JPH01149344A - Picture tube - Google Patents

Abstract

PURPOSE:To provide a certain reinforcing effect and reduce secondary destruction by installing a ring-shaped reinforcement with different degrees of tightening with respect to a glass bulb at the corners of a side glass panel or its adjacency in the width direction or in circumferential direction. CONSTITUTION:A ring-shaped reinforcing structure 20 with different degrees of tightening with respect to a glass bulb is furnished at the corners of a side glass panel 2B or its adjacency in the width direction and/or in circumferential direction. A glass cloth tape 21 is interposed between this ring-shaped reinforcement 20 and side glass panel 2B. This provides different surface pressure applied to the side glass panel 2B, and even dispersed shapes and dimensions of the side glass panel 2B and varied ring-shaped reinforcement 20 have the effect to give even reinforcement, wherein the phenomenon of secondary destruction is well reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a picture tube (hereinafter referred to as CRT) used in television receivers, computer terminals, and the like.

[Conventional technology]

FIG. 4 is a side view schematically illustrating the structure of a CRT having a rectangular screen, which has been conventionally used as a shadow mask type color CRT. A glass panel is formed from a front glass panel section 2A and a side glass panel section 2B.

A fluorescent screen 3 is provided on the inner surface of the front glass panel portion 2A of the glass panel 2, and a shadow mask 6 having a plurality of holes is arranged opposite to the fluorescent screen 3.

A funnel 4 is separably sealed and bonded to the end face of the side glass panel portion 2B of the glass panel 2 via a frit seal portion 7 made of frit glass. 5 is a neck portion that includes an electron gun (not shown).

In a CRTI configured in the shape of a glass vacuum container with the glass panel 2, funnel 4, and neck portion 5 described above, there is a possibility that scratches on the glass panel 2 may extend and lead to destruction, resulting in so-called implosion. are doing.

As a means to prevent such implosion, a paper tape 8 is usually wrapped around the outer surface of the side glass panel section 2B, and a metal band 10 is wound over the paper tape 8 so as to clamp and fix the ear 9. By tightening, explosion-proof treatment was performed to prevent cracks generated in the front glass panel portion 2A from extending toward the frit seal portion 7 side.

FIG. 5 is a front view of the above-mentioned CRT 1, which is used to define the X, Y, Z, and P axes for the convenience of the following explanation, where Z is the tube axis of the CRTI and the fluorescent screen 3 It matches the center 〇.

Furthermore, FIGS. 6 and 7 show a rimmed band reinforcement type structure that has been conventionally generally employed in large CRTs. In the figures, 11 is a reinforcing metal rim, It consists of a rim part 11A bent to the side and a side rim part 11B that covers the side glass panel part 2B. By filling the adhesive 12 such as resin and then winding and tightening the metal band 10, the structure is superior to the one shown in FIG. 4 in terms of explosion protection. In addition, 2 in Figure 7
1 is a glass cloth tape.

FIG. 8 shows an example in which the present invention is applied to a 37-inch CRT. In this FIG. 8, two metal bands 10 are installed on the side glass panel portion 2B. 13 is a reinforcing plate.

In addition, Fig. 9 is a side view for explaining the shrink-fitting method that has recently become more common in place of the tensile band method described above, and shows the X, Y, and P axes. Each cross section is shown in one figure.

Here, in the conventional shrink-fitting method, the metal band 10 and reinforcing metal rim 11 are composed of an annular reinforcing body 20 made of an aluminized steel plate and having a length of, for example, 8m+a, and the side glass panel portion 2B and the annular reinforcing body 20 are connected to each other. During this time, the glass is protected with, for example, glass cloth tape (not shown).

For attachment, the ears 9 are welded to the annular reinforcement 20. In the figure, the mounting at the corner is a general case with ears 9.

Hereinafter, the state in which the side glass panel portion 2B is generally tightened using the Tensilon band method or the shrink fitting method will be described.

Figure 10 shows the shape at the mold match line, which shows the largest shape part when considering the Z-axis cross section of the side glass panel part 2nd.
This is the part that is usually tightened with a metal band 10. The figure is the first
Only the quadrant (top right of the fluorescent screen 3 of the CRTI) is shown. As shown in the figure, the upper and lower parts have a radius of curvature RL,
The right and left side parts are composed of a radius of curvature R3, and the corner part is RL.

mutual radius of curvature RL with a smaller radius of curvature r than R3
, R3, and the center of its radius of curvature is (xo, yo).

FIG. 11 shows only the corner portion enlarged, and the point of contact between the radius of curvature R3 and r is Dl, and the point of contact between the radius of curvature RL and r is D2.

Also, in Figure 10, there is an X on the 2nd side glass panel section.

Let the maximum position in the y-axis direction be xM, yM (.

FIG. 12 explains the surface pressure that the side glass panel portion 2B receives when the side glass panel portion 2B is tightened with the metal band 10. Since the surface pressure is applied to the side surface in the vertical direction,
In the figure, the magnitude P of the surface pressure is shown in the vertical direction on the side glass panel portion 2B. PL is constant between YM-D2,
For D1 to D2, PDSDi to xM are constant loads of PS.

