JP2003178700A - Picture tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight picture tube by restraining the stress generated at a funnel of a vacuum envelope. <P>SOLUTION: Deformation (concavity and convexity generated at the funnel), caused by evacuation of the vacuum envelope is arranged at a predetermined position of the funnel beforehand. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube in a display device such as a television receiver.

[0002]

2. Description of the Related Art FIG. 9 is a partially cutaway side view of a conventional example of a color picture tube. The color picture tube 1 has a glass vacuum envelope 2 made up of a panel 3 and a funnel 4, and an electron beam 10 emitted from an electron gun 6 is electromagnetically deflected by a deflection yoke 7 to produce the panel 3 The fluorescent screen 8 on the inner surface is scanned. The funnel 4 of the vacuum envelope 2 has a funnel-like shape that expands from the cylindrical neck 5 toward the panel 3 side, and is joined to the rear end peripheral edge of the panel 3 at the sealing surface 11 at the front end peripheral edge thereof. Has been done.

FIG. 10 is a front view showing an example of the funnel 4 in the vacuum envelope 2. This funnel 4
Has a square cone structure in the front shape (hereinafter referred to as a square cone structure). In the figure, SA and LA
And DA represent the short axis, the long axis, and the diagonal axis in the square front shape, respectively. FIG. 11 shows respective cross sections corresponding to the three axes in the funnel 4 of FIG. In the figure, RS1 to RS6 indicate the radii of curvature of the respective portions in the short-axis cross section, RL1 to RL7 indicate the radii of curvature of the respective portions in the long-axis cross section, and RD1 to RD6 indicate the radii of curvature of the respective portions in the diagonal axis cross-section. . In the figure, for example, R134 indicates that the radius of curvature of the portion that is convex toward the outside of the funnel 4 is 134 mm, and -R120 is convex toward the inside of the funnel 4. It shows that the radius of curvature of the part is 120 mm.

On the other hand, FIG. 12 is a front view showing a conventional example of a funnel 4 having a rotationally symmetrical cone structure (the cross section of the cone portion 14 is a circular structure centering on the axis of the funnel 4). A hatched portion 13 on the inner surface of the funnel represents a portion where the electron beam 10 strikes. From this figure, of the inner surface of the funnel, the cone portion 1
It can be seen that the electron beam 10 strikes the diagonal axis DA of 4. From this, there is no problem in the shape of the funnel 4 in the direction of the short axis SA, for example, a shape that reduces the deflection angle, that is, a shape close to the axial center of the funnel 4. Based on these results, in the recent funnel 4 having a rectangular cone structure, as shown in FIG.
The shape of the cross section of the short axis and the cross section of the long axis of the cone portion 14 is made closer to the axial center of the funnel 4 as compared with the shape of the cross section of the diagonal axis so that the deflection yoke 7 can be brought closer to the electron beam 10 and the sensitivity of the deflection yoke 7 As a design to increase the energy consumption, the color picture tube 1 is designed to save energy.

By the way, in the color picture tube 1 as shown in FIG. 9, the inside of the vacuum envelope 2 is evacuated in the manufacturing process, but by the vacuum processing, the short axis cross section, the long axis cross section and the diagonal axis cross section are obtained. 13A to 13C undergo deformations as shown in FIGS. In the figure, the broken line shows the shape before deformation, and the solid line shows the shape after deformation. From this figure,
It can be seen that in the diagonal axis cross section, the deformation is small in portions other than the panel 3, and the short axis cross section and the long axis cross section have the same tendency of deformation. Such a deformation tendency associated with the vacuum processing is generally the same regardless of the size of the picture tube and the deflection angle.

FIG. 14 is a front view showing the front surface of the panel 3 when the vacuum envelope 2 is vacuum-processed, with the quadrant limited. The panel 3 was flat before the vacuum processing, and a state in which the panel 3 is recessed inside the envelope by the vacuum processing is shown by contour lines 16 in FIG. From this figure, it can be seen that in the short axis SA and the long axis LA of the panel 3, when the equidistant distance from the center is considered, the amount of depression toward the inside of the envelope is larger than that of the diagonal axis DA. This means that the funnel 4 inevitably has less deformation in the cross section of the diagonal axis because it is sandwiched by the changes in the depressions of the short axis SA and the long axis LA in the panel 3. FIG. 13 (C) showing the above shows this well (that is, well shows the phenomenon that the deformation of the funnel 4 in the diagonal direction becomes small).

