JPH06208833A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To achieve excellent explosion-proof effect by using a cloth tape consisting of a dense part and a coarse part in terms of cloth density, as a noncombustible cushioning material. CONSTITUTION:A noncombustible cushioning material 22 is wound around the vicinity of a front maximum outer peripheral part of a panel 1. The cushioning material 22 comprises glass cloth tape consisting of a dense part and a coarse part in terms of the cloth density. The cloth density of the cushioning material 22 is approximately 50 pieces/25mm in the side of a phosphor surface 4, while it is 15 pieces/25mm in the side of a funnel into which an adhesive is to be injected. A metal band 23 is tightly fastened on the cushioning material 22. The adhesive to be injected between a panel 1 and the band 23 after heating and exhausting processes, is surely permeated into the cushioning material 22, while the adhesive is not leaked, and the adhesion area between the panel 1 and the band 23 is expanded. The adhesive force between the panel 1 and the band 23 is thus increased, even when a bulb body is destructed and implodes, dispersion of glass fragments is minimized, and the explosion-proof effect can thus be improved.

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, and more particularly to a color cathode ray tube used for displaying a color image.

[0002]

2. Description of the Related Art In a color cathode ray tube in which the inside of the tube is evacuated to a high vacuum, a pressure corresponding to the atmospheric pressure is applied from the outside, so if the tube is damaged or impacted, There is a risk that the tube may be suddenly broken or imploded, causing glass fragments to scatter. As a countermeasure against such a situation, currently, in general, a metal band is tightened in the vicinity of the front maximum outer peripheral portion of the tubular body of the color cathode ray tube to relieve stress due to atmospheric pressure and suppress the propagation of cracks. Even if the air-tightness is broken due to the destruction of the glass, explosion-proof measures are taken to prevent the occurrence of implosion such that the glass is widely scattered.

FIG. 18 is a schematic sectional view showing a color cathode ray tube having such explosion-proof means. As shown in the figure, a panel 1 and a funnel 2 having a neck portion 3 constitute a tubular body, and a fluorescent surface 4 is provided on the inner surface of the panel 1.
A shadow mask 5 is provided so as to face the fluorescent screen 4, an electron gun 11 is provided at the neck portion 3, a cushioning material 20 is wound near the front maximum outer peripheral portion of the panel 1, and is tightened from above the cushioning material 20. It is fastened by a metal band 21 for preventing implosion, which is composed of a band and a mounting lug.

When manufacturing this color cathode ray tube,
After the heating and exhausting process of the pipe body is completed, the explosion-proof means such as the metal band 21 is provided. However, in order to release the adsorbed gas from the tubular body and the parts inside the tubular body, the tubular body is heated to about 400 ° C. in the exhausting process, so due to the temperature increase, the vacuum degree in the tubular body, and the atmospheric pressure gradually applied from the outside,
Even in the heating and exhausting process, stress is generated in each part of the pipe body. Further, when the heating and exhausting process is completed and the product is taken out of the exhaust furnace and exposed to the outside air at room temperature, the tube is rapidly cooled, so that stress also occurs at this time. Therefore, if the pipe is scratched or impacted, there is a great risk that the pipe will be suddenly broken or imploded and the glass will scatter during the heating / exhausting process or during unloading. Glass fragments are scattered and pollute the inside of the furnace.

In recent years, there is a tendency to prefer a flat face color cathode ray tube having a large display screen and a nearly flat surface, but such a color cathode ray tube is particularly likely to be imploded. Therefore, the thickness of the panel 1 is increased for safety, but in this case, the manufacturing cost is high and the time required for manufacturing is long because the temperature rising / falling rate must be suppressed. .

According to Japanese Patent Laid-Open No. 62-5533, a heat resistant heat insulating material is wound around the front maximum outer peripheral portion of the panel 1 before the heating and exhausting step, and the heat resistant heat insulating material is tightened with a metal band 21. Then, it is considered to heat and exhaust.

This method is effective in preventing destruction during rapid cooling when it is discharged from the exhaust furnace, and it is possible to reduce the thickness of the panel 1 and, at the same time, to reduce the thickness of the panel 1 by a thermal process. Can be shortened.

