JP2001307661A - Funnel sealing body for cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a funnel base for welding a plurality of neck tubes efficiently and in high quality by molding. SOLUTION: A funnel sealing body 3 has two or more yoke fitting parts and neck tubes 2 on the funnel base 1, wherein the yoke fitting parts are partially formed with the neck tubes 2, in which end parts are expanded in wide-angle shapes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a funnel seal for a cathode ray tube, and more particularly to a funnel seal for a cathode ray tube having two or more yoke mounting portions and a neck tube.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for high-definition cathode ray tubes capable of responding to high-definition broadcasting and large screens for cathode ray tubes such as color picture tubes for television. Various technical studies to respond are underway. As one of them, a cathode ray tube in which a plurality of neck tubes are provided and an electron gun is sealed to each of the neck tubes has been proposed.

A conventional cathode ray tube having a plurality of neck tubes includes a glass panel 20 having a fluorescent screen 24 on the inner surface and a plurality of neck tubes 2 sealed to a funnel-like body 15 as shown in FIG. And a funnel sealing body (see JP-A-61-256551). An electron gun 21 is sealed in each of the plurality of neck tubes 2, and an electron beam 25 emitted from each electron gun is deflected by a deflection coil 22 mounted on an outer wall surface of a funnel substrate, and a glass panel is formed. By scanning a predetermined area of the 20 phosphor screens, one image is formed as a whole.

A conventional cathode ray tube having a plurality of neck tubes has the same electron beam scanning, but has a glass panel 20 having a fluorescent screen 24 on the inner surface as shown in FIG.
And the small funnel portion 26 having the neck tube 2 in which the electron gun 21 is sealed, and integrally joined together with the intermediate member 16 whose cross section is hatched to form an envelope. (See Japanese Patent Application Laid-Open No. 7-45215).

[0005]

In these conventional examples, it is very difficult to mold a funnel-like body 15 for welding a plurality of neck tubes 2 using a mold as shown in FIG. In the cooling step, the mold is broken due to the difference between the expansion allowance of the mold and the glass, and it is extremely difficult to remove the mold even if it is not broken, so that there is a problem that productivity is significantly impaired. On the other hand, in the cathode ray tube of FIG. 8, a plurality of funnel portions 26 in which the neck tube is sealed in advance are integrated by welding at predetermined positions of the intermediate member 16, or the neck tube is welded to the intermediate member 16 after the funnel portion is welded. 2 to form a funnel-sealed body, which not only increases the number of manufacturing steps but also complicates the operation.

In order to improve the productivity, molding using the above-mentioned mold is promising. However, if the funnel-like body 15 having a plurality of convex portions serving as a yoke mounting portion is molded with a mold,
Since the dimensions of the convex portions are not always accurate, if a neck tube is welded to the tip of the electron gun and the electron gun is sealed, a deviation occurs in the position of the electron gun, and high-resolution image display cannot be performed.

Next, the deviation of the electron gun will be described with reference to FIGS.
This will be specifically described according to 2. FIG. 9 is a front view of a funnel-like body 15 formed by a mold, and FIG. 10 is a plan view thereof. To provide two neck tubes, a funnel 1
5 has two yoke mounting portions formed as convex portions, and has a narrow opening end 4 for welding a neck tube at the tip thereof. On the side wall near the wide opening end 6 of the funnel-like body 15, three reference projections (reference points) 5 for positioning are conveniently provided as shown in FIG. In other words, two reference projections are provided on the long sides of two adjacent sides of the rectangular wide opening end 6 and one reference projection is provided on the short side. Reference numeral 11 denotes a reference line passing through the two reference points on the long side, and reference numeral 12 denotes a reference point 5 orthogonal to the reference line 11 and on the short side.
Is a reference line passing through.

The two narrow opening ends 4 of the funnel 15
(Center axes) 9 and 10 can be positioned as distances from both of these reference lines, and (X ₀₂ , Y
₀₂ ), (X ₀₁ , Y ₀₁ ).

FIG. 11 shows a product specification of a funnel sealing body in which the neck tube 2 is welded to the narrow opening end 4 of the funnel-like body 15. Because of the product specifications, the tube axis of the neck tube 2 and the center of the narrow opening end 4 coincide with each other, and the dimensional positions of the centers 7, 8 of these two tubes are (X ₁₂ ,
Y ₁₂ ) and (X ₁₁ , Y ₁₁ ). (X ₁₂ , Y ₁₂ ), (X
₁₁ , Y ₁₁ ) are target dimensions set as product specifications.

