JP2002025457A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color cathode-ray tube that prevents generation of wrinkles at the skirt of the shadow mask and curved face errors of the shadow mask, and which is improved in display properties. SOLUTION: The shadow mask which faces the fluorescent is formed by press forming and formed in a gently sloping dome and comprises a mask effective portion 20 and a skirt portion 18, which extends from the periphery in the direction which nearly crosses the mask portion at right angles. In the skirt portion, plural notches 25, which respectively extend from the extended edge in the direction which crosses the mask effective portion at right angles and plural through-holes 24, which respectively extend in the direction which crosses the mask effective portion at right angles, are formed. The notches and the through holes are provided, shifted mutually in the direction which crosses the periphery of the mask effective portion at right angles and are provided with at least a part of it being mutually overlapped with a gap made in a direction parallel with the periphery of the mask effective portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color cathode ray tube having a press-molded shadow mask.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube is made of a glass panel having a substantially rectangular effective portion, a glass funnel connected to the panel, and a cylindrical glass connected to a small diameter portion of the funnel. A vacuum envelope comprising a neck is provided. On the inner surface of the effective part of the panel, a three-color phosphor layer in the form of dots or stripes emitting blue, green, and red light,
A phosphor screen including a black light-shielding layer is formed, and a shadow mask having a large number of electron beam passage holes is arranged in the vacuum envelope so as to face the phosphor screen. In addition, an electron gun that emits three electron beams is arranged in the neck,
A deflection yoke is mounted from the outer periphery of the neck to the outer peripheral surface of the funnel.

In the color cathode ray tube having the above structure, the three electron beams emitted from the electron gun are deflected in the horizontal and vertical directions by a horizontal and vertical deflection magnetic field generated by a deflection yoke, and the phosphor screen is irradiated with a high frequency through a shadow mask. And a vertical scan at a low frequency to display a color image.

[0004] There are two types of shadow masks: one is a press-molding type and the other is a type that applies tension. When forming a shadow mask by press molding, first, a flat mask base material is placed on a knockout and a die of a press molding machine. Then, the mask base is fixed by sandwiching the fixing part located at the peripheral part of the mask base by the blank holder and the die. Subsequently, after the mask base material is extended to a predetermined curved surface by a punch, the blank holder and the die are separated to open the peripheral part of the mask base material.

Next, the knockout and the punch are moved downward, and the peripheral portion of the mask substrate is drawn into the space between the punch and the die to be bent substantially at a right angle to form a skirt portion. Thereafter, all the molds are returned to the original state, and the formed shadow mask is taken out.

The shadow mask press-molded as described above is formed into a predetermined curved surface having a gentle dome shape and has a substantially rectangular effective portion having a large number of electron beam passage holes. A skirt portion extending perpendicularly to the electron gun side from the periphery of the effective portion. Further, a bead-shaped fixing portion is formed over the entire circumference of the skirt portion.

[0007] Such a shadow mask is fixed to a mask frame via a skirt portion, and the mask frame is removably supported by a stud pin projecting from a panel via an elastic support. . Since the press-molded shadow mask maintains a predetermined shape by itself, a simple and lightweight mask frame can be used,
The color cathode ray tube can be configured at low cost as compared with a tension applying type shadow mask that requires high accuracy and strength for the mask frame.

[0008]

However, in the case of a shadow mask obtained by press molding, since the effective portion is formed into a gentle dome shape, the boundary between the effective portion and the skirt portion is formed in an arc shape, and the skirt portion is formed. Also has an arcuate edge, and its length is shorter than before press molding. As a result, as the skirt portion approaches the extended end, a large surplus occurs during press molding, and wrinkles are generated in the skirt portion.

This wrinkle can be reduced to some extent by providing a notch extending from the extended edge of the skirt portion, that is, a notch, but the notch must be deepened to completely eliminate the wrinkle. .

