JPH0624102B2 - Picture tube device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a picture tube (hereinafter referred to as CRT) device used for a television receiver, a computer terminal, or the like.

[Conventional technology]

The conventional CRT has a rectangular screen, and its schematic structure is as shown in FIG. 5 (A). FIG. 5 (A) is a side view with a part broken away, which is generally used as a shade mask type color CRT. In FIG. 5 (A), a CRT 1 is composed of a panel screen portion 2A, a panel 2 forming a panel side surface portion 2B, a funnel-shaped funnel portion 4 connected to the panel 2 and a neck portion 5 including an electron gun (not shown). It is a vacuum glass container.

A fluorescent screen 3 is provided on the inner surface of the front panel screen portion 2A, and a shadow mask 6 having an innumerable number of holes is arranged facing it. Fluorescent screen 3
Since it is necessary to configure the screen 3 with a plurality of fluorescent materials, the sheer mask 6 needs to be attached and detached from the panel 2 multiple times, so that the panel 2 and the funnel 4 can be separated from each other. The panel 2 and the funnel 4 are sealed by the frit glass. This part is the frit seal portion 7.

In the CRT 1 as such a glass vacuum container, there is a possibility that a scratch or the like attached to the glass may spread and lead to destruction called "implosion". To prevent this, the paper tape 8 is usually wrapped around the side surface 2B of the panel, and the metal band 1
0 is tightened, and explosion-proof treatment is performed to prevent the clutch generated on the panel screen portion 2A side from extending to the frit seal portion side.

Also, a mounting ear 9 for mounting the CRT 1 on the receiver
Is held and fixed at the same time when the metal band 10 is wound.

FIG. 5 (B) is a front view of the CRT 1, and the rectangular fluorescent screen 3 defines X, Y, Z, and P axes as shown in the figure for convenience of explanation. Z is a tube axis, which coincides with the center of the screen 3.

By the way, such a CRT 1 is a CRT of a normal design.
Then, by applying a vacuum, the panel screen portion 2A
Is deformed so as to draw contour lines having substantially the same shape (square) as the square screen 3. The broken line in FIG. 6 shows the contour line.

This means that the main stress in the vicinity of the center of the square side (the direction along the X and Y axes) in the vicinity of the center of the square side becomes larger than in the diagonal direction P of the screen 3, The shaded area in Fig. 7 indicates the location where the principal stress is large.

FIG. 7 shows the CRT 1 in only 1/4 of the first quadrant,
The line that includes the center and runs along the Y-axis of the wall of the CRT is S.
A. Similarly, the lines along the X axis and the diagonal axis are LA and D respectively.
It is defined as A.

As can be seen from FIG. 7, the end portion of the panel screen portion 2A, the edge portion 2C, the side surface portion 2B of the panel, the vicinity of the frit seal portion 7 and the like are problematic points in terms of the strength of the CRT.

FIG. 7 shows the stress of a vacuum CRT without the metal band 10. Further, FIG. 8 shows a type called a band-reinforcing type with a rim that is generally performed in a large CRT, which has a rim bent portion 11A and a rim side portion 11 on a panel side surface portion 2B.
B (not shown in FIG. 8) with a metal rim,
An adhesive 12 such as an epoxy resin is interposed between the panel side surface portion 2B and a metal band 10 as a tension band is further wound and tightened thereon. 1
3 is a reinforcing plate.

This explosion-proof type is more expensive than the explosion-proof structure shown in Fig. 5 (A) and is mainly used in large size. What is different from the type shown in FIG. 5 (A) is that a rim bending portion 11A and a rim side surface portion 11B are wound under the metal band 10 over the entire circumference of the panel side surface (actually,
It is a two-part type that is above / below the CRT. ) And the lower side thereof, that is, the side surface of the panel, is mainly bonded with the adhesive 12.

In actual production, the adhesive 12 is applied to the inside of the rim side surface portion 11B in advance, the rim bending portion 11A and the rim side surface portion 11B are attached to the CRT, and the metal band 10 is tightened from above. The explosion-proof structure is completed.

In the band reinforcement section described above, the explosion-proof effect is that statically, when the CRT is in a vacuum, the panel side surface section 2B.
A part of the funnel 4 swells to the outside, but the swelling is effectively suppressed in the portion below the metal band 10.

That is, the stress under the metal band 10 of the CRT moves to the lower side. In other words, the panel side surface portion 2B of FIG.
Therefore, the high stress area is slightly lowered.

However, in reality, when the metal band 10 is tightened, the tension is applied only to the corner portion of the CRT (near the DA of the panel side surface portion 2B). The panel side surface portion 2B is remarkably effective, but as shown in FIG.
It has no definitive effect on the direction of SA and LA. For this reason, the shaded area in FIG. 7 is also the point of caution.

