JPH06150822A - Phosphor screen forming method for cathode-ray tube - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for forming a fluorescent screen of a cathode ray tube, by which dust adhered to the inner surface of a panel can be removed to obtain a good fluorescent screen. [Configuration] Before forming a fluorescent screen on the inner surface 2 of the panel 1,
The inner surface 2 of the panel 1 is cleaned by jetting high-pressure water 6 from the nozzle 3. The nozzle 3 is arranged 10 to 100 mm below the sealing surface 5 of the panel 1. Nozzle 3
Three panels 1 are arranged in a row in the y-axis direction of the panel 1. Nozzle 3
The opening angle θ of the high-pressure water 6 jetted from is 1 to 90 °. The inner surface 2 of the panel 1 is cleaned by moving the nozzle 3 from the left end of the panel 1 in the x-axis direction and making a U-turn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fluorescent screen of a cathode ray tube, and more particularly to a method for cleaning the inner surface of a panel.

[0002]

2. Description of the Related Art For example, in the step of forming a phosphor screen on the inner surface of a panel of a color cathode ray tube, the inner surface of the panel is washed to remove fine dust such as fibrous dust and cardboard residue attached to the inner surface of the panel. I have to. In this case, if the inner surface of the panel is not sufficiently cleaned and dust is attached, black spots are generated at that portion. Therefore, in order to complete the cleaning, conventionally, fluoridation with a weight concentration of 1 to 10% is conventionally performed. The inner surface of the panel was cleaned by injecting an aqueous solution of hydrogen acid onto the inner surface of the panel and melting the glass surface.

[0003]

However, in such a conventional example, when there is dust adhered to the glass surface on the inner surface of the panel, the cleaning liquid does not enter the adhesive surface between the dust and the glass surface. However, there is a problem that black spots are generated on the screen especially in a high definition tube.

The present invention has been made in view of the above-mentioned problems of the conventional example, and an object of the present invention is to remove the dust adhered to the inner surface of the panel to obtain a good fluorescent screen of a cathode ray tube. It is to provide a surface forming method.

[0005]

The present invention comprises a step of cleaning the panel inner surface 2 of a cathode ray tube with a high-pressure water jet, as shown in FIG. 1, for example. In this case, 50 to 10
Water pressure of 00 kg / cm ² and water of 1 to 90 ° 6
It is also possible to perform the cleaning at the opening angle θ. Alternatively, the photosensitive film may be formed after the inner surface 2 of the panel of the cathode ray tube is washed with a high-pressure water jet.

[0006]

In the present invention having such a structure, since the panel inner surface 2 is cleaned by high water pressure injection, the panel inner surface 2
Even if there is dust adhered to the surface, water will enter between the dust and the surface of the panel inner surface 2. In this case, the spray water pressure of 50 to 1000 kg / cm ² and 1 to
By performing the cleaning with the opening angle θ of the jet water of 90 °, the water effectively enters between the dust and the surface of the panel inner surface 2. If the inner surface 2 of the panel is cleaned by jetting high-pressure water and then the photosensitive film is formed, the fluorescent surface can be formed on the inner surface 2 of the panel without dust. Further, according to the present invention, since the aqueous solution of hydrofluoric acid, which has been conventionally used for cleaning, is unnecessary, no offensive odor is generated during cleaning, and the glass surface of the panel is not dissolved by the acid. .

[0007]

Embodiments of the method for forming a fluorescent screen of a cathode ray tube according to the present invention will be described below with reference to the drawings.

FIG. 2 shows in detail the step of forming a phosphor screen of a color cathode ray tube, particularly the step of forming a carbon stripe.

As shown in the figure, in this embodiment,
First, the inner surface of the panel is cleaned by the method described below (step).

Next, a photosensitive agent which becomes insoluble in the solvent by light is uniformly applied to the inner surface of the panel to form a photosensitive film (step).

After drying, an aperture grille, which is a color selection mechanism, is attached to the panel, and the same exposure stage as the phosphors to be applied later is used to irradiate ultraviolet rays with a mercury lamp placed at the polarization center position of each phosphor to expose it. (Process).

After that, the color selection mechanism was removed from the panel, and the unexposed portion of the photosensitive film was rinsed with pure water.
Develop (process). As a result, the photosensitive film remains in stripes.

Further, a carbon slurry is applied onto the stripe-shaped photosensitive film to uniformly form a carbon film (step).

Finally, the photosensitive film is decomposed with a chemical to remove carbon coated on the photosensitive film, and reverse development is performed (step,). In this way, a black stripe film of carbon is formed on the inner surface of the panel (step). After that, a known phosphor coating step or the like is performed to form a phosphor screen.