When comparing the dimensions of the centers 9 and 10 of the funnel-like body 15 molded with a mold with the dimensions of the centers 7 and 8 of this product specification, the actually formed funnel-like body 15 has a shape after molding. Due to deformation and molding errors due to heat shrinkage and the like, both dimensions are not substantially the same, and the former is different from the latter.

FIG. 12 shows an example of this deviation. The figure shows 2
Two neck tubes are shown together. FIG. 12 (a)
The tube axis of the neck tube 2 is connected to the narrow opening end 4 of the funnel-like body 15.
In this case, the neck tube is welded so as to coincide with the centers 9, 10. As shown, the funnel 15 and the centers 9, 10 of the neck tubes 2 welded to the funnel are:
There is a deviation from the centers 7, 8 defined as product specifications. As a result, a deviation also occurs in the mounting position of the electron gun sealed in the neck tube 2, so that the image resolution is reduced. FIG. 12 (b) shows a case where the tube axis of the neck tube 2 is welded so as to match the centers 7 and 8 of the product specification in order to eliminate this deviation. When the welding position is corrected in this manner, the external shape becomes poor and the strength of the welded portion of the neck tube decreases.

That is, in the case of a funnel sealed body having a single neck tube, it is easy to satisfy a predetermined dimension by controlling the conditions of molding and processing, but in the case of a funnel sealed body having a plurality of neck tubes, However, since the size of the welded portion of each neck tube is regulated, there is a disadvantage that it is difficult to obtain a funnel sealed body satisfying the product dimensional accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a funnel sealed body for a cathode ray tube, which has a plurality of neck tubes and these neck tubes conform to predetermined dimensions.

[0014]

According to the present invention, there is provided a funnel sealed body having two or more yoke mounting portions and a neck tube on a funnel base material, wherein a part of the yoke mounting portion has a wide-angle end. A funnel seal for a cathode ray tube characterized by being formed by an enlarged neck tube.

In this case, the funnel substrate has at least three reference projections on two adjacent sides of the side wall near the wide opening end, and serves as a reference surface in welding the neck tube or reforming the neck portion after welding. It is preferable to have

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a plurality of yoke mounting portions are provided on a funnel substrate. Usually, two yoke mounting portions are provided side by side along the long axis of the rectangular wide opening end portion, but the present invention is not limited to this. For example, three yoke attachment parts may be provided side by side, or four yoke attachment parts may be arranged at the vertices of a rectangle. Further, the cross section of the yoke mounting portion may be circular or square.

In the funnel sealing body of the present invention, a part of the yoke mounting portion, that is, a tip portion thereof is formed by an enlarged portion having a wide-angle end portion of the neck tube. Therefore, when molding the funnel base material, only the portion excluding the tip portion of the yoke mounting portion is simultaneously molded as a convex portion. The end of the convex portion is a narrow opening end, and the enlarged side of the neck tube whose tube end is enlarged in advance is welded to this end. The welding of the neck tube is performed by heating and softening the end portion and the narrow opening end portion of the neck tube as in the related art, but may be bonded by, for example, frit glass.

In the present invention, how much of the yoke mounting portion is formed by the neck tube is appropriately determined according to molding conditions, the size of the funnel base material, and the like. Usually, about 1/2 to 2/3 of the height h (see FIG. 5) of the yoke mounting portion is appropriate. Therefore, simultaneous molding as a convex portion during molding of the funnel base material is about 1/3 to 1/1 of the yoke mounting portion.
At 2, complement the rest with the neck tube. If this convex portion is smaller than 1/3 of the yoke mounting portion, the enlarged width of the neck tube end becomes large, and not only the forming process becomes difficult, but also the diameter of the neck tube end becomes large. The burden of welding work increases. On the other hand, if the yoke mounting portion exceeds half, the small-diameter yoke mounting portion is formed at the same time as the funnel base material, so that the above-described conventional method has a problem.