However, when the notch is deepened, the skirt portion is cut off by the notch, and the force of maintaining the shape of the shadow mask is extremely reduced, so that the shadow mask is easily deformed at the time of conveyance or assembly with the mask frame. In addition, when handling the mask base material before press molding, wrinkles easily grow from the notch into the mask effective part, and the fixed part at the time of press molding is cut off by the notch, and the fixed part slides partially and the shadow mask is removed. Problems such as the inability to mold into a predetermined curved surface are likely to occur. Therefore, conventionally,
It was difficult to make the notch deeper than the fixed part.

When the depth of the notch is limited to the fixed portion, not only the wrinkles of the skirt portion increase, but also the area between the fixed portion and the effective portion of the skirt portion where the notch does not exist is caused by excess thickness. Compressive stress remains. Then, at the skirt corner where no resistance against the compressive stress is generated, a force is generated which acts in the direction of expanding the skirt. This force acts to push the arc-shaped skirt straight back, so that each corner of the boundary line between the effective portion and the skirt is directed upward (toward the phosphor screen), and the vicinity of the center of each side is directed downward (electron). (In the direction of the gun) and acts on the effective portion.

Since the corner portion of the effective mask portion is a region where the long side and the short side of the skirt portion intersect, the rigidity is high with respect to the above-described upward force, and displacement of the effective mask portion hardly occurs. However, in the central region of each side of the mask effective portion, the rigidity is low with respect to the above-described downward force, and a downward displacement occurs at the central portion. Therefore, the curved surface of the shadow mask is displaced from the designed curved surface, causing a landing deviation or the like of the electron beam, which causes deterioration of color purity and the like.

JP-A-1-169847 and JP-A-9
JP-A-35657 discloses a configuration in which a plurality of round holes for absorbing stress are formed in a skirt portion. However, in the case of these techniques, the round hole is unlikely to be plastically deformed by the compressive stress generated in the skirt portion, and since there is a region where the round hole is not formed, the occurrence of wrinkles is sufficiently eliminated. In addition, it is difficult to obtain a sufficient effect of improving a curved surface error in the vicinity of the center of each side of the mask.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to prevent the occurrence of wrinkles in a skirt portion of a shadow mask, reduce a curved surface error of the shadow mask, and improve the display characteristics of a color cathode ray. To provide tubes.

[0015]

To achieve the above object, a color cathode ray tube according to the present invention comprises: a panel having a phosphor screen having a plurality of phosphors provided on an inner surface thereof;
An electron gun arranged to face the phosphor screen and emitting an electron beam toward the phosphor screen; and an electron gun arranged to face the phosphor screen and irradiate the corresponding phosphor with the electron beam. A shadow mask having an electron beam passage hole, wherein the shadow mask is formed by press molding, is formed into a gentle dome shape, and has a substantially rectangular mask effective portion having the electron beam passage hole. A skirt portion extending from a peripheral edge of the mask effective portion in a direction substantially perpendicular to the peripheral edge, and the skirt portion is substantially perpendicular to a peripheral edge of the mask effective portion from an extended edge of the skirt portion. A plurality of cuts extending in a direction substantially perpendicular to a peripheral edge of the mask effective portion are formed. And the through-holes are provided to be shifted from each other in a direction substantially perpendicular to the periphery of the mask effective portion, and are arranged with a gap along a direction parallel to the periphery of the mask effective portion, and the cut and at least At least some of the through holes are provided so as to overlap in a direction parallel to the peripheral edge of the mask effective portion.

According to the color cathode ray tube configured as described above, a plurality of through-holes and cuts are provided in the skirt portion of the shadow mask so as to overlap along the longitudinal direction of the skirt portion, and the skirt portion is substantially formed. By easily causing plastic deformation with respect to the longitudinal compressive stress over the entire area, wrinkles of the skirt portion and generation of compressive stress can be prevented without impairing the strength of the shadow mask, and at the same time, forming accuracy of the mask curved surface is improved. Thus, the display characteristics can be improved without deteriorating the color purity or the like.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color cathode ray tube according to an embodiment of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the color cathode ray tube device includes a vacuum envelope 10, which has a substantially rectangular panel 1 having a skirt portion 2 on its periphery and a flat outer surface, and a panel skirt. And a cylindrical neck 3 connected to the small diameter portion of the funnel.

