JP2002042677A - Color picture tube and mask frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube having excellent characteristics against an impact in production and transportation, and a mask frame capable of assuring torsional rigidity while suppressing increase in weight. SOLUTION: Joining bead workings 44a to 44d for joining long side walls 41a and 41b to short side walls 41C and 41d through side walls 41c and 41d are applied near the corners of a bottom surface 43, and the longitudinal direction of the joining beam workings is positioned generally orthogonal to a diagonal axis passing corner walls near the joining beads. Thus, an excellent impact resistance can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a shadow picture type color picture tube and a mask frame used for the color picture tube.

[0002]

2. Description of the Related Art A color picture tube of a shadow mask type is widely used at present. The shadow mask is for color-selecting an electron beam, and includes a rectangular mask body having a large number of electron beam passage holes formed therein, and a rectangular frame-shaped mask frame supporting the mask body. In order to display an image without color shift on the phosphor screen, the three electron beams that have passed through the electron beam passage holes of the mask body must properly land on each of the three color phosphor layers. For that purpose, it is necessary to hold the shadow mask in a correct positional relationship with respect to the panel. As a method of supporting the shadow mask inside the panel of the color picture tube, an elastic support is attached to a side wall of a corner portion of the mask frame, and the elastic support is locked to a stud pin provided on a skirt of the panel. In some cases, it is detachably supported.

In recent years, in color picture tubes, the arrangement pitch of the three-color phosphor layers has become smaller in order to meet the demand for higher resolution in response to multimedia. For this reason, there is a demand for a more accurate beam landing because the margin of the beam landing is small and color misregistration easily occurs.
On the other hand, the recent enlargement of the color picture tube has made the mask frame heavier.

[0004] It is also necessary to consider the impact received during the process of manufacturing a color picture tube and the process of transporting a product. The shock is designed to be absorbed by the elastic support.
In order to support a heavy mask frame without displacement due to impact, if the impact resistance of the elastic support is increased, the frame cannot withstand the force applied when attaching or removing the shadow mask in the color picture tube manufacturing process May be deformed. When the mask frame is deformed, the shadow mask locked on the mask frame is deformed, and there is a possibility that the position of the shadow mask is shifted with respect to the panel.

[0005] For these reasons, it is required that the mask frame be increased in strength without increasing its weight. As one example of this, bead processing (step) is provided on the side wall of the mask frame. Also,
In order to improve the rigidity of the mask frame against twisting about the diagonal direction, a beading 4 connecting the side wall 2 and the bottom surface 3 is provided near the corner of the mask frame 1 at the corner end as shown in FIG. Has also been done.

[0006]

However, in the mask frame structure shown in FIG. 7, since the beading is performed from the side wall at the corner end to the bottom surface, the variation with respect to a desired diagonal dimension of the mask frame becomes large. There was a problem. The variation in the diagonal size of the mask frame is due to the problem that the mask does not enter the mask frame when the diagonal size of the mask frame is small, and the mask does not fit into the mask frame when the diagonal size of the mask frame is large. It causes problems such as being easily deformed by being pulled.

[0007] These problems are particularly remarkable in a color picture tube having a flat face panel in which the curved surface of the shadow mask is almost flat compared to the conventional color picture tube, that is, the outer curved surface has an almost infinite radius of curvature. is there.

On the other hand, as shown in JP-A-6-44919, an annular horizontal bead 8 is formed on the bottom surface 7 of the mask frame 5.
And a vertical bead 9 extending from the horizontal bead 8 toward the frame side wall 6 (FIG. 8).