[0008]

However, when a glass cloth coated with an adhesive on both sides or one side is used as the heat resistant heat insulating material, the adhesive which is generally an organic substance burns at a high temperature in an exhaust furnace, The explosion-proof effect is drastically reduced because the color cathode ray tube itself in the exhaust furnace is contaminated and the adhesive of the heat resistant heat insulating material is lost.

Therefore, before the heating and exhausting step, the panel 1 is
A non-combustible cushioning material not coated with an adhesive is wound around the maximum outer peripheral portion in front of, and the non-combustible cushioning material is fastened with a metal band 21. Panel 1 by injecting a different adhesive
It is considered that the adhesive strength between the metal band 21 and the metal band 21 is provided, but if the cloth cloth tape as the non-combustible cushioning material has a high cloth density, the adhesive does not penetrate, and the glass cloth tape has a low cloth density. Then, the adhesive leaks. Therefore, in any case, the panel 1 and the metal band 2
The adhesive strength with 1 becomes small, and the explosion-proof effect cannot be improved so much.

The present invention has been made to solve the above problems, and an object thereof is to provide a color cathode ray tube having a good explosion-proof effect.

[0011]

In order to achieve this object, in the present invention, a non-combustible cushioning material is wound around the front maximum outer peripheral portion of the panel, and a metal band is tightened on the non-combustible cushioning material. In the above cathode ray tube, a cloth tape composed of a dense portion and a coarse portion of the cloth density is used as the non-combustible cushioning material.

[0012]

In this cathode ray tube, the adhesive injected between the panel and the metal band after the heating and evacuation process surely permeates and does not leak liquid, so that the bonding area between the panel and the metal band expands. , The adhesive force between the panel and the metal band increases.

[0013]

EXAMPLES The color cathode ray tube according to the present invention will be specifically described below with reference to examples.

FIG. 14 is a schematic sectional view showing a color cathode ray tube according to the present invention. In the figure, 1 is a panel,
2 is a funnel, 3 is a neck part, 4 is a fluorescent screen (screen),
5 is a shadow mask, 6 is a magnetic shield, 7 is a deflection yoke, 8 is a purity adjusting magnet, 9 is a center beam static convergence adjusting magnet, 10 is a side beam static convergence adjusting magnet, 11 is an electron gun, Bc is a center beam, Bs Is a side beam.

Convergence adjustment (static convergence) of such a color cathode ray tube is performed by first obtaining the convergence of the two side beams Bs and Bs, and then
The center beam Bc and the convergence points of the side beams Bs are concentrated.

On the outer surface of the panel 1, a thin film containing, for example, SnO ₂ , In ₂ O ₃ or the like, which prevents reflection and electrification, is formed in a single layer or multiple layers if necessary. further,
An inner conductive film (not shown) made of graphite or the like is coated on the inner surfaces of the funnel 2 and the neck portion 3. The inner conductive film contains graphite and titanium dioxide etc. in addition to graphite for the purpose of suppressing arcing. It controls the value. The interior conductive film electrically connects the high voltage terminal (not shown) to the electron gun 11.

FIG. 2 is a sectional view showing a part of the electron gun of the color cathode ray tube shown in FIG. 14, and the third grid (G ₃ ) and the fourth grid (G ₄ ) constituting the bipotential type main lens. FIG. 3 is a horizontal and vertical sectional view of FIG. In the figure, 111 is the outer periphery of the third grid, 121 is the outer periphery of the fourth grid, and 13 is the cup electrode. 112
Is an electrode plate for correcting astigmatism provided inside the outer peripheral portion 111 of the third grid, and 122 is the outer peripheral portion 12 of the fourth grid.
1 is an electrode plate for correcting astigmatism provided inside 1. The pole plate 112 is provided with a central aperture 114 through which the central beam passes and outer apertures 113 and 113 'through which the outer beam passes, and the polar plate 122 includes a central aperture 124 through which the central beam passes and outside. Outer holes 123, 1 through which the beam passes
And 23 'are provided in a line. In this embodiment, the openings 113, 113 ', 114, 123, 123'124 are elliptical, and the openings and the corresponding openings on the third grid side and the fourth grid side have the same shape and size. Outer holes 113, 113 ', 123, 123' and central hole 11
When 4 and 124 have the same shape and the same size, the lens focusing action in the horizontal direction of the main lens formed on the outer side becomes stronger, so that the outer holes 113, 113 ', 123, 1
The diameter of 23 'in the horizontal direction is made larger than the inner diameters of the central holes 114, 124 in the horizontal direction so as to equalize the focusing action in both the horizontal and vertical directions.

