JPH1186756A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely reinforce a cathode-ray tube having a completely flat front panel and to provide high shock resistance by providing recesses which relax or avoid the collisions with mold match lines at the positions, corresponding to the mold match lines on the outer periphery of a panel section at four corner sections of the panel section of a reinforcing band. SOLUTION: A reinforcing band 21 is fastened on the outer periphery of the skirt section 1 Ps of a panel section 1 P. Recesses 22 for relaxing or avoiding collisions with mold match lines 3 are provided at the positions, corresponding to the mold match lines 3 on the outer periphery at four corners of the panel section 1 P on the inner face of the reinforcing band 21. As a result, the concentration of fastening force at the corner sections can be mitigated, and the fastening force applied to a tube body by the reinforcing band 21 can be distributed to the front side (front panel side) rather than the mold match lines 3 and the rear side (funnel side).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube in which a reinforcing band is fastened around a panel portion of a cathode ray tube, particularly a cathode ray tube body.

[0002]

2. Description of the Related Art FIG. 7 shows a schematic side view of a general cathode ray tube in various display devices such as a television picture tube, and FIG.
As shown in FIG. 1, the cathode ray tube 1 is composed of a panel 1P, a funnel 1F, and a neck 1N. The panel portion 1P is formed by integrally molding glass with a front panel 1Pf having an inner surface coated with a phosphor screen (not shown) and a skirt portion 1Ps extending rearward from the periphery along the tube axis direction. You. Then, the rear open end face 1Pa of the skirt portion 1Ps is abutted against the front open end face 1Fa of the funnel portion 1F, and is air-tightly joined by, for example, a glass frit.

In a cathode ray tube, since the inside of the cathode ray tube 1 is made to have a high vacuum, an external pressure equivalent to the atmospheric pressure is constantly applied to the tube 1, and especially, the panel In the front panel 1Pf of the portion 1P, a stress is generated which causes a concave deformation (hereinafter referred to as a vacuum deformation) toward the inside of the tube due to the atmospheric pressure. Therefore,
In a normal cathode ray tube excluding a small tube such as a projector tube, a reinforcing band 2 is tightened around the outer periphery of the panel portion 1P to recover the vacuum deformation of the front panel 1Pf, that is, lower the tension due to the vacuum deformation of the front panel 1Pf. In this way, the strength of the tubular body 1 is improved, and the impact resistance is enhanced.

For example, as shown in a perspective view of FIG. 9 and a perspective view of a part of the reinforcing band 2 shown in FIG. 9, a band-shaped metal plate is bent in a width direction to form a ring. As shown in FIG. 7, this configuration is fitted to the outer periphery of the skirt portion 1Ps of the panel portion 1P by a so-called shrink fit to tighten the outer periphery of the panel portion 1P.

FIG. 11 is a sectional view of a part of a panel portion 1P in which the reinforcing band 2 is fitted on the outer periphery. As described above, the panel portion 1P is generally formed by molding a glass, and therefore, a so-called mold match line 3 is formed in the skirt portion 1Ps by die-cutting. That is, the skirt portion 1Ps of the panel portion 1P has a maximum diameter at an intermediate portion in the tube axis direction, and gradually decreases its diameter toward the front panel portion 1Pf side and the rear end face 1Pa side. Since it is a cylindrical surface having a U-shape, its largest diameter portion becomes a so-called mold match line 3.

Therefore, when the reinforcing band 2 is tightened on the outer periphery of the skirt portion 1Ps, the tightening force of the reinforcing band 2 is concentrated on the mold match line 3 at its four corners, that is, at the four corners. The large tightening works, and the above-described vacuum deformation of the front panel 1Pf can be effectively suppressed.

However, recently commercialized front panel 1
In a cathode ray tube in which Pf has a completely flat surface, no matter how strongly the reinforcing band 2 is fastened to the outer periphery of the skirt portion 1Ps of the panel portion 1P, the vacuum deformation of the front panel 1Pf is always sufficiently suppressed. Can not do. 6C and 6D show reinforcing bands 2 at corners of panel portion 1P when front panel 1Pf is flattened.
6C schematically shows the force acting on the front panel 1Pf by FIG. 6C, and FIG.
This is the case from the viewpoint. In this case, the reinforcing band 2
In the direction along the diagonal line in the plane perpendicular to the pipe axis (hereinafter referred to as the σR direction) near the corner portion due to the tightening, a force in the compression direction acts, but in the plane perpendicular to the pipe axis, σR In the direction perpendicular to the direction (hereinafter referred to as the direction of σT), a force in the tension (tension) direction acts. In particular, when the front panel is a completely flat panel as described above, the force due to the tightening of the reinforcing band with respect to the panel portion 1P is smaller in the direction along the tube axis direction than in the case of the conventional general front panel having a curved surface. When the tightening of the reinforcing band is increased, the tensile stress in the direction of σT increases, and a peak of the tensile stress occurs near the corner of the front panel. Therefore, the external impact on the panel is weakest near this corner.

