JPH1167118A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube which eliminates the deterioration of beam landing without decreasing the strength, even if a mask frame is made light-weight. SOLUTION: This picture tube is constituted to support a shadow mask 30 by a stud pin 22 installed in a panel 3 and an elastic support 21 which is installed on a mask frame 36. A differential step part 38 which is projected outward on at least one place of the mask frame 36 installed on the circumferential part of a mask main body 33, and at least one bead part 39 which is projected inward are formed. One of the bead parts 39 is arranged near the differential step part 38 to take a position located closer to the center side of a sidewall part than to the differential step part 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube, and more particularly, to a mask frame which is displaced with respect to a mask frame when a shadow mask is assembled by optimizing a shape of the mask frame, and a shadow mask in a color picture tube manufacturing process. The present invention relates to a color picture tube capable of reducing a beam landing deviation caused by a deformation of a mask main body caused by a deformation of a mask frame due to a force applied at the time of attachment / detachment.

[0002]

2. Description of the Related Art Generally, a color picture tube is shown in FIGS.
As shown in FIG. 1, an envelope comprising a substantially rectangular panel 3 provided with a skirt portion 2 around a curved effective surface 1 and a funnel 4 is provided.
The three electron beams 7B, 7G, and 7R emitted from the electron gun 6 disposed in the neck 5 of the lens are deflected by the deflecting device 8 mounted outside the funnel 4, and the electron beam of the shadow mask 9 having a substantially rectangular shape is obtained. The light absorbing layer 1 is passed through the through hole 10.
The phosphor screen 13 formed on the inner surface of the panel 3 is horizontally and vertically scanned so that the three-color phosphor layers 12B, 12G, and 12R are embedded in the gap 1, thereby forming a structure for displaying a color image. Have been.

As shown in FIG. 8, the shadow mask 9 has a plurality of electron beam passage holes 10 formed in a main surface portion 15 having a curved surface facing the phosphor screen, and a skirt is provided around the main surface portion 15. The mask body 17 includes a substantially rectangular mask body 17 provided with a portion 16, and a substantially rectangular mask frame 19 having a side wall portion 18 to be welded in contact with the skirt portion 16 of the mask body 17.

As a method of supporting the shadow mask 9, as shown in FIG. 6, a substantially wedge-shaped elastic support 21 is attached to the corner side wall of the mask frame 19, and the elastic support 21 is attached to the panel 3. Corner skirt 2
There is a method of detachably supporting the inside of the panel 3 by engaging with a stud pin 22 provided in the panel 3.

In such a color picture tube, in order to display an image without color shift on the phosphor screen 13, the three electron beams 7B, 7G, 7R passing through the electron beam passage holes 10 of the mask body 17 are used. It is necessary to ensure that each of the three color phosphor layers is properly landed. To do so, the shadow mask 9
Must be placed in the correct alignment.

In recent years, a color picture tube is a display tube used for a computer terminal device or the like corresponding to multimedia, and in order to improve the resolution, a three-color phosphor layer is used in comparison with a normal color picture tube. Are small, the margin of beam landing is small, and color misregistration is likely to occur. Therefore, more accurate beam landing is required.

However, in practice, since the mask frame is mounted substantially in contact with the entire circumference of the mask body, an unbalanced undesired force is applied to the mask body due to variations in the shape and dimensions of the mask frame. And the positional accuracy of the mask body with respect to the panel may be reduced. In particular, the aspect ratio that has been put to practical use in recent years is 1
In the 6: 9 color picture tube, since the long side of the mask frame is much longer than the short side compared with the conventional color picture tube, the mask main body is deformed due to deterioration of mechanical strength and variation in shape and dimensions. It's easy to do.

In the color picture tube manufacturing process, the attachment / detachment of the shadow mask to / from the panel is repeated, and the force applied at the time of attachment / detachment causes the mask frame to bend, and the mask frame also causes the mask body to bend.
The beam landing shifts with respect to the color phosphor layer, causing color shift.

Further, as described above, in the display tube,
Because the margin of beam landing is small,
It is necessary to reduce the displacement of the shadow mask due to an external impact as much as possible, and it is also necessary to reduce the load on the elastic support in order to reduce the displacement due to the external impact. However, when the weight of the mask frame is reduced to reduce the burden on the elastic support, the mechanical strength against the force applied when the shadow mask is attached or detached in the color picture tube manufacturing process is reduced, and the shadow mask is attached to the panel. Misalignment occurs.