By the way, the standards of each country as a means to measure the degree of band reinforcement for the explosion-proof effect are to purposely scratch the panel screen part 2A and give a shock with a metal ball, etc., and the crack generated from it will lead to the implosion of the CRT. In the end, do something like judging how much glass fragments fly to the front.

In contrast to such dynamic characteristics, the rim bent portion 11A and the rim side surface portion 11B are useful for finally increasing the rigidity of the panel side surface portion 2B.

Further, the rim has a bent portion 11A on the screen side, but this effect has the effects of (a) further improving the rigidity of the rim, and (b) suppressing the glass from jumping to the front side when the glass breaks. .

By intentionally imploding the rim-reinforced CRT as described above and observing it in detail, the central portion of the panel screen portion 2A constituting the face screen and its peripheral portion are It is sucked inward, and the screen end portion including the panel side surface portion 2B and the corner portion is not sucked inward and finally pops out toward the viewer (front). The bent portion 11B of the rim is particularly effective in suppressing the glass from protruding in this portion.

FIG. 9 is a view for explaining a part of the damage situation after the CRT is implosed, and almost no glass is left on the panel part because the panel part protrudes to the back side and the front side. For example, the panel side surface portion 2B is bonded to the rim side surface portion 11B by the adhesive 12.
It is the extent that a part of it adhered to remains. On the other hand, the funnel 4 is slightly left to form a shape.

Next, the effect of tightening the metal band 10 will be further described. Statically, by tightening the panel side surface portion 2B with the metal band 10, it is possible to prevent the panel side surface portion 2B from swelling due to vacuum, and the {diagonal direction (D
A)}> {Deformation by the size of the center direction of the side (SA and LA)}, and by extension, the deformation of the entire CRT. Therefore, (i) the vacuum strain is reduced, so that breakage that occurs when stress is applied to the glass for a long time is prevented, leading to improvement in reliability.

(ii) Dynamically, it is very effective in maintaining the rigidity of the panel glass 2 and the rigidity of the rim in the process that leads to the destruction of the glass bulb in the standard test.

(iii) Further, since the high stressed portion in the hatched diagram in FIG. 7 is lowered as much as possible, it is useful for suppressing the extension of the glass crack from the panel screen portion 2A side to the frit seal portion 7.

Based on the background described above, it is considered that the explosion-proof structure passes the specified test and the price is the most important design item.As a result, for example, various measures such as rim shape are considered. It was.

Regarding the glass bulb, for example, even if the thickness distribution is examined to improve the stress distribution shown in FIG. 7, unless the thickness is considerably uneven, the effect is not sufficient or the yield in the manufacturing process deteriorates. It became less practical as it became extreme.

In any case, the explosion-proof structure tightens the panel side surface portion 2B regardless of whether the side surface portion 2B of the panel is tightened with the metal band 10 or the shrink fit method which has recently been particularly widened. It does not change to That is, it is more efficient to tighten the side surface portion of the CRT at present including the price aspect as the explosion-proof structure.

Thus, despite the importance of tightening the panel side surface portion 2B, the shape of the panel 2 has not changed since the beginning of the development of the CRT. That is, the shape of the panel side surface portion 2B having a direct relationship with the explosion-proof structure described above will be described.

FIG. 10 shows the shape of the surface of the mold matching line showing the maximum shape portion in the Z-axis cross section of the panel side surface portion 2B, which is usually the portion tightened with the metal band 10.

This FIG. 10 shows the first quadrant (CRT panel screen 2a
(Upper right part of) is shown only.

As shown in FIG. 10, the upper and lower parts have a radius of curvature RL,
The right and left side surfaces are composed of a radius of curvature RS, and the corner part is smoothly connected to each other's radiuses of curvature RL, RS with a radius of curvature r smaller than the radiuses of curvature RL, RS. The center is (x0, y0).

FIG. 11 shows only the corner portion in an enlarged manner. The contact point between the radii of curvature RS and r is D1, the contact point between the radii of curvature RL and r is D2, and the center of the radius of curvature r at the corner (x0, y0) The angles formed with the x and y axis directions are θ1 and θ2, respectively.

Further, in FIG. 11, the maximum positions of the panel side surface portion 2B in the x and y axis directions are set to xM and yM.

FIG. 12 illustrates the surface pressure that the glass side surface portion 2B receives when the panel side surface portion 2B is tightened with the metal band 10. Since the surface pressure is applied to the side surface in the vertical direction, the panel side surface portion 2B is shown in FIG. The magnitude P of the surface pressure is shown in the direction.

The surface pressure PL is constant between yM and D2, D1 to D2 are surface pressure PD, and D1 to xM are constant pressure PS. That is, the metal band 10 is used to fasten a fixed portion with a curvature radius RL between yM and D2, and the same reason is applied to other portions.