On the other hand, IEC (International Electro-Technical Commis
sion) ball impact test, etc., which is a specified test equipment, which fixes the cathode ray tube, applies a 5.5 J impact to a specified point on the front panel of the cathode ray tube with an iron ball, and is destroyed. In such a case, it is specified that the amount of glass scattering does not exceed a certain amount. The worst case in this test is 25 mm from the corner of the phosphor screen on the front panel.
X 25 mm point.

In order to enhance the impact resistance at the corners, it is necessary to lower the surface tension of the front panel. The most common method is to increase the thickness of the panel glass. Although it is simple, increasing the thickness of the glass in this way is not preferable because it increases the weight of the cathode ray tube.

[0010]

As described above, according to the present invention, even in a cathode ray tube having a completely flat type front panel, the reinforcing band can be reliably reinforced by a reinforcing band, and high impact resistance can be obtained. A cathode ray tube is provided.

[0011]

In the cathode ray tube according to the present invention, a reinforcing band is fastened to the outer periphery of the panel portion of the cathode ray tube body, and the reinforcing band is provided at four corners of the panel portion. At a position corresponding to the mold match line on the outer periphery of the panel portion, a recess is provided for relaxing or avoiding contact with the mold match line.

According to the structure of the present invention, the reinforcing band is provided with a recess for relaxing or avoiding the contact with the mold match line at the corner of the panel portion of the cathode ray tube, so that the tightening force at the corner is reduced. Since the concentration can be reduced, the tension in the σT direction described above can be reduced, and the tightening force acting on the pipe by the reinforcing band due to the presence of the recess can be reduced in front of the mold match line (front panel). Side) and the rear side (funnel side), and can be more effectively acted on the front side than the mold match line as compared with the conventional case, so that the compression in the σR direction can be increased. That is, σ
The compression in the σR direction can be increased without increasing the tension in the T direction.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cathode ray tube according to the present invention will be described. The cathode ray tube according to the present invention has a configuration in which a reinforcing band is tightened along a mold match line on a mold match line around a panel portion of the cathode ray tube body, and the panel portion of the cathode ray tube body is attached to the reinforcing band. At the four corners, a concave portion such as a slit or a groove is provided at a position corresponding to the mold match line on the outer periphery of the panel portion.

The reinforcing band has, for example, a ring shape along the outer periphery of the panel portion, and the ring-shaped reinforcing band is fitted to the outer periphery of the panel portion of the cathode ray tube by shrink fitting. That is, the ring-shaped reinforcing band is first heated and thermally expanded, and is placed along the outer periphery of the skirt portion of the panel portion of the cathode ray tube, and then contracted by cooling (cooling down). As a result, the skirt portion of the panel portion of the cathode ray tube is fastened from its outer periphery, that is, tightened. However, the reinforcing band is not limited to such a ring-shaped structure or a method of fitting by shrink fitting. For example, a belt-like band is wound around the outer periphery of the skirt portion of the panel portion and tightened. Various configurations can be adopted.

Next, an example of a cathode ray tube according to the present invention will be described in detail with reference to FIGS. FIG. 1 shows a schematic side view of an example of a cathode ray tube according to the present invention. Also in this example, the cathode ray tube 1 includes a panel portion 1P, a funnel portion 1F, and a neck portion 1N. Panel part 1
P is a glass panel in which a front panel 1Pf having a phosphor screen (not shown) formed by applying a phosphor on the inner surface thereof and a skirt portion 1Ps extending rearward from the periphery thereof along the tube axis direction are integrally formed. It is formed by molding. The front panel 1Pf is formed as, for example, a completely flat surface or a substantially flat surface. The skirt 1 of the panel 1P
In Ps, a mold match line 3 is generated by die cutting. In the panel portion 1P, the rear opening end surface 1Pa of the skirt portion 1Ps is abutted against the front opening end surface 1Fa of the funnel portion 1F, and is air-tightly joined by, for example, a glass frit.

