JPH01149343A - Picture tube - Google Patents

Abstract

PURPOSE:To relieve the problem of secondary destruction because of the baked fitting method by combining tightening means of tightening force by different systems to the side glass panel part. CONSTITUTION:A picture tube is provided with a fynnel 4, frit seal 7, and side glass panel 2B. At the periphery of this side glass panel 2B a ring-shaped reinforcement 20 is installed as a tightening means by baked fitting system on the screen side, and a glass cloth tape 1 is interposed between this ring- shaped reinforcement 20 and side glass panel 2B to protect the glass. On the electron gun side, another tightening means by tension band system is installed adjoining to the first named tightening means by baked fitting system at the periphery of the side glass panel 2B. This relieves the problem of secondary destruction due to the baked fitting system.

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 schematic side view, partially cut away, of a CRT with a rectangular screen that has been commonly used as a shadow mask type color CRT;
The second glass panel is composed of 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 two front glass panel sections 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 the CFLTl, which is configured in the shape of a glass vacuum container with the glass panel 2, the funnel 4, and the neck part 5, scratches on the glass panel 2 may extend and lead to destruction, which may lead to 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 attached over the paper tape 8, and the metal band 10 is wrapped and tightened so as to clamp and fix the ear 9. By doing so, the front glass panel section 2
Explosion-proofing treatment was carried out to prevent the cracks generated in A from extending toward the frit seal portion 7 side.

FIG. 5 is a front view of the above-mentioned CRTI, which is used to define the x, y, z, and p axes for the convenience of the following explanation.
Z is the tube axis of the CRTI, which coincides with the center 〇 of the fluorescent screen 3.

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 an adhesive 12 such as a resin and then winding and tightening a metal band 10, the structure is superior to the one shown in FIG. 4 in terms of explosion protection.

FIG. 8 shows an example of application to a 37-inch CRT. As shown in the figure, the metal bands 10 are provided in two rows in the tube axis direction. Other parts are shown in Figures 4 to 7.
This is similar to the figure, and the same parts as in FIGS. 4 to 7 are given the same reference numerals. 13 is a reinforcing plate, and other parts are the same as those shown in FIGS. 4 to 7.

Figure 9 explains the firing method that has recently become more common in place of the tension band method described above. It is shown in the figure. Here, in the conventional firing method, the metal band 10 and the reinforcing metal rim 11 are made of, for example, an aluminized steel plate, and are composed of an annular reinforcing body 20 of, for example, tO of 8 m. 20, the glass is protected by, for example, a glass cloth tape (not shown). For attachment, the ears 9 are welded to the annular reinforcement 20. In the figure, mounting at a corner is a general case with ears 9.

Hereinafter, the state in which the side glass panel portion 2B is generally tightened using the tension band method or the firing method will be explained. FIG. 10 shows the shape of the mold match line which shows the largest shape part in a biaxial cross section of the side glass panel part 2B, and is the part which is usually tightened with the metal band 10. The figure shows only the first quadrant (the upper right corner of the CRT fluorescent screen 3).

As shown in FIG. 10, 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 smoothly touches each other's radii of curvature RL and R3 with a radius of curvature r that is smaller than that of RL and R5. The center is (xo p 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 Fig. 10, the side glass panel section 2B
Let the maximum positions in the Xs and Y-axis directions be xM and 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 and D2,
D1 to D2 are PD1Di 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.

In the following example of a 37-inch CRT, to give a specific example, xM=(
391,8,0), yM= (0,309,0), (
xO, yo) = (350, 40, 262, 80)
, RL=552). 9 m, RS = 5433.
8 wna, r = 35.0 sem, θ2 valve5.
1°, θ1#3.6°, P L = 5.060 X
10-3 kg f/IInt 2, P D = 7
．． 983 x 10-'kgf/mta'', ps=
5.142 x 10-'kgf/nn*''. What should be noted here is that since RL, R3>r, the corner portions of the metal band 10 are predominant.