As a measure for preventing the strength of the mask frame from decreasing, there is a method of forming a bead projecting inward on the side wall of the mask frame to prevent the mechanical strength from decreasing. However, even if the bead portion is formed, if the formation is not appropriate, a sufficient effect can not be obtained, and at present, it is deformed by the force applied when attaching and detaching the shadow mask in the color picture tube manufacturing process, As a result, a position shift of the shadow mask occurs.

Further, in a display tube or the like in which the arrangement pitch of the three-color phosphor layers is small, the thickness of the mask body is reduced in order to prevent unevenness of the phosphor screen. Reduction has been achieved. However, when the thickness of the mask body is reduced, its mechanical strength is reduced and the mask body is easily deformed. Particularly in a color picture tube having an aspect ratio of 16: 9, the intensity difference between the long side and the short side of the mask frame is large, and the mask main body is deformed by the deformation on the long side having low intensity. In addition, a shadow mask made of a low-thermal-expansion material such as amber, which has a large effect of suppressing a beam landing deviation due to doming caused by the heating and expansion of the shadow mask caused by the collision of the electron beam, is shown in FIG. As shown in FIG.
(Japanese Patent Laid-Open No. 5-12100).
No. 9). However, even when the projections 24 are provided, the mask frame 19 is in contact with the peripheral portion of the mask main body 17 on the surface, so that the shape and dimensions of the mask frame vary, the deformation during shadow mask assembly, and the strength is low. There is a problem with deformation on the long side.

[0012]

As described above, in a display tube used for a terminal device of a computer or the like, in order to improve the resolution, the arrangement pitch of the three-color phosphor layers is smaller than that of a normal color picture tube. In order to reduce the load on the elastic support for the purpose of reducing the displacement due to external impact, or to reduce the weight of the mask frame, or to reduce the unevenness of the phosphor screen, the thickness of the mask body is reduced, and the electron beam passage holes are reduced. The unevenness due to variations in the shape and dimensions of the semiconductor device is reduced.

In such a case, the design of the mask frame is important in order to prevent color shift due to the beam landing shift with respect to the three-color phosphor layer. There is a problem in mechanical strength, and there is a problem that deviation of beam landing cannot be sufficiently prevented.

[0014] The present invention has been made to solve the above problems, and even if the mask frame is reduced in weight,
An object of the present invention is to provide a color picture tube in which a beam landing does not shift due to a deformation of a mask frame without lowering its mechanical strength.

[0015]

[Means for Solving the Problems]

(1) A substantially rectangular shadow mask is arranged to face a phosphor screen formed on the inner surface of a substantially rectangular panel, and the shadow mask has a large number of electron beam passage holes on a surface facing the phosphor screen. It comprises a substantially rectangular mask body formed and a substantially rectangular mask frame having a side wall attached to a peripheral portion of the mask body. The shadow mask is attached to stud pins provided on a panel and the mask frame. In a color picture tube supported by an elastic support engaged with a stud pin, a step portion protruding outward and at least one bead portion protruding inward are formed in at least one portion of a side wall portion of a mask frame. Then, one of the bead portions is structured so as to approach the step portion and to be located closer to the center of the side wall portion than the step portion.

(2) In the color picture tube of (1),
The step portion and the bead portion were formed on at least the long side wall portion of the long side wall portion and the short side wall portion of the mask frame.

(3) In the color picture tube of (1),
The bead portion was formed on the side wall portion on the bottom side of the mask frame.

(4) In the color picture tube of (1),
The height of the plurality of beads in the side wall width direction was varied depending on the position of the side wall.

(5) In the color picture tubes of (1) to (4), the distance from the center of the side wall to the step is larger than the distance from the diagonal to the step of the mask frame.

(6) In the color picture tube according to any one of (1) to (4), the ratio of the area of the bead portion of the long side wall to the area of the long side wall is defined by the short side wall to the area of the short side wall. The ratio of the area of the bead part is larger than that of the bead part.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a color picture tube which is one embodiment of the present invention. This color picture tube has an envelope composed of a substantially rectangular panel 3 having a skirt portion 2 provided around a curved effective surface 1 and a funnel 4 having a funnel shape. A phosphor screen 13 is provided on the inner surface of the panel 3 so that a three-color phosphor layer that emits blue, green, and red light is embedded in a gap between the light absorbing layers. A substantially rectangular shadow mask 30 described later is arranged inside the phosphor screen 13 at a predetermined distance from the phosphor screen 13. on the other hand,
In the neck 5 of the funnel 4, three electron beams 7B, 7G,
An electron gun 6 for emitting 7R is provided. The three electron beams 7B, 7G, 7 emitted from the electron gun 6
R is deflected by a deflecting device 8 mounted on the outside of the funnel 4, and the phosphor screen 13 is horizontally and vertically scanned through a shadow mask 30 to display a color image.