FIG. 3 shows that in the embodiment shown in FIG. 2, the outer peripheral portions 111 and 121 have a horizontal diameter h = 20.0 mm, the vertical diameter v = 9.4 mm, and the central holes 114 and 124 have a vertical diameter. a ₁ = 8.4 mm, retreat amount of the electrode plate 112 d ₁ =
When 1.5 mm and the eccentric distance S = 6.6 mm, the ratio of the focus distances in both the horizontal and vertical directions to the horizontal diameter b ₁ of the central apertures 114 and 124 is obtained by computer simulation.

The term "horizontal or vertical focus distance" as used herein refers to an electron beam which is emitted from a point on the central axis at a certain emission angle and which passes through the horizontal or vertical symmetry axis of the central apertures 114 and 124 as the main lens. Is measured from the end surface of the third grid on the side of the fourth grid, where the distance from the third grid to the point where the center axis is crossed again. The distance from the same end surface to the fluorescent screen is set to 340 mm, emission points at which the emission angles match this value of 340 mm are obtained, and the electron beam is emitted from the intermediate point between these emission points at the same emission angle. FIG. 3 shows the ratio of the focus distances in both the horizontal and vertical directions at this time. As can be seen from the figure, if the horizontal diameter b ₁ ≈5.5 mm,
Since the vertical and horizontal focus distances match and the focusing action in both directions becomes equal in intensity, astigmatism can be eliminated.

The lens focusing action at this time is 1 m.
It has the same strength as a cylindrical bipotential lens with a diameter of 8 mm, which is abutted at an interval of m.

This is h = 20.0 mm, S = 6.6 mm
Then, L = h−2 × S (L = the limit value of the opening diameter,
The value is larger than the limit value of 6.8 mm for the electrode opening portion which is restricted by h = horizontal diameter of the opening and S = eccentric distance of the opening portion).

FIG. 4 shows the embodiment shown in FIG.
The relationship between the value of the horizontal diameter b ₂ of 3 ', 123, 123' and the horizontal spot movement distance of the outer electron beam on the fluorescent screen is obtained by computer simulation. 7kV for 3rd grid, 25k for 4th grid
V was applied and the distance from the fourth grid side end of the third grid to the phosphor screen was 340 mm. Since the outer electron beam and the central electron are separated by 6.6 mm in the horizontal direction, the spot movement distance required to obtain STC is 6.6 mm, but in reality the degree of freedom in color purity adjustment is increased. In order to leave it, it is often designed to be about 6.1 mm. In order to secure this movement distance, the value of the horizontal diameter b ₂ is 5.8.
mm.

FIG. 5 is a sectional view showing a main part of an electron gun of another color cathode ray tube according to the present invention, and is a view showing a vertical section of a third grid. The outer openings 41, 41 'and the central opening 42 provided in the electrode plate 112 have a shape in which the end points of two arcs are connected by two parallel straight lines. Aperture 41,
41 'and 42 are worse in spot shape on the phosphor screen 4 than the elliptical apertures, but since the apertures 41, 41' and 42 consist of arcs and straight lines, they have the advantage that they can be easily and accurately machined. Hold. Also in this embodiment, the openings 41, 4
The horizontal diameter of 1 ', 42 is smaller than the vertical diameter.