In general, a residual stress (strain) is generated in a material of a mask frame which is press-molded during molding. This residual stress is usually released by passing through the heat process. However, when a bead is provided so as to surround the opening of the mask frame as shown in FIG. This may cause deformation along the bead. This deformation affects the shape of the side wall and the opening of the mask frame. The long side and the short side of the side wall have lower rigidity than the corner, and the deformation of the side wall leads to the deformation of the mask body. Further, when the opening of the mask frame is deformed toward the electron gun (deformation such that the opening is substantially reduced), the electron beam is shielded more than necessary, and a non-light emitting area is generated. Is deformed toward the phosphor screen side (deformation such that the opening becomes substantially larger), there is a problem that the electron beam is insufficiently shielded and unnecessary light emission occurs.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a mask frame which secures torsional rigidity while suppressing an increase in weight. It is an object of the present invention to provide a color picture tube having good characteristics against impact in a process.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first invention is to provide a vacuum envelope having a rectangular panel having a center long axis and a short center axis orthogonal to each other. A phosphor screen formed on the inner surface of the panel; and an electron gun disposed at a distance from the phosphor screen along a tube axis orthogonal to the central long axis and the short axis, and emitting a beam toward the phosphor screen. And a color selection mechanism including a mask body having a rectangular effective portion disposed opposite to the phosphor screen and having a large number of electron beam passage holes formed thereon, and a mask frame to which the mask body is fixed. The mask frame includes a pair of long side walls parallel to the central long axis and opposed to each other, a pair of short side walls parallel to the central short axis and opposed to each other, and a corner side wall between the long side wall and the short side wall. A rectangular picture frame having a substantially L-shaped cross section having a bottom portion extending from the side wall portion toward the tube axis; a long side wall and a short side wall near the corner of the bottom portion with the corner side wall interposed therebetween. And a longitudinal direction of the continuous bead processing is substantially orthogonal to a diagonal axis passing through a corner side wall near the continuous bead.

Further, in the first invention, the longitudinal direction of the continuous bead processing is not parallel to a perpendicular line of a diagonal axis passing through the corner side wall on which the continuous bead processing is performed. Further, the continuous bead processing is connected to bead processing provided on at least one of the long side wall and the short side wall. Further, the color picture tube is characterized in that the corner side wall is flat.

Further, in the first invention, the corner side wall has a flat portion, and the flat portion is provided with an elastic support member which engages with a stud pin provided on the panel.

Further, the first invention is characterized in that the outer surface of the panel is substantially flat.

According to a second aspect of the present invention, there is provided a rectangular frame-shaped side wall portion including a pair of long side walls facing each other, a pair of short side walls facing each other, and a corner side wall between the long side wall and the short side wall. A bottom portion extending from the side wall portion to the center side of the rectangular frame;
In a rectangular frame-shaped mask frame having a substantially L-shaped cross-section, near the corner of the bottom surface portion, a continuous bead process for connecting the long side wall and the short side wall with the corner side wall interposed therebetween is performed. The direction is substantially orthogonal to a diagonal axis passing through a corner side wall near the connecting bead.

In the second aspect of the present invention, the longitudinal direction of the continuous bead processing is not parallel to a perpendicular line of a diagonal axis passing through the corner side wall on which the continuous bead processing is performed. Further, the continuous bead processing is characterized in that it is connected to bead processing provided on at least one of the long side wall and the short side wall.

Further, the corner side wall is flat.

[0018]

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a color picture tube according to one embodiment. This color picture tube is a 29-inch screen with a screen aspect ratio of 4: 3 used for TV sets, etc. (screen diagonal effective dimension 68 cm).
This is a color picture tube in which the curvature of the outer surface of the panel is almost a perfect plane.

This color picture tube has a long axis extending in the horizontal axis (X-axis) direction and a long axis extending in the horizontal axis (X-axis) direction, with the horizontal axis (X-axis) as the long axis and the vertical axis (Y-axis) as the short axis. It has a rectangular panel 11 having an extended short side, and an envelope 10 comprising a funnel 12 connected to an end of the panel 11 and having a funnel shape. In the rectangular effective area on the inner surface of the panel 11, the fluorescent light composed of a large number of red, green and blue three-color phosphor layers in the form of dots and a black striped light absorbing layer formed in the gaps between these phosphor layers. A body screen 13 is formed. Further, a shadow mask 20, which is a color selection mechanism, is separated from the phosphor screen 13 by a predetermined distance in the tube axis (Z-axis) direction.
1. The shadow mask 20 is supported inside the panel 11 by engaging a plurality of elastic supports 42 provided on an outer wall of a mask frame 40 described later with a plurality of stud pins 15 embedded in the side wall 14 of the panel 11. ing.