FIG. 15 is a perspective view showing the tensile stress of the outer surface generated on the short axis SA and the long axis LA of the vacuum envelope 2 due to the deformation shown in FIG. is there. In the figure, the hatched portion 15 is
Represents a site with high tensile stress. As described above, in the conventional color picture tube 1, since the vacuum envelope 2 has the portion 15 having a high tensile stress, it is difficult to make the envelope 2 thin, which is a bottleneck in reliability design and weight reduction design. There is.

In the vacuum envelope 2, its panel 3
16 has a radius of curvature RP that is convex toward the outside of the envelope 2 as shown by the solid line in FIG. 16, and is convex toward the inside of the envelope 2 as shown by the broken line in FIG. Curvature radius-RP
According to the result of calculation of the stress generated by the vacuum treatment in comparison with the case of having the same, the peak value of the stress in the high tensile stress portion extending from the side surface of the panel 3 to the funnel 4 is almost the same. Turned out to show.
This is an abstraction of the object into a general vacuum container.If the curved part of the vacuum container is convex outward or inward, the absolute radius of curvature of the curved part is absolute. If the values are the same, it suggests that the stresses generated in the vacuum vessel can be considered to be almost equal.

As a conventional technique for reducing the deformation of the funnel due to vacuum processing, there is a technique in which a bead structure consisting of linear convex portions or concave portions is provided on each portion of the inner surface or the outer surface of the funnel (special feature). Kaihei 8-779
No. 49).

[0010]

As described above, the prior art has not made a full-scale effort to reduce the weight of the picture tube. It is an object of the present invention to provide a picture tube capable of reducing the stress generated in the funnel of a vacuum envelope and reducing the weight thereof.

[0011]

SUMMARY OF THE INVENTION A picture tube according to claim 1 of the present invention is a funnel-shaped funnel whose diameter is changed forward from a cylindrical neck at the rear part in which an electron gun is arranged, and the funnel. A vacuum envelope composed of a panel having a rear end peripheral edge joined to a seal surface on the front end peripheral edge of the panel, and deflecting an electron beam emitted from the electron gun by a deflection yoke arranged on the outer surface of the funnel. In a picture tube adapted to project onto a fluorescent screen on the inner surface of the panel, the funnel is preliminarily deformed in accordance with the deformed shape of the funnel when the vacuum envelope is brought into a vacuum state. .

A picture tube according to a second aspect of the present invention is the picture tube according to the first aspect, wherein the outer surface of the funnel extends from the seal surface of the funnel to a reference line which substantially coincides with the center of the deflection magnetic field generated by the deflection yoke. When the creepage distance along the plane is 3 L, the cross-sectional shape of the funnel corresponding to the minor axis and / or the major axis of the panel is changed to the other part of the funnel within a range of the creeping distance of approximately L from the sealing surface of the funnel. May be a curved surface that is convex outside the funnel, and the cross-sectional shape of the other part of the funnel may be a curved surface that is convex outside the funnel from the sealing surface to the reference line.

The picture tube according to claim 3 of the present invention is the picture tube according to claim 1 or 2, further comprising approximately L to L from the sealing surface of the funnel.
The cross-sectional shape of the funnel corresponding to the short axis and / or the long axis of the panel within the range of the creeping distance of 2L may be a curved surface that is convex to the inside of the funnel rather than the other parts of the funnel.

A picture tube according to claim 4 of the present invention is the picture tube according to any one of claims 1 to 3, wherein the funnel is located in the vicinity of the reference line of the funnel and corresponds to a diagonal axis of the panel. The cross-sectional shape of may be a curved surface that is convex inside the funnel.

A picture tube according to claim 5 of the present invention is the picture tube according to any one of claims 1 to 4, further comprising a creeping distance of approximately L from the sealing surface of the funnel. The cross-sectional shape of the funnel corresponding to the diagonal axis of the panel may be a curved surface that is more convex inside the funnel than the other parts of the funnel.

A picture tube according to claim 6 of the present invention is the picture tube according to any one of claims 1 to 5, further comprising a creeping distance of approximately L to 2L from the sealing surface of the funnel. Then, the cross-sectional shape of the funnel corresponding to the diagonal axis of the panel may be a curved surface that is convex outside the funnel as compared to the other parts of the funnel.

