JP2001338596A - Color cathode-ray tube and color picture tube device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color cathode-ray tube that has good quality of external light reflection on the panel inside and reduces deterioration, etc., in color purity by shear in beam landing, and a color picture tube having the tube. SOLUTION: Thickness of an effective part 16 of a face panel is formed thicker at the peripheral part than that at the center. On the inner face of the effective part, the radius of curvature along the minor axis direction on the major axis X has, when the distance from the center of the face panel to the end of the major axis is taken as L, minimum value at a position apart toward the end of the major axis of more than L/2 from the center of the face panel, and then the face panel satisfy the following relations: TD<2.5Tc, Tv<2.0Tc, and TH<2.0Tc, wherein the thickness at the center of the face panel is taken as Tc, the thickness at an end of a diagonal effective diameter is taken as TD, the thickness at an end of the minor axis effective diameter is taken as Tv, and the thickness at an end of the major axis effective diameter is taken as TH.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color cathode ray tube having a shadow mask and a color picture tube device having the same.

[0002]

2. Description of the Related Art In general, a color cathode ray tube has a vacuum envelope having a substantially rectangular panel having a skirt portion provided around a curved effective surface and a funnel joined to the skirt portion. Have. On the inner surface of the effective surface of the panel, a phosphor screen having a three-color phosphor layer and a black non-light-emitting layer is formed. Further, a shadow mask is disposed inside the panel so as to face the phosphor screen, and the shadow mask has a substantially rectangular mask body including a curved surface formed with a large number of electron beam passage holes.
A substantially rectangular mask frame attached to the periphery of the mask body.

On the other hand, an electron gun that emits three electron beams is arranged in the neck of the funnel. Then, the three electron beams emitted from the electron gun are deflected by a magnetic field generated by a deflector mounted outside the funnel, and the phosphor screen is horizontally and vertically scanned through a shadow mask, whereby a color image is formed. Is displayed.

Generally, in order to display an image without color shift on a phosphor screen of a color cathode ray tube, an electron beam passing through an electron beam passage hole of a shadow mask is applied to a three-color phosphor layer of the phosphor screen. You must land correctly on each. For that purpose, it is necessary to maintain a proper distance (q value) between the panel and the shadow mask.

In recent years, in order to improve the visibility of a color cathode ray tube and reduce the reflection of external light, it has been required to increase the radius of curvature of the outer surface shape of the panel to near a flat surface. Accordingly, it is necessary to increase the radius of curvature of the inner surface of the panel from the viewpoint of visibility. Also,
In order to obtain an appropriate beam landing on the inner surface of the panel, the radius of curvature of the mask body in which the electron beam transmission holes are formed must be increased.

[0006]

However, if the radius of curvature of the mask body is increased, the strength of the curved surface is reduced, causing deformation of the shadow mask during the manufacturing process and greatly deteriorating the color purity of the manufactured color cathode ray tube. Let it.

Further, in the shadow mask type color cathode ray tube, the electron beam which passes through the electron beam passage hole of the shadow mask and reaches the phosphor screen due to its operation principle, the total amount of the electron beam emitted from the electron gun The remaining electron beam collides with the shadow mask and is converted into thermal energy to heat the shadow mask. As a result, the shadow mask swells toward the phosphor screen due to thermal expansion and causes doming.

If the distance between the phosphor screen and the shadow mask exceeds an allowable range due to the doming, the landing position of the electron beam with respect to the phosphor layer shifts, and the color purity deteriorates. In particular, when a high-luminance image pattern is locally displayed, local doming occurs in the shadow mask, and the deviation of the beam landing locally increases in a short time. When the radius of curvature of the mask body is increased, the local doming as described above also increases.

As a countermeasure, USP 6,025,67
According to the cathode ray tube disclosed in 6, the shape of the inner surface of the panel and the shape of the mask body, the radius of curvature in the major axis direction is infinite,
It is a cylindrical curved surface having a curvature only in the short axis direction.
According to this configuration, the problems of mask doming and mask curved surface strength can be almost solved.

However, in the case of the above-described configuration, the influence of external light reflection between the inner surface of the panel and the phosphor screen is increased, and the contrast of an image is reduced. This problem can be reduced by providing a filter that selectively transmits light between the inner surface of the panel and the phosphor screen.However, providing a filter increases the manufacturing cost and requires additional manufacturing equipment. Problem.