Further, a cylindrical neck portion 16 is connected to the funnel 12, and a single axis (X
An in-line type electron gun 18 that emits three electron beams 17B, 17G, and 17R arranged on the (axis) is sealed. Three electron beams 17B and 17 emitted from the electron gun 18
Since G and 17R have different angles of incidence on the electron beam passage holes of the shadow mask 4, it is possible to land on the target phosphor dot and emit a predetermined phosphor.

The electron beams 17B, 17G and 17R are electromagnetically deflected by a deflection yoke 19 arranged on the outer periphery near the boundary with the neck portion 16 of the funnel 12, and the panel 1 is deflected.
An image is displayed by scanning the phosphor screen 13 on the inner surface in the horizontal and vertical directions.

FIG. 2 shows a sectional structure of the shadow mask 20.
FIGS. 3 and 4 show the structure of the mask frame. The shadow mask 20 is made of an invar (36% Ni-Fe alloy, having a rectangular effective portion 22 in which a large number of electron beam passage holes 21 are formed at predetermined vertical and horizontal pitches and an invalid portion around the effective portion.
Mask body 3 formed by pressing a thin metal sheet made of a low thermal expansion material having a coefficient of thermal expansion of 1.2 × 10 ⁻⁶ / ° C.) into a predetermined shape.
0 and a mask frame 40 having a rectangular frame shape having an L-shaped cross section and made of a low carbon steel plate (coefficient of thermal expansion: 12 × 10 ⁻⁶ / ° C.) on which the mask body 30 is supported and fixed.

The mask body 30 is formed into a predetermined curved surface and has a rectangular effective portion 22 having a long side extending in the X-axis direction and a short side extending in the Y-axis direction, and is bent from the periphery of the effective portion 22. The skirt 23 extends along the tube axis (Z axis). The skirt portion 23 is fixed to the inside of the side wall 41 of the rectangular frame-shaped mask frame 40 by welding at a plurality of locations (indicated by crosses in the figure).

An elastic support 42 is provided outside the mask frame 40, and an opening formed in the elastic support 42 is engaged with a stud pin 15 formed on the inner surface of the panel 1, whereby the shadow mask 20 is formed. It is arranged in the panel 11. In addition, a bead processing described later is performed on the bottom surface of the mask frame.

The structure of the mask frame will be described in detail with reference to FIGS. Mask frame 40
Is a pair of long side walls 41a and 41b parallel to the central long axis (X axis) and facing each other, a pair of short side walls 41c and 41d parallel to the center short axis (Y axis) and facing each other, and the long side wall 4.
A side wall portion 41 including corner side walls 41e to 41h between the short side walls 41c and 41d;
And a bottom surface 43 extending toward the tube axis (Z axis) from the bottom. A large opening 45 through which the deflected electron beam can pass is provided on the bottom surface.

In the vicinity of the corner of the bottom portion 43, continuous bead processing 44a-4 connecting the long side walls 41a, 41b and the short side walls 41c, 41d with the corner side walls 41c, 41d interposed therebetween.
4d is applied. This continuous bead processing has a rectangular cross-sectional shape, and the processing width of the bead is 15 mm and the depth is 2 mm. In the present embodiment, only the continuous beaded portions 44a to 44d are recessed in the bottom surface portion 43, and the other regions are located on substantially the same plane.

The longitudinal direction of the connection bead portions 44a to 44d is substantially perpendicular to diagonal axes D1 and D2 passing through the corner side walls near the connection bead portions 44a to 44d. However, in the present embodiment, the state is not completely orthogonal and slightly deviated from orthogonal.