The picture tube according to claim 7 of the present invention is the picture tube according to any one of claims 2, 3, 5, and 6, wherein the funnel is the one other than the other part. It may have a shape in which irregularities are inverted.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. The same or equivalent members as those of the conventional example are designated by the same reference numerals.

<Embodiment 1> FIG. 1 is a side view showing a partially broken view of a color picture tube according to Embodiment 1 of the present invention. This color picture tube 1 has a glass vacuum envelope 2 made up of a panel 3 and a funnel 4, and emits an electron beam 10 emitted from an electron gun 6 arranged in a neck 5 at the rear end of the funnel 4. An image is displayed by electromagnetically deflecting by a deflection yoke 7 arranged outside the funnel 4 and scanning the fluorescent screen 8 on the inner surface of the panel 3. On the fluorescent screen 8,
Red, blue and green phosphors are arranged in order, and the electron beam 10 is regulated by a shadow mask 9 arranged in front of the phosphor screen 8 so that the red, blue, and
Properly hit the green phosphor.

The funnel 4 of the vacuum envelope 2 has a general shape in which the diameter increases in a funnel shape from the cylindrical neck 5 toward the panel 3 side. It is joined to the peripheral edge of the rear end. The deflection yoke 7 is arranged at the reference portion which is the outer surface of the portion where the funnel 4 changes in diameter from the cylindrical neck 5 at the rear end. The reference line 12 is a line that substantially coincides with the center of the deflection magnetic field generated by the deflection yoke 7.

FIG. 2 is a front view of the funnel 4 which constitutes the vacuum envelope 2. This funnel 4 has a prismatic cone structure. In FIG. 3, half lines of each cross-sectional shape of the funnel 4 corresponding to the short axis SA, the long axis LA, and the diagonal axis DA of the panel 3 in the vacuum envelope 2 are shown by solid lines. In this funnel 4, the sealing surface 1 around the front edge is
When the creeping distance along the outer surface of the funnel from 1 to the reference line 12 which coincides with the approximate center of the deflection magnetic field by the deflection yoke 7 is 3 L, the sealing surface 1
In the range of the creepage distance from 1 to L, the cross-sectional shape corresponding to the minor axis SA of the panel is a curved surface that is convex to the outside of the funnel 4 compared to the other parts of the funnel 4. This part shows a change when vacuum processing is performed in the conventional example.
This corresponds to a portion close to the panel 3 in the case of 3 (A).
That is, this portion is a portion that is deformed to the outside of the funnel in the conventional example. In FIG. 3, the radius of curvature of that portion is indicated by RS1. In addition, in the same creepage distance range 0 to L, the cross-sectional shape corresponding to the major axis LA of the panel 3 is also a curved surface that is convex to the outside of the funnel as compared to the other parts of the funnel 4. This portion corresponds to a portion close to the panel 3 in the case of FIG. 13B showing a change when the vacuum processing is performed in the conventional example. That is, this portion is also a portion that deforms to the outside of the funnel in the conventional example. In FIG. 3, the radius of curvature of that portion is indicated by RL1.

Further, in the range of the creeping distance of approximately L to 2L from the sealing surface 11, the cross-sectional shape corresponding to the minor axis SA is a curved surface which is convex to the inner side of the funnel 4 as compared with the other part of the funnel 4. This portion corresponds to the portion apart from the panel 3 in the case of FIG. 13A showing the change when vacuum processing is performed in the conventional example. In FIG. 3, the radius of curvature of that portion is indicated by RS2. Also, the same creepage distance range L to 2L
The cross-sectional shape corresponding to the long axis LA is also a curved surface that is more convex inside the funnel than the other parts of the funnel 4.
This portion corresponds to the portion apart from the panel 3 in the case of FIG. 13B showing the change when vacuum processing is performed in the conventional example. That is, this portion is a portion that is deformed inside the funnel in the conventional example. In FIG. 3, the radius of curvature of that portion is indicated by RL2. Explaining with a specific example of the 22-inch funnel 4, the cross section corresponding to the short axis in the range of the creepage distance 0 to L is a curved surface with a radius of curvature RS1 = + 62 (mm), and the cross section corresponding to the short axis in the range of the creepage distance L to 2L. Is the radius of curvature RS2 =
A curved surface of −500 (mm), a cross section corresponding to the major axis in the creeping distance range of 0 to L has a curved surface with a radius of curvature RL1 = + 50 (mm),
The cross section corresponding to the major axis in the range of the creepage distance L to 2L has a radius of curvature R
The curved surface is L2 = -1000 (mm).