According to the funnel base material of the present invention, the relatively thin and small-diameter end portions of the plurality of yoke mounting portions are formed by the neck tube expanded to a wide-angle shape as described above. As a result, the yoke mounting portion formed by the mold is a portion that is continuous with the funnel base material, and therefore is a thick and large diameter portion. The yoke mounting part, which is integrally molded with the funnel substrate, is shortened by the amount complemented by the neck tube. The problem of cracking and die cutting can be eliminated.

The larger the yoke mounting portion formed as a convex portion on the funnel base material, that is, the higher the convex portion, the greater the deviation of the narrow opening end for welding the neck tube. In this case, since a part of the convex portion is complemented by the enlarged portion of the neck tube and the convex portion is shortened, this deviation can be reduced.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sealed funnel for a cathode ray tube according to the present invention. This example is a case of a funnel sealing body having two neck tubes. FIG. 1 is a front view and FIG. 2 is a plan view. As shown, the funnel sealing body 3 includes a funnel substrate 1 and two neck tubes 2 welded to the funnel substrate.

The funnel base material 1 has a substantially rectangular wide opening end 6 at one end, and two adjacent long sides and one short side are provided on the side wall near the end. The reference projection 5 is provided as a positioning means for convenience. Further, at the other end of the funnel substrate 1, two convex portions are formed as a part of the yoke mounting portion, and a narrow opening end portion 4 for welding the neck tube 2 is provided at the tip of the convex portion. are doing. The reference projection 5 does not have to protrude as long as it can function as a reference point for positioning.

As shown in FIG. 3, the neck tube 2 has a wide-angle enlarged portion 13 at one end, and the end of the enlarged portion has substantially the same diameter as the narrow opening end 4 of the funnel substrate 1 described above. Have. Such a neck tube can be easily obtained, for example, by enlarging one end of a conventional cylindrical neck tube in a heated and softened state. In this case, if the width is simply increased, the wall thickness is reduced. Therefore, in order to maintain the wall thickness, it is preferable to expand while compressing in the tube axis direction.

When the end of the neck tube 2 is formed in a wide-angle shape,
The maximum outer diameter D ₂ of the enlarged portion 13 is larger than the outer diameter D ₁ of the non-expanded portion.
It is desirable that the diameter be increased to satisfy the relationship of 2 ≧ D ₂ / D ₁ > 1. When D ₂ / D ₁ > 2, of course, funnel substrate 1
As described above, the outer diameter of the narrow opening end portion 4 becomes large, so that the welding operation of the neck tube is difficult as described above, which takes time and also deteriorates the quality of the welded portion. In this example, approximately D ₂ / D ₁ =
Is a 1.8 Experience D ₂ / D ₁ is 1.5 to 1.
9 is desirable.

When the neck tube 2 is welded to the narrow opening end 4 of the funnel substrate 1, the tube axis is perpendicular to a plane substantially determined by the end surface of the wide opening end 6 of the funnel substrate 1. To At this time, the two neck tubes 2 are welded to the reference projections 5 at predetermined positions 7 and 8 determined by design specifications even if the tube axes are shifted from the central axes 9 and 10 of the narrow opening end 4. That is, the two neck pipes 2 are welded so that the respective pipe axes coincide with the positions 7 and 8 at the predetermined distances X ₁₂ and X ₁₁ defined in the design specifications. As a result, the distance X between the two pipe shafts is obtained.
_{1 is} also as designed.

On the other hand, the funnel substrate 1 formed by a mold
The central axes 9 and 10 of the narrow opening end 4 are located at X ₀₂ and X ₀₁ respectively from the reference projection 5, and the interval between both axes at this time is X ₀ . In a state where the neck tube 2 is welded to the narrow opening end portion 4, the tube axis of the neck tube 2 and the central axes 9 and 10 of the narrow opening end portion 4 are such that the funnel substrate 1 is formed according to design specifications. If they match. However, since the funnel substrate 1 undergoes thermal shrinkage deformation, X ₀₁ and X ₀₂ generally deviate from X ₁₁ and X ₁₂ , respectively, and X ₀ does not coincide with X ₁ . FIG. 4 shows a state in which the neck tube 2 has been shifted and welded.

