JPS62219431A - Formation of fluorescent screen of cathode-ray tube - Google Patents

Abstract

PURPOSE:To improve the workability in separating fluorescent material stuck to undesired portions of the inside surface of a bulb by forming a photosensitive resist film on the inside surface of the bulb and a fluorescent screen on the inside surface of a face-panel, thereafter separating, said resist film through a chemical treatment. CONSTITUTION:A positive type photosensitive resist is applied on the whole inner periphery surface of a bulb 4 to the predetermined thickness by the spin cord method or the like. Thereafter, said resist is dried by backing so as to obtain the photosensitive resist film 5. And the photosensitive resist film 5 the inner surface of the face-panel 4a of the bulb 4 is separated so as to form a window. After forming a window in the resist film 5, a fluorescent screen 8 if formed on the inner surface of the face-panel 4a by a dry method or the like. Thereafter, the resist film 5 stuck to a fannel 4b and neck 4c of the bulb 4 is melted by a chemical method using acetone or the like. And undesirable fluorescent screens 8', 8'... formed on the resist film 5 are separated rapidly and easily.

Description

[Detailed Description of the Invention] No. 1 The present invention relates to a method for forming a fluorescent film of a cathode ray tube, and in detail,
The present invention relates to a method of depositing and forming a fluorescent film on the inner surface of the face panel of a bulb.

For example, in the production of color cathode ray tubes used in television receivers, etc., a method of forming a fluorescent film on the inner surface of the bulb's face panel involves applying a photosensitive resin containing phosphor powder to the bulb's face. There is a slurry method in which it is applied to the inner surface of the panel, and a dry method in which phosphor powder is adhered to an adhesive layer that has been previously formed on the inside and surface of the face panel. In particular, forming a fluorescent film using the dry method has various advantages such as forming a highly accurate fluorescent film, reducing the number of steps, and improving productivity.

In this method of forming a fluorescent film using the dry method, an adhesive that becomes sticky when exposed to light, such as an aromatic diazonium/zinc chloride double salt, is mixed into polyvinyl alcohol, etc., with the neck opening end of the bulb facing upward. The material is supplied to the inner surface of the valve face panel. Then, with the valve positioned and arranged upside down, the face panel of the valve (1) (
A thin adhesive layer (2) is uniformly formed on the inner surface of 1a).

Thereafter, a predetermined portion of the adhesive layer (2) is made to develop adhesiveness, and a phosphor powder is attached to this portion to form a fluorescent film (3).
) is adhered and formed on the inner surface of the face panel (1a).

(However, in the conventional fluorescent film forming method described above, when forming the adhesive layer (2), only the inner surface of the face panel (1a) is used by means such as the spin cord method, as shown in Figure 7. Otherwise, the adhesive will adhere to the inner surface of the funnel (1b) and neck (1c) of the valve (1), forming an undesirable adhesive layer (2°) (2"). Part of the undesired adhesive layer (2°') (2') also developed adhesiveness, and when the phosphor powder was supplied, the adhesive 1i (2')
')(2°)--The phosphor powder adheres to the surface, and fluorescence 1)1(3°)(3°)- is formed at an undesired location. Therefore, in order to peel off and remove this undesirable fluorescence 1) (3') (3°) -, conventionally, a special jig such as a brush is used to remove the fluorescent film (3°) (3'') -. I had to scrape it off. Also, this fluorescent film (3°) (3")
・During the removal work, the fluorescence 1) (3) on the inner surface of the face panel (1a) may be damaged, which not only makes the work laborious and difficult, but also significantly reduces the yield. there were.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the work of removing phosphor adhered to undesired locations on the inner surface of a bulb.

The present invention was proposed in view of the above-mentioned problems, and the technical means for achieving the above-mentioned object is to coat a photosensitive resist film on the entire inner peripheral surface of a cathode ray tube bulb that is positioned and arranged. a step of peeling off and removing the photosensitive resist p on the inner surface of the face panel of the cathode ray tube bulb by exposure to open a window; a step of depositing and forming a fluorescent film on the inner surface of the face panel with the window open; This is a method for forming a phosphor film for a cathode ray tube, which comprises the steps of dissolving and peeling off photosensitive resists 1-II on the inner surface of the funnel and neck of the cathode ray tube bulb by chemical treatment.

According to the method of the present invention, a photosensitive resist film is previously deposited on the entire inner peripheral surface of a cathode ray tube bulb, and then a fluorescent film is formed on the inner surface of the face panel where the photosensitive resist film is opened. Therefore, the fluorescent film at undesired areas on the inner surface of the funnel and neck is formed on the photosensitive resist film, and the second photosensitive resist film is dissolved by chemical treatment! It is quickly peeled off and removed.

