube comprising four springs of substantially the same shape which are engaged with each other to detachably support the shadow mask structure, wherein the mask frame extends from the center of the long side of the mask frame to a fixing point of the spring. L ₁ the distance along the long side of, short of the mask frame from the center of the mask frame short side to fixing points of the spring The distance along the side is L ₂ , the distance along the long side of the mask frame from the engagement point of the spring on the long side of the mask frame with the stud pin to the fixing point of the spring is S ₁ , the short side of the mask frame The distance along the short side of the mask frame from the engaging point of the side spring to the stud pin to the fixing point of the spring is S ₂ , and 1/2 of the outer diameter of the long side of the mask frame is F ₁ , 1/2 of the outer diameter of the short side of the mask frame is F ₂ , a linear thermal expansion coefficient of the mask frame equivalent to the side direction of the mask frame is α _f , and a spring of the spring equivalent to the side direction of the mask frame is _s linear thermal expansion coefficient alpha, when the the alpha _p linear thermal expansion coefficient equivalent the face panel side direction of the mask frame, to substantially satisfy the following relationship (Equation 1), and the 4 Color cathode ray tube in which the spring fixing end of which is characterized in that arranged in the rotationally symmetrical direction. [Equation 1] 2. A bulb having a phosphor screen made of phosphors of a plurality of colors on an inner surface of a face panel, a substantially rectangular shadow mask provided in the bulb and having a large number of holes, and holding and fixing the shadow mask. Shadow mask structure consisting of a substantially rectangular mask frame, four stud pins planted on each side of the inner surface of the face panel, one end fixed to the shadow mask structure, and the other end fixed to the stud pin. A color cathode ray tube comprising four springs of substantially the same shape that are engaged with each other and detachably support the shadow mask structure, wherein the mask frame is formed from a center of a long side of the mask frame to a fixing point of the spring. The distance along the long side is L ₁ , and the short side of the mask frame from the center of the short side of the mask frame to the fixing point of the spring. The distance along the side is L ₂ , the distance along the long side of the mask frame from the engagement point of the spring on the long side of the mask frame with the stud pin to the fixing point of the spring is S ₁ , the short side of the mask frame The distance along the short side of the mask frame from the engaging point of the side spring to the stud pin to the fixing point of the spring is S ₂ , and 1/2 of the outer diameter of the long side of the mask frame is F ₁ , When 1/2 of the outer diameter of the short side of the mask frame is defined as F ₂ , the relationship of the following (Equation 2) is satisfied, and the four spring fixing end sides are arranged in rotationally symmetric directions. Characteristic color cathode ray tube. [Equation 2] 3. The color cathode ray tube according to claim 1, wherein the face panel and the shadow mask are substantially flat. 4. The color cathode ray tube according to claim 1, wherein a reinforcing panel is fixed to the front surface of the face panel. 5. The color cathode ray tube according to claim 1, wherein tension is applied to the shadow mask in at least one direction substantially parallel to the face panel.