JPS6340232A - Spray mask for color selection electrode - Google Patents

Abstract

PURPOSE:To avoid adhesion of coating liquid to the flange part of a color selection electrode so as to obtain superior picture quality and withstand voltage characteristics of the spray mark in the caption, by constituting said mark in such a way that high pressure gas blown off from the top opening of an outside pipe surrounds the apertureformed surface of a perforated part. CONSTITUTION:When high pressure air is introduced from a high pressure gas inlet 24 to a space 23, the introduced air is blown off toward the perforated part 8 of a color selection electrode 5 through the lower end opening 21 of an outside pipe 19 which is surrounding the lower end opening 20 of an inside pipe 18. The blown off high pressure air will hit the perforated part 8 and reflect from it or pass the electron beams through-aperture 5a then surrounds the aperture-formed surface 8a of the perforated part 8. In this condition, a coating liquid 14 which is sprayed from the upper end opening 22 of the inside pipe 18 by a spray gun 13 is prevented from diffusing toward the flange part 9 of the color selection electrode 5 by the inside pipe 18 and the blown off high pressure air. Thus, the coating liquid will not adhere to the flange part 9 but the apertureformed surface 8a only is coated with it and a coating film 7 is formed. Therefore, the coating film 7 can never be peeled off to become any foreign substance so that a cathode-ray tube will be superior in its picture quality and withstand voltage charactereistics.

Description

[Detailed Description of the Invention] [Industrial Application] This invention relates to a color selection electrode used when forming a coating film by spraying a coating liquid on a color selection electrode built into a color cathode ray tube. This relates to spray masks.

[Conventional technology]

As shown in Figure 2, a color cathode ray tube (1) generally used in color televisions etc. has an evacuated envelope (
2), an electron gun (3) that emits multiple electron beams, and a phosphor film lined inside the front screen (2a) (
4), color selection [1] provided close to the phosphor film (4)
i (5). The phosphor film (4) is red;
It is a regularly arranged array of light emitters that emit blue and green light. The color selection electrode (5) has a thickness of 0.1 to 0.2
It is made of a low carbon steel plate of approximately s+s+, and is provided with a large number of electron beam holes (6a).

In such a cathode ray tube (1), eight electron beams emitted from the electron gun (3) are scanned by a deflection device (6) and are directed to the electron beam aperture (5a) of the color selection 1111 i (5). The electron beam passing through the hole (5a
) is made to emit light from the phosphor of the phosphor film (4).

At this time, approximately 80% of the electron beam emitted from the electron gun (3) collides with the color sorting [i (5) without passing through the electron beam hole (5a), and the kinetic energy is converted into thermal energy. The temperature of the color selection electrode (5) is increased.

As a result, the color selection electrode (5) thermally expands and the positional relationship between the electron beam hole (5a) and the phosphor in the phosphor film (4) is distorted, causing the electron beam to accurately irradiate the desired phosphor. Color shifts appear in the projected image.

In particular, when the color cathode ray tube (1) is operated at high brightness, a large amount of electron beam is used for color selection t Wi (5).
Since the K collision occurs, the amount of thermal expansion also increases, and the color blurring of the projected image becomes noticeable and the image quality deteriorates.

Therefore, in order to reduce the thermal expansion lu of the electrode (5) for color selection, for example, as disclosed in Japanese Patent Application Laid-open No. 55-76558, the electron gun (3) side of the color selection electrode (5) is The surface is coated with a coating called an electron reflective coating (7) containing heavy metals or their compounds, such as bismuth, lead or tantalum.
is formed.

This coating film (7) efficiently reflects the electron beam that collides with the color selection electrode (5), reduces the rate at which the kinetic energy of the collided electron beam is converted into thermal energy, and prevents color shift in images. To prevent.

Generally, the coating film (7) is formed by spraying a coating liquid made by adding water glass as a binder to bismuth oxide (Bi20B) on the surface of the color selection electrode (5) on the electron gun (3) side. be done.

As shown in FIG. 8, the color selection electrode (5) is formed into a rectangular shape with a substantially flat surface and has a large number of electron beam holes (6a).
a flange portion (9) formed from the outer peripheral end of the perforated portion (8) and substantially perpendicular to the perforated portion (8)
). This flange part (9) has a color selection electrode (
5) is the frame (
(not shown), this is the part that becomes the welding allowance. Actually, it is the perforated part (8) that requires the formation of the coating film (7) (Fig. 2), and the coating film (7) (Fig. 2) is formed on the flange part (9). However, it will peel off during the later welding process.