In order to improve the contrast without providing a filter, it is necessary to form a panel with glass having a transmittance of about 50%. In this case, the luminance at the peripheral portion of the panel is lower than the luminance at the central portion, and the uniformity of the luminance is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to provide a color cathode ray tube in which the quality of external light reflection on the inner surface of a panel is good and the deterioration of color purity due to a deviation in beam landing is reduced. , And a color picture tube provided with the same.

[0013]

In order to achieve the above object, a color cathode ray tube according to the present invention has a substantially flat outer surface and an inner surface on which a phosphor screen is formed. A vacuum envelope having a substantially rectangular face panel having a major axis and a minor axis orthogonal to each other, and a pair of major sides substantially parallel to the major axis and a pair of minor sides substantially parallel to the minor axis. And a shadow mask provided in the vacuum envelope facing the phosphor screen, and an electron beam is applied to the phosphor screen via the shadow mask provided in the vacuum envelope. An electron gun, wherein the thickness of the face panel is formed such that a peripheral portion is formed thicker than a central portion, and a radius of curvature along a short axis direction on the long axis on an inner surface of the face panel is Face pad Assuming that the distance from the center of the face panel to the long axis end is L, the distance has a minimum value at a position farther than L / 2 from the center of the face panel to the long axis end, and the thickness of the center part of the face panel is Assuming that Tc is the thickness at the diagonal effective diameter end, TD, the thickness at the short axis effective diameter end is Tv, and the thickness at the long axis effective diameter end is TH, the face panel has the following expression: TD <2.5Tc Tv <2 0.0Tc TH <2.0Tc.

According to the color cathode ray tube of the present invention, in the area between the short axis and the short side of the face panel, the thickness on the long axis and the long side in a cross section parallel to the short axis are provided. The difference with the upper wall thickness is characterized in that it has a maximum value at a position separated from the center of the face panel by a shorter side than L / 2.

According to the color cathode ray tube of the present invention,
On the inner surface of the face panel, the radius of curvature along the major axis on the major axis is L from the center of the face panel.
It is characterized in that it has a minimum value at a position farther to the long axis end side than / 2.

According to the color cathode ray tube of the present invention,
A radius of curvature of the inner surface of the face panel along a direction parallel to the minor axis is at least in a region from the center of the face panel to L / 2 toward the end of the major axis from the major axis to the major side. It is characterized in that it is set to decrease. According to the color cathode ray tube of the present invention, the mask body of the shadow mask is also formed in substantially the same shape as the inner surface of the face panel.

A color cathode ray tube configured as described above,
According to the color picture tube device having the same, by setting the curvature of the mask body and the inner and outer surfaces of the face panel under appropriate conditions, the visibility of the external light reflection on the inner surface of the face panel is improved while the visibility is good. In addition, it is possible to reduce the deterioration of the color purity of the color cathode ray tube due to the doming of the shadow mask during the operation of the color cathode ray tube and the deterioration of the color purity caused by the deviation of the beam landing caused by the deformation of the mask body during the manufacturing process.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment in which the present invention is applied to a color picture tube provided with a color cathode ray tube having an aspect ratio of 4: 3 and a diagonal size of 60 cm will be described in detail. . As shown in FIGS. 1 and 2, the color picture tube device includes a substantially rectangular box-shaped housing 8.
A color cathode ray tube is housed in this housing. The color cathode ray tube includes a vacuum envelope 10, which has a face panel 12 and a funnel 14. The face panel 12 includes a substantially rectangular effective portion 16 having a substantially flat outer surface, and a skirt portion 18 erected around the effective portion. The face panel 12 has a major axis (X axis) orthogonal to the tube axis Z, and a minor axis (Y axis) orthogonal to the major axis and the tube axis. The funnel 14 is joined to the skirt 18. The face panel 12 has a transmittance of 60%.
It is formed by the following glass.

As shown in FIG. 3, on the inner surface of the effective portion 16 of the face panel 12, stripe-shaped phosphor layers 11 of three colors emitting blue, green, and red light are formed, and a gap is formed between the phosphor layers. The phosphor screen 20 having the striped black non-light-emitting layer 17 is formed.

