JPS61281443A - Picture tube having step section at circumference of face - Google Patents

Abstract

PURPOSE:To block emission of light from unavailable screen while to improve the appearance by applying a light shield film onto the glass surface along the step section of picture tube having step section along the circumference of face. CONSTITUTION:Step section 5 is provided along the circumference of the face 4 of picture tube 3 then the bezel 7 and the face 4 of cabinet are matched to assemble a picture tube unit. Here, a light shielding film 13 composed of heat-resistant and chemical-resistant inorganic material such as solder glass or ceramic is applied onto the glass surface along the step section 5. Consequently, hindering emission of light from the step section 5 is eliminated to block emission of light at the unavailable screen 11 thus to improve the quality. Consequently, the film 13 can be provided with peeling performance withstandable against long term usage while the entire appearance of picture tube unit is improved resulting in improvement of product value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a picture tube having a stepped portion on the peripheral edge of the face.

[Summary of the invention]

By applying a light-shielding coating to the nine glass surfaces (the stepped portion of the picture tube that has a stepped portion on the face periphery),
This eliminates interfering light emission from the stepped portion.

[Conventional technology]

As shown in the horizontal cross-sectional view of the TV receiver in FIG.
An I-Koshiji receiver has been proposed so that the planes of 7 Ace 4 and 7 Ace 4 are aligned.

[Problem that the invention seeks to solve]

In general, the phosphor 8 is coated in stripes on 111ffii of the face 4, and as shown in the partially enlarged sectional view of FIG. 4, and as shown in the front view of the picture tube in FIG. The inner area is the effective screen 9.

t7t Carbon 10 is placed along the inner circumferential edge of face 4.
2 is applied, and the part of the sun becomes an invalid screen 11.

The area of the invalid screen 11 does not emit light in a general picture tube, but in the picture tube 3 having the stepped portion 5, the area of the effective screen 9
Leakage light such as refracted light and reflected light from the area is condensed by the lens action of the sharp edge with minute curvature shown by A% B of the stepped portion 5 in Figure t44, as shown by the thick line in Figure 5. Stepped portion 5
The invalid screen 11 emits light in a linear manner along the edge of the screen. For this reason, the reality is that such stepped picture tubes have not been commercialized.◎ One idea is to perform a process such as pasting a transparent layer of adhesive tape along the stepped portion 5 at the periphery of the face 4. It will be done. However, pasting adhesive tape reduces the appearance and value as a product, and also has the problem of being easily peeled off and lacking in reliability for long-term use. Adhesive tape has a large difference in texture from glass, which is the material of the receiver, and tends to give off a sense of discomfort.

In consideration of this problem, the present invention can effectively eliminate the invalid screen light emission, and has a good appearance. As shown in the enlarged sectional view of the main part in FIG. 2, a light-shielding coating 13 is applied to the glass surface along a stepped portion 5 formed at the periphery of the face 4.

The material of the coating 13 is preferably a heat-resistant and chemical-resistant inorganic material such as solder glass or ceramic. These materials can be applied by firing in a heating furnace or by plasma spraying, and are fused (integrated) with the glass surface.
Light-shielding coating 13 with approximately 0% light transmittance that does not peel off easily
becomes. Very good peeling performance against scratches and thermal cycles.

The thickness of the coating 13 is desirably 100 μm or less, so that it is not obvious that it is an S-broken deposit. The edge line of the coating 13 formed around the periphery of the face 4 can be made into a resharp straight line or curve by masking or taping during manufacturing.

The color of the coating 13 can be variously selected depending on the color of the material itself and colored contaminants. An achromatic color such as black, gray, or white is preferable so that the color of the face 4 and the bezel 7 can be unified in design.

[Implementation row]

An example using solder glass as the coating material is shown.

Both amorphous and crystalline solder glasses can be used. Alternatively, a mixture of both may be used. Solder glass mixed with manganese or the like as a colorant and called "black frit" is generally available.

Carbon may be further mixed as a coloring material.

The ruptured membrane 13 is formed by first spraying solder glass (powder) onto the stepped portion 5 of the nine picture tubes 3 to be masked or taped using a spray gun, and then firing. The firing process is the firing process (
A pin seal furnace) can be used. Therefore, only the spray coating process for the solder glass is increased, the firing process is not increased, and there is no large increase in cost.

Alternatively, it is also possible to use a baking treatment in a prepaking step or a frit sealing step after forming the fluorescent surface.

The coating 13 formed by firing exhibits a black color in the case of black frit, and light emission along the stepped portion 5 is completely blocked.

It completely fuses with the glass surface of the picture tube 3 and does not peel off at all. The edges of the coating are very sharp, and even if the peripheral edge of the face 4 is exposed, the commercial value will not be affected. During the cleaning process using acids and organic solvents during the manufacturing process of the picture tube 3, the coating 13 is not attacked by these chemicals, and has excellent peeling resistance from scratches and thermal cycles of long-term use. It does not deteriorate and is very strong. Alternatively, the light-shielding coating 13 can be formed by plasma spraying. As the material, powdered ceramics such as forsterite and alumina can be used. Plasma spraying of metal materials such as manganese and nickel is also possible. These materials also have excellent chemical resistance, heat resistance, and peeling resistance. Since the firing process is not necessary, the coating 13 can be applied both at the component stage of panel 1 and at the completed pipe stage.
can be formed.

Note that an organic (synthetic resin, etc.) coating may be applied as long as it has the required performance (chemical resistance, heat resistance, etc.).

〔Effect of the invention〕

As described above, in the present invention, the transparent coating 138 is deposited along the stepped portion 5 of the periphery of the 7 ace 4 of the picture tube 3, so that it is possible to prevent light emission that would cause damage to the invalid screen. 7 Even if it is exposed at the periphery of the work surface, the appearance will not be impaired. The coating film 13 is integrally adhered to the glass surface of the picture tube, and has peeling performance that can withstand long-term use.

[Brief explanation of drawings]

Fig. 1 is a front view of a picture tube according to the present invention, Fig. 2 is an enlarged horizontal cross-sectional view of the main parts, Fig. 3 is a horizontal cross-sectional view of the entire picture tube with a step, and Fig. 4 is a conventional picture tube. FIG. 5 is an enlarged cross-sectional view of the main part of the tube, and is a front view of a conventional picture tube in which ineffective screen light emission occurs. In addition, using t symbol 1 in drawing 5, 1......Panel 2...
・・・・・・・・・・・・Funnel 3・・・・・・・・・
......Picture tube 4...Face 5...Step part 7...
・・・・・・・・・Pezle 8・・・・・・・・・・・・
..... Fluorescent body 9 ..... Valid screen 11 ..... Invalid screen 13
・・・・・・・・・・・・・・・It is a light-shielding coating.

Claims (1)

[Claims] 1. A picture tube having a stepped portion on the periphery of the face, characterized in that a light-shielding coating is applied to the glass surface along the stepped portion formed on the periphery of the face.