The skirt portion 1Ps of the panel portion 1P
The reinforcing band 21 is tightened around the outer periphery of the slab. FIG. 2 is a cross-sectional view of a corner portion of the panel portion 1P in which the reinforcing band 21 is fitted on the outer periphery. On the inner surface of the reinforcing band 21, recesses 22 are provided at four corners of the panel portion 1P at positions corresponding to the mold match line 3 on the outer periphery thereof to alleviate or avoid the contact with the mold match line 3. Become.

As shown in the sectional view of FIG. 4A or B, the reinforcing band 21 is formed by cutting a band-shaped metal plate folded in a hairpin shape in the width direction into two along the peripheral surface of the skirt portion 1Ps of the panel portion 1P. For example, as shown in FIG. 3, the connecting plate 23 can be welded into a ring shape over both ends of the metal plate. When the reinforcing band 21 is tightened to the outer periphery of the skirt portion 1Ps of the panel portion 1P of the cathode ray tube 1 only at the inner corner portion of the reinforcing band 21, it exactly matches the mold match line 3. At the contact position, this mold match line 3
Is formed along the mold match line 3, that is, to reduce or avoid the contact with the mold match line 3. These recesses 22 are, as shown in FIG. 4A or FIG. 4B, of the two folded plate portions.
It can be configured by forming a slit 22s or a groove 22g in the first plate portion 21A on the side located inside the ring.

Next, an example of a method of manufacturing the ring-shaped reinforcing band 21 will be described with reference to FIGS. First, as shown in FIG. 5A, for example, a band-shaped flat metal plate 31 having a thickness of 1 mm
For example, it is prepared by cutting from a metal plate of Fe. As shown in FIG. 5B, the flat metal plate 31 is formed at the position where the above-described recess 22 formed in the target reinforcing band is formed.
The slit 22s or the groove 2 described in FIG.
2 g is formed by press working or the like. As shown in FIG. 5C, the band-shaped metal plate 31 is
Fold it up. In this case, the folded first plate portion 2
1A and a second plate portion 21B, the respective widths W ₁ and W
_{When 2} is set, W ₁ > W ₂ . Then, the slit 22s or the groove 22g is formed in the wide first plate portion 21A.
22s or groove 22g so that
Is selected, such as a formation position, a folding position, and the like.

In this manner, the recess 22 is formed, and the folded metal plate 31 is folded as shown in FIG.
The cathode ray tube tube 1 is formed into a shape along the periphery of the skirt portion 1Ps of the panel portion 1P, that is, in a ring shape, for example, by pressing using a mold, and is formed into a ring shape and straddles both ends of the metal plate. The ring 23 is welded to form a ring-shaped reinforcing band 21. The reinforcing band 21 is provided with, for example, an ear-shaped mounting member 41 having a mounting hole (not shown) for mounting the cathode ray tube according to the present invention to a fixed portion such as a chassis or a cabinet. Attach to the four corners by welding or the like. Then, the ring-shaped reinforcing band 21 formed as described above is fitted around the outer periphery of the skirt portion 1Ps of the panel portion 1P of the cathode ray tube 1 by shrink fitting. That is, the reinforcing band 21 is heated and fitted on the mold match line 3 on the outer periphery of the skirt portion 1Ps of the panel portion 1P, thereby lowering the temperature. In this case, the reinforcing band 21 contracts with the temperature decrease, and the reinforcing band 21 is placed on the outer periphery of the skirt portion 1Ps.
The panel portion 1P is firmly fitted so as to be tightened. In this case, the bending edge of the reinforcing band 21 is
That is, it is positioned on the front panel 1Pf side so that the double structure portion of the first and second plate portions 21A and 21B is located on the front side of the mold match line 3, and on the rear side of the mold match line 3, At least at the rear edge thereof, only the first plate portion 21A is arranged, so that it is arranged asymmetrically on the front side and the rear side of the mold match line 3. Further, each recess 22 is positioned so as to face the mold match line 3 at the corner.