When spraying the coating liquid on the color selection electrode (5), use a cylindrical spray mask α1 with openings at both ends, that is, the top and bottom ends, as shown in Figure 4. cover the perforated part (8) of. This spray mask αQ has an electron gun (3) in which the lower end opening I is the perforated part (8) of the color selection electrode (5).
) (Fig. 2), and the coating liquid α is sprayed from the upper end opening toward the perforated portion (8) by a spray gun. Here, the above-mentioned perforated part (8)
The shape of the lower end opening I facing the perforated part (8) is a rectangular shape of the same size as the perforated part (8), and when spraying the coating liquid α4, the lower end 4 of the spray mask αG is located at the color selection vt pole. (5) is butted against the tip aG of the flange portion (9).

[Problem that the invention seeks to solve]

The conventional color selection ¥7L pole (5) spray mask αQ is
When the lower end opening mouth is placed opposite the perforated part (8) K of the color sorting pole (5) and the perforated part (8) is covered, the lower end 4 forming the lower end opening 0 is the color selecting electrode (5). The trap is formed so as to be butted against the tip αG of the 7th flange part (9).

Therefore, the coating liquid α sprayed from the upper end opening of the spray mask αG toward the perforated part (8) passes through the spray mask αG, and then passes through the electron gun (3) in the perforated part (8). (Second
There was a problem in that the coating was applied to the surface of the side shown in FIG. Furthermore, the sprayed coating liquid α is sprayed out of the spray mask oO from a small gap between the lower end of the butted spray mask αQ and the tip αG of the 7th flange (9), and the paint film is (7) Outer surface (9b) of flange portion (9) that does not need to be formed
There was a problem that K also adhered.

As mentioned above, the seventh flange IF (9) is the part that becomes the welding allowance, so the inner and outer surfaces (9a
).

(9b) peels off during the later welding process, etc., and becomes a foreign substance in the color cathode ray tube (1) shown in Fig. 2. ) The color i-ray tube (1) may become clogged and adversely affect the image quality.
This resulted in a loss of withstand voltage characteristics.

This Sep3 was created to solve the above problems, and it prevents the coating liquid from adhering to the flange part of the color selection electrode, making it possible to improve color cathode ray tubes with excellent image quality and withstand voltage characteristics. The purpose of the present invention is to provide a color-selecting tW spray mask that can contribute to manufacturing.

[Means for solving problems]

The color sorting [pole spray mask] according to the present invention is formed as a double-layered cylindrical body, which covers the perforated part of the color sorting electrode, and has an opening at a predetermined distance from the coating surface of the perforated part. It has an inner cylinder facing each other, into which a spray gun for spraying a coating liquid toward the perforated part is inserted into the base end opening, and an outer cylinder surrounding the side surface of the inner cylinder, and the inner cylinder and the outer cylinder Between,
A high-pressure gas passage is formed through which high-pressure gas is blown out from the tip opening of the outer cylinder so as to surround the hole-forming surface of the perforated portion.

[Effect]

According to this invention, when the spray mask covers the perforated part of the color selection electrode, the high-pressure gas blown out from the tip opening of the outer cylinder surrounds the pore-forming surface of the perforated part, so that the high-pressure gas is not sprayed from the spray gun. The spray mask and the high-pressure gas prevent the coating liquid from dispersing to the flange formed at the outer circumferential end of the perforated portion, so that the coating liquid does not adhere to the flange and is applied only to the hole-formed surface.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the spray mask α'a includes an inner cylinder rs and an outer cylinder 09. Above inner cylinder (to) and outer cylinder 0
1, each lower end is supported by a support (not shown) K, and an is a lower end opening (A) which is the tip opening of the inner cylinder side and an outer cylinder 0g, and an is a color sorting member. It faces the surface of the perforated portion (8) of the electrode (5) on the electron gun (3) (FIG. 2) side with a distance of about 10U. The shape of the lower end opening (A) of the inner tayQ81 facing the perforated part (8) is similar to the shape of the perforated part (8) and slightly reduced,
Of the surfaces forming the perforated portion (8), the electron beam through hole (5)
a) is formed and has a rectangular shape that is approximately the same size as the hole forming surface (8a) which requires a coating film (7) for the fire pit. The upper end opening (A), which is the base end opening of the inner cylinder a, has a perforated part (8
) is inserted with a spray gun 0 that sprays coating liquid α4.