On the inner surface of the panel 1, there are formed a plurality of phosphors respectively emitting red, green and blue light, and a phosphor screen 6 comprising a light shielding layer. A deflection yoke 7 having horizontal and vertical deflection coils is mounted on the outer periphery from the neck 3 to the funnel 4. In the neck 3, a center beam 8G and a pair of side beams 8 passing on the same horizontal plane are directed toward the phosphor of the phosphor screen 6.
An electron gun 9 that emits three electron beams in a row composed of R and 8B is arranged.

In the vacuum envelope 10, a shadow mask 12 is provided so as to face the phosphor screen 6, and is attached to a rectangular mask frame 14. As will be described later, the shadow mask 12 has a mask effective portion in which a large number of electron beam passage holes for color identification are formed, extends from the periphery of the mask effective portion, and has the mask frame 1.
And a skirt portion fixed to the base member 4, and is formed by press molding. Then, the shadow mask 12 is provided with a stud pin 17 projecting from the inner surface of the skirt portion 2 of the panel 1 with the elastic support 15 fixed to the mask frame 14.
By being engaged with the panel, it is detachably supported on the panel.

The vacuum envelope 10 including the panel 1 is
A tube axis Z extending through the center of the panel and the electron gun 9, a long axis (horizontal axis) X extending perpendicular to the tube axis, a short axis (vertical axis) Y extending perpendicular to the tube axis and the long axis, have.

In the color cathode ray tube having the above structure, the three electron beams 8B and 8 emitted from the electron gun 9 are used.
G and 8R are deflected by a deflection yoke 7 mounted outside the funnel 4, and the phosphor screen 6 is horizontally and vertically scanned through an electron beam passage hole of a shadow mask 12, thereby displaying a color image.

As shown in FIG. 2, the shadow mask 12 is formed by press molding, and has a substantially rectangular mask effective portion 20 formed in a gentle dome shape, and a mask effective portion extending over the entire circumference of the mask effective portion. And a skirt portion 18 extending substantially perpendicularly to the mask effective portion from the peripheral edge 21 of the portion. A large number of electron beam passage holes 19 each extending in the vertical axis Y direction are formed in the mask effective portion 20 at a predetermined arrangement pitch. The boundary between the effective mask portion 20 and the skirt portion 18, that is, each side of the peripheral edge 21 of the effective mask portion has a substantially arc shape convex toward the phosphor screen side. The extension edge of 18 also has an arc shape.

The skirt portion 18 has a fixed portion 22 which is pressed during press forming.
Are formed substantially in parallel with the peripheral edge 21 of the lens and over the entire circumference. Then, the skirt portion 18 of the shadow mask 12
Has a number of notches and through holes, which will be described in detail below.

As shown in FIGS. 3 and 4, a plate-shaped mask substrate 5 before press-forming to form a shadow mask
Reference numeral 0 has a rectangular mask effective portion 20 and a skirt portion 18 located around the mask effective portion 20. An electron beam passage hole 19 is formed in the mask effective portion in advance. Then, at the time of press molding, the mask effective portion 20 is formed into a gentle dome shape, and the skirt portion 18 is formed around the peripheral edge 21 of the mask effective portion 20.
Is bent almost at right angles.

A large number of notches 25 and a large number of through holes 24 are formed almost all over the skirt portion 18. The notch 25 has an elongated rectangular shape, extends from the extending edge of the skirt portion 18 in a direction orthogonal to the peripheral edge 21 of the mask effective portion 20, and has a depth ranging from the fixing portion 22 of the skirt portion 18. Is set. The notches 25 are arranged with a predetermined gap along a direction parallel to the peripheral edge 21 of the mask effective portion 20.

Each of the plurality of through holes 24 is formed in an elongated slit shape extending in a direction perpendicular to the peripheral edge 21 of the mask effective portion 20. Of these through holes 24, the through holes 24 located adjacent to the notch 25 and over the fixing portion 22 are provided.
Are alternately arranged with the notches 25 along the longitudinal direction of the skirt portion 18, that is, along the direction parallel to the peripheral edge 21 of the mask effective portion. At the same time, the notch 25 and the through hole 24 adjacent to each other are provided so as to be shifted from each other in a direction orthogonal to the peripheral edge 21 of the mask effective portion 20, and at least a part thereof has a predetermined gap Are placed on top of each other.