The rigidity of the mask frame structure in the present embodiment is as follows. The conventional example for comparison is a mask frame according to the present embodiment having no connection bead.
Here, the evaluation was made based on the amount of displacement (hereinafter referred to as the proof stress coefficient) when a force of 1 kg was applied to the remaining corners with the three corners of the frame fixed. The thickness of the mask frame was 1 mm, and the diagonal dimension was 663 mm. The evaluation results are as follows.

Strength coefficient Diagonal opening diameter Side wall height This embodiment: 1.711 [kg / mm] 544 mm 53 mm Conventional example: 1.482 [kg / mm] 500 mm 60 mm As is clear from the results, this embodiment is performed. The mask frame of the embodiment has a better yield strength coefficient than the mask frame of the conventional example while reducing the height of the side wall. Since the amount of materials used can be reduced, the cost and weight are also effective.

(Embodiment 2) Next, another embodiment will be described with reference to FIGS. Similar to the first embodiment, the mask frame 50 in the present embodiment includes a pair of long side walls 5 that are parallel to the central long axis (X axis) and face each other.
1a, 51b, a pair of short side walls 51c, 51d parallel to the central short axis (Y axis) and facing each other, and a long side wall 51a,
Corner side wall 51 between 51b and short side walls 51c, 51d
A rectangular frame having a substantially L-shaped cross section has a side wall portion 51 composed of e to 51h and a bottom surface portion 43 extending from the side wall portion 51 to the tube axis (Z axis) side. A large opening 55 through which the deflected electron beam can pass is provided on the bottom surface.

In the vicinity of the corner of the bottom portion 53, continuous bead processing 54a-5 connecting the long side walls 51a, 51b and the short side walls 51c, 51d across the corner side walls 51c, 51d.
4d is applied. This continuous bead processing has a rectangular cross-sectional shape, and the processing width of the bead is 15 mm and the depth is 2 mm. In the present embodiment, only the continuous beaded portions 54a to 54d are recessed in the bottom surface portion 43, and the other regions are located on substantially the same plane.

The longitudinal direction of the connection bead portions 54a to 54d is substantially perpendicular to diagonal axes D1 and D2 passing through the corner side walls near the connection bead portions 54a to 54d. However, in the present embodiment, the state is not completely orthogonal and slightly deviated from orthogonal.

In the vicinity of the bottom surface of each of the side walls 51a to 51d, bead processing 56a, 56 extending from the side wall to the bottom surface 53 is also provided.
b, 57a and 57b are provided. In this embodiment,
End portions of the side wall side 51 of the connected bead portions 56a to 59 near the corners are side wall reinforcement bead portions 56a, 56b, 57.
a, 57b, 58, 59. The length along the tube axis of the bead processing 56a, 56b, 57a, 57b of this side wall is 22 mm, and the depth is 7 mm. The length along the pipe axis of the bead processing 58, 59 on the side wall is 22 mm, and the depth is 7 mm.

In this embodiment, only the beaded portions 54a to 54d and 56a to 59 of the bottom portion 53 are recessed, and the other regions are located on substantially the same plane.

The rigidity of the mask frame structure in this embodiment is as follows. The conventional example for comparison is a mask frame according to the present embodiment having no connection bead.
The thickness of the mask frame is 1 mm, and the diagonal dimension is 663.
mm. The evaluation results are as follows.

Strength coefficient Diagonal opening diameter Side wall height This embodiment: 2.013 [kg / mm] 544 mm 53 mm Conventional example: 1.744 [kg / mm] 500 mm 60 mm As is apparent from the results, this embodiment is as follows. The mask frame of the embodiment has a better yield strength coefficient than the mask frame of the conventional example while reducing the height of the side wall. Further, the yield strength coefficient is better than that of the first embodiment. Since the amount of materials used can be reduced, the cost and weight are also effective.

[0037]

As described above, according to the present invention, it is possible to provide a mask frame which secures torsional rigidity while suppressing an increase in weight. In addition, it is possible to provide a color picture tube having good characteristics against impacts in a color picture tube manufacturing process and a transportation process.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a cross section along a diagonal axis of a shadow mask structure of the color picture tube shown in FIG.

