JPS61250939A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To scatter the deflection of external light thus to obtain an easy-to- view display image by spraying alcohol solution of ethyl-silicate onto the inner face of panel of cathode-ray tube then burning and forming a fine projected/ recessed layer of silicon oxide. CONSTITUTION:Ethyl-silicate alcohol solution is sprayed onto the inner face of panel 2 then burnt to form a fine projecting/recessed layer 3 of silicon oxide then fluorescent material 4 is applied. While a well known non-reflection coating 1 is formed through multi-layer coating employing vacuum deposition onto the outer face of the panel 2 thus to form a cathode ray tube to be employed in information processing terminal. Reflection from the outer surface is prevented by non-reflection coating 1 to scatter the light arriving to the inner face of panel 2 by the projecting/recessed layer 3. Consequently, a scattering layer hand to be damaged can be obtained through simple processing which will never cause polution resulting in an easy-to-view picture image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cathode ray tube that diffuses the reflection of external light that illuminates the panel surface to make the displayed image easier to see.

[Background of the invention]

Even in environments where the panel surface of a cathode ray tube is illuminated by bright external light, a multilayer vacuum-deposited film has been conventionally applied to the outside surface of the panel to prevent the displayed image from becoming difficult to see due to the reflection of external light from the panel surface. Conventional methods include forming a well-known anti-reflective coating, or pasting a panel treated with an anti-reflective coating on the outer surface of the bulb with an adhesive. However, although this method can prevent reflections on the outer surface, it is not perfect because external light that reaches the inner surface of the panel glass is specularly reflected and clearly comes out to the front. Therefore, internal reflections were prevented by etching the inner surface of the valve panel with hydronic acid to make the surface uneven, or by attaching Si0 particles through phase separation of water glass (an aqueous solution of alkali salts of silicic acid). However, since the former uses hydrochloric acid, there are problems with pollution, scratches easily, and reprocessing is impossible, and the latter has weak film strength and interference with the panel surface. It has the disadvantage of causing color.

The above-mentioned problem of difficulty in viewing displayed images is particularly noticeable in the case of high-definition display tubes for information processing device terminals.

[Purpose of the invention]

An object of the present invention is to eliminate the problem of the conventional cathode ray tubes, in which even if external light illuminates the fluorescent surface of the cathode ray tube, the viewer of the displayed image will hardly notice the effects of the reflection. The object of the present invention is to provide a cathode ray tube that does not cause such problems.

[Summary of the invention]

In order to achieve the above object, the present invention sprays an alcohol solution of ethyl silicate onto the panel of a cathode ray tube to form a fine uneven layer of silicon oxide, which diffuses the reflection of external light and makes the displayed image easier to see. I made it so.

If a well-known anti-reflection coating is formed on the outer surface of the panel using a multilayer coating method using vacuum deposition, reflection from the outer surface can be prevented from peeling off, but the reflection of light that reaches the inner surface of the panel will become more obvious. In order to suppress this internally reflected light, before coating the inner surface of the panel with the phosphor, an alcoholic solution of ethyl silicate according to the present invention is sprayed, dried and fired to form a fine uneven layer of silicon oxide. A remarkable effect can be obtained by forming a diffusion layer. The method according to the present invention does not cause pollution problems, and since the film has a high strength, it is hard to be scratched and does not generate unnecessary interference colors. Regeneration processing is also possible.

[Embodiments of the invention]

FIG. 1(a) is a partially cutaway view of the vicinity of the fluorescent surface of an embodiment of the present invention, and FIG. 1(b) is an enlarged sectional view of section A in FIG. In the figure, 1 is an anti-reflection coating, 2 is a panel glass, 3 is a fine uneven layer of silicon oxide, and 4 is a phosphor. After applying an anti-reflection coating to the outer surface of the panel glass 2 using a predetermined method, ethyl silicate (S
1 (QC2Hr)4) was dissolved in ethyl alcohol,
A solution to which H2O and an acid catalyst were added was preheated (30~
Spray on the inner surface of the panel glass, which has been heated to 80'C), for about 1 to 3 minutes using a spray gun. This is heated and baked at 100 to 200°C for about 10 to 60 minutes. By heating and baking, ethyl silicate undergoes hydrolysis and hydrolysis condensation reactions, resulting in 5
A film with a thickness of approximately 1 μm with fine irregularities containing i02 as a main component is formed. Note that the present invention is not particular about the order in which the anti-reflection coating and the silicon oxide fine unevenness layer are formed.

The film formed by the above method can be coated with hot water or weak alkali IJ (
p) 110) It has excellent durability against chemical solutions, does not peel off even after being rubbed with an eraser more than 300 times, has excellent mechanical strength, and has excellent phosphor coating properties, and does not cause any problems in the manufacturing process. It was found to have stable properties.

Next, a comparison of the gloss levels according to JIS Z-8741 (gloss measurement method) shows that the results are shown in Table 1 (next page), and the spray coating of the alcohol solution of ethyl silicate according to the present invention lowers the gloss level, making it easier to display. The effect of making images easier to see was recognized. However, in Table 1, No. 3 and No. 4 are examples of the present invention, and No. 1, No. 2, N.
No. 5 is a reference example. *No. 2 is a panel in which an anti-reflection coating is applied only to the outer surface of the panel and a fine uneven layer of silicon oxide according to the invention in Table 1 is further formed. The reflection from the inside of the panel was quite strong and clear, giving the impression of a slight glare. Although not shown in the table, even if a fine uneven layer of silicon oxide according to the present invention is formed only on the inner surface of the panel and no anti-reflection coating is applied to the outer surface of the panel, no treatment at all (first It is obvious that it is easier to see than No. 5) in the table.

〔Effect of the invention〕

As explained above, according to the present invention, by simply adding simple processing, even in an environment where the fluorescent surface is illuminated by external light, the viewer of the displayed image is hardly affected by the reflection of external light. A cathode ray tube with easy-to-see images that is not distracting can be obtained.

[Brief explanation of the drawing]

FIG. 1(a) is a partially cutaway view of the vicinity of the fluorescent surface of an embodiment of the present invention, and FIG. 1(b) is an enlarged sectional view of section A in FIG. 1-・Anti-reflective coating, 2- Panel glass 3
・-・Fine uneven layer of silicon oxide, 4- Fluorescent box
1 Figure (6L) (b)

Claims (1)

[Claims] 1. Spray an alcohol solution of ethyl silicate on at least the inner surface of the valve panel of a cathode ray tube and heat and bake it to form a fine uneven layer of silicon oxide to diffuse reflection of external light. A cathode ray tube characterized in that the displayed image is made easier to see. 2. The cathode ray tube according to claim 1, wherein an anti-reflection coating is applied to the outer surface of the panel, and a fine uneven layer of silicon oxide is formed on the inner surface of the panel by spraying an alcoholic solution of ethyl silicate. 3. The outer surface of the panel is provided with an anti-reflection coating and a fine uneven layer of silicon oxide formed by spraying an alcohol solution of ethyl silicate, and the inner surface of the panel is provided with a layer of silicon oxide formed by spraying an alcohol solution of ethyl silicate. The cathode ray tube according to claim 1, wherein the cathode ray tube is provided with a fine uneven layer.