FIGS. 6 and 7 are cross-sectional views showing the main parts of an electron gun of another color cathode ray tube according to the present invention, which are cross-sectional views of the third grid and the fourth grid in the vertical direction, respectively. The central apertures 52, 62 have vertical symmetry axes, while the outer apertures 51, 51 ', 61, 61' do not have vertical symmetry axes. The outer openings 51, 51 ', 61, 61' are a combination of two ellipses having the same major axis and different minor axes. In the third grid, as shown in FIG. 6, the outer openings 51 and 51 'are formed by combining two ellipses whose minor axis of the outer ellipse is smaller than that of the inner ellipse. When the outer openings 51, 51 'of the third grid are formed in such a shape, the force for concentrating the electron beam toward the center is larger than that of one elliptical opening like the outer openings 113, 113' of FIG. Since ST becomes stronger, STC can be obtained even if the diameter in the horizontal direction is made smaller. On the contrary, in the fourth grid, as shown in FIG. 7, the outer openings 61, 61 'are formed by combining two ellipses whose minor axis of the inner ellipse is smaller than that of the outer ellipse. , The force to concentrate the electron beam toward the center becomes stronger.

In this way, the outer openings 51, 51 ', 6
When 1, 61 'are made asymmetric with respect to the vertical direction, the concentration of the electron beam is increased and the STC can be easily obtained. Further, if the concentration is too strong, the concentration can be weakened by using the holes of FIG. 6 on the fourth grid side and the holes of FIG. 7 on the third grid side.

In such a color cathode ray tube, red, green and blue 3 are formed on the same horizontal plane while the outer shape of the electron gun is restricted.
It is possible to construct a main lens with a weaker focusing effect than when a cylindrical electrode with the largest diameter is possible when arranging the main lenses corresponding to colors in parallel. There is an effect that can be remarkably improved.

Furthermore, the amount of retreat of the electrode plate and the shape of the hole formed in the electrode plate can be adjusted without displacing the central axes of the outer holes formed in the third and fourth grids forming the main lens. Since the STC can be obtained by selecting properly, a jig having the same diameter and the same axis can be used for the third grid and the fourth grid at the time of assembly, and the assembly accuracy can be improved.

FIG. 8 is a partially cutaway perspective view showing an essential part of an electron gun of another color cathode ray tube according to the present invention. Electrode plate 13
3, 143 have elliptical apertures 135, 145 respectively for the central beam as in the pole plate of FIG. 2, but for the side beams on both sides the elliptical aperture is cut in half,
Portions in contact with the outer peripheral electrodes 131 and 141 at both left and right ends are removed. The passage of the central beam is defined by the pole plates 133, 14
3, the side beam passages on both sides are partially surrounded by the ends of the electrode plates 133 and 143, and the remaining portions are surrounded by the outer electrodes 131 and 141. Surrounded by. With this configuration, the diameter of the main lens for the side beam can be maximized, and since the area of the electrode plate is small, it is easy to increase the flatness and the elliptical aperture forming part that requires high accuracy. Since it has a small amount, there is an advantage that processing becomes easy. d ₃ and d ₄ represent the amount of retreat, and either the same or different values are adopted.

In the embodiment shown in FIG. 8, the shape of the aperture is an ellipse, but if the diameter of the aperture in the vertical direction is larger than the diameter in the horizontal direction, the astigmatism can be removed with other shapes.

Further, as shown in FIG. 9, the electrode plates 133,
The astigmatism can also be removed by a structure in which 143 is curved and the retreating amounts of the pole plates 133 and 143 are continuously changed. At this time, the vertical diameters of the openings 135 and 145 do not necessarily have to be larger than the horizontal diameter. When the electrode plate 133 of the third grid is convex on the fourth grid side as shown in the drawing, the horizontal focusing force can be strengthened, and conversely, the electrode plate 143 of the fourth grid is convex on the third grid side. Then, the vertical focusing force can be increased.

Further, as shown in FIG.
It is also possible to correct the astigmatism by providing protrusions 137 and 147 around 5, 145 and adjusting the protrusion amount of the protrusions 137 and 147. Also in this case, the opening 135,
The vertical diameter of 145 need not be larger than the horizontal diameter.

In the embodiment shown in FIGS. 9 and 10, the opening 13
It is possible to correct astigmatism while leaving 5, 145 as perfect circles, and in this case, there is an advantage that both component processing and electrode assembly are easier than in the case of non-circular apertures.