The cross-sectional shape of the other part of the funnel 4 is a curved surface convex toward the outside of the funnel that gradually decreases in diameter from the sealing surface 11 to the reference line 12, as in the conventional case. The portion shows the sectional shape in the case of the conventional example. Therefore, the cross-sectional shape of the panel 3 corresponding to the diagonal axis DA is also a curved surface convex toward the outer side of the funnel that gradually decreases in diameter from the seal surface 11 to the reference line 12. In the vicinity of the reference line 12 near the neck 5, the diagonal axis DA
The cross-sectional shape corresponding to is a curved surface that is convex inside the funnel. As a result, the deflection yoke 7 arranged outside the funnel 4 can be brought closer to the electron beam 10 emitted from the electron gun 6, and the sensitivity of the deflection yoke 7 can be increased.

FIG. 4 is a schematic diagram showing changes in unevenness when the cross-sectional shape of the short axis SA or the long axis LA of the funnel 4 is compared with the conventional example. In the figure, the horizontal axis represents the creeping distance of the funnel 4 from the seal surface 11 to the reference line 12, the vertical axis represents the amount of change in and out of the funnel 4 with respect to the conventional example, and the vertical axis +
The side means convex to the outside of the funnel, and the minus side means convex to the inside of the funnel.

FIG. 5 schematically shows a change in the unevenness when the funnel 4 is compared with the conventional example, as viewed from the front side in a quadrant. In the figure, the part with a + sign represents a curved surface that is more convex outside the funnel than in the case of the conventional example, and the part with a − sign is a curved surface that is more convex inside the funnel than in the case of the conventional example. The parts with "0" are the parts that have no change from the conventional example.

FIGS. 6A and 6B are side views of a vacuum glass container having a shape similar to that of the vacuum envelope 2 shown for explaining the operation of the funnel 4 in the first embodiment. . In the vacuum glass container 17 shown in the same figure, the broken line shows the state of the face surface 17a before being evacuated, and the solid line shows the state of the face surface 17a after being evacuated. Further, in the vacuum glass container 17 of FIG. 6 (A), the face surface 17a before being evacuated is a flat surface, and FIG.
In this vacuum glass container 17, the face surface 17a before being evacuated has an arc-shaped cross section that is convex inside the container,
The shapes of the other parts are the same. When both of the vacuum glass containers 17 are placed in the same vacuum state as shown in FIG.
The face surface 17a of the vacuum glass container 17 of (A) is Δ1.
Only the inside of the container is deformed and the vacuum glass container 1 of FIG.
The face surface 17a of No. 7 is deformed inward by Δ2.
In this case, since the face surface 17a having a curvature has higher rigidity than the flat face surface 17a,
Between the two deformation amounts Δ1 and Δ2, Δ1> Δ
The magnitude relationship of 2 holds. In other words, FIG.
The stress generated on the face surface 17a of the vacuum glass container 17 of (A) is larger than the stress generated on the face surface 17a of the vacuum glass container 17 of FIG. 6 (B).

Looking at the funnel 3 in the first embodiment in light of such a mechanism, a cross section corresponding to the minor axis and a major axis in the creeping distance 0 to L range in which a high stress is generated when vacuum processing is performed. Since the shape of the corresponding cross section is a curved surface which has the same cross section as that of the conventional example and is convex outside the funnel, it is possible to reduce the tensile stress generated in these parts. That is, since these portions, which tend to be deformed to the outside of the funnel when subjected to vacuum processing, have curved surfaces that are convex to the outside of the funnel as compared to other portions, tensile stress can be reduced. As a result, the funnel 4 of the vacuum envelope 2
It is possible to reduce the stress that occurs in the body and reduce the weight.

In the cross section corresponding to the short axis and the cross section corresponding to the long axis in the range of the creepage distance L to 2L, the stress when vacuum-treated is smaller than that in the range of the creepage distance 0 to L. The part has a curved surface that is convex to the inside of the funnel more than the other part having the same cross-sectional shape as the case of the conventional example. Therefore, the tensile stress generated in these portions can also be reduced, and the stress generated in the funnel 4 of the vacuum envelope tube 2 can be further reduced and the weight can be reduced. That is, since these portions, which tend to deform toward the inside of the funnel when subjected to vacuum processing, have curved surfaces that are more convex toward the inside of the funnel than other portions, the tensile stress at these portions can be suppressed to a low level.