As shown in FIG. 1, a shadow mask 22 is disposed inside the face panel 12 in the vacuum envelope 10. The shadow mask 22 has a substantially rectangular mask body 34 facing the phosphor screen 20 and having a large number of electron beam passage holes 42 formed thereon, and a substantially rectangular mask frame supporting a peripheral portion of the mask body. 35. The shadow mask 22 includes a plurality of stud pins 30 protruding from the inner surface of the skirt 18 of the face panel 12, a plurality of elastic supports 32 attached to a mask frame 35,
Are engaged and detachably supported inside the face panel 12. In the neck 15 of the funnel 14, three electron beams 17B, 17G, 17R
Is provided.

A deflecting device 26 is mounted on the outer periphery of the funnel 14, and the deflecting circuit 7 is connected to the deflecting device. The power supply circuit 6 for driving the electron gun, the amplifier circuit 5, and the signal circuit 4 are connected to the electron gun 24. These circuits 4 to 7 constitute a drive circuit according to the present invention.

In the color cathode ray tube, the electron gun 24
The three electron beams 17B, 17G, and 17R emitted from the device are deflected by the magnetic field generated by the deflecting device 26, and the phosphor screen 20 is horizontally and vertically scanned through the shadow mask 22, thereby displaying a color image.

In the above color cathode ray tube, as shown in FIG. 4, the effective portion 16 of the face panel 12 is formed such that its peripheral portion is thicker than its central portion. For example, in the effective portion 16, the thickness TC of the central portion is set to 12.
5 mm, the thickness TD at the effective diameter end in the diagonal axis D direction is 2
8.3 mm, the thickness TV at the effective diameter end in the short axis Y direction is 22.0 mm, and the thickness TH at the effective diameter end in the long axis X direction.
Is set to 21.9 mm, TD = 2.26Tc Tv = 1.76Tc TH = 1.75Tc.

When the thickness of the effective portion 16 is made thicker at the peripheral portion than at the central portion, the luminance at the peripheral portion of the screen decreases. The inner surface of the face panel 12 and the phosphor screen 20
When the face panel 12 is formed of a glass having a low transmittance, for example, a glass having a transmittance of 60% or less in order to reduce external light reflection at an interface between the panel effective portion and the color cathode ray tube, The luminance difference between the center and the periphery of 16 is large, and the uniformity of the luminance of the screen is deteriorated.

FIG. 5 shows that the transmittance at the center of the face panel 12 is 50%, and the ratio of the black non-light-emitting layer 17 per unit area at the center of the phosphor screen 20 (hereinafter referred to as BLK) is 45%. In addition, the black uniformity (the black uniformity of the screen when the color cathode ray tube is not operated) and the operation of the color cathode ray tube when the thickness of the peripheral portion is changed with respect to the thickness of the central portion of the effective portion 16. 4 shows the result of evaluating the uniformity of the luminance of the screen at the time. In FIG. 5, ○ indicates good, Δ indicates slightly good, and × indicates bad.

From the above evaluation results, according to the present embodiment, the thickness Tc of the central portion, the thickness Tv of the short-axis effective diameter end, and
The thickness TH at the long axis effective diameter end and the thickness TD at the diagonal effective diameter end are as follows: TD <2.5Tc, Tv <2.0Tc, TH <2.0T
The range is set so as to satisfy the relationship of c. In addition, since the distance from the center of the effective portion 16 is long at the effective end of the diagonal axis, the thickness can be set to be larger than that of the short axis end and the long axis end.

In order to reduce the deterioration of the luminance of the peripheral portion with respect to the central portion of the effective portion 16, at least the diagonally effective end BLK of the peripheral portion of the effective portion 16 is replaced with the central BLK.
Is set equal to or smaller than In the present embodiment, when the BLK at the central portion is 45%, the BLK at the peripheral portion is 41% at the short axis effective diameter end, 51% at the long axis effective diameter end, and 42% at the diagonal effective diameter end. %
Deterioration of luminance uniformity is reduced.

