JPH03250540A - Braun tube and its manufacturing method - Google Patents

Abstract

PURPOSE:To prevent reflection of external light without ill influencing a coating of fluorescent substance by coating the inner surface of a face plate with alcoholic solution of Si(OR)4 to which particulate of SiO2 is added, baking the result, and providing a reflex preventive layer. CONSTITUTION:Ethylsilicate is dissolved in ethanol, and SiO2 particulate arranged to 2000+ or -100Angstrom is added to an aqueous solution of nitric acid as catalyst, followed by pH adjustment and through dispersing. The mentioned solution is dripped onto the inner surface 1 of a face plate preheated to approx. 50 deg.C and spread evenly by means of spinning. When a reflex preventive layer 3 is dried and fixed and when stabilized condition is attached with progressed hydrolysis, a fluorescent substance layer and a black matrix layer are formed over the inner surface of the plate by a certain specified process. The mentioned reflex preventive layer 3 consists of SiO2 particulate and SiO2 binder and excels in the chemical, mechanical, and thermal strengths, and the surface is very smooth, which facilitates performance of the subsequent processes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cathode ray tube having an antireflection layer for extraneous light on the face plate, and particularly to an antireflection layer suitable for preventing reflection of extraneous light on the inner surface of the cathode ray tube. The present invention relates to a cathode ray tube and a method for manufacturing the same.

[Prior Art] Cathode ray tubes such as cathode ray tubes generally have a glossy faceplate surface (image display surface) that strongly reflects external light, making it difficult to read the image displayed on the faceplate surface. was there. Particularly recently, in addition to television receivers, display devices consisting of various cathode ray tubes have become widely used as information equipment terminals, and the problem of external light reflection mentioned above has become widespread in the field of VOR (visual display terminals). As a result, the demand for anti-reflection has become stronger.

Various methods have been taken to prevent the reflection of external light. For example, the glass surface is etched with hydrofluorosilicic acid (StF) to a depth of 50 to 30,000. A product with an anti-reflection function by adding unevenness with a pitch of 100 to 200 OA (U.S. Patent No. 24)
No. 90662), or alkoxysilane (Si(O
There is one in which an alcohol solution of R), , R is an alkyl group is sprayed onto a glass surface and then fired to form irregularities made of SiO and M (Japanese Patent Laid-Open No. 118932/1983).

In addition, MgF,
A method has been put into practical use in which one layer or multiple layers of metal compounds or polymer compounds such as SiO2, SiO2, etc. are laminated, and the thickness and refractive index of the layers are precisely controlled to weaken the reflected light by utilizing light interference. ing.

[Problems to be Solved by the Invention] However, all of the above methods are anti-reflection methods that target the outer surface of the face plate of the cathode ray tube.
It was found that if this was done alone, the effect of external light reflected on the inner surface of the face plate would appear strongly on the surface, making it difficult to see the image.

Therefore, it is possible to form an anti-reflection film as described above on the inner surface of the face plate, but it is necessary to coat the inner surface of the face plate of the cathode ray tube with a phosphor, and to prevent the effects of this coating from occurring sufficiently. The anti-reflection layer had to be of a high quality, and there were various pressure points. That is, for example, H, SiF.

The method of roughening the inner surface of the face plate by etching has disadvantages in that the resulting rough surface changes due to various chemical treatments during the application of the phosphor, and that the phosphor cannot be applied smoothly. Further, in the case of No. 51 (OR), a method in which an uneven surface is formed by spraying an alcohol solution, there is a drawback that the phosphor does not adhere well because the unevenness of the surface is so severe.

Furthermore, in the case of laminated layers of metal compounds or polymer compounds, which are generally formed by vacuum evaporation or sputtering, the film quality is extremely susceptible to deterioration, and the reflectance can be greatly increased by heat treatment or chemical treatment during phosphor coating. There is a problem with this.

An object of the present invention is to solve the above-mentioned problems of the prior art, to provide a face plate inner surface that can withstand various treatments during phosphor coating, does not adversely affect phosphor coating, and has a fully satisfactory inner surface. An object of the present invention is to provide a cathode ray tube having an antireflection layer having antireflection properties for external light, and a method for manufacturing the same.

[Means to solve the problem] The above purpose is to infiltrate the inner surface of the face plate.

Si(O
After applying the alcohol solution of R), it is fired to form SiO
This can be achieved by forming an antireflection layer consisting of 2 fine particles and a SiO2 binder that fixes them.

