JP2001110330A - Shadow mask structure and color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove an inexpendience that, when pressing forces are applied on two mutually facing sides of a mask frame to give a tension necessary for mounting on a shadow mask, corner portions where stress of the pressing force concentrates causes plastic distortion and does not return to the original shape after the pressing force is removed. SOLUTION: This mask structure is characterized in that corners of the mask frame 101 is reinforced with reinforcing plates 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a color cathode ray tube,
In particular, it relates to the structure of a shadow mask structure of a color CRT.

[0002]

2. Description of the Related Art A panel surface is a flat tube or a part of a cylindrical surface having a very large radius of curvature (approximately equal to a flat surface) or a part of a spherical surface having a very large radius of curvature (visually a flat surface). Color cathode-ray tubes). In a flat tube, since the surface of the panel is flat or quasi-plane, the shadow mask also needs to have a flat or quasi-plane shape. Here, an example of a conventional shadow mask structure used for a flat tube will be described with reference to FIG.

FIG. 5 is a perspective view, XX 'sectional view and YY' sectional view showing an example of a conventional shadow mask structure.
, Reference numeral 500 denotes a shadow mask structure, 501 denotes a mask frame, and 502 denotes a shadow mask (mask frame 5).
01 only shows the outer periphery to make it easier to see the internal structure).

In the shadow mask structure 500, a shadow mask 502 is stretched on a mask frame 501 as follows. A horizontal pressing force F is previously applied to two opposite sides 501A and 501B of the mask frame 501.
Is applied, the sides 501A and 501B are elastically deformed, and in this state, two sides of the shadow mask 502 are
A, Weld to the upper end surface of side 501B. After the welding, side 5
When the pressing force F applied to 01A and the side 501B is removed, the sides 501A and 501B return to their original shapes, whereby the tension required for stretching the shadow mask 502 is applied to the shadow mask 502.

[0005]

As described above, when a pressing force F is applied to two opposing sides 501A and 501B of the mask frame 501 in order to apply a tension necessary for stretching the shadow mask 502, the pressing force is The corner portion 501C of the mask frame 501, where the stress of F is concentrated, undergoes plastic deformation, and often fails to return to the original shape even after the pressing force F is removed. The cross section of the shadow mask structure 500 when the plastic deformation has occurred is shown in the XX ′ cross-sectional view and the YY ′ cross-sectional view. In the XX ′ cross section including the stress concentration portion 501C, the sides 501A and 501B are
Are tilted and the shadow mask 502 is not stretched normally. Y- near the center not including the stress concentration portion 501C
As shown in the figure, the side 501A and the side 501B are normal in the section Y ', and the shadow mask 502 is stretched normally. If the shadow mask 502 is not properly stretched even partially, color shift occurs and the commercial value of the color CRT is lost.

The above-described plastic deformation of the mask frame 501 can be prevented by increasing the thickness of the mask frame 501. However, this increases the weight of the shadow mask assembly 500, which is contrary to the demand for light weight of a color cathode ray tube, which is a market requirement. In addition, since the required pressure F increases, the size of the shadow mask pasting device and the like also increase, which causes an increase in cost.

An object of the present invention is to prevent the weight of the shadow mask structure from increasing and the pressurizing force at the time of attaching the shadow mask by improving the structure of the mask frame. The realization of a cathode ray tube.

[0008]

According to a first aspect of the present invention, a shadow mask is stretched on two opposite sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame. In the shadow mask structure described above, a corner portion of the mask frame is reinforced by a reinforcing plate.

According to a second aspect of the present invention, there is provided a shadow mask structure in which a shadow mask is stretched on two opposite sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame. Are reinforced by inward bending.

According to a third aspect of the present invention, in a shadow mask structure in which a shadow mask is stretched on two opposite sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame, the corner portion of the mask frame has It is reinforced by a reinforcing plate, and an inner peripheral portion of the mask frame is reinforced by inward bending.

According to a fourth aspect of the present invention, in a shadow mask structure in which a shadow mask is stretched on two opposite sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame, at least a corner portion of the mask frame is provided. The flat portion between the outer peripheral portion and the inner peripheral portion is reinforced by a square pipe.