As shown in FIG. 2, the shadow mask 30 has a plurality of electron beam passage holes formed in a main surface portion 31 having a curved surface facing the phosphor screen, and a skirt portion is formed around the main surface portion 31. A substantially rectangular mask body 33 provided with an inner projection 32 (bottom portion) at one end of a side wall portion 34 welded in contact with the skirt portion 32 around the mask body 33. And the mask frame 36
A substantially wedge-shaped elastic support 21 attached to the side wall 35 at the corner of the panel 3 is engaged with a stud pin 22 provided on the inner surface of the skirt 2 at the corner of the panel 3 so as to be detachably supported inside the panel 3. Have been.

Particularly, in this embodiment, a step 38 and a bead 39 are provided on the opposite long side wall 34a of the mask frame 36, respectively.

The step portion 38 is formed so as to project outward symmetrically with respect to the short axis (Y axis). The distance L1 from the short axis (the center of the side wall 34a) of the pair of steps 38 is
In the illustrated example, the distance between the opposing long side wall portions 34a at the step portion 38 is larger than the distance L2 from the diagonal portion of the mask frame 36 to the step portion 38. It is larger than the interval of 34a.

On the other hand, the bead portion 39 is
4a, between the pair of steps 38, 2 mm to 1 mm from the step 38.
The projections are formed to protrude inside the mask frame 36 at a distance of 0 mm. In the illustrated example, four bead portions 39 are formed on the inner projecting portion 35 side of the mask frame 36 at a distance of 3 mm from the step portion 38, and the bead portion 39 located on the short axis side of the bead portion 39 is located on the side of the step portion 38. The protrusion amount to the inside of the mask frame 36 is larger than that of the portion 39, and the long side wall portion 34a
The height in the width direction is high.

As described above, when the step 38 and the bead 39 are provided on the long side wall 34a of the mask frame 36,
Due to the formation of the step portion 38, the skirt portion 32 around the mask body 33 and the long side wall portion 34 of the mask frame 36 are formed.
There is a portion that does not touch between a and the mask body.Because the entire circumference of the mask body is conventionally welded and fixed to the mask frame, undesired poor balance of the mask body due to variations in the shape and dimensions of the mask frame. A force acts, which can effectively prevent a decrease in the positional accuracy of the mask main body with respect to the panel. In addition, the formation of the bead portion 39 makes it possible to strengthen the longer side of the mask frame having relatively low mechanical strength, and reduces the force applied to the mask frame 36 when the shadow mask 30 is attached and detached in the color picture tube manufacturing process. So that the shadow mask 30 can be prevented from reaching the center of the long side.
It is possible to prevent deformation near the center of the long side of the mask frame, which is likely to occur when attaching and detaching the mask frame.

In particular, as in this embodiment, the amount of protrusion of the bead portion 39 located on the short axis side toward the inside of the mask frame 36 and the height in the width direction of the long side wall portion 34a are determined on the side of the step portion 38 side. When it is larger than 39, the long side central portion of the mask frame having low mechanical strength is effectively reinforced,
The three-color phosphor can be effectively prevented from deteriorating the positional accuracy of the mask body with respect to the panel due to variations in the shape and dimensions of the mask frame, and from deformation near the center of the long side of the mask frame, which tends to occur when the shadow mask 30 is attached and detached. A color picture tube in which the beam landing does not shift with respect to the layer can be obtained.

Next, another embodiment will be described.

The shadow mask 30 shown in FIG. 3 has a step portion 38 and a bead portion 39 provided on a long side wall portion 34a and a short side wall portion 34b of a substantially rectangular mask frame 36, respectively.

The step portions 38 of the side walls 34a, 34b on the long and short sides are formed so as to protrude symmetrically with respect to the short axis and the long axis (X axis), respectively. The distance between the opposing long side wall portions 34a at this point is larger than the distance between the opposing long side wall portions 34a on the short axis, and the distance between the opposing short side wall portions 34b at the step portion 38 of the short side wall portion 34b. The interval is larger than the interval between the opposed short side wall portions 34b on the long axis.