The above concept is basically the same whether it is the Tensilon band method or the 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]

By the way, a commonly used method for measuring the degree of reinforcement for explosion-proofing is to intentionally scratch the side glass panel section 2A, and then hit it with a metal ball or the like to detect cracks that occur from the scratched area. This is a method of determining how much glass shards are ultimately thrown forward by the implosion of a CRT.

Using this evaluation method, when comparing the Tensilon band method and the shrink-fitting method, it is possible to achieve almost the same level of performance.

However, the shrink fitting method has the following disadvantages. In other words, when a CRT "implodes",
This is a phenomenon in which the glass breaks when the temperature inside goes from vacuum to 1 atm.Although the evaluation method described above evaluates this phenomenon, in the shrink-fitting method, CRT
Secondary destruction will occur even if the inside of the tank reaches 1 atmosphere (atmospheric pressure).

(Hereafter referred to as secondary destruction.) This tendency is particularly noticeable in large CRTs, and it may be difficult to distinguish between primary destruction (implosion) and secondary destruction when evaluating explosion-proof performance. This is the problem.

By the way, this secondary destruction does not mean that the individual broken glass fragments fly towards the viewer with a huge amount of energy as in the case of the primary destruction of implosion. Since fragments are affected by gravity, it is important to distinguish between primary and secondary destruction in their evaluation.

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

This invention was made to solve this problem, and can alleviate the adverse effects of secondary fracture caused by the shrink-fitting method, and ensure stable quality during safety confirmation tests conducted by foreign organizations. The purpose is to obtain a picture tube that can ensure the following.

[Means for solving problems]

The picture tube according to the present invention is provided with tightening means for applying tightening force using a plurality of different methods on the side glass panel portion.

[For production]

In the present invention, by tightening the side glass panel portion using a plurality of different tightening means, it acts to alleviate the adverse effects of secondary destruction.

〔Example〕

Embodiments of the picture tube of the present invention will be described below with reference to the drawings. Before explaining the specific embodiments, first, in order to facilitate understanding of the present invention, an overview of the shrink-fitting method and the Tensian band method will be given. do.

As already mentioned, the decisive difference between the shrink-fitting method and the Tensian band method is whether the metal ring corresponding to the reinforcing metal rim remains tight (shrink-fitting method) or easily loosens (Tensian band method). It is in.

That is, in FIG. 8, which is a typical example of the conventional Tensian band method, the reinforcing metal rim 11 is a two-part type in which the reinforcing metal rims 11 shown in FIG. 7 are used in combination from the top and bottom, for example. Yes, and the metal band 10 is caulked using a clip (not shown).

It is well known that this clip is susceptible to loosening due to external impact, as mentioned above. That is, when two people impact the front glass panel with a metal ball or the like and cause cracking, the tensile vibration 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 ν from becoming smaller.

On the other hand, in the shrink-fitting method, the annular reinforcing body 20 (FIG. 9) is attached to the reinforcing metal rim 11 in the tensile shoulder band method.
The metal band 10 is welded to the metal band 10 and will not loosen.

Therefore, in the case of the shrink-fitting method, the inside of the CRT is 1
Even if the atmospheric pressure is high, if the surface pressure corresponding to the tension method of the band is strong, the glass will break, resulting in secondary breakage.

Next, we will move on to a detailed description of the invention. Figure 1 shows an embodiment applied to a large CRT.
The corner of the T is shown. In FIG. 1, for example, the screen side is reinforced with a shrink-fitting type of tightening means, and the electronic mirror side is reinforced with a tensilan band type of tightening means.

That is, in FIG. 1, 4 is a funnel, 7 is a frit seal part, and 2B is a side glass panel part. On the outer peripheral surface of this side glass panel part 2B, as described above, the screen side is shrink-fitted. An annular reinforcing body 20 is attached as a tightening means, and a glass tape 2) is interposed between this annular reinforcing body 20 and the side glass panel portion 2B to protect the glass. Also,
In this annular reinforcement body 20, the side glass panel portion 2B
A lug 9 is attached to each corner portion by welding.

Further, on the electron gun side, a tensile band type tightening means is provided adjacent to the shrink fitting type tightening means on the outer peripheral surface of the side glass panel portion 2B.

