JPH05198276A - Cathode ray tube and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Structure] The sealing material 9 is interposed between the sealing surface 26 of the panel 21 having the fluorescent film 2 formed on the inner surface and the sealing surface 29 of the funnel 22. In a cathode ray tube formed by joining a panel and a funnel, a plurality of convex portions are formed on the sealing surface of the panel.
In addition to forming 28, a concave portion 30 into which the convex portion fits was formed on the sealing surface of the funnel. As a manufacturing method thereof, after forming a fluorescent film on the inner surface of the panel, the top of the convex portion is polished, and the panel polished on the top and the funnel are joined. [Effect] It is possible to prevent cracks in the envelope and improve implosion resistance and voltage resistance.

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 such as a color picture tube and a method for manufacturing the same, and more particularly to cracks and implosion resistance of an envelope caused by scratches on a sealing surface of a panel to a funnel. The present invention relates to a cathode ray tube that prevents deterioration of withstand voltage performance and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, a cathode ray tube is constructed as shown in FIG.
It has an envelope 1 made of glass evacuated to a high vacuum, and a fluorescent film 2 provided inside the envelope 1 is scanned by an electron beam 4 emitted from an electron gun 3 to form an image on the fluorescent film 2. Is formed to display. Particularly in a color picture tube, the envelope 1 is composed of a panel 7 made of glass with a skirt portion 6 provided on the periphery and a funnel-shaped funnel 8 made of glass, and the skirt portion 6 of the panel 7 is The end surface and the end surface of the funnel 8 having a large diameter are used as sealing surfaces, and these sealing surfaces are joined together by a sealing material made of frit glass 9 interposed therebetween. In addition, 10 is a panel facing the fluorescent film 2.
It is a shadow mask placed inside 7.

Generally, a cathode ray tube having an envelope 1 made of glass evacuated to a high vacuum as described above is
There is a possibility of implosion due to mechanical shock or atmospheric pressure applied to 1. Therefore, high implosion-proof performance is required so that a disaster accident does not occur due to scattering of glass fragments generated when implosion occurs.

As a method for improving the implosion-proof performance, there is a conventional explosion-proof reinforcement method. Various types of reinforcement methods are already known as this explosion-proof reinforcement method, but in order to further increase the reliability against implosion, it is important to increase the strength of the envelope itself as well as explosion-proof by this reinforcement means. ..

However, the conventional envelope of the cathode ray tube has the following problems. That is, the envelope of the color picture tube described above is formed by joining the panel 7 and the funnel 8 with the sealing material made of the frit glass 9. Normally, this frit glass 9 is used for bonding as shown in FIG.
As shown in (a), the sealing surface 12 of the large-diameter portion of the funnel 8 is
In the central portion of, the coating solution obtained by suspending the powder of frit glass in a butyl acetate solution using nitrocellulose as a binder and drying it to form a coating layer 13 of frit glass, and then through this coating layer 13. The skirt 6 of the panel with the fluorescent film formed on the sealing surface 11 of the large-diameter part of the funnel 8
The sealing surface (14) is positioned and placed. The panel 7 and the funnel 8 are heat-treated according to a predetermined temperature schedule, and the sealing surfaces 12 and 14 are bonded to each other by the crystallized frit glass 9 as shown in FIG. ing.

In the production of a color picture tube, the electron gun attached to the glass stem is sealed in the neck of the funnel 8 joined by the frit glass 9 and then heated according to a predetermined temperature schedule. It is manufactured by exhausting the inside of the envelope while processing.

However, when the panel 7 and the funnel 8 are joined by the above method, the implosion resistance and the like greatly depend on the state of the sealing portion. That is, if the sealing surface 14 of the panel 7 and the sealing surface 12 of the funnel 8 are damaged, not only the implosion resistance performance of the color picture tube is significantly deteriorated, but also the sealing process between the panel 7 and the funnel 8 is performed. For example, cracks may occur due to the scratches. Furthermore, when a color picture tube is used, the high voltage difference applied to the inside and outside of the envelope may deteriorate the withstand voltage performance and cause dielectric breakdown of the sealing portion. Especially for the sealing surface 14 of panel 7,
Before the sealing with 8, the fluorescent film is formed on the inner surface by a complicated method such as a photo printing method, and thus there is a high possibility that the fluorescent film will be damaged in the forming process.

That is, the fluorescent film of the color picture tube has a fluorescent substance slurry mainly containing a fluorescent substance and a photosensitizer on the inner surface of the panel.
Further, it is formed by applying a photosensitizer and baking a pattern corresponding to the electron beam passage hole of the shadow mask on the phosphor slurry layer or the photosensitizer layer. In the exposure step of baking a pattern corresponding to the electron beam passage hole of the shadow mask, a shadow mask is attached to the inside of the panel on which the phosphor slurry layer or the photosensitizer layer is formed, and the panel on which the shadow mask is attached. Is positioned and mounted on the panel mounting portion of the exposure table for exposure, and when the exposure is completed, the substrate is removed from the panel mounting portion. This exposure is repeated three times in the formation of the fluorescent film composed of the three-color phosphor layer, and when forming the fluorescent film having the light absorption layer, the exposure for forming the light absorption layer is added. In this case, since the conventional panel is formed in a mirror-like state in which the sealing surface is flat along with the funnel, when the panel is positioned and mounted on the panel mounting section and is removed from the panel mounting section, the panel 7 is sealed. Almost the entire surface is moved so as to rub against the surface of the panel mounting portion.

By the way, generally, in consideration of durability, the panel mounting portion of the exposure table is formed by polishing the surface of a steel plate to a roughness of about 6 μm, and then performing hard chrome plating on it. Even if the surface of the panel mounting portion is formed to be uneven as described above, the sealing surface of the panel 7 is hardly damaged by the unevenness of the roughness. However, if a hard substance such as fine metal scraps or phosphor powder that has fallen off the inner surface of the panel adheres to this panel mounting part, this hard substance will fall between the surface of the panel mounting part and the sealing surface of the panel. When sandwiched, the panel is positioned and placed, and the sealing surface is damaged by friction with the panel placing portion when the panel is removed.

Normally, the exposure for forming the fluorescent film of the color picture tube is performed in a dust-free space to the extent that the formation of the fluorescent film is not hindered by forced ventilation. However, in the exposure step of forming this fluorescent film, various operating devices such as an exposure table and a conveyer are arranged, and therefore, hard materials such as metal powder from the operating device and phosphor particles from the inner surface of the panel are used. Dropping is inevitable, and it is difficult to completely remove such a hard material from the panel mounting portion of the exposure table. The particle size of the metal powder, phosphor particles, and the like adhered to the panel mounting portion is often about 5 to 10 μm, which damages the sealing surface of the panel.

The occurrence of scratches on the sealing surface of the panel is
Not only on the exposure table, but also on the transfer conveyor that transfers the panels.

Focusing on such a problem, Japanese Patent Laid-Open No. 63-
As shown in FIG. 9, Japanese Patent No. 143720 discloses that the sealing surface 14 of the panel 7, which is normally in a mirror surface state, is a rough surface having an average roughness of 3 to 6 μm. When the sealing surface 14 of the panel 7 is roughened in this way, the weight is relatively light.
With respect to the small-sized to large-sized panel 7 having a size of 0 to 29 inches, it is possible to reduce the occurrence of scratches on the sealing surface 14. However, in a horizontally developed ultra-large HD color picture tube with an aspect ratio of 16: 9, such as a 36-inch 90 degree deflection picture tube, the weight of panel 7 is about 3%.
21kg medium color picture tube panel which weighs 0.6kg
It is about 3.5 times the weight of 7 about 8.8 kg,
Further, since the area of the sealing surface 14 is increased more than the size, the sealing surface 14 has a scratch of about 3 μm which is visible from a depth of 1 μm.

Thus, when the panel 7 with the damaged sealing surface 14 is joined to the funnel and exhausted, the damage causes cracks in the envelope during the sealing process and implosion after the exhausting process. It tends to occur. In addition to cracking and implosion, the color picture tube is used by applying a high voltage of about 25 to 32 kV inside the tube through the anode terminal provided on the funnel and grounding the outside of the tube for use. If the mounting surface 14 has a scratch that traverses the inside and outside of the pipe, and the scratch is dirty, the insulation resistance inside and outside the pipe at that portion deteriorates, causing dielectric breakdown.

[0014]

As described above, in the envelope of the color picture tube, the sealing surface of the panel having the fluorescent film formed on the inner surface and the sealing surface of the funnel are bonded through the sealing material. It is formed by In this case, if the sealing surface has scratches, cracks are likely to occur in the envelope, and implosion resistance performance and voltage resistance performance are likely to deteriorate. Conventionally, the sealing surface of the panel is a flat mirror surface state generally obtained when molding the panel, but the sealing surface of the panel in the mirror surface state is
For example, if a hard material such as metal powder or phosphor particles adheres to the panel mounting part of the exposure table used when forming a fluorescent film on the inner surface, it is easily rubbed and scratched. It is easy to cause cracks, implosion resistance and withstand voltage. In order to prevent the deterioration of the implosion resistance performance, it is known that the sealing surface of the panel is a rough surface having an average roughness of 3 to 6 μm. However, even if the surface is roughened in this way, it becomes difficult to prevent the occurrence of scratches on the sealing surface when the weight becomes heavy like the panel of a super-large color picture tube,
Degradation of implosion resistance is inevitable.

The present invention has been made in view of the above problems, and prevents the sealing surface of the panel from being scratched.
It is an object of the present invention to obtain a cathode ray tube which is less likely to cause cracks and to be impaired in implosion resistance and withstand voltage, and a manufacturing method thereof.

[0016]

[Means for Solving the Problems] A sealing material is interposed between a sealing surface of a panel having a fluorescent film formed on its inner surface and a sealing surface of a funnel, and the panel and the funnel are bonded by this sealing material. In the cathode ray tube thus formed, a plurality of convex portions were formed on the sealing surface of the panel, and a concave portion into which the convex portion was fitted was formed on the sealing surface of the funnel.

Further, a sealing material is interposed between the sealing surface of the panel having the fluorescent film formed on the inner surface thereof and the sealing surface of the funnel, and the sealing material of the cathode ray tube for joining the panel and the funnel. In the manufacturing method, a fluorescent film is formed on the inner surface of the panel using a panel having a plurality of convex portions formed on the sealing surface, and after the fluorescent film is formed, the top portion of the convex portion is polished and the top portion is polished. In addition, a concave portion into which the convex portion fits is formed on the sealing surface of the panel and is joined to the funnel.

Further, using a panel in which a plurality of convex members are detachably attached to a flat sealing surface, a fluorescent film is formed on the inner surface of this panel, and after forming the fluorescent film, the convex member is removed,
The panel from which the convex member was removed was joined to a funnel having a flat sealing surface.

Furthermore, a fluorescent film is formed on the inner surface of the panel, and after forming the fluorescent film, a colloidal solution of silica is applied to the sealing surface of the panel and dried and baked to form a silica layer. The formed panel was bonded to the funnel.

[0020]

As described above, when a plurality of convex portions are formed on the sealing surface of the panel, it is possible to avoid contact between the sealing surface other than the convex portion and the hard substance, and therefore, the sealing surface other than the convex portion of the sealing surface is prevented. The part can be barely scratched. Moreover, since the concave portion into which the convex portion fits is formed in the sealing surface of the funnel, the panel and the funnel can be joined together without any trouble. Even if the top of the convex portion is scratched, this scratch does not reach the inner and outer surfaces of the envelope after sealing, so stress concentration on the scratched portion is relieved and the scratch on the sealing surface is reduced. It is possible to prevent the occurrence of cracks and the deterioration of implosion resistance due to the cause.

Further, after the fluorescent film is formed, the top of the convex portion of the sealing surface of the panel is polished, and the panel whose top is polished is joined to the funnel, whereby the scratches on the top of the convex portion are easily removed by polishing. Therefore, it is possible to prevent the occurrence of cracks caused by scratches on the sealing surface and the deterioration of implosion resistance.

Furthermore, a fluorescent film is formed on the inner surface of the panel using a panel having a plurality of convex members removably attached to a flat sealing surface, and after the fluorescent film is formed, the convex member is removed to form the convex film. The same effect can be obtained by joining the panel from which the member has been removed to the funnel.

Furthermore, after the fluorescent film is formed, a colloidal solution of silica is applied to the sealing surface of the panel and dried and baked to form a silica layer, which is then joined to a funnel, and scratches are formed on the sealing surface of the panel. Is filled with silica, and since this silica has a good affinity with a sealing material such as frit glass, the same effect can be obtained.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows a color picture tube which is an embodiment of the present invention. This color picture tube has an envelope 23 composed of a panel 21 made of glass on which a skirt portion 20 is formed and a funnel-shaped funnel 22 made of glass on the periphery.
A phosphor film 2 made of a three-color phosphor that emits blue, green, and red is formed on the inner surface of the panel 21 so as to face the shadow masker 10 arranged inside the panel 21. Also, an electron gun that emits three electron beams 4 into the neck 24 of the funnel 22
3 are arranged. Then, the three electron beams 4 emitted from the electron gun 3 are deflected by a magnetic field generated by a deflection yoke (not shown) mounted outside the funnel 22 to horizontally and vertically scan the fluorescent film 2. Thus, a structure for displaying a color image is formed on the fluorescent film 2.

In particular, in the color picture tube of this example, as shown in FIG. 2, a plurality of convex portions 28 having a flat top 27 are sealed on the end surface of the skirt portion 20 of the panel 21, that is, the sealing surface 26 with the funnel. The surface 26 is distributed over the entire circumference. On the other hand, the end surface of the large-diameter portion of the funnel 22, that is, the sealing surface 29 with the panel 21, corresponds to each convex portion 28 of the sealing surface 26 of the panel 21, and a plurality of these convex portions 28 are fitted. A recess 30 is provided. Then, with the frit glass 9, these convex portions 28
And the sealing surfaces 26 and 29 provided with the recesses 30 are integrally joined.

As shown in FIG. 3, each convex portion 28 of the sealing surface 26 of the panel 21 has the width of the sealing surface 26 as W, the width of the top portion 27 as w, and the length of the top portion 27 as L, When the height of the convex portion 28 is h, w = about W / 3 L = about 2W h = about W / 10, and the convex portion 28 is positioned at the center of the sealing surface 26 in the width direction. Is formed. Specifically, for example, in the case of a 36-inch 90-degree deflection HD color picture tube, W = 12.9 mm, w = 4.0 mm L = 26.0 mm h = 1.3 mm.

As described above, the convex portion 28 is formed on the sealing surface 26 of the panel 21.
By providing, it is possible to prevent damage to the portion other than the convex portion 28 of the sealing surface 26 in the manufacturing process of the color picture tube,
It is possible to prevent cracks in the envelope and deterioration in implosion resistance caused by scratches on the sealing surface of the conventional panel.

That is, the color picture tube is manufactured by forming the fluorescent film 2 on the inner surface of the panel 21 and integrally joining the panel 21 on which the fluorescent film 2 is formed with the funnel 22. The fluorescent film 2 is formed on the panel by photo printing.
A phosphor slurry containing a phosphor and a photosensitizer as main components is further coated on the inner surface of 21 to form a pattern corresponding to the electron beam passage hole of the shadow mask 10 on the phosphor slurry layer or the photosensitizer layer. It is formed by baking, and the exposure table shown in FIG. 4 is used for baking the pattern.

This exposure table has a panel mounting portion 32 in which a flat steel plate is plated with chrome, and the panel 21 is positioned and mounted on this panel mounting portion 32, and is emitted from the light source 33. The light 34 that passes through the panel is passed through various optical systems 35 such as a correction lens and the shadow mask 10 attached to the panel 21.
The phosphor slurry layer 36 and the photosensitizer layer formed on the inner surface of 21 are projected, and a pattern corresponding to the electron beam passage holes of the shadow mask 10 is formed.

In such an exposure table, its panel mounting portion is
When the panel 21 is positioned and mounted on the 32, the end surface (sealing surface 26) of the skirt portion 20 of the panel 21 is positioned while rubbing the upper surface of the panel mounting portion 32. Therefore, in a conventional panel having a flat sealing surface, a hard substance undesirably adhered to the upper surface of the panel mounting portion may damage the sealing surface, but like the panel 21 of this example. When the convex portion 28 is provided on the sealing surface 26, the sealing surface 26 is formed on the upper surface of the panel mounting portion 32 and the convex portion 28.
Only the contact is made at the top 27 of the, and the other parts are not contacted. As a result, even if the top portion 27 of the convex portion 28 is damaged, it is possible to prevent the other portions of the sealing surface 26 from being damaged. Moreover, in the convex portion 28, the width w of the top portion 27 is about 1/3 of the width W of the sealing surface 26 (w = about W / 3), which is narrower than the width of the sealing surface 26, Even if the top 27 of the convex portion 28 is scratched, the scratch is covered with the frit glass 9 and the panel 21 and the funnel 22 are joined by the frit glass 9 because it is located in the center of the inside in the direction. It does not extend to the inner and outer surfaces of the obtained envelope 23, but the panel 21 and the funnel 22.
It becomes localized in the sealing part with.

When the scratches are localized at the sealing portion, the glass member is generally strong against the compressive stress but weak against the tensile stress even if the surface is scratched, and the tensile stress is weak. When applied to, it grows and cracks occur. However, since the scratches on the top portion 27 of the convex portion 28 are localized in the sealing portion between the panel 21 and the funnel, tensile stress is not concentrated and applied to the scratched portion, and therefore the scratches grow and crack. It never happens.

Further, when the convex portion 28 is provided on the sealing surface 26 of the panel 21 as described above, the sealing surface 26 is prevented from being scratched across the inner and outer surfaces of the envelope 23. It is possible to significantly reduce the occurrence of cracks in the envelope and the deterioration of the implosion-proof performance caused by the scratches on the surface.

Next, a method of manufacturing a color picture tube will be described.

In the above-mentioned embodiment, the case where the top of the convex portion of the sealing surface of the panel is damaged is directly joined to the funnel, but as an actual manufacturing method of the color picture tube, it is shown in FIG. As described above, after the fluorescent film 2 is formed on the inner surface of the panel 21 by the photo printing method, the cover 39 having the hole 38 in which only the convex portion 28 of the sealing surface 26 is exposed is sealed before being joined to the funnel. Attached to the surface 26, cover the inside of the panel 21, polish the top of the convex portion 28 with a polishing device (not shown) such as a rotating grindstone to remove the scratches, and then bond it to the funnel with frit glass. Good.

When the tops of the protrusions 28 of the sealing surface 26 of the panel 21 are polished to remove the scratches and then joined to the funnel as described above, cracks in the envelope and implosion resistance are deteriorated. Therefore, a more reliable and safe color picture tube can be easily manufactured.

That is, even with a conventional flat panel having no convex portion on the sealing surface, it is possible to remove the scratches on the sealing surface by polishing the sealing surface after forming the fluorescent film. However, in this case, the flatness of the sealing surface is impaired, and when the frit glass is joined to the funnel, the thickness of the frit glass becomes non-uniform, and the implosion resistance performance based on the non-uniformity of the frit glass thickness Deterioration occurs. In addition, since the position of scratches is uncertain, the entire sealing surface will be polished,
It takes time to polish. On the other hand, in the panel 21 in which the convex portion 28 is provided on the sealing surface 26, since the occurrence of scratches is limited to the top portion of the convex portion 28, only the top portion of the convex portion 28 needs to be polished. Since the area is small, it can be completely polished in a short time of about several tens of seconds, and a panel without a scratch on the sealing surface can be easily obtained.

As another manufacturing method, instead of providing the convex portion on the sealing surface of the panel, a plurality of members having a certain thickness are attached to the flat sealing surface of the conventional panel to form the convex portion, A color picture tube is manufactured by forming a fluorescent film on the inner surface of, and removing the mounting member after the fluorescent film is formed and joining it to the funnel. In this case, the member may be attached to the sealing surface by an adhesive agent, or may be attached by a mechanical fixing means such as fitting across the sealing surface. Especially when attaching with an adhesive, an adhesive soluble in an organic solvent may be used.

Even if a color picture tube is manufactured by such a method, it is possible to prevent the sealing surface of the panel from being scratched. As in the above-mentioned embodiment, the cracks and the implosion resistance of the envelope are prevented. It is possible to easily produce a reliable and safe color picture tube by preventing deterioration of the color picture tube.

Further, as another manufacturing method, after forming a fluorescent film on the inner surface of the panel having the convex portion formed on the sealing surface,
Before bonding this panel to a funnel, a silica sol (a colloidal solution of silica) composed of silica alkoxide is applied to the top of the convex portion and dried to form a silica layer. Then, the panel on which the silica layer is formed is bonded to a funnel to manufacture a color picture tube.

As described above, when silica sol is applied to the top of the convex portion of the sealing surface and joined to the funnel, the implosion resistance and withstand voltage performance caused by the damage on the sealing surface of the panel are prevented from being deteriorated. can do.

That is, generally, the size of the scratches generated on the glass varies from large to small, but the scratches that are particularly problematic in the cathode ray tube have a depth of several μm or more, and whether the scratches grow or not. Greatly influences the implosion resistance performance and the withstand voltage performance. As shown in FIG. 6A, a scratch 42 is formed on the surface of the glass 41,
When the tensile stress 43 acts on the scratch 42, the stress is concentrated on the tip portion in the depth direction of the scratch 42, and when the stress concentration is increased to some extent, the scratch 42 grows and cracks occur. That's right.

In the case of the sealing surface of the above panel, the depth of the scratch formed on the top of the convex portion is generally about 5 to 15 μm. Therefore, as shown in FIG.
If the frit glass 9 is applied to the panel 21 having 42 and joined to the funnel, the average particle diameter of the frit glass 9 that is normally used is about 5 to 7 μm,
It is difficult to embed the frit glass 9 up to the tip of the flaw 42 in the depth direction, and a space 43 where the frit glass 9 is not embedded is likely to be formed at the tip of the flaw 42 in the depth direction. When such a space 43 is formed, the color picture tube has 25 to 3 inside.
Since a high voltage of about 2 kV is applied and the outside of the tube is grounded, it is used as a starting point from the tip of the flaw 42 in which the space 43 is formed, causing dielectric breakdown or slow leak of the sealing part. It may happen.

However, if silica sol is applied to the tops of the convex portions to form a silica layer before bonding to the funnel as described above, the silica particles constituting the silica sol will be formed as shown in FIG. 6 (c). Since it is much smaller than the particles of the frit glass 9, it is possible to embed the scratch 42 having a depth of about 5 to 15 μm in the depth direction. Moreover, since the silica has good adhesion to both the glass and the frit glass 9, it relaxes the tensile stress applied to the scratch 42 and prevents the growth of the scratch 42. As a result, it is possible to greatly prevent the implosion resistance performance and the withstand voltage performance from being deteriorated due to scratches on the sealing surface of the panel 21.

The method of applying silica sol to the sealing surface to form a silica layer and then joining it to a funnel can be applied to a panel by forming a convex portion on the sealing surface.

[0046]

The sealing material is interposed between the sealing surface of the panel having the fluorescent film formed on the inner surface and the sealing surface of the funnel panel, and the panel and the funnel are joined by this sealing material. In the cathode ray tube formed by forming a plurality of convex portions on the sealing surface of the panel and forming a concave portion to which the convex portion fits on the sealing surface of the funnel, the sealing surface other than the convex portion is not damaged. By forming the concave portion into which the convex portion fits on the sealing surface of the funnel, which is almost nonexistent, the panel and the funnel can be joined together without any trouble. Even if the top of the convex portion is damaged, this damage does not reach the inner and outer surfaces of the envelope after sealing.Therefore, the generation of cracks due to stress concentration on the damaged portion is prevented, and the implosion resistance A cathode ray tube with good performance can be obtained.

As a method of manufacturing a cathode ray tube, after the fluorescent film is formed, the top of the convex portion is polished, and the polished panel on the top is formed into a funnel having a concave portion where the convex portion fits on the sealing surface. When bonded, the scratches on the tops of the convex portions can be easily removed by polishing, the generation of cracks due to the stress concentration on the scratched portions can be eliminated, and a cathode ray tube with good implosion resistance can be obtained.

Further, a plurality of convex members are detachably attached to the flat sealing surface, a fluorescent film is formed on the inner surface using the panel to which the convex members are attached, and after the fluorescent film is formed, the convex members are removed. The same effect can be obtained even if it is left and joined to the funnel.

Furthermore, after forming the fluorescent film, a colloidal solution of silica is applied to the sealing surface of the panel and dried and baked to form a silica layer, which is then bonded to a funnel. The generated scratches can be filled with silica, and since this silica has a good affinity with a sealing member such as frit glass, the same effect can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a color picture tube which is an embodiment of the present invention.

FIG. 2 is a perspective view showing the configuration of the panel.

FIG. 3 is a perspective view for explaining the shape of a convex portion provided on the sealing surface of the panel.

FIG. 4 is a diagram for explaining a relationship between a panel having convex portions on a sealing surface and an exposure table used for forming a fluorescent film.

FIG. 5 is a diagram for explaining a method of polishing the tops of the protrusions provided on the sealing surface of the panel.

6 (a) to 6 (c) are views for explaining the effect when silica sol is applied to the tops of the projections provided on the sealing surface of the panel.

FIG. 7 is a sectional view showing a configuration of a conventional color picture tube.

8A and 8B are views for explaining a conventional method for joining a panel and a funnel, respectively.

FIG. 9 is a view showing a conventional panel having a roughened sealing surface.

[Explanation of symbols]

 2 ... Fluorescent film 9 ... Frit glass 20 ... Skirt 21 ... Panel 22 ... Funnel 23 ... Envelope 26 ... Panel sealing surface 27 ... Convex top 28 ... Convex portion 29 ... Recess 30 ... Funnel sealing surface 32 ... Panel rest of exposure table 39 ... Cover 42 ... Scratch 44 ... Silica layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinji Ohama, 1-9-2 Harara-cho, Fukaya-shi, Saitama Prefecture Fukaya Electronics Factory, Toshiba Corp. (72) Inventor Hitoshi Koji 72 Horikawa-cho, Kawasaki-shi, Kanagawa Address Within Toshiba Electronic Engineering Co., Ltd.

Claims (4)

[Claims] 1. A sealing material is interposed between a sealing surface of a panel having a fluorescent film formed on an inner surface thereof and a sealing surface of a funnel, and the panel and the funnel are bonded by this sealing material. In the cathode ray tube which becomes, while forming a plurality of convex portions on the sealing surface of the panel,
A cathode ray tube, wherein a concave portion into which the convex portion fits is formed on a sealing surface of the funnel. 2. A cathode line for interposing a sealing material between a sealing surface of a panel having a fluorescent film formed on an inner surface thereof and a sealing surface of a funnel, and for joining the panel and the funnel by the sealing material. In the method for producing a tube, a fluorescent film is formed on the inner surface of this panel using a panel having a plurality of convex portions formed on the sealing surface, and after the fluorescent film is formed, the top portion of the convex portion is polished and A method for manufacturing a cathode ray tube, characterized in that a recessed portion into which the above-mentioned convex portion fits is formed on a sealing surface of a polished panel and is joined to a funnel. 3. A cathode line for interposing a sealing material between a sealing surface of a panel having a fluorescent film formed on its inner surface and a sealing surface of a funnel, and for joining the panel and the funnel with the sealing material. In the method for producing a tube, a panel having a plurality of convex members removably attached to a flat sealing surface is used to form a fluorescent film on the inner surface of this panel, and after the fluorescent film is formed, the convex member is removed. A method for manufacturing a cathode ray tube, characterized in that the panel from which the convex member has been removed is joined to a funnel having a flat sealing surface. 4. A cathode line for interposing a sealing material between a sealing surface of a panel having a fluorescent film formed on its inner surface and a sealing surface of a funnel, and for joining the panel and the funnel with the sealing material. In the method for producing a tube, a fluorescent film is formed on the inner surface of the panel, and after forming the fluorescent film, a colloidal solution of silica is applied to the sealing surface of the panel and dried and baked to form a silica layer on the sealing surface. A method for manufacturing a cathode ray tube, which comprises joining the panel on which the silica layer is formed to a funnel.