On the other hand, the bead portion 39 is formed on the inner projecting portion 35 side between the pair of step portions 38 of the long and short side both side wall portions 34a, 34b, and in the illustrated example, three bead portions 3 are provided.
9 project inside the mask frame 36. The protrusion amount of the bead portion 39 to the inside of the mask frame 36 is:
Regarding the bead portion 39 of the long side wall portion 34a, the bead portion 39 on the center (short axis and long axis side) side of the long side wall portion 34a.
Is larger than the bead portion 39 on the side of the step portion 38, but the bead portion 39 of the short side wall portion 34b is
It is constant from the center to the step 38 side. The height of each bead portion 39 (each of the side wall portions 34a, 34b)
Regarding the height in the width direction, the bead portion 39 at the center of each of the side wall portions 34a and 34b is higher than the bead portion 39 at the step portion 38 side.

When the step portion 38 and the bead portion 39 are provided on the long and short side walls 34a and 34b of the mask frame 36 as described above, the formation of the step portion 38 allows the mask body 3 to be formed.
3 is formed between the skirt portion 32 and the long side wall portion 34a and the short side wall portion 34b of the mask frame 36. Conventionally, the entire periphery of the mask body is fixed by welding in contact with the mask frame. Due to variations in the shape and dimensions of the mask frame, unbalanced and undesired forces act on the mask body, and the resulting decrease in the positional accuracy of the mask body with respect to the panel is reduced only to the long side wall portions shown in FIG. This can be more effectively prevented as compared with the case where a step portion and a bead portion are provided. Moreover, by forming the bead portion 39, both the long side and the short side of the mask frame can be strengthened. When the shadow mask 30 is attached or detached in the color picture tube manufacturing process, the force applied to the mask frame 36 is blocked by the step portion 38. The bead portion 3 can be prevented from reaching the center of the long side.
9, the deformation near the center of the long side of the mask frame, which is likely to occur when the shadow mask 30 is attached and detached, is more effective than the case where the step 38 and the bead 39 are provided only in the long side wall 34a. And a color picture tube in which the beam landing does not shift with respect to the three-color phosphor layer can be obtained.

The shadow mask 30 shown in FIG. 4 has long and short side walls 34a, 3a of a substantially rectangular mask frame 36.
4b is provided with a stepped portion 38 and a bead portion 39, respectively. In this embodiment, the long side wall portion 34 is provided.
The distance between the opposing long side wall portions 34a at the step portion 38 of a is
The distance between the opposing long side wall portions 34a on the short axis is equal to the distance between the opposing short side wall portions 34a at the steps 38 of the short side wall portions 34b.
The distance between the adjacent short side walls 34b is also equal to the distance between the opposed short side wall portions 34b on the long axis.

Also, the bead portion 39 has a protrusion amount and height inward of the mask frame 36 which are different from those of the side wall portions 34a, 3a.
4b is constant from the center to the step 38 side.

Even with this configuration, a shadow mask having the same effect as the shadow mask shown in FIG. 3 can be obtained.

The shadow mask 30 shown in FIG. 5 has a step portion 38 and a bead portion 39 on a long side wall portion 34a of a substantially rectangular mask frame 36, and only a bead portion 39 on a short side wall portion 34b. Things. The long side wall 34
The distance between the opposing long side wall portions 34a at the step portion 38 of a is
It is equal to the distance between the opposing long side walls 34a on the short axis.

On the other hand, the bead portion 39 has a long side wall portion 34a.
Are formed in a pair of step portions 38, and five bead portions 39 are provided in the illustrated example. On the other hand, one bead 39 is provided on the short side wall 34b. The amount of protrusion of the bead portion 39 of the long side wall portion 34a toward the inside of the mask frame 36 is such that the bead portion 39 located at the center of the long side wall portion 34a is larger than the bead portion 39 located at the step portion 38 side. It is getting bigger. The height of the bead portion 39 of the long side wall portion 34a in the width direction of the mask frame 36 is higher in the bead portion 39 located in the center portion than in the bead portion 39 located in the step portion 38 side.

In this embodiment, in particular, the ratio Sa2 / Sa1 of the area Sa2 of the bead portion 39 of the long side wall portion 34a (the total area of the plurality of bead portions 39) to the area Sa1 of the long side wall portion 34a. , The area Sb1 of the short side wall portion 34b
Sb2 of the area of the bead portion 39 of the short side wall portion 34b with respect to
The ratio Sb2 / Sb1 is larger than the ratio Sb2 / Sb1, and Sa2 / Sa1> Sb2 / Sb1.

By configuring the mask frame 36 in this manner, both the vicinity of the center of the long side and the short side of the mask frame can be reinforced, and the same effect as the shadow mask in each of the above embodiments can be obtained. 16: 9
To reduce the deformation of the long side with low mechanical strength, balance the long side and short side of the mask frame caused by the force applied when attaching and detaching the shadow mask, and apply the three color phosphor layer. A color picture tube in which the beam landing does not deteriorate.