Incidentally, these sectional shapes are made to be convex outside the funnel or inside the funnel in accordance with the tendency of inward and outward deformation when vacuum processing is performed, but as is clear from the description of FIG. 16 in the conventional example. In addition, since there is no difference in the tensile stress generated whether it is convex on the outside or convex on the inside, the same effect can be obtained by inverting the convexes and concaves with the same radius of curvature.

In the first embodiment, the case where both the cross section corresponding to the short axis and the cross section corresponding to the long axis have the above-described shape is shown, but only the cross section corresponding to the short axis or only the cross section corresponding to the long axis may have the above shape. Also in this case, the tensile stress generated in the funnel 4 can be reduced to some extent.

In the first embodiment, the creepage distance 0 to
The case where the cross section corresponding to the short axis and the cross section corresponding to the long axis are formed into the shape in the range of L and the range of the creeping distances from L to 2L is shown. Also in this case, the tensile stress generated in the funnel 4 can be sufficiently reduced.

<Second Embodiment> In the second embodiment,
In the funnel 4 of the first embodiment, the diagonal axis DA of the panel 3 is further set in the range of the creepage distance 0 to L.
The cross-sectional shape of the funnel 4 corresponding to the above is a curved surface convex to the inner side of the funnel more than other parts of the funnel 4, and the funnel corresponding to the diagonal axis DA of the panel 3 within the creeping distance L to 2L. The cross-sectional shape of No. 4 is a curved surface that is convex outside the funnel 4 as compared to the other parts of the funnel 4. These portions correspond to the portions shown in FIG. 13 (C), which show changes when vacuum processing is performed in the conventional example. Two
Explaining with a concrete example of the 2 type funnel 4, the creepage distance is 0.
The cross section corresponding to the diagonal axis in the range of to L is the radius of curvature RD1 = -5
A curved surface of 0 (mm) and a cross section corresponding to the diagonal axis in the range of the creeping distance L to 2L are curved surfaces with a radius of curvature RD2 = + 1000 (mm). Other numerical values are the same as those in the first embodiment.

FIG. 7 schematically shows changes in the unevenness when the cross-sectional shape of the funnel 4 in the second embodiment is compared with the conventional example. In the figure, the horizontal axis represents the creepage distance of the funnel 4 from the sealing surface 11 to the reference line 12, the vertical axis represents the amount of change in and out of the funnel 4 with respect to the conventional example, and the + side of the vertical axis represents the funnel. It means that it is convex to the outside, and the minus side means that it is convex to the inside of the funnel.

FIG. 8 is a schematic diagram showing a change in unevenness when the funnel 4 in the second embodiment is compared with a conventional example, as viewed from the front side in a quadrant. . In the figure, the portion with a + sign represents a curved surface portion that is convex outside the funnel as compared with the case of the conventional example,
A portion with a symbol represents a curved surface portion that is more convex inside the funnel than that in the conventional example, and a portion with "0" represents a portion that does not change from the conventional example.

In the second embodiment, the cross section corresponding to the diagonal axis has the above-described shape in the creeping distance 0 to L range and the creeping distance L to 2L range, so that the tensile stress generated in the funnel 4 is further reduced. Can be made. That is, the portion on the panel 3 side, which tends to deform slightly inside the funnel when subjected to vacuum processing, has a curved surface that is more convex toward the inside of the funnel than other portions, and is separated from the panel 3 that tends to deform slightly toward the outside of the funnel. Since the part is formed as a curved surface that is convex to the outside of the funnel as compared with the other part, the tensile stress in these parts can be suppressed to be small.

Further, in the present embodiment, the above-described shape of the cross section of the diagonal axis is formed in both the range of the creepage distance 0 to L and the range of the creepage distance L to 2L. The above effect can be obtained.

Here, these cross-sectional shapes are made to be convex to the outside of the funnel or the inside of the funnel in accordance with the tendency to deform inward and outward when vacuum processing is performed, but it is also clear from the description of FIG. 16 in the conventional example. As described above, since there is no difference in the tensile stress generated between the convex and concave on the outside, the same effect can be obtained by inverting and forming the concave and convex with an equal radius of curvature.

In each of the first and second embodiments, the creepage distance from the seal surface 11 of the funnel 4 to the reference line 12 is set to 3L, and L is used as a parameter to define the convex and concave portions. It should be understood that L in this case defines a rough range rather than a strict one, as there will be some variation depending on the individual picture tube.