According to a fifth aspect of the present invention, there is provided a color cathode ray tube provided with the shadow mask structure according to the first to fourth aspects.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the shadow mask structure of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a shadow mask structure 100 according to a first embodiment of the present invention, and a sectional view taken along line AA '. In FIG. 1, 100 is a shadow mask structure, 101 is a mask frame, and 102 is a shadow mask (mask frame 10).
(Only the outer circumference is shown to make it easier to see the internal structure of 1).
03 is a reinforcing plate.

In the shadow mask structure 100, the shadow mask 102 is stretched on the mask frame 101 in the same manner as in the case of the conventional shadow mask structure 500 as follows. Opposite two sides 101 of the mask frame 101
A horizontal pressing force F is applied to A and 101B in advance to elastically deform the sides 101A and 101B, and in this state, two sides of the shadow mask 102 are welded to the upper end surfaces of the sides 101A and 101B. After the welding, the side 101
A, when the pressing force F applied to the side 101B is removed,
The sides 101A and 101B return to the original shape, whereby the tension required for stretching the shadow mask 102 is applied.

Here, the difference between the shadow mask structure 100 of the first embodiment of the present invention and the conventional shadow mask structure 500 is that a reinforcing plate is provided at the corner of the mask frame 101 where stress is concentrated when a pressing force F is applied. 103 is welded. For this reason, the strength of the corner portion is particularly high, and the plastic deformation of the corner portion, which occurs in the conventional mask frame 501, is less likely to occur. Therefore, after removing the pressing force F, the sides 101A and 101B return to their original shapes. Therefore, tension is evenly applied to the shadow mask 102, and the shadow mask 102 is stretched to a predetermined position without any trouble.

In this case, there is a concern that the weight of the reinforcing plate 103 will increase as compared with the conventional shadow mask structure 500, but it can be canceled by reducing the thickness of the entire mask frame 101. Further, since the required pressing force F is the same as the conventional one, there is no need to increase the size of the shadow mask pasting machine.

FIG. 2 is a perspective view of a shadow mask structure 200 according to a second embodiment of the present invention, and a sectional view taken along line AA '. In FIG. 2, reference numeral 200 denotes a shadow mask structure, 201 denotes a mask frame, and 202 denotes a shadow mask (mask frame 20).
(Only the outer circumference is shown to make it easier to see the internal structure of 1)), 2
03 is an inward bend.

In the shadow mask structure 200, the method of stretching the shadow mask 202 on the mask frame 201 is the same as in the case of the shadow mask structure 100 of the first embodiment, and a description thereof will be omitted.

Here, the shadow mask structure 2 of the second embodiment
The feature of 00 is that the inwardly bent portion 203 is provided not only at the corner portion of the mask frame 201 but also at the entire inner peripheral portion. Therefore, the strength of not only the corner portion but also the entire inner peripheral portion is high with respect to the bending caused by the pressing force F, so that the plastic deformation of the corner portion which occurs in the conventional mask frame 501 is unlikely to occur.

Also in this case, the conventional shadow mask structure 50 is used.
Although there is a concern about an increase in weight compared to 0, this increase in weight can be canceled by slightly reducing the thickness of the entire mask frame 201. Further, since the required pressing force F is the same as the conventional one, there is no need to increase the size of the shadow mask pasting machine.

FIG. 3 is a perspective view of a shadow mask structure 300 according to a third embodiment of the present invention, and is a sectional view taken along line AA '. 3, reference numeral 300 denotes a shadow mask structure, 301 denotes a mask frame, and 302 denotes a shadow mask (mask frame 30).
(Only the outer periphery is shown to make it easier to see the internal structure of 1)), 3
03 is a reinforcing plate, 304 is an inward bend.

In the shadow mask structure 300, the method of stretching the shadow mask 302 on the mask frame 301 is the same as that of the shadow mask structure 100 of the first embodiment, and a description thereof will be omitted.

Here, the shadow mask structure 3 of the third embodiment
The feature of 00 is that the corner portion of the mask frame 301 is reinforced by the reinforcing plate 303, and the entire inner peripheral portion is reinforced by inward bending 304. Therefore, both the corner portion and the inner peripheral portion have high strength against bending due to the pressing force F, and the plastic deformation of the corner portion which occurs in the conventional mask frame 501 is extremely unlikely to occur.

Also in this case, the conventional shadow mask structure 50 is used.
Although there is a concern that the weight increases as compared with 0, this weight increase can be canceled by reducing the thickness of the entire mask frame 301. Further, since the required pressing force F is the same as the conventional one, there is no need to increase the size of the shadow mask pasting machine.