According to the present embodiment, in the skirt portion 18, the peripheral edge 21 of the mask effective portion 20 and the fixed portion 2
A large number of through holes 24 are also formed in a region between the peripheral edge 21 and the peripheral edge 21.
They are arranged at a predetermined gap along a direction parallel to 1. Furthermore, the through holes 24 adjacent in the direction parallel to the peripheral edge 21
Are provided so as to be shifted from each other in a direction orthogonal to the peripheral edge 21, and at least partially overlap with each other with a predetermined gap in a direction parallel to the peripheral edge 21.

The through hole 24 and the notch 25 are arranged in a direction substantially perpendicular to the peripheral edge 21 of the mask effective portion 20 so that the skirt portion can be easily plastically deformed by a force acting in the longitudinal direction of the skirt portion 18. It is desirable to have an elongated elongated shape. Preferably, the length L1 of the through hole 24 along a direction orthogonal to the longitudinal direction of the skirt portion 18
The length L2 of the notch 25 is preferably 4 mm or more. Also, the through-hole 2 along the longitudinal direction of the skirt portion 18
The width W1 and W2 of the notch 4 and the notch 25 are preferably set to 0.2 mm or more in consideration of the amount of plastic deformation of the skirt. Of course, since the amount of plastic deformation is greater at the extension end side of the skirt portion, the through hole 24 and the notch 25 may be formed in a wedge shape with a large width at the extension end side of the skirt portion.

Further, it is desirable that the distance D1 between the adjacent through holes 24 and the notches 25 along the longitudinal direction of the skirt portion 18 and the distance D2 between the adjacent through holes are set to 3 mm or less. When the distances D1 and D2 are 3 mm or less, the portion between the adjacent through-holes 24 and the notch 25 or the portion sandwiched between the adjacent through-holes 24 becomes thin, and the force acting in the longitudinal direction of the skirt portion 18 is reduced. On the other hand, plastic deformation becomes easy.

Also, when the radius of curvature of the end of the through hole 24 or the notch 25 is set to 1 mm or less, stress concentrates on this end and the skirt is easily plastically deformed.

In a portion where the through hole 24 and the notch 25 adjacent to each other in the longitudinal direction of the skirt portion 18 overlap in the longitudinal direction, the overlapping width V1 in the direction orthogonal to the longitudinal direction is provided.
The overlap width V2 between two through holes 24 adjacent in the longitudinal direction is preferably formed to be 2 mm or more.

In the first embodiment shown in FIG.
The pitch of the notch 25 along the longitudinal direction of the skirt 18 is set to 6 mm. The length L1 of the through hole 24 and the length L2 of the notch 25 are such that the through hole is formed at 5 mm and the notch is formed at 6 mm, respectively.
The widths W1 and W2 of 5 are each formed to 1 mm. Further, a distance D1 between the adjacent through holes 24 and the notch 25 along the longitudinal direction, and a distance D2 between the adjacent through holes.
Is set to 2 mm. The distance d1 between the through holes 24 and the notch 25 arranged in a direction orthogonal to the peripheral edge 21 of the mask effective portion 20 and the distance d2 between the adjacent through holes 24 are 1
mm. Further, the through hole 24 and the notch 25
And the overlap width V2 of the two through holes 24 adjacent in the longitudinal direction are set to 2 mm.

According to the shadow mask 12 press-formed by using the mask base material 50 having the above-described structure, as shown in FIG. 5, the skirt portion 18 in which the through holes 24 and the notches 25 are arranged differently from each other is provided. When a force F along the longitudinal direction is applied, the skirt can easily absorb the force P by plastically deforming at the portion of the through hole and the notch. As a result, excess stress in the skirt portion generated when the shadow mask is press-molded is absorbed by plastic deformation of the skirt portion, causing wrinkles in the skirt portion and a curved surface near the center of each side of the mask effective portion 20. The occurrence of an error can be almost completely prevented.