The outer surface of the effective portion 16 of the face panel 12 is set to have a radius of curvature of 10 m or more and is formed substantially flat. The radius of curvature of the inner surface of the effective portion 16 is set as follows. That is, the solid line A- in FIG.
As shown by D, and as shown in FIG. 6B, the radius of curvature along the minor axis direction on the minor axis Y is the effective portion 16
Is near R2200 in the vicinity of the center, but gradually decreases toward the periphery in the short-axis direction, about R1800 near the middle between the long axis X and the long side 16a, and R1000 near the outermost effective portion.
It has become about.

As shown in FIG. 2, when the distance from the center of the effective portion 16 to the effective end of the long axis X is L, the relationship between the radii of curvature along the short axis Y direction as described above, >
Middle part> effective part outermost relationship is L / 2 from the center of the effective part
Area. FIG. 6A shows a dashed line C
As shown by −F, the radius of curvature along the short axis Y in the short side 16b is about R3300 near the center, about R3200 near the middle, and about R3000 near the outermost effective portion, and is almost a single curvature. The radius or the radius of curvature represented by a function whose secondary component is 80% or more. This is because if the number of higher-order components in the function increases, undulation occurs on the inner surface of the effective portion 16 and undulation occurs in the effective diameter shape of the short side 16b.

As shown by solid lines A′-C ′ in FIG. 7A and as shown in FIG. 7B, the radius of curvature along the short axis Y on the long axis X is the effective portion 16. R at the center of
It is set to about 2200, about R2000 at the middle part, and R3300 at the short side 16b. Further, this radius of curvature takes a minimum value in the vicinity of being separated from the center by 2L / 3 toward the end of the effective diameter of the long axis, and is about R1800. In this case, the radius of curvature along the minor axis direction on the major axis X has a minimum value in a region separated by more than L / 2 from the center of the effective portion 16 to the major axis effective end side.

The radius of curvature along the minor axis direction on the major axis X is set to be minimum at a position away from the center of the effective portion 16 toward the major axis effective diameter end side by more than L / 2. Just do it.

As shown by the solid line in FIG. 8A and the radius of curvature along the major axis on the major axis X as shown in FIG. 8A and FIG. At R30000
Degree, about R2300 in the middle part, effective part outermost, that is,
The short side 16b is R330, and is set so as to take the minimum value at a position further than L / 2 from the center of the effective portion to the long axis effective end side.

FIG. 9A shows the thickness distribution of the effective portion of the face panel 12 described above. Then, as shown in FIG. 4, in the effective portion 16, the thickness at the central portion is TC, and the thickness at the effective diameter end in the diagonal axis D direction is T.
D, the thickness at the effective diameter end in the short axis Y direction is TV, and the long axis X is
The thickness at the effective diameter end in the direction is TH, the thickness at the intermediate portion 120 mm away from the center along the major axis X is THM, and the thickness at the intermediate portion 120 mm away from the minor axis Y is along the long side 16a. Assuming TLM, the effective portion 1 of the face panel 12
6 is formed so as to satisfy the following relationship. (TD-TH) <(TV-TC) ≦ (TLM-THM) That is, as shown in FIGS. 9B and 9C, the major axis in each cross section parallel to the minor axis Y of the effective portion 16 When the difference between the wall thickness on X and the wall thickness on the long side 16a is observed, the wall thickness difference is maximum near the middle between the short axis Y and the short side 16b.

On the other hand, as shown in FIG. 10, the mask body 34 of the shadow mask 22 has a substantially rectangular effective portion 34a in which a large number of electron beam passage holes are formed, and a through hole located around the effective portion. And a non-porous portion 34b that is not provided. The effective portion 34a is formed in substantially the same shape as the inner surface of the effective portion 16 of the face panel 12.

As shown in FIGS. 10 and 11, the effective portion 34a of the mask body 34 is such that the drop amount of each portion along the tube axis Z direction with respect to the height of the center O is the drop amount at the end of the diagonal axis D. Is ZD, the drop amount ZV at the short axis Y end, and the long axis X
Assuming that the drop amount at the end is ZH, it is formed so as to satisfy the relations of Zv <0.8ZD and ZH <0.8ZD. In the present embodiment, for example, ZD is 13.0 mm and ZV is 8.9 m.
Assuming that m and ZH are 8.8 mm, Zv = 0.68ZD ZH = 0.68ZD is set.