In the case of the present invention, even if the neck tube 2 is displaced with respect to the narrow opening end 4 in this way, the displacement amount is not so large because the narrow opening end 4 for welding the neck tube 2 is relatively thick. If it is not big enough, it can cope. When the thickness of the narrow opening end 4 is thin like the end of the conventional yoke mounting portion,
If the neck tube 2 is displaced, the tube end will come off the narrow opening end 4 or good welding will not be obtained until it does not come off. On the other hand, if the narrow opening end 4 is thick, the neck tube will be slightly displaced. Even so, the pipe end can be kept within the end face of the narrow opening end 4. It should be noted that such a displaced welded portion can be formed into a favorable shape by re-forming while it is in a heat-softened state.

FIGS. 5 and 6 show another welding method of the neck tube 2. In this method, as shown in FIG.
The central axis 9 of the narrow opening end 4 of the funnel substrate 1,
Weld to match 10. Usually, since the central axes 9 and 10 of the narrow opening end 4 cannot be obtained according to the product specifications, the tube axes (corresponding to 9 and 10) of the neck tube 2 are positioned at the original positions 7 and 8 determined by the product specifications. Occurs. Therefore, this method reshapes the welded portion while the welded portion is in a softened state by heating, moves the tube axis of the neck tube 2 to predetermined positions 7 and 8, and corrects the position of the neck tube. FIG. 6 shows the neck tube 2 after the position correction, and the dotted line is the neck tube before the correction. According to this method, the welded portion is not shifted as shown in FIG. 4, so that a good welded portion can be obtained.

For reference, the yoke mounting portion when the neck tube 2 is welded will be described with reference to FIG. 5. A portion h is the entire yoke mounting portion, and b is a funnel base material in the yoke mounting portion. 1 is a part integrally formed at the time of molding, and a is a part formed by the enlarged portion 13 of the neck tube 2.

Although the present invention has been described with reference to the deviation of the neck tube in the longitudinal direction of the funnel sealing body having a plurality of neck tubes, the present invention is similarly applicable to the deviation of the neck tube in the short axis direction. Works.

[0031]

According to the funnel sealing body for a cathode ray tube of the present invention, a part of the yoke mounting portion can be formed by the neck tube whose end portion is enlarged in a flared shape, so that a funnel base material for welding a plurality of neck tubes is provided. Can be reduced by that much. As a result, the molding of the funnel base material by the mold becomes easy, and the funnel base material can be manufactured efficiently and with high quality by the die molding.

Further, since the neck tube can be attached to the convex portion of the funnel base material with high accuracy with respect to the reference point of the funnel sealing body, the image resolution does not decrease due to the deviation of the mounting position of the electron gun. High quality cathode ray tubes can be manufactured.

[Brief description of the drawings]

FIG. 1 is a front view of a funnel sealing body according to an embodiment of the present invention.

FIG. 2 is a plan view of the funnel sealing body of FIG. 1;

FIG. 3 is a front view of a neck tube used for the funnel sealing body of FIG. 1;

FIG. 4 is a front view of a welded portion of the neck tube according to the present invention.

FIG. 5 is a front view of another welded portion of the neck tube according to the present invention.

FIG. 6 is a front view of a welded portion obtained by correcting the position of the neck tube of FIG. 5;

FIG. 7 is a sectional view of a conventional cathode ray tube.

FIG. 8 is a sectional view of another conventional cathode ray tube.

FIG. 9 is a front view of a conventional funnel-like body for a cathode ray tube.

FIG. 10 is a plan view of the funnel-like body for a cathode ray tube of FIG. 6;

FIG. 11 is a plan view of a funnel-like body for a cathode ray tube showing product specifications.

12A is a front view of a neck tube welding portion of a conventional funnel sealed body for a cathode ray tube, and FIG. 12B is a front view of another neck tube welding portion.

[Explanation of symbols]

 1: Funnel substrate 2: Neck tube 3: Funnel sealing body 4: Narrow opening end 6: Wide opening end 13: Enlarged part

Claims (2)

[Claims] 1. A funnel sealing body having two or more yoke mounting portions and a neck tube on a funnel base material, wherein a part of the yoke mounting portion is formed by a neck tube whose end is enlarged to a wide angle shape. A funnel sealed body for a cathode ray tube. 2. When the non-expanded outer diameter of the neck tube is D ₁ , and the outer diameter of the end expanded to a wide-angle shape is D ₂ , 2 ≧ D ₂ / D
_{2. The} funnel sealed body for a cathode ray tube according to claim 1, wherein ₁ > 1.