That is, a paper tape 8 is wrapped around the outer peripheral surface of the side glass panel section 2B, a reinforcing metal rim 11 is attached from the upper surface of the paper tape 8, and a metal band 1 is attached to the outer peripheral surface of this reinforcing metal rim 11.
0 is tightened.

As shown in Part B, tensile strength belts (
Alternatively, if the surface pressure (on the panel side wall) is plotted on the vertical axis and time t is plotted on the horizontal axis, the result will be as shown in FIGS. 2(a) and 2(b). In both FIG. 2(4k) and FIG. 2(b), (-1'l) is the shrink fitting method, and (b) is the tensilan band method.

Fig. 3 shows the conventional method (Fig. 8) corresponding to Fig. 2. Fig. 3(a) shows the shrink-fitting method, and the two lines are the corresponding two rows of zones on the side of the panel (( In contrast to (a) and (b)), in the case of the shrink-fitting method, the contact pressure does not change for any two rows, and in the case of reinforcing the tensilan band method in Fig. 3(b), the clip metal band 10 at
This indicates that the is loosening. The difference between (a) and (b) means that secondary destruction occurs.

However, in the present invention, as shown in the case of FIG. 2, secondary fractures can be reduced more than in the conventional case.

Note that the present invention may be implemented as shown in FIG. 2(b), in which the initial tension is higher in the tensilan band method than in the shrink fitting method.

Further, although FIG. 1 shows an example in which the tightening means is brought to the screen side by a shrink-fitting method, it goes without saying that the opposite may be used.

Furthermore, in another embodiment of the present invention, as an alternative to the shrink-fitting method of the above example, a tensilan band method is used, but instead of caulking the metal band 10 at the end (instead of welding it). Good too.

〔Effect of the invention〕

As explained above, this invention is configured to combine a plurality of different types of tightening force tightening means on the side glass panel portion, so that two
Since the negative effects of secondary destruction can be alleviated, stable quality can be ensured during safety confirmation tests conducted by foreign organizations.

[Brief explanation of the drawing]

FIG. 1 is a side view of a corner portion of a picture tube according to an embodiment of the present invention, FIGS. 2(a) and 2(b) are characteristic diagrams for explaining the tightening force in the same embodiment, and FIG. Diagram (a)
3(b) is a characteristic diagram of the tension of the shrink-fitting method in a conventional picture tube, FIG. 3(b) is a characteristic diagram of the tension band method in a conventional picture tube, and FIG. Fig. 5 is an explanatory diagram illustrating the coordinates of the screen of the picture tube shown in Fig. 4, and Fig. 6 is a side view of the side glass panel explaining the rim reinforced type of the conventional picture tube. , FIG. 7 is a perspective view of the rim of a conventional picture tube, FIG. 8 is a perspective view of a conventional picture tube equipped with the rim of FIG. FIGS. 10 to 12 are explanatory diagrams of the shrink-fitting method for picture tubes, and are explanatory diagrams illustrating that in reinforcement using the tension band method, surface pressure is applied only to the corner portions of the panel side surface. 2B... Side glass panel part, 4... Funnel part, 7... Frit seal part, 8... Paper tape, 9...
... Attachment is ears, 10... Metal band, 11... Metal rim for reinforcement, 20... Annular reinforcement body, 2)... Glass cloth tape. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (5)

[Claims] (1) A picture tube that provides an explosion-proof effect by applying a tightening force to the side glass panel, characterized in that the side glass panel is equipped with tightening means using a plurality of different methods. (2) The picture tube according to claim 1, wherein the tightening means is of a caulking type tension band type and a shrink-fitting type. (3) The picture tube according to claim 1, wherein the tightening means is a caulking type tension band system or a welding type tension band system. (4) Claim 1, characterized in that at least one of the plurality of different methods is a method in which the tension is reduced by impact, and the other method is a method in which the tension does not change. picture tube. (5) The picture tube according to claim 1, wherein the surface pressure applied to the bulb by the initial caulking type tension band method is greater than the surface pressure applied to the bulb by the shrink-fitting method.