The radius of curvature of the mask body 34 along the minor axis along the major axis X decreases from the center of the mask body toward the major axis end, and the distance from the center O of the mask body to the major axis end is reduced. Let d be d from the center of the mask body.
/ 2 has a minimum value of the radius of curvature at a position further to the long axis end side than / 2. The radius of curvature along the major axis direction on the major axis X is
It has a minimum value at a position away from the center O of the mask body 34 toward the long axis end side than d / 2. Further, the mask body 34
The radius of curvature along the direction parallel to the short axis Y decreases from the center O of the mask body to d / 2 toward the long axis end side from the long axis X toward the long side of the mask body. Is set to

FIG. 12 shows a comparison of the amount of movement of the electron beam spot caused by doming of the shadow mask between the color cathode ray tube configured as described above and the conventional example. 13 (a) to 13 (c)
The result of simulating the displacement of the mask body when a load of about 1 G is applied to the effective surface of the mask body is as follows:
The color cathode ray tube according to the present embodiment is compared with a conventional tube. FIG. 13A shows, as shown in FIG.
FIG. 13B shows the amount of deformation at each position along the short axis Y of the mask body 34, and FIG.
The amount of deformation at each position along the separated axis is shown. FIG. 13C shows the amount of deformation at each position along an axis parallel to the short axis Y and 180 mm away from the short axis. .

As can be seen from FIG. 12, according to the color cathode ray tube according to the present embodiment, by forming the inner surface of the face plate 12 and the mask body 34 as described above, the inner surface of the effective portion 16 and the mask body 34 are formed. Even when the radius of curvature of was large, the amount of movement of the electron beam spot by the shadow mask doming did not increase, and a result almost equivalent to the conventional product was obtained. As can be seen from FIGS. 13A to 13C, the amount of displacement of the mask main body 34 with respect to the load is slightly reduced on the short axis Y, but is smaller at the peripheral portion of the mask main body than in the conventional product. are doing.

When the mask body 34 is deformed, as shown in FIG. 3, the electron beam spots 18H, 18V, and 18D formed on the phosphor screen 20 are respectively 19
As shown by H, 19V, and 19D, it moves toward the periphery of the phosphor screen. For this reason, on the major axis X or on the diagonal axis D, even if the mask body is slightly deformed toward the periphery, the color purity is deteriorated even if the mask body is slightly deformed. Therefore, as described above, according to the present embodiment, the displacement amount of the mask main body 34 is slightly reduced on the short axis Y, but is reduced around the mask main body. Color purity can be obtained.

Therefore, according to the color cathode ray tube configured as described above and the color picture tube provided with the same, the curvature of the mask body 34 and the inner and outer surfaces of the face panel 12 are set under appropriate conditions, thereby enabling visual recognition. Degree of quality is good, but the quality of external light reflection on the inner surface of the face panel is good, and the color purity of the color cathode ray tube deteriorates due to the doping of the shadow mask during the operation of the color cathode ray tube, and the deformation of the mask body that occurs in the manufacturing process , The deterioration of the color purity caused by the deviation of the beam landing caused by the deviation can be reduced.

[0041]

As described above in detail, according to the present invention, a color cathode ray tube having good quality of external light reflection on the inner surface of a panel and reducing deterioration of color purity due to beam landing deviation, and the like. A color picture tube provided with this can be provided.

[Brief description of the drawings]

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

FIG. 2 is a plan view showing a face panel of a color cathode ray tube in the color picture tube.

FIG. 3 is an enlarged plan view showing a part of a phosphor screen of the color cathode ray tube.

FIG. 4 is a perspective view schematically showing a part of the face panel.

FIG. 5 is a diagram showing evaluation results of black uniformity and luminance uniformity of a screen according to the thickness of a peripheral portion with respect to a central portion of the face panel.

FIG. 6 is a diagram showing a radius of curvature of the inner surface of the effective portion of the face panel along the minor axis direction, and a perspective view schematically showing the inner surface of the effective portion.

FIG. 7 is a diagram showing a radius of curvature of the inner surface of the effective portion of the face panel along the minor axis direction, and a perspective view schematically showing the inner surface of the effective portion.