An example of the 37-inch CRT will be described below. As a specific example, xM = (391.8,0), yM = (0,307.
0), (x0, y0) = (350.40, 262.8)
0), RL = 5521.9mm, RS = 5433.8mm, y = 35.0mm,
θ2≈5.1 ° θ1≈3.6 °, PL = 5.060 × 10 ^-3 kgf / mm ² ,
PD = 7.983 × 10 ^-1 kgf / mm ² and PS = 5.142 × 10 ^-3 kgf / mm ² .

Here, it should be noted that (i) RL, RS >> r, so that the metal band 10 is mostly predominantly at the corner portion, (ii) θ2> θ1, and (iii) The angle formed by the line connecting (x0, y0) to the screen center and the x-axis is 36 ° 52'12 ".

Regarding these three points, although there are some numerical differences,
The CRT has such a structure from a small size to a large size.

Here, the direction of the approximate surface pressure load in the case of FIG. 11 will be described with reference to FIG. 13, as described above, since the diagonal surface pressure is dominant, the corner surface The approximate combined pressure load will be in the direction of the angle α with the x-axis as shown. In the above example, α = θ1 + 1/2 (90- (θ1 + θ2)) = 44.25 °, which is a different direction from 36 ° 52'12 ". Therefore, this direction intersects the x axis. Intersect in the + direction of x rather than the center.

[Problems to be solved by the invention]

As described above, in the conventional CRT, the panel side surface portion 2B is tightened, and the type having the explosion-proof effect always has the same tendency.

The present invention has been made in consideration of such a point, it is possible to lower the high stress portion than before, it is also possible to consider the dynamic crack extension as a part of its countermeasures, more explosion-proof structure. An object is to obtain an effective picture tube device.

[Means for solving problems]

In the picture tube device according to the present invention, the shape of a panel having a substantially rectangular screen or a corner portion forming a square of a screen of the funnel portion is formed with a non-constant radius of curvature instead of a uniform radius of curvature. .

[Work]

In the present invention, since the shape of the corner portion has a non-constant radius of curvature, the load distribution is changed with respect to the load from the outside, and the high stress portion is made lower.

〔Example〕

Hereinafter, an embodiment of the picture tube device of the present invention will be described with reference to the drawings, but first, an outline will be described.

In this invention, the side surface portion 2 of the panel, which is important as an explosion-proof structure,
The shape of B in particular at the corner is not made to have a uniform radius of curvature as in the conventional case, but is represented by, for example, a mathematical expression. When the panel side surface 2B is wound and tightened, the panel side surface 2
The purpose of this is to make the distribution of the load on B different from the conventional one and finally make the explosion-proof structure more effective.

This restores the deformation caused by the vacuum of the CRT to the original method by forcibly tightening the deformation from the outside, and is more preferable when the glass bulb has been damaged and broken for some reason. It allows us to change in the direction of destruction.

Specifically, for example, the same idea is applied to the side surface portion 2B of the panel glass through the rim with the metal band 10 (the same applies without the rim, and also in the case of a shrink fit method). Note that when tightened, the corner portion is predominantly subjected to the load of the surface pressure by the metal band 10 due to the characteristic of the shape of the rectangular CRT, and by changing the shape of the corner portion, The conventional load distribution is changed.

In changing the distribution of load, the shape can be determined by paying attention to the following points, for example.

(1) For example, by using the metal band 10, the amount of deformation caused by applying a vacuum to the center of the panel screen portion 2A should be returned to a larger number of original directions.

(2) As shown in FIG. 7, for example, we would like to lower the high stress area at the center of the side as much as possible.

(3) For example, we want to increase the strength of the valve in the SA direction because of the standard test.

The improvement items noted above as examples may not always result in improvement in all three points, but if the shape is decided in the direction of improvement by paying attention to the weakest point in the CRT. Good.

In the above description, the panel 2 has the panel screen portion 2A and the panel side surface portion 2B, and the load is applied from the outside to the side surface portion. However, for example, the panel 2 is only the flat panel screen portion 2A, The same applies to the case where the external load is applied to the funnel 4 instead of the panel 2.

Next, the embodiment shown in FIG. 1 will be specifically described. FIG. 1 shows only the first quadrant of the panel side surface portion 2B showing an embodiment of the present invention, and corresponds to FIG. 10 of the prior art.

Further, FIG. 2 is an enlarged view of the corner portion of FIG. 1 and corresponds to FIG. 11 of the prior art. FIG. 3 is a diagram for explaining the load distribution on the panel side surface portion 2B.