That is, this is because the metal band 10 is tightened at a certain location with the same radius of curvature RL of yM-DI, and the same reason applies to other locations.

Below, using the example of a 37-inch CRT, to give a specific example, xM=
(391,8,0),yM= (8,309,0)
, (xo, yo) = (350,40,262,8
0), RL=5521.9mn, RS=5433
．． 8 am, r = 35.0 m, 6245, 1@
, 01 doo 3.6°, P L = 5.060 x 1G
-'kgf/關2, P D = 7.983 X 10
-'kgf/■2, PS-5,142X 10-'kg
It is of the order of f/wm2.

What should be noted here is that RL, R8>r, so
The corner portions of the metal band 10 are predominant.

The above concept is basically the same whether it is a tension band method or a shrink-fitting method. The only difference is that the means for achieving this is different between the reinforcing metal rim 11 and metal band 10 and the annular reinforcing body 20.

By the way, between the tension band method and the shrink fitting method described above, the adiabatic firing method is more advantageous in terms of manufacturing cost.

[Problem that the invention seeks to solve]

A commonly used method to measure the degree of reinforcement for explosion-proofing is to intentionally scratch the front glass panel, and then hit the front glass panel with a metal ball or the like to detect cracks that occur from the scratched area. This method is based on the implosion of the CRT, and the final judgment is based on how far the glass shards fly forward.

When comparing the tension band method and the shrink fitting method using this evaluation method, the performance can be at the same level as Hotohachi. However, the shrink fitting method has the following disadvantages. In other words, if the CRT is “
"Implosion" is a phenomenon in which glass breaks when the temperature inside goes from vacuum to 1 atm, and although the evaluation method described above evaluates this phenomenon, Even if the inside of the CRT reaches 1 atmosphere (atmospheric pressure), secondary destruction occurs (hereinafter referred to as secondary destruction).

This tendency is particularly noticeable in large CRTs, and is a problem because it is difficult to distinguish between primary destruction (implosion) and secondary destruction when evaluating explosion-proof performance.

By the way, in this secondary destruction, unlike the primary destruction of implosion, the individual broken glass fragments do not fly towards the viewer with considerable energy, but are mostly caused by gravity. Because the fragments are affected, primary and secondary destruction should be clearly distinguished in their evaluation.

In addition, the evaluation method described above may have fairly strict standards in some countries, so in this sense as well, it is necessary to take measures against secondary damage in the shrink-fitting method.

This invention has been made to solve this problem, and even if there are variations in the shape and dimensions of the side glass panel portion and the shape of the annular reinforcement, it is possible to obtain a constant reinforcing effect and at the same time cause secondary damage. The objective is to obtain a picture tube that can reduce the phenomenon of

[Means for solving problems]

The picture tube according to the present invention is provided with an annular reinforcing structure having at least a plurality of different degrees of tightening against the glass bulb in the width direction and/or circumferential direction at the corner portion of the side glass panel portion and in the vicinity thereof.

[For production]

In this invention, since the degree of tightening of the annular reinforcing structure at and around the corners of the side glass panel section by the shrink fitting method has a plurality of different degrees, the surface pressure applied to the side glass panel section in the tube axis direction or radial direction is Even if the shapes and dimensions of the side glass panel parts and the annular reinforcing structure vary, a certain level of reinforcement can be obtained.

〔Example〕

Embodiments of the picture tube of the invention of B will be described below based on the drawings, but before giving a detailed explanation of the embodiments, in order to facilitate understanding of this invention, the shrink-fitting method and the tension band method will first be further outlined. .

The decisive difference between the shrink fitting method and the tension band method lies in whether the metal ring corresponding to the reinforcing metal rim 11 remains tight (shrink fitting method) or easily loosens (tension band method). That is, in FIG. 8, which is a typical example of the conventional tension band method, the reinforcing metal rim 11
is a two-part type in which the parts shown in Fig. 7 are combined from the top and bottom, and one metal band is used.
゜ is caulked using a clip (not shown).

It is a well-known fact that this clip is susceptible to loosening due to external impacts. That is, when the front glass pulse portion 2A is given a southern part with a metal ball or the like and crackle breaks, the tension of the metal band 10 tends to be small, and at that time, the reinforcing metal rim 11 is divided into two parts. Therefore, there is no force to prevent the equivalent tension from becoming smaller.

On the other hand, in the shrink fitting method, the annular reinforcing body 20 is welded to the reinforcing metal rim 11 and the metal band 10 in the tension band method, so that the annular reinforcing body 20 does not loosen.

Therefore, in the case of the shrink-fitting method, the inside of the CRT is 1
Even if the atmospheric pressure increases, if the surface pressure equivalent to the tension of the metal band is still strong, the glass will break, resulting in secondary damage! It will be destroyed.