Since the through hole 24 and the notch 25 are formed independently with a gap therebetween, the skirt portion 18 has continuity between the through holes 24. Thereby, it is possible to reduce problems such as a decrease in the shape maintaining force of the shadow mask 20, generation of folds and wrinkles at the time of handling the mask base material before press molding, and slippage of the fixing portion 22 at the time of press molding. .

Accordingly, wrinkling of the skirt portion 18 and generation of compressive stress can be prevented without impairing the strength of the shadow mask 20, and at the same time, the molding accuracy of the curved surface of the mask can be improved, and deterioration in color purity and the like can be prevented. A color cathode ray tube having excellent characteristics can be obtained.

In the first embodiment described above, the through-hole 24 is provided up to the vicinity of the peripheral edge 21 of the mask effective portion 20, but wrinkles and excessive stress are hardly generated in the vicinity of the peripheral edge. A portion of the through hole may be omitted, and the distance between the peripheral edge 21 and the through hole closest to the peripheral edge 21 may be set to 2 to 7 mm, preferably 3 mm or more. Similarly, it is preferable that the distance between the through hole closest to the extending end edge of the skirt portion 18 and the extending end portion is set to 3 mm or more.

The shape of the through hole 24 is not limited to a linear slit shape, but may be any shape capable of absorbing excess stress. For example, a cross shape, a diamond shape, and the like as shown in FIG. Alternatively, the shape may be the wedge shape described above. However, in consideration of friction and catch acting on the skirt portion 18 during press molding, it is desirable that the width of the through hole and the notch along the longitudinal direction of the skirt portion be small.

Next, a shadow mask used in a color cathode ray tube according to a second embodiment of the present invention will be described. In the first embodiment described above, the number of through holes and notches provided is large, the strength of the skirt portion 18 after press molding is slightly weak, and there is a possibility that the shape maintaining force of the shadow mask is slightly reduced. Therefore, according to the second embodiment,
The number of the through holes 24 and the notches 25 is significantly reduced.

As shown in FIG. 7, in the mask base material 50 before the shadow mask 20 is formed by press molding,
The skirt portion 18 is provided with a plurality of stress absorbing portions 27 each formed by combining one notch 25 and three through holes 24, separated from each other in the longitudinal direction of the skirt portion.

In each stress absorbing portion 27, one through hole 24 is formed with respect to notch 25 so as to surround peripheral edge 2 of mask effective portion 20.
They are provided side by side in a direction orthogonal to 1. The other two through holes are provided on both sides of the notch with respect to the longitudinal direction of the skirt portion 18, respectively, and are shifted from the notch and the one through hole in a direction orthogonal to the peripheral edge 21. The portions are provided so as to overlap in the longitudinal direction of the skirt portion 18.

In each of the stress absorbing portions 27, the length L1 of the through hole 24 along the direction perpendicular to the peripheral edge 21 is 8
mm, and the length L2 of the notch 25 is 6 mm. The widths W1 and W2 of the through hole 24 and the notch 25 along the longitudinal direction of the skirt 18 are each formed to 1 mm. Also, the through holes 24 adjacent along the longitudinal direction
The distance D1 between the notch 25 and the notch 25 and the distance D2 between the adjacent through-holes are set to 2 mm, and the distance d1 between the notch 25 and the through-holes 24 arranged in a direction orthogonal to the peripheral edge 21 is 2 mm.
Is set to Further, an overlap width V1 of the through hole 24 and the notch 25 along a direction orthogonal to the peripheral edge 21 and an overlap width V2 of two through holes 24 adjacent in the longitudinal direction.
Are set to 3 mm, respectively.

The stress absorbing portions 27 are rough at the center of each side of the skirt portion, and are provided with a higher density in a region closer to the corner portion of the skirt portion 18. This is because, in press molding, the area closer to the corner of the skirt 18 has more excess. The formation density of the stress absorbing portions 27 may be an appropriate distribution for each shadow mask according to the curved shape of the peripheral edge 21 of the mask effective portion 20.

According to the shadow mask of the second embodiment, it is possible to improve the strength of the skirt portion while eliminating the occurrence of wrinkles in the skirt portion 18 and the curved surface error near the center of the side. Was.