On the other hand, the outer cylinder 01 surrounds the side surface on the inner cylinder side, and forms a space between it and the inner cylinder. The outer cylinder 09 has two high-pressure gas inlets (c) facing each other near its upper end, and an inlet pipe (c) is attached to these high-pressure gas inlets (c) from the outside. .

The upper end opening (to) which is the base end opening of the outer cylinder Og is closed by the upper plate @. Lower end opening el of outer cylinder 09
D serves as an outlet for the high pressure gas introduced into the space UK. In other words, the space (2) serves as a high-pressure gas passage.

In the above configuration, when high-pressure air of approximately 0.5 Kl/m2 is introduced into the space (c) from the high-pressure gas inlet @, the introduced air will press the lower end opening button of the inner cylinder 0&. From the lower end opening (goods) of the surrounding outer cylinder 01, color sorting K
It is blown out toward the perforated part (8) of m, (5). The high-pressure air that is blown out hits the perforated part (8) and is reflected, or passes through the electron beam hole (5a), and the perforated part (
8) surrounding the hole forming surface (8a).

In this state of deafness, the coating liquid α4 sprayed by the spray gun 03 from the upper end opening (2) of the inner cylinder (end) is transferred to the color-selecting electrode (
5) is prevented from dispersing to the flange part (9), so it does not adhere to the flange part (9) and is applied only to the pore forming surface (8a) of the perforated part (8), resulting in a coating film (7). form.

Therefore, select one color! ffl (5) flange part (
Since coating liquid α4 does not adhere to 9), 1
This prevents the coating film (7) (Fig. 4) on the flange portion (9) from becoming a foreign object inside the color cathode ray tube (1) (Fig. 2) due to it being punctured during the subsequent welding process, etc. The color negative FFI ray tube has excellent image quality and withstand voltage characteristics.

In addition, in the above embodiment, the inner cylinder (to) and the outer cylinder α9 are
Although formed in a funnel shape, the present invention is not limited thereto, and may be formed as other cylindrical shapes such as an inner cylinder (to) and an outer cylinder (/9) D', for example, an inner cylinder. may be done.

〔Effect of the invention〕

As described above, according to the present invention, the sprayed coating liquid is applied only to the hole forming surface of the perforated part of the color sorting pole, and is not applied to the flange part formed at the outer peripheral end of the perforated part. from,
Since the generation of foreign matter within the cathode ray tube is prevented, the image quality and withstand voltage characteristics of the color cathode ray tube are improved.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a spray mask showing an embodiment of the present invention, Fig. 2 is a partial sectional view of a color cathode ray tube, Fig. 3 is a perspective view of a color selection electrode, and Fig. 4 is a conventional spray mask. FIG. (5)... Color selection electrode s (5a)... Electron beam hole, (8)... Perforated part s (sa)... Hole forming surface, (9)... Flange part, (To)... Spray gun, α4... Paint liquid, αη... Spray mask, Shout...
・Inner cylinder, 09... Outer cylinder, ■... Tip opening of inner cylinder,
QlJ...Distal end opening of the outer cylinder, Kanji...Proximal opening of the inner cylinder, Kanji...High pressure gas passage, (to)...Proximal opening of the external cylinder. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) Color sorting consisting of a perforated part that is formed on a substantially flat surface and has many electron beam holes, and a flange part that is formed on the outer peripheral edge of this perforated part and is almost perpendicular to the perforated part. This is a spray mask that prevents the dispersion of the coating liquid when spraying the coating liquid onto the electrode, and is formed as a double-walled cylindrical body with an inner and outer layer that covers the above-mentioned perforated part, and the tip opening is located on the application surface of the above-mentioned perforated part. an inner cylinder that faces at a predetermined interval from the inner cylinder and into which a spray gun for spraying a coating liquid toward the perforated part is inserted into the base end opening; and an outer cylinder that surrounds the side surface of the inner cylinder; A color-selecting electrode spray mask in which a high-pressure gas passage is formed between an inner cylinder and an outer cylinder, through which high-pressure gas is blown out from an opening at the tip of the outer cylinder so as to surround the hole-forming surface of the perforated part.