According to this embodiment, the halo generated in the inner direction of the side beam can be removed, the effective aperture diameter of the main lens of the electron gun 11 can be sufficiently enlarged, and the focusing characteristics can be remarkably improved. There is. In addition, since the areas of the electrode plates of the main lens that face each other are small, flatness can be easily obtained during processing, and further, since there are relatively few processing points, molding is easy.

The cathode ray tube electron gun according to the present invention can of course be applied to the main lens of the above-mentioned bipotential type or any other type. Further, in the above description, an example in which the present invention is applied to both of the pair of grids forming the main lens has been described, but the same effect can be obtained by applying the present invention to only one of the grids.

FIG. 11A is a front view showing an electron gun of a color cathode ray tube according to the present invention, FIG. 11B is a side view thereof, FIG. 11C is a rear view thereof, and FIG. 11 in the figure
11 is the first grid, 1112 is the second grid, 111
3 is a third grid, 1114 is a fourth grid, 1115
Is a fifth grid, 1116 is a sixth grid, and 1119 is a cathode. This electron gun uses multiple main lenses,
Good focus characteristics can be obtained. In order to obtain a bright and high-resolution image, it is necessary to increase the value of the anode voltage Eb, and the anode voltage Eb is usually 25 to 35 kV. The focus voltage Ec ₃ is about 30% of the anode voltage Eb, the applied voltage Ec ₂ of the second grid 1112 is about 400 to 700 V, the first grid 1111 is grounded, and the cathode 111
A signal voltage Ek of 200 V or less corresponding to the brightness of each picture element is applied to 9. Further, 1127 is a third grid power supply line, 1128 is a fifth grid power supply line, and one end 1127a of the third grid power supply line 1127 is fixed to the third grid 1113 as shown in FIGS. 11B and 11C. At the same time, a part of the intermediate portion 1127b is formed as a bent portion 1127c extending substantially parallel to a plane orthogonal to the tube axis, and the bent portion 112
7c is passed through the middle of the rear surface of the bead glass 1120 and the inner wall surface (not shown) of the neck portion 3 within the overall length 1 of the third grid 1113 in the tube axis direction, and the other end 1127d is a stem lead (not shown). ) Is connected with. This causes the same operation as the shield wire. On the other hand, the fifth grid connecting the third grid 1113 and the fifth grid 1115
As shown in FIGS. 11A and 11B, the grid feeder 1128 has one end 1128a fixed to the third grid 1113 and the other end 1128d fixed to the fifth grid 1115, and a part of the intermediate portion 1128. Is a bent portion 1128c extending substantially parallel to a plane orthogonal to the tube axis, and the bent portion 1128c is the total length 1 of the third grid 1113 in the tube axis direction.
It is arranged symmetrically on the same plane inside the bent portion 1127c and the tube axis with the tube axis sandwiched therebetween, and the intermediate portion between the back surface of the bead glass 120 and the inner wall surface of the neck portion 3 is passed therethrough, similarly to the shield wire. Perform an action. That is, the bent portion 1
Since the tube axis is sandwiched between 127c and the bent portion 1128c and symmetrically arranged in the same plane orthogonal to the tube axis, the whole circumference in the neck portion 3 is larger than that in which the shield wire is arranged only on one side. It has an excellent feature that it exhibits the effect of suppressing arc discharge over the entire range.

Further, as in this embodiment, the third grid 11
By arranging both the bent portions 1127c and 1128c symmetrically across the tube axis within the total length of 13 in the tube axis direction, the number of arc discharge occurrences can be reduced to a fraction or less as compared with the conventional one. At the same time, the dark current value can be reduced to a few hundredths or less. That is, in terms of shielding the bead glass and the wall of the neck tube from the anode voltage, it is better to provide the bent portion near the grid to which the anode voltage is applied. It is also possible that arc discharge easily occurs. On the other hand, when the bent portion of the focus voltage applying power supply line is too close to the second grid side, the focus voltage is as high as the anode voltage. The risk of generating a low voltage application electrode and arc discharge increases.

Regarding the position of the bent portion of the focus voltage applying power supply line, the bent portion was examined based on various experiments based on various effects such as arc discharge suppressing effect, dark current suppressing effect, and electrode assembly workability. Is the total length l of the third grid in the tube axis direction
Optimally, it is provided at a position facing the side surface inside.