FIG. 8 is a view showing a radius of curvature of the inner surface of the effective portion of the face panel along a long axis direction, and a perspective view schematically showing the inner surface of the effective portion.

FIG. 9 is a diagram illustrating a thickness distribution of an effective portion of the face panel, a diagram illustrating a thickness difference of the effective portion, and a diagram illustrating a thickness difference of the effective portion.

FIG. 10 is a plan view showing a shadow mask in the color cathode ray tube.

FIG. 11 is a perspective view schematically showing a part of the shadow mask.

FIG. 12 is a diagram showing a movement amount of an electron beam spot caused by doming of a shadow mask in comparison between the color cathode ray tube and a conventional product.

FIG. 13 is a view showing a mask main body modified example of a shadow mask in comparison between the color cathode ray tube and a conventional product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Vacuum envelope 12 ... Face panel 14 ... Funnel 16 ... Effective part 20 ... Phosphor screen 22 ... Shadow mask 24 ... Electron gun 34 ... Mask main body 35 ... Mask frame

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masayo Inoue 1-9-2, Hara-cho, Fukaya-shi, Saitama F-term in Fukaya Plant, Toshiba Corporation (Reference) 5C032 AA02 BB02 BB06 BB08 BB09

Claims (16)

[Claims] 1. A substantially flat outer surface, an inner surface on which a phosphor screen is formed, a long axis and a short axis orthogonal to the tube axis and orthogonal to each other, and a pair of long sides substantially parallel to the long axis. And a pair of short sides substantially parallel to the short axis,
A vacuum envelope having a substantially rectangular face panel having: a shadow mask provided in the vacuum envelope facing the phosphor screen; and a shadow mask provided in the vacuum envelope. An electron gun for irradiating the phosphor screen with an electron beam through the shadow mask, wherein the thickness of the face panel is formed such that a peripheral portion is formed thicker than a central portion, and an inner surface of the face panel is formed. When the distance from the center of the face panel to the long axis end is L, the radius of curvature along the short axis direction on the long axis is farther from the center of the face panel to the long axis end side than L / 2. The thickness at the center of the face panel is Tc, the thickness at the diagonal effective diameter end is TD, and the thickness at the short axis effective diameter end is T
v, where the thickness at the effective end of the major axis is TH, the face panel satisfies the following relationship: TD <2.5Tc Tv <2.0Tc TH <2.0Tc. 2. In a region between a short axis and a short side of the face panel, a difference between a thickness on the long axis and a thickness on the long side in a cross section parallel to the short axis is at least the face. 2. The color cathode ray tube according to claim 1, wherein the color cathode ray tube has a maximum value at a position away from the center of the panel on the shorter side than L / 2. 3. An inner surface of the face panel has a minimum radius of curvature along a major axis direction on the major axis at a position farther from the center of the face panel than L / 2 toward the major axis end. The color cathode ray tube according to claim 1, wherein 4. The phosphor screen has a phosphor layer and a black non-light-emitting layer, and the ratio of the black non-light-emitting layer per unit area at least near a diagonal axis end of the face panel is equal to or less than that of the face panel. The color cathode ray tube according to any one of claims 1 to 3, wherein a ratio of the black non-light-emitting layer per unit area in the central portion is equal to or smaller than the ratio. 5. The color cathode ray tube according to claim 1, wherein a transmittance at a central portion of the face panel is 60% or less. 6. A substantially rectangular mask body facing the phosphor screen and having a large number of electron beam passage holes, and a substantially rectangular mask body supporting a peripheral portion of the mask body. A mask frame, wherein ZD represents a drop amount at a diagonal axis end of the mask body along the tube axis direction with respect to a height of a central portion of the mask body, a drop amount Zv at a short axis end, and a drop at a long axis end. When the amount is ZH, the mask body satisfies the following relationship: Zv <0.8ZD ZH <0.8ZD, and the radius of curvature along the short axis direction on the long axis is longer than the center of the mask body from the center of the mask body. The distance from the center of the mask body to d /
The radius of curvature along the long axis direction on the long axis has a minimum value at a position farther to the long axis end side than 2, and the radius of curvature along the long axis direction on the long axis is farther to the long axis end side than d / 2 from the center of the mask body. 6. The method according to claim 1, wherein the position has a minimum value.