Next, a shadow mask used in a color cathode ray tube according to a third embodiment of the present invention will be described. In the above-described second embodiment, since the strength of the skirt portion 18 is locally reduced at the stress absorbing portion 27 by providing the stress absorbing portion 27, when the shadow mask is incorporated into the mask frame, the stress absorbing portion 27 is provided. The shadow mask may be bent and deformed in the vicinity of. Therefore, according to the third embodiment, the through holes 24 and the notches 25 are arranged discretely in the longitudinal direction of the skirt portion 18.

That is, as shown in FIG. 8, the mask substrate 50 before press-forming the shadow mask 20 is formed.
In the skirt portion 18, a plurality of through holes 24 and a plurality of notches 25 are formed. Skirt 18
The distance D1 between the adjacent through-holes 24 and the notch along the longitudinal direction and the distance D2 between the two adjacent through-holes 24 are:
The length is set to 4 mm or more, and is set to be narrower from the center of each side to the corner of the skirt.

The length L1 of the through hole 24 along the direction perpendicular to the peripheral edge 21 of the mask effective portion 20 is 8 mm, and the notch 25
Is formed to have a length L2 of 6 mm, and the widths W1 and W2 of the through holes 24 and the notches 25 along the longitudinal direction of the skirt portion 18.
2 are each formed to 1 mm. In addition, peripheral edge 2
The overlap width V1 of the through hole 24 and the notch 25 along the direction orthogonal to the direction 1 and the overlap width V2 of two through holes 24 adjacent in the longitudinal direction are each set to 3 mm.

According to the shadow mask of the third embodiment described above, the strength of the skirt portion is further improved while eliminating the occurrence of wrinkles in the skirt portion 18 and the curved surface error in the vicinity of the center of each side. Was completed.

Next, a shadow mask used in a color cathode ray tube according to a fourth embodiment of the present invention will be described. In the second embodiment, the strength of the skirt portion 18 is reduced by providing the stress absorbing portion 27, and the third
In the embodiment, the absorption effect of the excess thickness is slightly reduced by separating the through hole and the notch. Therefore, according to the fourth embodiment, as shown in FIG. 9, the through holes 24 and the notches 25 are formed in pairs in the mask base 50 before the shadow mask 20 is formed by press molding. The first pair 28 and the second pair 2 having two through holes 24 as a set.
9 are arranged alternately along the longitudinal direction of the skirt 18 and discretely from each other. The arrangement density of the first and second pairs 28 and 29 is set higher in a region that is rougher at the center of each side of the skirt portion 18 and closer to a corner portion of the skirt portion 18.

The length L1 of the through hole 24 along the direction perpendicular to the peripheral edge 21 of the mask effective portion 20 is 8 mm, and the notch 25
Is formed to have a length L2 of 6 mm, and the widths W1 and W2 of the through holes 24 and the notches 25 along the longitudinal direction of the skirt portion 18.
2 are each formed to 1 mm. Each first pair 2
8, the distance D1 between the through hole 24 and the notch 25 along the longitudinal direction of the skirt 18 is set to 2 mm, and in each second pair 29, the distance between the through holes 24 along the longitudinal direction of the skirt 18 D2 is set to 2 mm. Further, a through hole 24 along a direction orthogonal to the peripheral edge 21 is provided.
Width V1 between the notch 25 and the notch 25, and the overlap width V2 between two through holes 24 adjacent in the longitudinal direction are each 3 m.
m.

According to the shadow mask of the fourth embodiment, the distance between the through hole 24 and the notch 25 and the distance between the two through holes in the first and second pairs 28 and 29 are reduced. The generation of wrinkles in the skirt portion 18 and the curved surface error in the vicinity of the central portion of each side are eliminated in the same manner as in the first and second embodiments, and the strength of the skirt portion is improved in the same manner as in the third embodiment. We were able to.

In the above-described embodiment, each pair is constituted by two through holes, or through holes and notches, but may be constituted by three or more through holes, or through holes and notches.