According to this embodiment, since both ends of the power supply line are fixed to the electrodes and the like, there is no fear of becoming a source of stray electrons, and there are effects of preventing arc discharge and suppressing dark current.

Next, FIG. 12 is a partially cutaway perspective view showing details of an example of the fluorescent screen 4 and the shadow mask 5 of the color cathode ray tube shown in FIG. 14, and the fluorescent screen 4 formed on the inner surface of the panel 1 part. Is a light-absorbing strip 2 that extends seamlessly in the vertical direction.
24 are arranged side by side in the horizontal direction, and these light absorption strips 224
A plurality of red phosphor strips 225R, green phosphor strips 225G, and blue-green phosphor strips 225B, each of which has a different emission color and extends seamlessly over the entire vertical direction, are arranged in a horizontal direction in a fixed order. A large number of them are arranged, and the curved surface corresponding to the inner surface of the panel 1 is arranged corresponding to the fluorescent surface 4, and the shadow mask 5 corresponds to the fluorescent strip 225 which extends without interruption over the entire vertical direction. The slit-shaped through holes 228, which are elongated in the vertical direction and are separated from each other through the bridge portion 229 in the vertical direction, are arranged in a row at a predetermined pitch in the horizontal direction.

As another shape of the phosphor screen 4, FIG.
As shown in FIG. 5, it has dot-shaped red phosphor fine dots 226R, green phosphor fine dots 226G, blue phosphor fine dots 226B, and a light absorption film 227 filling the surroundings.

The shadow mask 5 is made of a steel plate material, an amber material having a small thermal expansion coefficient, or the like. Further, although not shown, the shadow mask 5 may be covered with, for example, bismuth, which suppresses thermal expansion. Further, instead of the slit-shaped through hole 228, a round through hole is also used.

FIG. 16 shows a flat panel 1 according to the present invention.
FIG. 17 shows a part of the color cathode ray tube shown in FIG. 16 in which a non-combustible cushioning material 22 is wound around the skirt part of and a metal band 21 is tightened on the color cathode ray tube. It is sectional drawing shown.

As shown in FIG. 17, a non-combustible cushioning material 22 is wound around the front maximum outer peripheral portion of the panel 1. The non-combustible cushioning material 22 is made of glass cloth tape, and the non-combustible cushioning material 22 is provided with a dense portion and a coarse portion of the cloth density. That is, as shown in FIG. 15, the cross density of the non-combustible cushioning material 22 is 50 pieces / 25 mm on the phosphor screen 4 side.
It is about 15 mm / 25 mm on the funnel 2 side where the adhesive is injected. A metal band 21 is tightened on the non-combustible cushioning material 22.

Next, a method for tightening the metal band 21 will be described. First, a non-combustible cushioning material 22 to which no adhesive is applied is wound around the front maximum outer peripheral portion of the panel 1 provided with the fluorescent screen 4. With respect to the metal band 21, both ends of the band are welded to form a frame shape according to the outer peripheral shape and size of the panel 1 at the place to be tightened with the metal band 21 in advance. Let it expand by heating,
It is put on the non-combustible cushioning material 22 and cooled and tightened.
Thereafter, the panel 1 and the funnel 2 are fusion-bonded to each other with a low-melting glass, and the electron gun 11 is fusion-sealed in the neck portion 3 together with the glass stem having the exhaust pipe to form a tubular body. In the evacuation process, in order to release the gas adsorbed on the surface of each part of the pipe body, about 400
While heating to ℃, the gas in the tube is exhausted by an exhaust pump through an exhaust tube provided in the glass stem. Finally, an adhesive made of acrylic resin is injected from the funnel 2 side. In this case, an adhesive having a shear adhesive strength in the range of 3 to ²⁰ kg / cm ² is used. The viscosity of the adhesive should be determined according to the cross density of the non-combustible cushioning material 22,
The viscosity of the adhesive can be up to about 20-200 cp,
About 100 cp is preferable.