[0039]

According to the picture tube of the first aspect of the present invention, the funnel-shaped funnel having a cylindrical neck on the rear side in which the electron gun is disposed expands and the diameter is changed forward, and the sealing surface around the front end of the funnel. Has a vacuum envelope composed of a panel having a rear end peripheral edge joined to it, and an electron beam emitted from the electron gun is deflected by a deflection yoke arranged on the outer surface of the funnel to cause fluorescence on the inner surface of the panel. In the picture tube that is made to hit the screen, the deformed shape of the funnel when the vacuum envelope is brought into a vacuum state is matched,
Since the funnel is deformed in advance, the funnel can have rigidity with respect to a vacuum state, and the stress applied to the funnel can be reduced, so that the thickness of the funnel can be reduced. It leads to the weight reduction of the funnel.

A picture tube according to a second aspect of the present invention is the picture tube according to the first aspect, further comprising: a sealing surface of the funnel;
When the creepage distance along the outer surface of the funnel along the reference line that coincides with the approximate center of the deflection magnetic field by the deflection yoke is 3L, the minor axis of the panel is within a range of the creepage distance of approximately L from the seal surface in the funnel. And / or the cross-section of the funnel corresponding to the long axis is a curved surface that is convex outside the funnel than the other part of the funnel, and the cross-section of the other part of the funnel is convex outside the funnel from the sealing surface to the reference line. Since the curved surface has a curved surface, the stress generated in the funnel of the vacuum envelope can be suppressed to a small extent by a slight deformation of the funnel, and the weight of the picture tube can be reduced.

A picture tube according to a third aspect of the present invention is the picture tube according to the first or second aspect, further comprising: a creeping distance of approximately L to 2L from the sealing surface of the funnel. Since the cross-sectional shape of the funnel corresponding to the short axis and / or the long axis is a curved surface that is convex to the inside of the funnel more than other parts of the funnel, the stress generated in the funnel of the vacuum envelope can be further suppressed. It is possible to further reduce the weight of the picture tube.

A picture tube according to a fourth aspect of the present invention is the picture tube according to any one of the first to third aspects, wherein a cross section of the funnel corresponding to a diagonal axis of the panel is provided near a reference line in the funnel. Since the shape is a curved surface that is convex inside the funnel, the deflection yoke arranged outside the funnel can be brought close to the electron beam emitted from the electron gun, and the sensitivity of the deflection yoke can be increased.

A picture tube according to a fifth aspect of the present invention is the picture tube according to any one of the first to fourth aspects, further comprising the panel within a creeping distance of approximately L from the sealing surface of the funnel. Since the cross-sectional shape of the funnel corresponding to the diagonal axis of is a curved surface that is more convex inside the funnel than the other parts of the funnel, the stress generated in the funnel of the vacuum envelope can be further reduced, and the image receiving The tube can be made even lighter.

A picture tube according to a sixth aspect of the present invention is the picture tube according to any one of the first to fifth aspects, further comprising approximately L to L from the sealing surface of the funnel.
In the range of the creeping distance of 2L, the cross-sectional shape of the funnel corresponding to the diagonal axis of the panel is a curved surface that is convex outside the funnel than the other parts of the funnel, so that it occurs in the funnel of the vacuum envelope. The stress can be minimized, and the weight of the picture tube can be minimized.

A picture tube according to a seventh aspect of the present invention is the picture tube according to any of the second, third, fifth and sixth aspects, wherein the funnel has the irregularities other than the other portion. Since it is an inverted shape, there is no difference in the tensile stress generated whether it is convex on the outside or convex on the inside, and like the above, the stress generated in the funnel of the vacuum envelope can be suppressed to a small level, The weight of the pipe can be reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a picture tube according to Embodiment 1 of the present invention.

FIG. 2 is a front view showing a funnel in the vacuum envelope of the picture tube.

FIG. 3 is a diagram showing each cross section of a funnel corresponding to a minor axis, a major axis, and a diagonal axis of a panel in the vacuum envelope.

FIG. 4 is a schematic diagram showing a change in unevenness when the cross-sectional shape of the funnel is compared with a conventional example.

FIG. 5 is a schematic diagram showing a change in unevenness when the same funnel is compared with a conventional example, as viewed from the front side only in a quadrant.

FIG. 6 is an explanatory diagram showing the principle of operation of the funnel.