FIG. 3 is a perspective view showing the structure on the bottom side of the mask frame.

4A and 4B are views showing a structure in which an elastic support is provided on the mask frame shown in FIG. 3, wherein FIG. 4A is a bottom plan view and FIG.
Is the side view on the long side, and (c) is the side view on the short side

FIG. 5 is a view showing another form of the mask frame, and is a perspective view showing a bottom side structure.

6A and 6B are views showing a structure in which an elastic support is provided on the mask frame shown in FIG. 5; FIG.
Is a side view on the long side, and (c) is a side view on the short side.

FIG. 7 is a view showing a conventional shadow mask structure;
(A) is a cross-sectional view in a direction along a diagonal, and (b) is a view showing a part of the bottom surface of the mask frame.

FIG. 8 is a view for explaining another embodiment of a conventional shadow mask structure.

[Explanation of symbols]

40 Mask frame 41a, 41b, 51a, 51b Long side wall 41c, 41d, 51c, 51d Short side wall 41e-41h, 51e-51h Corner side wall 43 Bottom part 44a-44d, 54a-4d Connection bead 56a, 56b, 57a, 57b, 58,59 Side wall reinforcement bead

Claims (10)

[Claims] A vacuum envelope having a rectangular panel having a central major axis and a central minor axis orthogonal to each other; a phosphor screen formed on an inner surface of the panel; a central major axis and a central minor axis; An electron gun that is disposed apart from the phosphor screen along a tube axis perpendicular to the screen, and that emits an electron beam toward the phosphor screen; A mask body having a rectangular effective portion having a beam passage hole formed therein, and a color selection mechanism including a mask frame to which the mask body is fixed, wherein the mask frame is parallel to the central long axis. A side wall portion including a pair of long side walls facing each other, a pair of short side walls parallel to the center short axis and facing each other, and a corner side wall between the long side wall and the short side wall; A color picture tube having a substantially L-shaped cross-section having a bottom surface extending toward the tube axis from the long side wall and the short side near the corner of the bottom surface with the corner side wall interposed therebetween. A color picture tube, wherein a connecting bead processing for connecting to a side wall is performed, and a longitudinal direction of the connecting bead processing is substantially orthogonal to a diagonal axis passing through a corner side wall near the connecting bead. 2. The collar according to claim 1, wherein a longitudinal direction of the connecting bead processing is not parallel to a perpendicular line of a diagonal axis passing through a corner side wall on which the connecting bead processing is performed. Picture tube. 3. The color picture tube according to claim 1, wherein said continuous bead processing is connected to bead processing provided on at least one of said long side wall and said short side wall. 4. The color picture tube according to claim 1, wherein said corner side wall is flat. 5. The corner side wall is a flat portion,
An elastic support that engages with a stud pin provided on the panel is provided on the flat portion,
A color picture tube according to any one of claims 1 to 4. 6. The color picture tube according to claim 1, wherein an outer surface of the panel is substantially flat. 7. A rectangular frame-shaped side wall portion including a pair of long side walls facing each other, a pair of short side walls facing each other, a corner side wall between the long side wall and the short side wall, and A rectangular frame having a substantially L-shaped cross-section having a bottom surface extending toward the center side of the rectangular frame; and connecting the long side wall and the short side wall with the corner side wall interposed in the vicinity of the corner of the bottom portion. A mask frame, wherein a continuous bead processing is performed, and a longitudinal direction of the continuous bead processing is substantially orthogonal to a diagonal axis passing through a corner side wall near the continuous bead. 8. The mask according to claim 7, wherein a longitudinal direction of the connecting bead processing is not parallel to a perpendicular line of a diagonal axis passing through a corner side wall on which the connecting bead processing is performed. flame. 9. The mask frame according to claim 7, wherein the continuous bead processing is connected to a bead processing provided on at least one of the long side wall and the short side wall. 10. The mask frame according to claim 7, wherein said corner side wall is flat.