One embodiment of the method for forming a fluorescent film for a cathode ray tube according to the present invention will be described with reference to FIGS. 1 to 5. First, as shown in Figure 1, a positive type photosensitive resist is applied to the entire inner circumferential surface of the bulb (4) to a predetermined thickness using a spin code method, etc., and then dried by baking to coat the photosensitive resist with a sun odor. (5
) is deposited and formed. And as shown in FIG. 2, there is a photosensitive resist (II) on the □ inner surface of the face panel (4a) of the bulb (4)! (5) Peel and remove to open the window. To open the window in the photosensitive resist film (5), for example, as shown in FIG. 1, a mask (6) is positioned and arranged above the face panel (4a) of the bulb (4), and The effective screen area of the face panel (4a) of the bulb (4), that is, the area where the fluorescent film is to be formed, is irradiated with ultraviolet rays through the hole (6a). Due to this ultraviolet irradiation, the bulb (4)
The photosensitive resist film (5) on the inner surface of the face panel (4a) is exposed to light, and the photosensitive resist film (5) is peeled off and removed by the subsequent development process. During this ultraviolet irradiation, the exposure time is set so that only the photosensitive resist Ill (5) on the inner surface of the face panel (4a) is peeled off. In addition, photosensitive resist Hll (5
) For example, an optical fiber may be inserted into the bulb, and the tip of the optical fiber may be connected to the face panel (4).
a) By scanning below the photosensitive resist film (5) on the inner surface, the photosensitive resist III (5) is irradiated with ultraviolet rays from the tip of the optical fiber, and the face panel (4a
) Only the photosensitive resist film (5) on the inner surface may be exposed.

After the photosensitive resist film (5) is exposed, a fluorescent film is formed on the inner surface of the face panel (4a) by, for example, a dry method. That is, as shown in FIG. 3, a photosensitive adhesive that becomes sticky when exposed to light, such as a mixture of P-dimethylaminobenzenediazonium/zinc chloride double salt into ethylene glycol, polyvinyl alcohol, etc., is applied to the bulb (4). The adhesive layer (7) is uniformly formed *i* by supplying it to the inner surface of the face panel (4a) and applying it to a predetermined thickness by a spin code method or the like, and then drying it by baking. Thereafter, as shown in FIG. 4, the adhesive layer (7) is exposed to ultraviolet light,
Develops stickiness. Adhesive 1 has developed adhesive properties by supplying phosphor powder! (7) The above phosphor powder is applied to form a phosphor film (8) on the inner surface of the face panel (4a).

On the other hand, as shown in FIGS. 3 to 5, when forming the adhesive II (7) as in the past, by means such as a spin cord method, not only the inner surface of the face panel (4a) but also
Funnel (4b) and neck (4c) of valve (4)
An adhesive layer (7°) is placed on the inner photosensitive resist film (5) (
7°)-・ is formed, and furthermore, this adhesive # (7°
) (7°)... A part of it also develops adhesiveness, and the phosphor powder adheres to this adhesive layer (7°) (7') -- resulting in an undesirable fluorescent film (8') (8 ') -... are formed.

Therefore, in the method of the present invention, after forming the fluorescent film (8) on the inner surface of the face panel (4a) of the bulb (4), the funnel of the bulb (4) is treated with chemicals such as acetone or N-butyl acetate i-liquid. (4b) and neck (4
c) The remaining photosensitive resist film (5) is melted, and the undesired fluorescent film (8°) (8')... formed on the photosensitive resist film (5) is quickly and easily removed. Peel and remove. At this time, if the fluorescent film (8) formed on the inner surface of the face panel (4a) is fixed with ammonia gas, the photosensitive resist (Iff!) formed by the above-mentioned chemical treatment can be fixed. (
At the time of peeling and removal in step 5), the fluorescent film (8) is not damaged by the chemical.

In the above embodiment, a method for forming a fluorescent film on a monochrome cathode ray tube was explained, but the present invention is not limited thereto, and can also be applied to a color cathode ray tube. Of course, the same applies to formation.

According to the method of the present invention, a photosensitive resist film is previously deposited on the inner surface of the funnel and neck other than the face panel of the bulb, and a fluorescent film is formed on the inner surface of the face panel.
Since the photosensitive resist (Ill) is peeled off and removed by chemical treatment, it is possible to quickly remove the phosphor attached to undesired parts of the inner surface of the bulb by a simple means. There is no damage to the fluorescent film. Therefore, the workability in the fluorescent film forming process is greatly improved, and it is also easy to improve the yield.

[Brief explanation of drawings]

1 to 5 are process diagrams for explaining the method for forming a fluorescent film of a cathode ray tube according to the present invention. FIG. 6 is a cross-sectional view showing the state of fluorescent film formation in the conventional method, and FIG. 7 is a cross-sectional view for explaining problems in the conventional method. (4)---Bulb, (4a)---Face panel, (4b)---Funnel, (4c)---Neck, (5)---Photosensitive resist film, (8)--- Fluorescent film. Patent applicant ka. E□□□1, -'m Agent l'x Shogo Hara Shi-2j Figure 1
帛 2 Figure Th3=ko
, i(4"〈Fig. 5 6.!f huff ra

Claims (1)

[Claims] (1) A process of depositing a photosensitive resist film on the entire inner peripheral surface of the bulb consisting of the face panel, funnel, and neck, and a process of peeling off and removing the photosensitive resist film on the face panel portion by exposure to open a window. A cathode ray method comprising: a step of depositing and forming a fluorescent film on the face panel portion where the window is opened; and a step of dissolving and peeling off the photosensitive resist film on the funnel and neck portions by chemical treatment. Method for forming fluorescent film on tubes.