FIG. 4 is a perspective view of a shadow mask structure 400 according to a fourth embodiment of the present invention, and a sectional view taken along line AA '. 4, reference numeral 400 denotes a shadow mask structure, 401 denotes a mask frame, and 402 denotes a shadow mask (mask frame 40).
(Only the outer circumference is shown to make it easier to see the internal structure of 1)), 4
03 is a square pipe.

In the shadow mask structure 400, the method of extending the shadow mask 402 on the mask frame 401 is the same as the method of the shadow mask structure 100 of the first embodiment, and the description is omitted.

Here, the shadow mask structure 4 of the fourth embodiment
The feature of 00 is that not only the corner portion of the mask frame 401 but also the entire inner peripheral portion is reinforced by the square pipe 403. Square pipe 403 and mask frame 401
As shown in the figure, a gap is provided between the sides of the mask frame 401 and the square pipe 403 does not become an obstacle even when the side of the mask frame 401 is bent inward when the shadow mask 402 is stretched.
As is well known, the square pipe 403 is light and resistant to bending. Therefore, both the corner portion and the inner peripheral portion have extremely high strength against bending caused by the pressing force F, and the plastic deformation of the corner portion, which occurs in the conventional mask frame 501, is very unlikely to occur. As an application of this embodiment, the mask frame 401
It is also possible to provide the square pipe 403 only at the corners of. If reinforcement only at the corners is sufficient, the configuration is sufficient.

Also in this case, the conventional shadow mask structure 50 is used.
Although there is a concern that the weight increases as compared with 0, this weight increase can be canceled by reducing the thickness of the entire mask frame 401. Further, since the required pressing force F is the same as the conventional one, there is no need to increase the size of the shadow mask pasting machine.

[0030]

As described above, the shadow mask structure of the present invention reinforces the corner portion or the inner peripheral portion of the mask frame to increase the strength of the mask frame, prevent plastic deformation, and provide an abnormal shadow mask structure. It is possible to prevent a stretched state. Also, by reducing the thickness of the mask frame, an increase in the weight of the mask frame structure can be prevented. Further, a conventional shadow mask pasting machine can be used.

By mounting the shadow mask structure of the present invention, it is possible to realize a color cathode ray tube with good image quality while being light in weight and low in cost.

[Brief description of the drawings]

FIG. 1 is a perspective view and a sectional view of a shadow mask structure according to a first embodiment of the present invention.

FIG. 2 is a perspective view and a sectional view of a shadow mask structure according to a second embodiment of the present invention.

FIG. 3 is a perspective view and a sectional view of a shadow mask structure according to a third embodiment of the present invention.

FIG. 4 is a perspective view and a sectional view of a shadow mask structure according to a fourth embodiment of the present invention.

FIG. 5 is a perspective view and a sectional view of a conventional shadow mask structure.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 shadow mask structure 101 mask frame 102 shadow mask 103 reinforcing plate 200 shadow mask structure 201 mask frame 202 shadow mask 203 inward bending 300 shadow mask structure 301 mask frame 302 shadow mask 303 reinforcing plate 304 inward bending 400 shadow mask structure 401 mask frame 402 Shadow mask 403 Square pipe 500 Shadow mask structure 501 Mask frame 502 Shadow mask

Claims (5)

[Claims] 1. A shadow mask structure in which a shadow mask is stretched on two opposing sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame, wherein a corner portion of the mask frame is reinforced by a reinforcing plate. Shadow mask structure. 2. A shadow mask structure in which a shadow mask is stretched on two opposite sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame, wherein an inner peripheral portion of the mask frame is reinforced by inward bending. And the shadow mask structure. 3. A shadow mask structure in which a shadow mask is stretched on two opposing sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame, wherein a corner portion of the mask frame is reinforced by a reinforcing plate. A shadow mask structure, wherein an inner peripheral portion is reinforced by inward bending. 4. A shadow mask structure in which a shadow mask is stretched on two opposite sides of an outer peripheral portion of a substantially rectangular frame-shaped mask frame, wherein at least a corner portion of the mask frame has an outer peripheral portion and an inner peripheral portion. A shadow mask structure, wherein a plane portion between the two is reinforced by a square pipe. 5. A color CRT comprising the shadow mask structure according to claim 1.