Next, we will move on to a detailed description of the invention. FIG. 1 shows one embodiment of the invention, and is a diagonal cross-sectional view, in which an annular reinforcing body 20 is opposed to a side glass panel portion 2B parallel to the tube axis (Z-axis). The plane θ is inclined at about 21°.

Further, the plate thickness of the annular reinforcing body 20 is, for example, to, 8 ml.
11, and the width is 40 mm. There is a flap on the fluorescent screen side. In the figure, it is shown floating above the side glass panel portion 2B for emphasis, but it is drawn in an extreme manner for the sake of explanation, and is not floating.

A glass cloth tape 21 is interposed between the annular reinforcing body 20 and the side glass panel portion 2B. In addition,
4 is a funnel, 7 is a frit seal portion, and 9 is a mounting ear, which are the same as the conventional ones.

Next, the operation will be explained. Figure 2(a), Figure 2(b)
1 is a detailed explanation of the present invention, and FIG. is made to have smaller dimensions.

In the case of 37 inches, for example, ds=2.0mm, dg=0
．． 5+++n+.

By heating such an annular reinforcing body 20 and fitting it into a CRT, the surface pressure P applied to the corner part of the side glass panel part 2B becomes as shown in FIG. The gun side is Ps and Pg, respectively, and the surface pressure P has a slope.

Circular? 11? Surface pressure P on the fluorescent screen side due to the strong body 20
s. Similarly, regarding the surface pressure Pg on the electron gun side, for example, in the conventional structure, if a surface pressure Ps like - is applied, secondary fracture is a problem, and when a surface pressure Pg similar to - is applied, the side glass panel Shape of part 2B and annular? When the dimensions of the lf1 strong body 20 vary, a problem arises in the CRT's reinforcing effect.

However, in the case of the present invention, as explained above, even if there is some variation in size, the explosion-proof reinforcing effect and secondary destruction can be reduced.

Figure 3 (al) is another embodiment of the present invention; in Figure 1 the annular reinforcing body 20 is inclined in the width direction;
), the side glass panel part 2 has a distribution in the radial direction.
I'm changing the way I hit B. FIG. 3(,) is a schematic development view of the annular reinforcing body 20, and the hatched portions indicate portions to which uniform surface pressure is applied. For reference, FIG. 3(b) shows a conventional case corresponding to FIG. 3(a) of the present invention.

In addition, in this embodiment, the shrink fitting is performed on the side glass panel portion 2B.
However, it goes without saying that 1ζ can also be applied when provided in the funnel 4.

〔Effect of the invention〕

As explained above, the present invention is configured such that the annular reinforcing bodies are attached to the glass bulb at different degrees of tightening in the width direction or the circumferential direction at the corners of the side glass panel portion and in the vicinity thereof. Even if there are variations in the shape of the panel side surface and the shape of the annular reinforcing body, it is possible to obtain a certain reinforcing effect and at the same time reduce the phenomenon of secondary fracture.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a cross-sectional view of a corner diagonal of a picture tube according to an embodiment of the present invention, and FIG. 2 fa) and FIG. FIG. 3 is an explanatory diagram for explaining the operation of another embodiment of the picture tube of the present invention, and FIG. 3(b) is an explanatory diagram for explaining the operation of another embodiment of the picture tube of the present invention. An explanatory view for explaining the operation of a conventional picture tube corresponding to the present invention, FIG. 4 is a partially cutaway side view of a conventional band-reinforced type picture tube, and FIG. An explanatory diagram for explaining the coordinates of the screen of a picture tube, FIG. 6 is a cross-sectional view of a part of a conventional picture tube equipped with a reinforcing metal rim, and FIG. 7 is a diagram for explaining the coordinates of the screen of a picture tube. 8 is a perspective view of a conventional picture tube equipped with the reinforcing metal rim shown in FIG. 7, FIG. 9 is a side view of a conventional fired picture tube, and FIG. Figures 1 through 12 are explanatory diagrams for explaining that blood pressure is applied only to the corner portion of the panel side surface of a conventional tensi-band type receiving tube. 2B: Side glass panel portion, 4 ...Funnel, 7
... Fritton rule part, 20 ... Annular reinforcement body, 21
91. Glass cloth tape. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) In a picture tube with a rectangular fluorescent screen that has an explosion-proof function when an annular reinforcing structure is fitted to the picture tube,
A picture tube characterized in that the degree of tightening of the glass bulb in the width direction and/or circumferential direction of the reinforcing structure at the corners and in the vicinity of the corners of the side glass panel portion of the picture tube is varied in at least a plurality of ways. (2) A patent claim characterized in that the surface of the glass portion of at least a corner portion of the panel portion or funnel portion constituting the picture tube and the surface of the reinforcing structure that faces the surface are inclined. The picture tube according to item 1. (3) The reinforcing structure is characterized in that the surface of the reinforcing structure that faces the surface of the glass portion of at least the corner portion of the panel portion or funnel portion constituting the picture tube is composed of a plurality of surfaces. A picture tube according to claim 1.