As described above, in the cathode ray tube according to the present invention, the reinforcing band 2 having the recess 22 formed at the corner corresponding to the mold match line 3 corresponds to the outer periphery of the skirt 1Ps of the panel 1P. With this configuration, excellent shock resistance can be obtained even when the front panel 1Pf is flat. That is, in the case of this configuration, the reinforcing band is provided with the concave portion 22 for relaxing or avoiding the contact with the mold match line 3 at the corner portion of the panel portion 1P of the cathode ray tube 1, so that the tightening force at the corner portion is reduced. Since concentration can be reduced, FIGS. 6A and 6B show schematic diagrams of the force acting on the front panel 1Pf by the reinforcing band 21 when viewed from the front and when viewed from the side thereof. Since the tightening force can be dispersed as shown by arrows a ₁ and a ₂ in FIG. 6A, the tension in the σT direction at the corner portion can be reduced, and the presence of the recess allows the reinforcing band 21 to be used. The tightening force acting on the tube 1 is changed to the front side (front panel side) and the rear side of the mold match line 3. Funnel side)
6B, it can be dispersed as schematically shown by arrows b ₁ and b _2, and in this example, over a wider width in front of the mold match line 3 than in the rear. With the double structure of the first and second plate portions 21A and 21B, the fastening force can be increased on the front side, and the center of gravity of the fastening force can be brought forward. ΣR without increasing the tension in the σT direction more effectively.
Direction compression can be increased.

In the above-described example, as shown in FIG. 5B, a slit 22 forming a recess is formed in a flat metal plate 31.
The case where the s or the groove 22g is formed by press working or the like is not limited to the above-described example, for example, it can be formed by press forming or the like when forming a ring. Further, in the above-described example, although the metal sheet is folded in two to increase the front-side tightening force, the present invention is not limited to such a configuration, and the cross-sectional shape of the panel portion 1P, the tightening position of the reinforcing band, and the like. The same effect can be obtained by selecting the above. In addition, reinforcement band 2
Is not limited to a configuration in which a ring is previously formed as in the above-described example.
Various configurations, such as a configuration of winding around the outer periphery of P, can be adopted.

[0022]

As described above, according to the present invention, the reinforcing band is provided with the concave portion for relaxing or avoiding the contact with the mold match line at the corner of the panel portion 1P of the cathode ray tube tube 1. As a result, the concentration of the tightening force at the corners can be reduced,
The above-mentioned tension in the σT direction can be reduced, and the tightening force acting on the pipe by the reinforcing band due to the presence of the concave portion is reduced by the forward side (front panel side) and the rear side (funnel side) of the mold match line. , And can effectively act on the front side of the mold match line as compared with the related art, so that the compression in the σR direction can be increased. That is, the compression in the σR direction can be increased without increasing the tension in the σT direction, and a necessary and sufficient impact resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an example of a cathode ray tube according to the present invention.

FIG. 2 is a sectional view of a main part of a tightening portion of a reinforcing band of an example of the cathode ray tube according to the present invention.

FIG. 3 is a perspective view of an example of a reinforcing band of a cathode ray tube according to the present invention.

FIGS. 4A and 4B are cross-sectional views of an example of a reinforcing band of a cathode ray tube according to the present invention.

FIGS. 5A to 5C are diagrams showing a process of manufacturing a reinforcing band as an example of the cathode ray tube according to the present invention.

FIGS. 6A and 6B are explanatory diagrams of the operation of the reinforcing band in the cathode ray tube according to the present invention. C and D are explanatory views of the operation of a reinforcing band in a conventional cathode ray tube.

FIG. 7 is a schematic side view showing an example of a conventional cathode ray tube.

FIG. 8 is a schematic side view showing an example of a conventional cathode ray tube.

FIG. 9 is a perspective view of a reinforcing band of a conventional cathode ray tube.

FIG. 10 is a partial perspective view of a cross section of a part of a reinforcing band of a conventional cathode ray tube.

FIG. 11 is a cross-sectional view of a main part of a conventional cathode ray tube.

[Explanation of symbols]

1 ... Cathode tube body, 1P ... Panel part, 1Pf
..Front panel, 1Ps ... skirt part, 1Pa ...
・ Rear open end face, 1F ... Funnel part, 1Fa ...
Front opening end face, 1N: Neck, 2, 21 ... Reinforcement band, 3: Mold match line, 22 ...
Recess, 22 s ... slit, 22 g ... groove, 31.
..Metal plates, 41 ... Mounting members

Claims (4)

[Claims] 1. A reinforcing band is fastened to an outer periphery of a panel portion of a cathode ray tube tube. The reinforcing band is provided at a position corresponding to a mold match line on an outer periphery of the panel portion at four corners of the panel portion. A cathode ray tube provided with a recess for relaxing or avoiding contact with the mold match line. 2. The cathode ray tube according to claim 1, wherein a front panel of the cathode ray tube has a flat surface. 3. The method according to claim 1, wherein the reinforcing band has a ring shape, and the ring band is fitted around the outer periphery of a panel portion of the cathode ray tube by shrink fitting.
A cathode ray tube according to claim 1. 4. The cathode ray tube according to claim 1, wherein the recess is constituted by a slit or a groove formed in a reinforcing band.