[0041]

As described above, when the step portion and the bead portion are provided on the side wall portion of the mask frame of the substantially rectangular shadow mask, the step portion is formed, so that the gap between the peripheral portion of the mask body and the mask frame is formed. There is a part that does not touch the
Since the entire circumference of the mask body is welded and fixed in contact with the mask frame, unbalanced undesired force acts on the mask body due to variations in the shape and dimensions of the mask frame, and the resulting position of the mask body with respect to the panel. A decrease in accuracy can be prevented. In addition, the formation of the bead allows the mask frame to be strengthened, so that when the shadow mask is attached or detached in the process of manufacturing the color picture tube, the force applied to the mask frame is blocked by the step so that it does not reach the center of the long side. The deformation of the mask frame, which tends to occur when the shadow mask is attached or detached, can be prevented by the reinforcement by the bead portion. Thereby, even if the mask frame is reduced in weight, it is possible to configure a color picture tube in which the beam landing does not deteriorate for the three-color phosphor layer.

[Brief description of the drawings]

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

FIG. 2A is a plan view showing the configuration of the shadow mask of the color picture tube with a part cut away, FIG. 2B is a front view showing a cross section thereof, and FIG. It is the side view similarly shown in the cross section.

FIG. 3A is a plan view showing a configuration of a shadow mask according to another embodiment of the present invention with a part cut away, and FIG. 3B is a front view showing a cross section of the configuration; 3 (c) is a side view similarly shown in cross section.

FIG. 4A is a plan view showing a configuration of a shadow mask according to another embodiment of the present invention, which is partially cut away, and FIG. 4B is a front view showing a cross section of the configuration; FIG. 4 (c)
Is a side view similarly shown in cross section.

FIG. 5A is a plan view showing a configuration of a shadow mask according to still another embodiment of the present invention, partially cut away, and FIG. 5B is a front view showing a cross section thereof; , FIG.
(C) is a side view similarly shown by the cross section.

FIG. 6 is a diagram showing a configuration of a conventional color picture tube.

FIG. 7 is a diagram showing a configuration of a main part of a conventional color picture tube.

FIG. 8 (a) is a plan view of the conventional color picture tube shown in FIG.
(B) is the front view shown in the cross section.

9A is a plan view showing a configuration of a conventional shadow mask in which a convex portion is provided on a mask frame, and FIG. 9B is a front view showing a cross section of the configuration. FIG. is there.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 ... Panel 13 ... Phosphor screen 21 ... Elastic support 22 ... Stud pin 30 ... Shadow mask 32 ... Skirt part 33 ... Mask main body 34 ... Side wall part 34a ... Long side wall part 34b ... Short side wall part 35 ... Inside overhang part 36: mask frame 38: step 39: bead

Claims (6)

[Claims] 1. A substantially rectangular shadow mask is disposed opposite a phosphor screen formed on an inner surface of a substantially rectangular panel, and the shadow mask is provided with a large number of electron beams on a surface facing the phosphor screen. A substantially rectangular mask main body having a through hole formed therein, and a substantially rectangular mask frame having a side wall attached to a peripheral portion of the mask main body, wherein the shadow mask is provided with a stud pin provided on the panel and In a color picture tube attached to a mask frame and supported by an elastic supporting member engaged with the stud pin, a stepped portion projecting outward at least at one portion of a side wall portion of the mask frame and at least one projecting inwardly are provided. One bead portion is formed, and one of the bead portions is closer to the step portion and the side wall portion is larger than the step portion. Color picture tube, characterized in that located on the center side. 2. The color picture tube according to claim 1, wherein the step portion and the bead portion are formed on at least the long side wall portion of the long side wall portion and the short side wall portion of the mask frame. 3. The color picture tube according to claim 1, wherein the bead portion is formed on a side wall portion on the bottom side of the mask frame. 4. The method according to claim 1, wherein the height of the plurality of beads in the width direction of the side wall varies depending on the position of the side wall.
A color picture tube as described. 5. The method according to claim 1, wherein the distance from the center of the side wall to the step is larger than the distance from the diagonal of the mask frame to the step. Color picture tube. 6. The ratio of the area of the bead portion of the long side wall portion to the area of the long side wall portion is larger than the ratio of the area of the bead portion of the short side wall portion to the area of the short side wall portion. The color picture tube according to any one of claims 1 to 4, wherein