JPH097511A - Manufacture of color cathode-ray tube - Google Patents

Abstract

PURPOSE: To obtain sufficient development capacity so as to prevent deficiency such as fog resulting from the low development capacity, and improve the quality of a color cathode-ray tube by providing a wetting process moistening a fluorescent face in advance before a development process in which pure water is directly sprayed. CONSTITUTION: In a formation of the fluorescent face of a cathode-ray tube, at first carbon stripes 13 are formed on a fluorescent face 11. Inside its panel 14, for example, green fluorescent substance slurry is filled, and aging is conducted as rotating the panel 14 at a low speed at a certain angle. High speed rotation sprinkle is conducted, and the extra slurry is removed by skirt trimming so as to form a fluorescent substance slurry film having a fixed film thickness. The fluorescent substance film is dried. The panel 14 is set to an exposure base, and is exposed via aperture grill. After the detachment of the grill, and before its development, fine water particles 22 generated from a two fluid nozzle 21 is sprayed to the inner face of the rotating panel 14 so as to moisten the fluorescent film, and thereafter, the development is conducted. That is, an unexposed portion is removed by the jet of the pure water to the panel inner face, and an exposed portion is left as it is so as to form fluorescent substance stripes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube manufacturing method, and more particularly to improvement of the developing process thereof.

[0002]

2. Description of the Related Art When a phosphor stripe is formed on the inner surface of a panel of a color cathode ray tube, a process of removing the water-soluble unexposed portion by spraying pure water (hereinafter referred to as "developing"
There is). That is, for example, to form a green phosphor stripe, a green phosphor slurry (a solution of polyvinyl alcohol containing a small amount of ammonium dichromate,
A suspension of green phosphor) is applied to the inner surface of the panel and dried. After that, ultraviolet rays are exposed from the inner surface of the panel through a color selection mechanism (aperture grill) to form an insoluble green phosphor portion in the exposed portion. After the exposure is completed, in the developing process, pure water is contained in the phosphor in an amount of 30 to 90.
By spraying for a second, only the water-soluble unexposed portion is removed, and the insoluble exposed portion is formed as a green phosphor stripe. In the production of a color cathode ray tube, this development process is repeated in the same manner, so that blue and red phosphor stripes are sequentially formed.
It was formed between predetermined carbon stripes to obtain a desired color phosphor screen.

[0003]

However, in the conventional development, since the developing ability is not sufficient, it is difficult to perform reliable and rapid development, and the unexposed portion which should be originally removed cannot be removed. There was a risk of affecting the quality. That is, as shown in FIG. 4A, when the blue phosphor stripe 3 is formed after the green phosphor stripe 1 is formed, the unexposed portion of the blue phosphor 5 that should be originally removed is green phosphor. It may remain on the body stripe 1 and cause so-called fog. This fog may cause a color mixture in the green phosphor stripe 1 and reduce the color purity, thereby deteriorating the quality of the phosphor screen. Further, after the green and blue phosphor stripes 1 and 3 are formed, the red phosphor stripe 7 is further formed in the same manner as shown in FIG. 4B, but at this time as well. In some cases, the red phosphor 9 that should originally be removed by development may remain on the blue phosphor stripe 3, for example, and there is a risk of causing the same problem as described above. The present invention has been made in view of the above circumstances, and provides a color cathode ray tube manufacturing method capable of eliminating defects such as fog caused by low developing ability by obtaining sufficient developing ability, and improving the quality of the color cathode ray tube. The purpose is to

[0004]

In order to achieve the above object, a method for manufacturing a color cathode ray tube according to the present invention comprises spraying pure water on a fluorescent film coated on the inner surface of a panel to form a water-soluble fluorescent film in an unexposed portion. In the color cathode ray tube manufacturing method in which the developing process for removing is performed for each of the fluorescent films of the first color, the second color, and the third color, and the fluorescent films of a plurality of colors are developed stepwise, the fluorescent film is humidified. The wetting step is performed before the developing step.

[0005]

[Function] Before the water-soluble fluorescent film, which is the unexposed portion, is directly developed with pure water, it is gradually humidified in the wetting process so that the fluorescent film becomes hydrated and the compatibility with water in the subsequent development becomes good. Therefore, the ability of the development to be performed later will be enhanced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a color cathode ray tube manufacturing method according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view of a fluorescent screen forming procedure in the manufacturing method of the present invention,
FIG. 2 is a cross-sectional view showing the state of the phosphor screen in the phosphor screen forming process, and FIG. 3 is a diagram illustrating the wetting process.
In the formation of the fluorescent screen in the color cathode ray tube, first, the carbon stripe 13 is formed on the fluorescent screen 11. The carbon stripe 13 is a water-soluble ultraviolet curable resin (PV
A) is exposed through an aperture grill, the unexposed portion is developed with pure water, then carbon is applied, the photoresist stripe is dissolved with an acid, and the PVA stripe is developed with pure water. It is formed in stripes (see FIG. 2a).

150 to 250 ml of phosphor slurry, for example, green phosphor slurry 15 is injected into the inner surface of the panel 14 on which the carbon stripe 13 is formed, and the panel 14 is slowly rotated at a constant angle in order to obtain a uniform coating film. The so-called aging of rotating is performed. Then 150-250 per minute
Performs high-speed swing-off and skirt streaming,
Excessive green phosphor slurry 15 is removed from the inner surface of the panel skirt to obtain a green phosphor slurry 15 having a constant film thickness.
Film 17 (hereinafter referred to as "green fluorescent film") is formed.
After that, while rotating the panel 14, an infrared heater,
The green fluorescent film 17 is dried by air blowing.