FIG. 2 shows a corner portion for explaining the present invention. In the figure, the shape of the corner portion D is represented by, for example, a mathematical formula,
It is not made with a constant radius of curvature as in the past. In the figure, the short side and the long side may be expressed by a mathematical expression, but since it is not so essential here, a constant radius of curvature RL1,
It has RS1. Further, as described above, the corner portion D does not have a constant radius of curvature, but locally near-equivalent radiuses of curvature near the contact point with the radius of curvature RL1 and near the radius of curvature RS1 are ▲ ▼ and ▲, respectively. ▼ is ▲
▼ <▲ ▼.

With such a shape, as shown in FIG. 3, the load on the panel side surface portion 2B is PD1-P at the corner portions.
It has a distribution of D2.

In this case, PD1 <PD2. For example, by doing so, the shape of PD1 <PD <PD2 can be obtained, so that the deformation due to the vacuum on the long side can be made smaller than in the conventional case.

FIG. 4 shows only the shape of the corner portion for the purpose of explaining a specific example, and the center of the coordinates will be moved as shown in FIG. 4 for simplicity. Let D be the conventional diagonal shape and D be an example of the present invention.
Then, for example, the following formula is obtained.

D x ² + y ² = 35 ² D In this example, in case of D ▲ ▼ ≒ 22.52, ▲ ▼
= 53.32 and the surface pressure is PD2 ≒ PL ≒ 1.24kgf / mm,
PD1≈PS≈0.52 kgf / mm. By the way, the conventional surface pressure D
In the case of 1, PD≈0.80.

The above description has been made in the case of band reinforcement, but it goes without saying that the same applies to a shrink fit reinforcement method in which a load is applied from the outside. In addition, depending on the shape of the CRT and the explosion-proof type, there may be cases of ▲ ▼ ＞ ▲ ▼.

〔The invention's effect〕

As described above, the present invention has a more complex non-constant radius of curvature than the conventional radius of curvature of a single R, so that when an external load is applied to the side surface of the panel as an explosion-proof structure, The distribution can be changed relatively easily.
Therefore, as shown in FIG. 7, for example, the high stress portion can be made lower than before. Along with this, dynamic crack expansion can be considered as part of the measures.

[Brief description of drawings]

FIG. 1 is a view showing only a first quadrant of a side surface portion of a panel of an embodiment of the picture tube device of the present invention, FIG. 2 is an enlarged view of a corner portion of the above embodiment, and FIG. 3 is a view of the above embodiment. FIG. 4 is a diagram for explaining a distribution of a load applied to a side surface portion of the panel when the CRT is subjected to an explosion-proof treatment, FIG. 4 is a diagram for explaining a diagonal shape of the same embodiment by a mathematical expression, and FIG. ) Is a side view showing a schematic structure of a conventional CRT with a part broken away, and FIG. 5 (B) is FIG.
The figure explaining the screen and coordinate system of the (A) CRT, 6th
FIG. 7 is a diagram for explaining the deformation of the panel screen portion of the conventional CRT due to the vacuum, FIG. 7 is a diagram for explaining the high stress caused by the vacuum of the conventional CRT, and FIG. 8 is for the conventional large CRT, etc. The figure for demonstrating the metal band reinforced type explosion-proof structure used, FIG. 9 is a figure for demonstrating the damage condition of the panel part at the time of the implosion of the conventional CRT, 1st.
FIG. 0 is a diagram showing the shape of the first quadrant of the side surface of the conventional CRT panel, FIG. 11 is a diagram for explaining the details of the corner portion of FIG. 10, and FIG. 12 is a conventional CRT. FIG. 13 is a diagram for explaining the distribution of the explosion-proof structure when a load is applied from the outside, and FIG. 13 shows the relationship between the radius of curvature forming the corner and the radius of curvature forming the side in FIG. It is a figure for explaining. 1 …… CRT, 2A …… Panel screen, 2B ……
Panel side, 3 ... Screen, 4 ... Funnel,
10 ... metal band, 11 ... rim, 11A ... rim bent portion, 11B ... rim side surface portion, 12 ... adhesive, R
L: long side radius of curvature, RS: short side radius of curvature,
γ ... Corner radius, PL, PS, PD ... Load,
▲ ▼, ▲ ▼ …… The local approximate radius of curvature near the long side and short side of the corner, RL1, RS1 ...
... a constant radius of curvature, the same reference numerals in the drawings indicate the same or corresponding portions.

Claims (2)

[Claims] 1. A picture tube device characterized in that a panel having a substantially rectangular screen or a corner of a corner of a funnel screen has a non-constant radius of curvature. 2. The rectangular screen is substantially rectangular,
The radius of curvature ▲ ▼ is locally approximately equivalent to the point of contact between the long side and the shape of the corner, and the radius of curvature ▲ ▼ is approximately equivalent to locally near the point of contact between the short side and the shape of the corner.
The picture tube device according to claim 1, characterized in that there is a relationship of ▲ ▼ ≠ ▲ ▼.