[Function] The antireflection layer formed on the inner surface of the face plate as described above is made of fine particles of SiO2 and has an extremely smooth surface, making it easy to apply phosphor or black matrix graphite onto the surface of the layer. be able to. Also, Si
Because Shizu's fine particles are firmly fixed by the SiO2 binder formed by the decomposition of Si (OR), they have excellent chemical, mechanical, and thermal strength, and have excellent durability against various chemical treatments and heat treatments. Show your gender.

Next, the reason why the presence of the antireflection layer reduces reflection of external light on the inner surface of the face plate is as follows. First, Fig. 1 is a sectional view showing the schematic structure of the cathode ray tube of the present invention, and Fig. 2 is an enlarged view of the main part of section A in Fig. 1. The light is reflected from the outer surface and becomes Ll, and a portion of the light is incident on the inner surface of the face plate, causing a roar. Here, if there is no anti-reflection layer 3, the light will be reflected from the E surface and come out again, but the E portion of the inner surface of the face plate will be S.
io, and its refractive index is about 1.47, so it passes through the E plane due to its interference effect, causing a roar. If the D surface is a smooth inner surface, the beam will be reflected by the D surface, but there will be fine hemispherical unevenness inside the D surface, and the refractive index of the layer inside the D will gradually gradually decrease. Since this layer becomes smaller in size, the light L is subjected to re-interference by this layer, passes through this layer, and travels further inside as L4.

Now, let us say that the refractive index between E and D of the antireflection layer 3 is 08, the refractive index of the C part slightly inside of it is nl, the refractive index of the further inner B part is nl, and the refractive index of the internal space is n. Then,
The condition for the minimum internal reflectance R is (n+ ng - n, n, )', and from this, non-reflection performance is obtained when the condition 0°jl, = (2) is satisfied.

Here, the value of n, /n, is determined by the shape of the unevenness,
Si (OR) with added SjO,m particles as above
.

By applying an alcohol solution and firing, unevenness that approximately satisfies the above formula is formed.

[Examples] Hereinafter, the cathode ray tube of the present invention and the method for manufacturing the same will be specifically explained using examples.

First, a solution was prepared by dissolving ethyl silicate (Si(QC,H,),) in ethanol, and adding H, O for hydrolysis and HNO as a catalyst. Sin size adjusted to ±100 people.

After adding fine particles and adjusting the pH of the solution to 14 to obtain sufficient dispersion, the above solution is placed on the inner surface of the face plate on which the antireflection layer is to be formed, which has been heated to about 50°C in advance. was applied dropwise and applied uniformly by spinning.

After the coating layer was dried and fixed and hydrolysis progressed to a certain extent to reach a stable state, a phosphor layer and a black matrix layer were formed on the inner surface of the face plate by a predetermined method. In this case, the phosphor layer and black matrix layer could be applied extremely uniformly. Note that dry fixation and decomposition can be carried out by a method suitable for the manufacturing process of cathode ray tubes. Furthermore, although heating is not particularly necessary before applying the phosphor or black matrix, it is natural that the layer strength will be greater if heating is applied.

Regarding the antireflection layer obtained as described above, He-N
As a result of measuring the intensity at a reflection destination at a predetermined angle using an e-laser, it was found that a cathode ray tube with an untreated inner surface had an inner reflectance of 4%, whereas the inner reflectance was 1 to 2%. Stopped.

[Effects of the Invention] As described above, by making the cathode ray tube a cathode ray tube having the structure of the present invention and applying the manufacturing method of the present invention, the problems of the prior art can be solved and the phosphor ml・j can be used for various treatments during coating, and does not adversely affect phosphor coating.

Moreover, it has been possible to provide a cathode ray tube and a method for manufacturing the same which have a sufficiently satisfactory characteristic of stopping external light reflection lIJ on the inner surface of the face plate. Further, by using the method of the present invention, the antireflection layer can be formed by a simple and safe process, and the manufacturing cost can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the schematic structure of the cathode ray tube of the present invention;
FIG. 2 is an enlarged view of the main part of section A in FIG. 1. l... Inner surface of face plate, 2... Outer surface of face plate, 3... Antireflection layer, 4... Face plate, 5... SiO2 binder, 6... SiO2 fine particles, 7...・Incoming light. Figure 2

Claims (1)

[Claims] 1. Si(OR)_4(R) containing SiO_2 fine particles
is an alkyl group) coated with an alcohol solution and fired, Si
A cathode ray tube characterized in that it has an antireflection layer made of O_2 fine particles and a SiO_2 binder on the inner surface of its face plate. 2. A method for manufacturing a cathode ray tube, which comprises applying an alcoholic solution of Si(OR)_4 to which SiO_2 fine particles have been added to the inner surface of the face plate and then baking it to provide an antireflection layer made of SiO_2 fine particles and a SiO_2 binder.