Next, a shadow mask used in a color cathode ray tube according to a fifth embodiment of the present invention will be described. As shown in FIG. 10, according to the present embodiment, the mask base material 50 before forming the shadow mask 20 by press molding is provided on the skirt portion 18 as in the above-described second embodiment. A plurality of stress absorbing portions 27 provided at the center of each side of the skirt portion.
It has been modified to increase the distance between

That is, when the shadow mask 20 is incorporated into a mask frame, deformation due to friction or snagging is likely to occur. This deformation is likely to occur at the center of each side of the skirt portion 18 due to work, and therefore, as in the fifth embodiment, the through holes 24 of the stress absorbing portions 27 provided at the center of each side as in the fifth embodiment.
Is shortened and the distance from the peripheral edge 21 of the mask effective portion 20 is increased, so that the skirt portion near the through hole can be less likely to be bent. In general, since the excess stress generated near the center of each side of the skirt portion is small, even when the distance between the through hole 24 and the peripheral edge 21 of the mask effective portion 20 is increased at the center of each side as described above, It is possible to prevent wrinkles and curved surface errors from occurring in the skirt.

According to the shadow mask of the color cathode ray tube according to the sixth embodiment of the present invention shown in FIG. 11, the number of through holes 24 is further reduced from that of the fifth embodiment, and In the side, one stress absorbing portion 27 is provided only in the vicinity of both ends thereof, and the other portions are notches 2.
Only 5 are provided.

According to such a configuration, when the shadow mask is incorporated into the mask frame, it is possible to reduce the breakage of the skirt near the through-hole and to absorb the stress on both ends of each side where excess stress is likely to occur. By leaving the portion 27, it is possible to prevent wrinkles and curved surface errors from occurring in the skirt portion.

In the second and third embodiments described above, as shown in FIG.
1 in the through hole 24 provided adjacent to the
The end 24a on the side may be formed in a circular shape having a diameter larger than the width W1 of the through hole. In this case, the concentration of the stress can be reduced by the end portion 24a, and the bending deformation of the skirt portion can be reduced.

In the above-described second to sixth embodiments, the other structure of the color cathode ray tube is the same as that of the first embodiment, and a detailed description thereof will be omitted. Also,
The present invention is not limited to the above-described embodiment,
Various modifications can be made within the scope of the present invention. For example, as for the number of the through holes and the notches in the skirt portion of the shadow mask, the installation density, and the shape, the size of the color cathode ray tube can be variously selected depending on the kind and the like as long as the above-mentioned conditions are satisfied.

[0058]

As described in detail above, according to the present invention, a plurality of through holes and cuts are provided in the skirt portion of the shadow mask so as to overlap along the longitudinal direction of the skirt portion, and By giving elasticity to the compressive stress in the longitudinal direction over almost the entire area, the generation of wrinkles in the skirt portion is prevented without impairing the strength of the shadow mask, the molding accuracy of the mask curved surface is improved, and the display characteristics are improved. A color cathode ray tube device can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a color cathode ray tube according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a shadow mask and a mask frame in the color cathode ray tube.

FIG. 3 is a plan view showing a mask base material used for press-molding the shadow mask, and an enlarged plan view showing a skirt portion.

FIG. 4 is an enlarged plan view showing a through hole and a notch provided in the skirt.

FIG. 5 is a plan view corresponding to FIG. 4, schematically showing a state in which the skirt is plastically deformed by excess stress when the shadow mask is press-molded.

FIG. 6 is a view schematically showing a modification of a through hole formed in the skirt.

FIG. 7 is a plan view showing a mask base material of a shadow mask used for a color cathode ray tube according to a second embodiment of the present invention.

FIG. 8 is a plan view showing a mask base material of a shadow mask used for a color cathode ray tube according to a third embodiment of the present invention.

FIG. 9 is a plan view showing a mask base material of a shadow mask used for a color cathode ray tube according to a fourth embodiment of the present invention.

FIG. 10 is a plan view showing a mask base material of a shadow mask used for a color cathode ray tube according to a fifth embodiment of the present invention.

FIG. 11 is a plan view showing a mask base material of a shadow mask used for a color cathode ray tube according to a sixth embodiment of the present invention.