FIG. 7 is a schematic diagram showing changes in unevenness when the cross-sectional shape of the funnel in the vacuum envelope of the picture tube according to Embodiment 2 of the present invention is compared with that in the conventional example.

FIG. 8 is a schematic diagram showing a change in unevenness when the same funnel is compared with a conventional example, as viewed from the front side only in a quadrant.

FIG. 9 is a partially cutaway side view of a conventional picture tube.

FIG. 10 is a front view of a funnel in the vacuum envelope of the picture tube.

FIG. 11 is a view showing each cross section of a funnel corresponding to a short axis, a long axis, and a diagonal axis of a panel in the vacuum envelope.

FIG. 12 is a front view showing a portion of the funnel that is hit by an electron beam.

13A is a sectional view corresponding to a short axis showing changes in the same funnel before and after vacuum processing, FIG. 13B is a sectional view corresponding to the same long axis, and FIG. 13C is a sectional view corresponding to the same diagonal axis.

FIG. 14 is a front view showing the front surface of the panel when the vacuum envelope in the conventional example is subjected to vacuum processing, with only a quadrant.

FIG. 15 is a perspective view showing the tensile stress on the outer surface generated in the short axis and the long axis after vacuum processing in the same vacuum envelope, limited to the quadrant.

FIG. 16 is an explanatory diagram of stress after vacuum processing in the vacuum envelope.

[Explanation of symbols]

1 color picture tube, 2 vacuum envelope, 3 panel, 4
Funnel, 5 neck, 6 electron gun, 7 deflection yoke, 8 fluorescent screen, 10 electron beam, 11 sealing surface, 12 reference line, SA panel short axis, LA panel long axis, DA panel diagonal axis.

Claims (7)

[Claims] 1. A funnel-shaped funnel, the diameter of which changes from a cylindrical neck at the rear of which an electron gun is disposed to the front, and a panel whose rear end peripheral edge is joined to a sealing surface of the front end peripheral edge of the funnel. A cathode ray tube having a vacuum envelope made of, wherein an electron beam emitted from the electron gun is deflected by a deflection yoke arranged on the outer surface of the funnel and projected onto a fluorescent screen on the inner surface of the panel. 2. The picture tube according to claim 1, wherein the funnel is deformed in advance according to the deformed shape of the funnel when the vacuum envelope is brought into a vacuum state. 2. The picture tube according to claim 1, wherein the creeping distance along the outer surface of the funnel from the seal surface of the funnel to the reference line that is substantially coincident with the center of the deflection magnetic field by the deflection yoke is 3L. In the range of the creeping distance of approximately L from the sealing surface of the funnel, the cross-sectional shape of the funnel corresponding to the short axis and / or the long axis of the panel is a curved surface that is convex to the outer side of the funnel as compared to other parts of the funnel. 2. The picture tube according to claim 1, wherein the cross-sectional shape of the other part of the funnel is a curved surface that is convex toward the outside of the funnel from the sealing surface to the reference line. 3. The picture tube according to claim 1 or 2, further comprising: a minor axis and / or a major axis of the panel within a creeping distance of approximately L to 2L from the sealing surface of the funnel. The picture tube according to claim 1 or 2, wherein a cross-sectional shape of the corresponding funnel is a curved surface that is convex inward of the funnel as compared to the other part of the funnel. 4. The picture tube according to claim 1, wherein a cross-sectional shape of the funnel corresponding to a diagonal axis of the panel is convex inside the funnel near a reference line in the funnel. The picture tube according to any one of claims 1 to 3, wherein the picture tube has a curved surface. 5. The picture tube according to any one of claims 1 to 4, further comprising: a funnel corresponding to a diagonal axis of the panel within a creeping distance of approximately L from the sealing surface of the funnel. 5. The picture tube according to any one of claims 1 to 4, wherein the cross-sectional shape is a curved surface that is convex inward of the funnel as compared to the other part of the funnel. 6. The picture tube according to claim 1, further comprising a diagonal axis of the panel within a creeping distance of approximately L to 2L from the sealing surface of the funnel. The picture tube according to any one of claims 1 to 5, wherein the cross-sectional shape of the funnel is a curved surface that is convex outside the funnel as compared to the other part of the funnel. 7. The picture tube according to any one of claims 2, 3, 5, and 6, wherein the funnel has a shape in which the irregularities other than the other portion are inverted. Claim 2, claim 3, characterized in that
The picture tube according to any one of claims 5 and 6.