Next, the panel 14 is mounted on an exposure table (not shown).
And is exposed to ultraviolet rays (UV) through the aperture grill 18 to which the green fluorescent film 17 is attached again. The green fluorescent film 17 has an exposed portion insoluble in water, while an unexposed portion retains water solubility.

After the attachment and removal of the aperture grill 18, in the conventional process, development is performed by spraying pure water. In the manufacturing method of the present invention, the wetting shown in FIGS. 1e and 2e is performed before this development process. Done. As shown in FIG. 3, the wetting device has a two-fluid nozzle (high pressure air: 2.5 to 2.5) on the inner surface of the rotating panel 14.
Fine water particles (0.5 to 25 μm) 22 generated from 4.0 kg / cm ² , pure water 21 are sprayed onto the fluorescent film 17
Humidify.

In this way, after the water-soluble fluorescent film is humidified, the same development as in the conventional case is performed. That is, by injecting pure water onto the inner surface of the panel, the unexposed portion is removed, while the exposed portion remains and the green phosphor stripe 23 is formed. Hereinafter, by repeating the same procedure for forming the green phosphor stripe 23 described above, the blue phosphor stripe and the red phosphor stripe are sequentially formed on the inner surface of the panel.

In the cathode ray tube manufacturing method according to this embodiment,
Before the water-soluble fluorescent film which is the unexposed portion is directly developed by spraying pure water, it is gradually humidified in the wetting process. This humidification increases the developing ability for the water-soluble fluorescent film that is performed later. That is, in the conventional case in which pure water directly contacts the water-soluble fluorescent film in a dry state, the liquid phase of pure water is unlikely to easily penetrate into the solid phase of the fluorescent film due to the interfacial tension of water. On the other hand, when the wetting is applied, fine water particles of 0.5 to 25 μm penetrate into the solid phase of the fluorescent film, and the fluorescent film becomes in a water-containing state, which is well compatible with water in the subsequent development. Therefore, the developing ability is improved.

As described above, according to the color cathode ray tube manufacturing method of this embodiment, the wetting process for humidifying the fluorescent film 17 is provided in advance before the conventional developing process in which pure water is directly sprayed. The developing ability of the process can be improved and the development can be surely performed. As a result, for example, when the blue phosphor stripe is formed after the green phosphor stripe 23 is formed,
The blue phosphor remaining on the green phosphor stripe 23 is surely removed, and the fog of the blue phosphor on the green phosphor stripe 23 can be prevented. Further, similarly to this, it is possible to prevent the fog of the red phosphor on the blue phosphor stripe when the red phosphor stripe is formed.

Further, according to the color cathode ray tube manufacturing method of this embodiment, since the developing ability is enhanced, the developing time becomes short, the process time can be shortened, and the amount of developing water used can be reduced. it can.

In the above embodiment, the case where the wetting process is provided before all the developing processes, including the green phosphor stripe 23 formed first, has been described. The wetting step may be provided only before the development of the phosphor stripe after the step. That is, the phosphor stripe is green (first color),
When the blue (second color) and the red (third color) are formed in this order, the wetting process is performed only before the development of the blue phosphor stripe or before the development of the blue phosphor stripe and the red phosphor stripe. It may be provided only in. In the first place, the wetting process is for improving the developing ability afterwards, but by providing it before the next stage of development after the phosphor stripe has already been formed in this way, it is possible to obtain a ready-made phosphor stripe. The adhering phosphor in the next stage is surely removed, and the effect is further enhanced. Therefore, for the purpose of removing the fog, the process time can be shortened by omitting the wetting process at the time of forming the first phosphor stripe.

In the above embodiment, the two-fluid nozzle 2 is used.
Although the case of performing humidification by generating fine water particles by using 1 has been described, the humidifying means uses, for example, a steam generating means by a heater or a water spray generating means by an ultrasonic vibrator. May be

[0016]

As described above in detail, according to the color cathode ray tube manufacturing method of the present invention, a wetting process for humidifying the fluorescent film is provided before the conventional developing process of directly spraying pure water. Therefore, the developing ability in the subsequent developing step can be enhanced, and the development can be surely performed. As a result, it is possible to eliminate defects such as fogging due to the low developing ability, and improve the quality of the color CRT.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a fluorescent screen forming procedure in the manufacturing method of the present invention.

FIG. 2 is a cross-sectional view showing a state of a fluorescent screen during a fluorescent screen formation process.

FIG. 3 is a diagram illustrating a wetting process.

FIG. 4 is a diagram illustrating fogging that occurs in conventional development.

[Explanation of symbols]

 14 panels 17 fluorescent film

Claims (3)

[Claims] 1. A developing step of spraying pure water onto a fluorescent film applied to the inner surface of a panel to remove the water-soluble fluorescent film in an unexposed portion, the first color, the second color, and the third color In the method for manufacturing a color cathode-ray tube, which is carried out for each phosphor film in stepwise, and which develops phosphor films of a plurality of colors in a stepwise manner, a wetting process for humidifying the phosphor film is provided before the developing process. Method. 2. The color cathode ray tube manufacturing method according to claim 1, wherein the wetting step is provided before the second color developing step of the second step. 3. The color cathode ray tube according to claim 1, wherein the wetting step is provided before the second color developing step of the second step and before the third color developing step of the third step. Production method.