As described above, the cross density of the non-combustible cushioning material 22 is about 50 pieces / 25 mm on the side of the phosphor screen 4 and about 15 pieces / 25 mm on the side of the funnel 2, so that the panel 1 and the metal band are heated and exhausted. Since the adhesive injected between the panel 1 and the metal band 21 is surely permeated into the non-combustible cushioning material 22 and the adhesive does not leak.
The adhesion area with For this reason, since the adhesive force between the panel 1 and the metal band 21 is increased, even if the tubular body is broken and implodes, the scattering of glass fragments is suppressed to a minimum and the explosion-proof effect is good. Also, the shear adhesive strength is 3
Since the adhesive in the range of up to ²⁰ kg / cm ² is used, the propagation speed of cracks at the time of implosion is low and the adhesive strength is large, so that the explosion-proof effect can be further improved.
Further, in the above-mentioned tightening method, since heating and exhausting are performed after tightening the vicinity of the front maximum outer peripheral portion of the panel 1 with the metal band 21, there is a risk of explosion proof even during the heating and exhausting step or in the rapid cooling state thereafter. Since the adhesive is injected after heating and exhausting, the pipe body and the inside of the exhaust furnace are not contaminated during the heating and exhausting process.

Although the panel 1 and the funnel 2 are fusion-bonded to each other with the low melting point glass after the metal band 21 is attached to the panel 1 in the above-described embodiment, the panel 1 and the funnel 2 are connected with the low melting point glass. The metal band 21 may be attached after fusion bonding. Also, as shown in FIG.
It goes without saying that in the metal band 23 in which the adhesive injection portion 23a is provided on the metal band 21, the workability of the adhesive injection work is significantly improved and the same effect can be obtained.

[0047]

As described above, in the cathode ray tube according to the present invention, since the adhesive force between the panel and the metal band becomes large, the explosion-proof effect becomes good. This significantly improves the implosion prevention and the reliability of the color cathode ray tube.

[Brief description of drawings]

1 is a cross-sectional view showing a part of the color cathode ray tube shown in FIG.

2 is a sectional view showing a part of an electron gun of the color cathode ray tube shown in FIG.

FIG. 3 is a characteristic diagram of the electron gun shown in FIG.

FIG. 4 is a characteristic diagram of the electron gun shown in FIG.

FIG. 5 is a sectional view showing a main part of an electron gun of another color cathode ray tube according to the present invention.

FIG. 6 is a sectional view showing a main part of an electron gun of another color cathode ray tube according to the present invention.

FIG. 7 is a sectional view showing a main part of an electron gun of another color cathode ray tube according to the present invention.

FIG. 8 is a partially cutaway perspective view showing an essential part of an electron gun of another color cathode ray tube according to the present invention.

FIG. 9 is a partially cutaway perspective view showing an essential part of an electron gun of another color cathode ray tube according to the present invention.

FIG. 10 is a partially cutaway perspective view showing an essential part of an electron gun of another color cathode ray tube according to the present invention.

FIG. 11 is a view showing an electron gun of another color cathode ray tube according to the present invention.

12 is a partially cutaway perspective view showing details of an example of a fluorescent screen and a shadow mask of the color cathode ray tube shown in FIG.

FIG. 13 is a plan view showing a phosphor screen of another color cathode ray tube according to the present invention.

FIG. 14 is a schematic sectional view showing a color cathode ray tube according to the present invention.

FIG. 15 is a view showing a part of the non-combustible cushioning material according to the present invention.

FIG. 16 is a schematic partial cutaway view showing a color cathode ray tube having explosion-proof means according to the present invention.

17 is a cross-sectional view showing a part of the color cathode ray tube shown in FIG.

FIG. 18 is a schematic structural sectional view showing a conventional color cathode ray tube having explosion-proof means.

[Explanation of symbols]

 1 ... Panel 22 ... Incombustible cushioning material 21 ... Metal band

Continuation of the front page (72) Inventor Kawa ▲ Hirosaki ▼ 3681 Hayano, Mobara-shi, Chiba Hitachi Device Engineering Co., Ltd.

Claims (1)

[Claims] 1. A cathode ray tube in which a non-combustible cushioning material is wound near the front maximum outer peripheral portion of the panel, and a metal band is tightened on the non-combustible cushioning material. A cathode ray tube characterized by using a cross tape composed of a rough part and a rough part.