FIG. 12 is a view schematically showing another modified example of the through hole formed in the skirt portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 3 ... Neck 4 ... Funnel 6 ... Phosphor screen 9 ... Electron gun 10 ... Vacuum envelope 12 ... Shadow mask 18 ... Skirt part 19 ... Electron beam passage hole 20 ... Mask effective part 21 ... Peripheral edge 22 ... Fixed part Reference numeral 24: Through hole 25: Notch 27: Stress absorbing part 28: First pair 29: Second pair 50: Mask base material

Claims (13)

[Claims] 1. A panel having a phosphor screen having a plurality of phosphors provided on an inner surface thereof; an electron gun arranged to face the phosphor screen and emitting an electron beam toward the phosphor screen; A shadow mask which is disposed opposite to the phosphor screen and has an electron beam passage hole for irradiating the corresponding phosphor with the electron beam, wherein the shadow mask is formed by press molding, and has a smooth dome. A substantially rectangular mask effective portion having the electron beam passage hole formed in a shape, and a skirt portion extending from a peripheral edge of the mask effective portion in a direction substantially orthogonal to the peripheral edge, The skirt has a plurality of cuts extending from the extended edge of the skirt in a direction substantially perpendicular to the periphery of the effective mask portion. A plurality of through holes extending in a direction substantially perpendicular to the periphery of the mask effective portion are formed, and the cuts and the through holes are provided so as to be shifted from each other in a direction substantially perpendicular to the periphery of the mask effective portion. Arranged with a gap along a direction parallel to the peripheral edge of the mask effective portion, the cut and at least a part of the through-hole,
A color cathode ray tube wherein at least a part thereof is provided so as to overlap in a direction parallel to a peripheral edge of the mask effective portion. 2. The skirt portion has a fixing portion extending substantially in parallel with a peripheral edge of the effective mask portion and having a fixing portion which is pressed during press forming of the shadow mask. 2. The fixing device according to claim 1, wherein the fixing portion is formed at a depth within a range from the edge to the fixing portion.
The color cathode ray tube as described. 3. The color cathode ray according to claim 2, wherein the through hole includes a through hole provided in a region between a fixing portion of the skirt portion and a peripheral edge of the mask effective portion. tube. 4. The apparatus according to claim 1, wherein said through hole includes a through hole provided alongside said notch along a direction substantially orthogonal to a peripheral edge of said mask effective portion. 2. A color cathode ray tube according to claim 1. 5. A distance between the through hole and a peripheral edge of the mask effective portion and a distance between the through hole and an extended edge of the skirt portion are set to 3 mm or more. A color cathode ray tube according to any one of claims 1 to 4. 6. The through-hole includes a through-hole that is disposed closer to the cut by a distance of 3 mm or less in a direction parallel to a peripheral edge of the mask effective portion. A color cathode ray tube according to any one of claims 1 to 5. 7. The through-hole according to claim 1, wherein the through-hole includes a through-hole arranged close to the other through-hole in a direction parallel to the peripheral edge of the mask effective portion to be 3 mm or less. The color cathode ray tube according to any one of claims 1 to 6, wherein 8. The apparatus according to claim 1, wherein each of said through holes is formed to have a length of at least 4 mm in a direction substantially orthogonal to a peripheral edge of said mask effective portion. Color cathode ray tube. 9. The method according to claim 1, wherein an overlap width of the notch and the through hole adjacent in a direction parallel to a peripheral edge of the mask effective portion is formed to be 2 mm or more. The color cathode ray tube as described. 10. The apparatus according to claim 1, wherein a width of each of said through holes along a direction substantially parallel to a peripheral edge of said effective mask portion is 1 mm or less. Color cathode ray tube. 11. The skirt portion according to claim 11, wherein the number of the through-holes provided in the skirt portion is larger at a corner portion of the skirt portion than at a central portion of each side of the skirt portion. Item 11. A color cathode ray tube according to any one of items 1 to 10. 12. The through-hole according to claim 1, wherein the end portion on the mask effective portion side includes a through-hole having a locally large diameter. Item 2. A color cathode ray tube according to item 1. 13. The space between the through hole and the periphery of the mask effective portion is set to be larger at the center of each side of the skirt than at the corner of the skirt. The color cathode ray tube according to claim 1.