FIG. 1 shows a step of cleaning the inner surface of the panel. As shown in the figure, in this embodiment, the panel 1 is arranged so that the inner surface 2 of the panel 1 faces downward, and a nozzle 3 for injecting high-pressure water is arranged below the panel 1. Three nozzles 3 are provided on the support member 4 in a row in the y-axis direction of the panel 1, and each nozzle 3 is connected to a pump (not shown). In this case, the nozzle 3 is the sealing surface 5 of the panel 1.
10 to 100 mm below.

As shown in FIG. 1B, from each nozzle 3,
The high-pressure water 6 is jetted upward toward the inner surface 2 of the panel 1. In that case, the opening angle θ of the high-pressure water 6 is θ = 1 to
The angle is preferably 90 °, and most preferably around 15 °. The range of pressure of the high-pressure water 6 when ejected from the nozzle 3 is 50 to 1000 kg / cm ² , and especially 100 to 100 kg / cm ² .
It is preferably 500 kg / cm ² .

When cleaning the inner surface 2 of the panel 1,
As shown in FIG. 1C, the high pressure water 6 is jetted while moving the nozzle 3. That is, as understood from the locus 7 of the nozzle 3 shown in the same figure, the injection of the high-pressure water 6 is started from the left end portion of the inner surface 2 of the panel 1, the nozzle is moved in the x-axis direction of the panel 1, and the inner surface of the panel 1 is moved. When the right end of 2 is reached, the nozzle 3 is slightly moved in the y-axis direction, and made a U-turn to return to the original position. As a result, the high pressure water 6 is sprayed onto the entire inner surface 2 of the panel 1. The moving time of the nozzle 3 is, for example, 0.6 to 10 seconds in total for a 20-inch size panel.

According to the present embodiment having such a structure, the high-pressure water 6 is sprayed onto the inner surface 2 of the panel 1, and water also enters between the dust and the glass surface of the panel 1, so that the inner surface 2 of the panel 1 is covered. The adhered dust can be easily removed.

Incidentally, when the 20-inch panel was actually washed by the above-mentioned method, the dust generation rate on the inner surface of the panel was reduced from 0.86% to 0.31%. The number of samples was N = 11627 (sheets).

Further, according to the present embodiment, the conventionally used aqueous solution of hydrofluoric acid is no longer necessary, so that it is possible to perform the work under a good environment with no offensive odor.

Further, since hydrofluoric acid is not used, the inner surface 2 of the panel 1 is not eroded in the cleaning step,
As a result, the dimensional accuracy of the panel 1 with respect to the color selection electrode can be improved.

In the above embodiment, three nozzles are used.
However, the present invention is not limited to this, and the number of nozzles can be changed according to the pipe type. Also, various modifications can be made to the arrangement and movement direction of the nozzles.

Further, in the above-mentioned embodiment, the photosensitive film is formed after cleaning the inner surface of the panel, but the present invention is not limited to this, and any other process can be used as long as it is a step of cleaning the inner surface of the panel. Can also be applied to.

In addition, the present invention can be applied not only to a cathode ray tube using an aperture grill as a color selection electrode but also to one using a shadow mask.

[0025]

As described above, according to the present invention, dust (fibers, glass scraps, small pieces of paper, etc.) adhered to the inner surface of the panel is easily removed by cleaning the inner surface of the panel with high-pressure water. be able to. In this case, 50-1000k
By performing the cleaning with the water pressure of g / cm ² and the opening angle of the water spray of 1 to 90 °, the dust removing effect can be enhanced. Further, if the inner surface of the panel is washed with a high-pressure water jet and then the photosensitive film is formed, a fluorescent surface can be formed on the inner surface of the panel without dust, and black spots are prevented from appearing on the screen. be able to. Furthermore, according to the present invention, since the aqueous solution of hydrofluoric acid, which has been conventionally used for cleaning, is not required, it is possible to perform the work in a favorable environment without any offensive odor, and the surface of the panel is dissolved by the acid. Since it is not damaged, the dimensional accuracy of the panel with respect to the color selection electrode can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a main part of an embodiment of a phosphor screen forming method according to the present invention.

FIG. 2 is a flowchart showing a carbon stripe forming process of the same example.

[Explanation of symbols]

 1 Panel 2 Inner surface 3 Nozzle 6 High pressure water θ Opening angle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiichiro Kondo 30 Ibarjima, Oya-cho, Inazawa-shi, Aichi Sony Inazawa Corporation

Claims (3)

[Claims] 1. A method for forming a fluorescent screen of a cathode ray tube, comprising the step of cleaning the inner surface of the panel of the cathode ray tube with a high-pressure water jet. ^2. The method for forming a fluorescent screen of a cathode ray tube according to claim 1, wherein the cleaning is carried out at a water spray pressure of 50 to 1000 kg / cm ² and an opening angle of the water spray of 1 to 90 °. 3. The photosensitive film is formed after the inner surface of the panel of the cathode ray tube is washed with a high-pressure water jet.
Or the method for forming a fluorescent screen of a cathode ray tube according to item 2;