Item 7. A color cathode ray tube according to item 1. 7. A radius of curvature of the mask body along a direction parallel to the short axis is from the long axis to the long side in a region from the center of the mask body to d / 2 toward the long axis end. 7. The color cathode ray tube according to claim 6, wherein the color cathode ray tube is set so as to decrease toward. 8. A color cathode ray tube according to claim 1, a driving circuit for driving an electron gun of the color cathode ray tube, and a housing accommodating the color cathode ray tube and the driving circuit. A color picture tube device comprising: 9. A substantially flat outer surface, an inner surface on which the phosphor screen is formed, a major axis and a minor axis orthogonal to the tube axis and orthogonal to each other, and a pair of major sides substantially parallel to the major axis. And a pair of short sides substantially parallel to the short axis,
A vacuum envelope having a substantially rectangular face panel having: a shadow mask provided in the vacuum envelope facing the phosphor screen; and a shadow mask provided in the vacuum envelope. An electron gun for irradiating the phosphor screen with an electron beam through the shadow mask, wherein the thickness of the face panel is formed such that a peripheral portion is formed thicker than a central portion, and an inner surface of the face panel is formed. When the distance from the center of the face panel to the long-axis end is L, the radius of curvature along the long-axis direction on the long axis is a position farther from the center of the face panel to the long-axis end side than L / 2. The thickness at the center of the face panel is Tc, the thickness at the diagonal effective diameter end is TD, and the thickness at the short axis effective diameter end is T
v, where the thickness at the effective end of the major axis is TH, the face panel satisfies the following relationship: TD <2.5Tc Tv <2.0Tc TH <2.0Tc. 10. A difference between a thickness on the long axis and a thickness on the long side in a section parallel to the short axis in a region between the short axis and the short side of the face panel. 10. The color cathode ray tube according to claim 9, wherein the color cathode ray tube has a maximum value at a position further away from L / 2 on the short side than L / 2. 11. A radius of curvature of the inner surface of the face panel along a direction parallel to the short axis is at least from the center of the face panel to L / 2 toward the end of the long axis from the long axis. 10. The color cathode ray tube according to claim 9, wherein the color cathode ray tube is set to decrease toward the side. 12. The phosphor screen has a phosphor layer and a black non-light-emitting layer, and a ratio of the black non-light-emitting layer per unit area at least near a diagonal axis end of the face panel is equal to or less than that of the face panel. The color cathode ray tube according to any one of claims 9 to 11, wherein a ratio of the black non-light-emitting layer per unit area in the central portion is equal to or smaller than the ratio. 13. The method according to claim 9, wherein a transmittance at a central portion of the face panel is 60% or less.
3. The color cathode ray tube according to any one of 2. 14. The shadow mask, which is opposed to the phosphor screen and has a substantially rectangular mask body having a number of electron beam passage holes, and a substantially rectangular mask body which supports a peripheral portion of the mask body. A mask frame, wherein ZD represents a drop amount at a diagonal axis end of the mask body along the tube axis direction with respect to a height of a central portion of the mask body, a drop amount Zv at a short axis end, and a drop at a long axis end. When the amount is ZH, the mask body satisfies the following relationship: Zv <0.8ZD ZH <0.8ZD, and the radius of curvature along the short axis direction on the long axis is longer than the center of the mask body from the center of the mask body. The distance from the center of the mask body to d /
The radius of curvature along the long axis direction on the long axis has a minimum value at a position farther to the long axis end side than 2, and the radius of curvature along the long axis direction on the long axis is farther to the long axis end side than d / 2 from the center of the mask body. The color cathode ray tube according to any one of claims 9 to 13, wherein the color cathode ray tube has a minimum value at a position. 15. A radius of curvature of the mask main body along a direction parallel to the short axis is from the long axis to the long side in a region from the center of the mask main body to d / 2 toward the long axis end. 15. The color cathode ray tube according to claim 14, wherein the color cathode ray tube is set to decrease toward. 16. A color cathode ray tube according to claim 9, a driving circuit for driving an electron gun of the color cathode ray tube, and a housing accommodating the color cathode ray tube and the driving circuit. A color picture tube device comprising: