JPH06243784A - Panel defect repairing method for cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide a repairing method by which a defect such as a flaw and stain generated on the outside surface is repaired for reuse by spraying the specific abrasive liquid at a high speed from the front to the defect generated on the panel surface. CONSTITUTION:A cathode-ray tube is fixed sideways, and an abrasive liquid 21 is jetted at a high speed to a defective part from a nozzle 20, which is arranged to face a panel 1 of the cathode-ray tube. water containing 2-20volume% of an abrasive material such as cerium oxide group, whose particle diameter mainly ranges from 20 to 1mum, is used as the abrasive liquid 21. The abrasive liquid 21 is jetted with a jetting pressure of 2.0-6.0kg/cm<2>, so that a defect part generated by a flaw or adhesion of stain can be repaired in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a panel defect repairing method of a cathode ray tube for repairing defects such as scratches and stains on a panel of a color cathode ray tube and a panel which is a component thereof, and in particular, the outer surface is uneven The present invention relates to a panel defect repairing method for a cathode ray tube capable of effectively repairing a defect generated in a non-glare panel.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube is shown in FIG.
As shown, the panel 1 made of glass and this panel 1
It has an envelope made of a funnel-shaped funnel 2 made of glass that is integrally bonded to the panel 1. The inner surface of the panel 1 has a three-color phosphor layer or a light-absorbing layer in which a three-color phosphor layer is arranged. The phosphor screen 3 is provided, and the shadow mask 4 is arranged inside the phosphor screen 3 so as to face the phosphor screen 3. An internal magnetic shield 6 located inside the large-diameter portion 5 of the funnel 2 is attached to the shadow mask 4. On the other hand, in the neck 8 of the funnel 2, 3
An electron gun 10 that emits an electron beam is sealed. Also, the inner conductive film 11 extends from the inner surface of the large-diameter portion 5 of the funnel 2 to the inner surface of the adjacent portion of the neck 8, and the large-diameter portion of the funnel 2 also extends.
An outer conductive film 12 is formed by coating on the outer surface of 5. Further, a deflection yoke 14 is attached outside the boundary between the large-diameter portion 5 of the funnel 2 and the neck 8.

Further, in the side protection type explosion-proof type cathode ray tube, a tension band 17 having a lug plate 16 for attaching the cathode ray tube to the cabinet is attached to the outside of the panel 1.

The panel 1 of the above-described color cathode ray tube has conventionally used a mirror surface having a smooth outer surface, but in recent years, with respect to the color cathode ray tube used in a computer or the like, image deterioration due to reflection of external light is caused. Non-glare panels are used to reduce glare and glare.

Generally, as the non-glare treatment of this panel, there are a method of lowering the light transmittance of the glass material, a method of depositing a metal deposition film on the outer surface, a method of forming fine irregularities on the outer surface, and the like. Panel of the above color CRT
As shown in FIG. 3 (b), 1 has fine irregularities 19 formed therein. A standard non-glare panel with such an uneven surface has an uneven height of about 0.6.
5 μm, and this unevenness is 2,000 on the entire outer surface.
It is formed at a rate of 000 to 2,500,000 pieces / cm ² .

The fine irregularities of such a non-glare panel are formed by spraying alundum powder on the outer surface of the panel to form irregularities of the base, and corroding the irregularities of the base with hydrofluoric acid. To be done.

By the way, the normal color cathode ray tube is shown in FIG.
It is manufactured by the process shown in. That is, a panel and a shadow mask are combined to assemble a panel / mask assembly, and a phosphor screen is formed on the inner surface of the panel of the panel / mask assembly by a photo printing method. On the other hand, an inner conductive film is applied and formed on the inner surface of the funnel, and frit glass is applied to the end surface of the large diameter portion. Then, a shadow mask is attached to the panel on which the phosphor screen is formed, and the panel on which the shadow mask is attached and the funnel on which the inner conductive film is applied are placed in a heating furnace,
The frit glass applied to the end surface of the funnel is integrally joined (sealed).

Next, the electron gun is sealed in the neck of the envelope composed of the panel-funnel integrally joined as described above,
Then, the inside of the sealed envelope of the electron gun is evacuated. After that, the getter arranged in this envelope is flushed, and the aging of the cathode of the electron gun, the withstand voltage treatment, the test, etc. are performed. Further, an outer conductive film is formed by coating on the outer surface of the large-diameter portion of the funnel. Explosion-proof cathode ray tubes are then produced by further tightening the outside of the panel with a tension band in which lug plates are arranged.

As described above, the color cathode ray tube is manufactured through many steps in which various members are arranged inside and outside the envelope. Therefore, the surface of the panel 1, particularly the outer surface thereof, is liable to be scratched or scratched, and dirt or the like is often adhered firmly. In particular, a non-glare panel having an outer surface with fine irregularities has a large frictional resistance due to the fine irregularities, and when it comes into contact with other members, the convex portions are chipped and are easily scratched. Moreover, the scratches are noticeable,
There is a problem in that even a small minor scratch will significantly damage the appearance.

When the outer surface of the panel 1 is scratched as described above, for the non-non-glare panel whose outer surface has a smooth mirror surface, the scratched portion is formed by sandpaper or a buff with an abrasive. By performing rough polishing, medium polishing, finish polishing, etc., repair can be relatively easily performed. However, if the non-glare panel is repaired in the same way as the non-non-glare panel, normal convex parts will be worn out before the defects on the uneven surface and the surface irregularity will change, so repair it. I can't. Since there is no other suitable repair method for this non-glare panel at present, once it is scratched, the color CRT is disassembled to separate the panel, and the scratch is removed by the same method as the above non-glare panel. It is necessary to remove all the irregularities and then form the irregularities again.

[0011]

As described above, the color CRT has an envelope formed by a panel made of glass and a funnel, and many members are arranged inside and outside of this envelope. It is manufactured through the steps of.
Therefore, the surface of the panel, particularly the outer surface thereof, is liable to be scratched or scratched, and dirt or the like is firmly attached to the panel, often resulting in defects. In particular, a non-glare panel having fine irregularities formed on the outer surface has a large frictional resistance due to the fine irregularities, and is easily scratched due to the lack of convex portions due to contact with other members. Moreover, the scratches are conspicuous, and even small minor scratches can significantly damage the appearance.

When the outer surface of the panel is scratched in this manner, the non-glare panel having a smooth mirror-like outer surface is rough-polished with sandpaper or a buff with an abrasive. It is possible to repair relatively easily by performing middle polishing and finish polishing. However, when repairing non-glare panels by the same method as non-non-glare panels, normal convex parts are worn away before the defects on the uneven surface and the surface irregularity changes, so repair it. I can't. Moreover, there is currently no other suitable repair method for this non-glare panel. Therefore, if this non-glare panel is scratched, it is necessary to disassemble the color CRT to separate the panel, eliminate the scratches on the separated panel, remove all the irregularities, and then form the irregularities again. . Therefore, there is a problem that waste of members and processing costs, defective reproduction occurs, and economic loss is large.

The present invention has been made in view of the above problems, and reuses defects generated on the surface of the panel, particularly defects such as scratches and stains generated on the uneven surface such as the outer surface of the non-glare panel. The purpose is to get a way to repair possible.

[0014]

In a method of repairing a panel defect of a cathode ray tube, polishing containing 2 to 20% by volume of an abrasive having a distribution mainly in a grain size of 20 to 1 .mu.m from the front in a defective portion formed on the surface of the panel. The liquid was sprayed at high speed to repair the defect.

[0015]

As described above, when a polishing liquid containing 2 to 20% by volume of an abrasive having a particle size distribution of 20 to 1 μm from the front is sprayed at a high speed on the defective portion formed on the surface of the panel, For scratches, for example, the sharp corners can be removed and the panel repaired to prevent the extraordinary reflections that occur at the sharp corners.

In this case, the polishing can be performed by spraying only the abrasive, but in the non-glare panel having fine irregularities, the abrasive is accumulated in the recesses to hinder uniform polishing. However, when a polishing liquid is used, the liquid successively rinses away the polishing material, and evenly polishes the convex portions and the concave portions, thereby preventing the unevenness of the surface of the panel from changing.

Since the abrasive also abrades parts other than defects, the particle size of the abrasive greatly affects the surface condition of the panel. If you use an abrasive with a large particle size,
The corners of the scratch can be quickly removed, but the recess is not polished. In particular, if the particle size of the abrasive is too large, the normal projections are worn away so much that the unevenness of the surface of the panel changes, resulting in poor appearance. When an abrasive having a small particle size is used, both the convex portion and the concave portion are polished, and the difference in polishing is small, so that the change in the unevenness of the surface of the panel can be made small, but the corner portion of the scratch can be removed. Become slow. For this reason, the optimum abrasive removes the corners of the scratch without changing the surface condition of the panel, and includes an abrasive having a large particle diameter and an abrasive having a small particle diameter. An abrasive having a distribution mainly in the range of ˜1 μm and an average diameter of 2 to 6 μm, which is approximately equal to the interval between the irregularities of the non-glare panel, efficiently repairs the defects without changing the surface condition of the panel.

Further, the higher the content of the abrasive in the polishing liquid, the faster the polishing rate, and the defects can be repaired in a short time. However, if the polishing rate is increased, the polishing quality may be impaired. As a result, a polishing liquid containing 2 to 20% by volume of an abrasive is preferable from the viewpoint of polishing speed, polishing quality, convenience in handling the polishing liquid, and the like.

[0019]

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

As shown in FIG. 1, a color cathode ray tube is laid sideways, and a polishing liquid 21 is jetted at a high speed from a nozzle 20 which is arranged so as to face the panel 1, so that the polishing liquid 21 is frontally applied to a defective portion of the panel 1. To spray. As the polishing liquid 21, an abrasive having a distribution mainly in the range of 20 to 1 μm in diameter is used.
20% by volume and 98-80% by volume of water are used. By spraying this polishing liquid at a spraying pressure of 2.0 to 6.0 kg / cm ² , scratches and stains may be attached in a short time. The resulting defective portion can be repaired.

For example, in the case of a non-glare panel, as shown in FIG. 2 (a), there is almost an unevenness 23 having a comparatively gentle top and bottom with a height of about 0.65 μm on the entire outer surface of the panel. 2,000,000 to 2, evenly
It is formed at a rate of 500,000 pieces / cm ² ,
When the outer surface composed of this uneven surface is scratched, the scratch damages the convex portion and has a shape with a sharp corner portion 25, as shown in (b), and the sharp corner portion 25 causes abnormalities. Reflection occurs, and there is a difference in appearance from the surrounding normal parts. However, when the polishing liquid of the above composition is sprayed onto the scratched portion at a high speed, the sharp corner portion 25 is removed in a short time as shown in (c), so that the scratched portion and the normal portion around it are removed. It is possible to reduce the difference between the two and to repair it in an uneven state that cannot be visually discerned.

Further, the scratches are not only the protrusions of the unevenness 23 but also the recesses 27.
Even if such a case is reached, when the abrasive having the above particle size distribution is used, the abrasive having a relatively large particle diameter polishes the convex portion, and the abrasive having a relatively small particle diameter reaches the concave portion 27 and polishes the concave portion 27. However, the panel 1 can be repaired without significantly changing the unevenness of the outer surface of the panel 1.

Similarly, even if the dirt adheres strongly, the dirt can be removed in a short time by the abrasive having the above particle size distribution.

Some specific examples will be described below.

Concrete Example 1. Non-glare in which irregularities having a height of about 0.65 μm are formed at a rate of 2,000,000 to ^2.5 million pieces / cm ² on the entire outer surface of a panel of a 14-inch color CRT. -Using a panel, a scratch having an average depth of about 0.3 µm, a width of 0.2 mm and a length of about 5 mm was formed on the outer surface of the panel. The number of damage to the convex part due to this scratch is about 20,
The number is 2,000 to 25,000. As shown in Table 1, from the nozzle to this scratched portion, a cerium oxide-based abrasive having an average particle size of about 0.4 μm, which has a distribution (94%) mainly in the particle size range of 20 to 1 μm (Shin Nippon Metal Chemical Co., Ltd.) The polishing liquid containing 2 to 20% by volume of "Celico") and 98 to 80% by volume of water was sprayed at a high speed of a spraying pressure of ^{2 to} 6 kg / cm ² for polishing.

[0026]

[Table 1] As a result, it was possible to eliminate the abnormal reflection of external light by removing the sharp corners generated on the convex portion in general and to obtain a color cathode-ray tube with no problem in appearance.

More specifically, regarding the relationship between the spraying pressure applied to a polishing liquid containing 5% by volume of an abrasive and the repair time, 90 seconds and 3.0 kg at a spraying pressure of 2.0 kg / cm ^2.
/ When cm ² 50 seconds, when the 4.5 kg / cm ² 18 seconds,
It was possible to repair in 8 seconds at 6.0 kg / cm ² , and it was shown that the polishing rate increased with the magnitude of the injection pressure. However, in the case of a long scratch that needs to be performed while moving the nozzle, if the polishing speed is high, the polishing amount becomes non-uniform due to difficulty in operation, and partial over-polishing occurs. Therefore, the optimum injection pressure was 2 to 5 kg / cm ² .

Further, regarding the relationship between the content of the abrasive in the polishing liquid and the repair time when the injection pressure was 3.0 kg / cm ² , 125 seconds when the content of the abrasive was 2% by volume and 50 when the content of the abrasive was 5% by volume. It can be repaired in 13 seconds at 20% by volume for 20 seconds, and it was shown that increasing the content of the abrasive increases the polishing rate. However, increasing the content of the abrasive tends to impair the polishing quality. In addition, the amount of loss that adheres to the panel and is discarded increases in proportion to the content of the abrasive. Therefore, polishing rate, polishing quality, amount of abrasive loss,
For convenience of handling the polishing liquid, the content of the abrasive in the polishing liquid is preferably 2 to 20% by volume.

The content of the abrasive in the polishing liquid is 5% by volume,
Gloss value in repairing scratches when the injection pressure was 3.0 kg / cm ² (change in the amount of light reflection that represents glare)
Is a Pacific Guardian Gloss Guard II
It was increased by 0.4% as measured by a type gloss meter. Furthermore, when the injection time is compulsorily increased by 5 times to 4 minutes and 10 seconds,
The gross value increased by 2.1%. The non-glare panel is
Even in the normal case, the gloss value has a variation of about 3%, and it is practically difficult to distinguish the variation of 6% or less, and there is no problem in appearance. , The injection pressure of 3.0 kg / cm ² indicates that repair of scratches that does not pose a problem can be performed.

The polishing liquid for the panel is best sprayed at right angles from the front. When the spray angle to the panel is tilted, the corners of the scratch located on the back side of the protrusion are less likely to be polished when viewed from the nozzle side, not only does it take time to repair the scratch, but abnormal appearance is also recognized depending on the viewing angle. Occasionally, it will happen.

Further, depending on the color tone of the panel surface and the degree of polishing, when the polishing is local, the polishing marks may be conspicuous. In such a case, it is advisable to further polish the periphery of the scratch in a relatively wide range.

Concrete example 2. For a 14-inch color CRT having a scratch formed on the outer surface of the non-glare panel in the same manner as in Example 1, the particle size was 20
Average particle size 0.2μ with distribution mainly in the range of up to 1μm
Polishing was performed by spraying a polishing liquid containing 5% by volume of m 3 cerium oxide-based abrasive (“Cerico” manufactured by Shin Nippon Metal Chemical Co., Ltd.) and 95% by volume of water at a high speed of an injection pressure of 3 kg / cm ² .

[0033]

[Table 2] In this case as well, it was possible to remove the sharp corners of the scratches and repair them so that abnormal reflection of external light did not occur, but it took 180 seconds to repair the scratches, and the injection pressure in Concrete Example 1 was 3 kg / cm ²
It took a longer time to repair the scratch than 50 seconds in the case of. This is because the abrasive used in Example 1 had an average particle size of 0.4 μm, while the abrasive used in Example 2 had an average particle size of 0.2 μm.
This is because the content ratio of the abrasives of large particles is small.

In this case, the gloss value increased by 0.2%. This is because the content ratio of the large particle abrasive is small, so that the damage of the convex portion is small, and the small particle abrasive enters the concave portion and polishes the concave portion well, so that there is little change in the uneven shape. It is shown that the change of the gloss value can be reduced by increasing the content ratio of the small particle abrasive.

Concrete Example 3. For a 14-inch color CRT in which a scratch was formed on the outer surface of the non-glare panel in the same manner as in Example 1, the particle size was 5 μm from the nozzle as shown in Table 3.
A small particle cerium oxide-based abrasive having a mean particle size of 0.7 mm (“Serico” manufactured by Shin Nippon Metal Chemical Co., Ltd.) having a distribution mainly in the range of m or less was used in the same manner as in Example 2 at 5% by volume and 9% of water.
Polishing liquid containing 5% by volume was sprayed at a high speed of spraying pressure of 5.0 kg / cm ² and 3.0 kg / cm ² .

The abrasives having the particle size distribution shown in Table 3 are
It was obtained by separating an aqueous dispersion of "Celico" using a centrifugal separator.

[0037]

[Table 3] In this case, it took about 30 minutes to repair the scratch in the same state as in the specific example 1 and the specific example 2. As described above, it takes a long time to repair a scratch because the particle size is small and no large particles are contained, so that the corner portion of the scratch is hardly worn.

Concrete Example 4. For a 14-inch color CRT having a scratch formed on the outer surface of the non-glare panel in the same manner as in Example 1, as shown in Table 4, the particle size was 60.
A relatively large particle cerium oxide-based abrasive with a distribution mainly in the range of μm or less (“Fukushima sand” manufactured by Daiwa Kenzai Co., Ltd.)
Was polished in the same manner as in Example 2 by injecting a polishing liquid containing 5% by volume and 95% by volume of water at high speeds of an injection pressure of 5/0 kg / cm ² and 3.0 kg / cm ² .

[0039]

[Table 4] In this case, the corners of the scratch could be removed in about 5 seconds, but the scratch marks were visually recognized as a new defect, and the non-glare panel could not be regenerated. This is because the grain size of the abrasive is large with respect to the intervals of the unevenness of the non-glare panel, so that the normal protruding parts are worn away significantly, and the unevenness around the scratches is generally low, and This is due to variations in the polishing amount due to the difference in the hitting strength of the spray patterns.

The gloss value after spraying for 25 seconds is 2
It increased by 0 to 25% and markedly lowered the non-glare quality.

In the above embodiments, the repair of the scratches on the outer surface of the non-glare panel on which fine irregularities are formed has been described. However, the present invention is directed to the dirt attached to the outer surface of the panel and the inner surface of the panel. The same can be applied to the repair of defects such as scratches and stains on the uneven surface.

The present invention can also be applied to repair of defects such as scratches and stains on the inner and outer surfaces of a panel (face plate) of a Braun tube other than the color Braun tube.

[0043]

EFFECTS OF THE INVENTION A defective portion formed on the surface of a panel is repaired by spraying a polishing liquid containing 2 to 20 volumes of an abrasive having a particle size distribution of 20 to 1 μm from the front at a high speed. Then, for example, the sharp corner of the scratch can be removed to eliminate the extraordinary reflection caused by the corner. In addition, stains can be easily removed.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a method of repairing a scratch generated on an outer surface of a non-glare panel of a color CRT which is an embodiment of the present invention.

2A to 2C are views for explaining a repaired state of a scratch generated on the outer surface of the non-glare panel.

FIG. 3 (a) is a diagram showing a configuration of a color cathode ray tube, and FIG. 3 (b) is a diagram showing irregularities of a non-glare panel having irregularities formed on its outer surface.

FIG. 4 is a diagram showing a manufacturing process of a color CRT.

[Explanation of symbols]

 1… Panel 21… Polishing liquid 22… Nozzle 23… Asperity 24… Protrusions 25… Corners 27… Recesses

Claims (1)

[Claims] 1. A defective portion formed on the surface of a panel is sprayed at high speed with a polishing liquid containing 2 to 20% by volume of an abrasive having a particle size distribution of 20 to 1 μm from the front side at a high speed. A panel defect repairing method for a cathode ray tube characterized by repairing