JPH08279341A - Electrification preventive low reflection type cathode-ray tube and its manufacture - Google Patents

Abstract

PURPOSE: To bring an electrification preventive low reflection film formed by a sol-gel method into close contact with an outside surface of a face plate of a cathode-ray tube with sufficient strength. CONSTITUTION: In an electrification preventive low reflection type cathode ray tube, an electrification preventive low reflection film 11 composed of a light interferential two-layer film by a sol-gel method, is formed on an outside surface of a glass face plate 3. A silica film 15 having a film thickness of 50 to 100 angstrom by a sol-gel method, is arranged between the outside surface of the face plate 3 and the electrification preventive low reflection film 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antistatic low reflection type cathode ray tube having an antistatic low reflection film formed of an optical interference two-layer film and a method for manufacturing the same.

[0002]

2. Description of the Related Art For example, in a cathode ray tube such as a color picture tube, a phosphor screen is provided on the inner surface of a glass panel (face plate) having a smooth curved outer surface.
The phosphor screen is formed into a structure for displaying an image by scanning the phosphor screen with an electron beam emitted from an electron gun sealed in the neck of the funnel. In such a cathode ray tube, since a high-luminance image is usually displayed on the phosphor screen, a high voltage of about 20 to 30 kV is applied to the phosphor screen and the final acceleration electrode of the electron gun. Therefore, in such a cathode ray tube,
The voltage applied to the phosphor screen is induced and charged on the outer surface of the face plate. Therefore, if it comes into contact with the outer surface of the face plate, a strong electric shock may occur. Further, due to the electrification, dust and dirt in the atmosphere adhere to the outer surface of the face plate, which makes it difficult to see the image. In addition to the above charging, external light is reflected on a smooth outer surface, and this external light reflection overlaps with the image on the phosphor screen seen through the face plate and deteriorates the image quality. In particular, in a computer display or the like, the screen is often viewed from a close range, so that there is a problem that the reflection of the external light promotes eye fatigue.

Therefore, in order to solve such a problem, there is a conventional cathode ray tube in which an antistatic low reflection film is formed on the outer surface of a face plate.

As a method of forming the antistatic low reflection film,
A dispersion of conductive metal oxide fine particles in an alcohol solution of silicon alkoxide is applied to the outer surface of the face plate by a spray method, dried and baked to form an uneven film. There is a method of forming an antistatic low reflection film that reduces reflectance by diffusing and reflecting light. However, this antistatic low reflection film is
Due to the unevenness of the surface, the resolution of the image drawn on the phosphor screen is deteriorated, and in an extreme case, the outer surface of the face plate becomes frosted glass, the screen becomes whitish, and the phosphor seen through the face plate There are problems such as lowering the contrast of the image on the screen.

As another method for preventing electrification and reflection, an optical interference multilayer film is formed on a glass plate by a vapor phase method such as a vacuum evaporation method or a sputtering method, and this glass plate is formed on the outer surface of the face plate of the cathode ray tube. There is a method of sticking and suppressing reflection of external light by the light interference effect. However, this antistatic charging method requires a large-scale manufacturing apparatus and is costly. Therefore, there is a problem that it can be used only in some high-end models.

As a method for solving the above problems of the antistatic reflection method, a method of directly forming an antistatic low reflection film composed of an optical interference multilayer film on the outer surface of a face plate of a cathode ray tube by a sol-gel method has been developed. ing. According to this sol-gel method, it is possible to form an antistatic low-reflection film without lowering the resolution or the contrast, using a low-cost material and a simple manufacturing facility.

Generally, the antistatic low reflection film by the sol-gel method is a two-layer optical interference film in which a high refractive index layer is formed on the outer surface side of a face plate and a low refractive index layer is formed on the high refractive index layer for ease of formation. In many cases However, by the sol-gel method,
When an antistatic low reflection film composed of such an optical interference two-layer film is formed, in general, most materials used for the high refractive index layer have poor adhesion to the glass face plate,
Even if the low-refractive-index layer is made of silica, which has good adhesion to the face plate, the anti-static low-reflection film is sufficient for the face plate by baking at a temperature of about 200 ° C., which is necessary for forming the two-layer optical interference film. Cannot be adhered with sufficient strength.

[0008]

As described above, as an antistatic low reflection film on the outer surface of the face plate of the cathode ray tube, an antistatic layer consisting of a two-layer optical interference film is directly formed on the outer surface of the face plate by the sol-gel method. There is a method of forming a low reflection film. In general, the antistatic low-reflection film formed of the optical interference two-layer film by the sol-gel method has a high-refractive index layer on the outer surface side of the face plate and a low-refractive index layer formed thereon to form a two-layer film. However, when an antistatic low reflection film composed of such an optical interference two-layer film is formed by the sol-gel method,
Since many materials used for the high refractive index layer have poor adhesion to the glass face plate, even if the low refractive index layer is made of silica, which has good adhesion to the face plate, the optical interference two-layer film is formed. There is a problem that the antistatic low reflection film cannot be adhered to the face plate with sufficient strength by baking at a temperature of about 200 ° C. necessary for the above.

The present invention has been made in order to solve the above problems, and an antistatic low reflection film formed by a sol-gel method is adhered to the outer surface of the face plate of a cathode ray tube with sufficient strength. The purpose is to let.

[0010]

In order to achieve the above object, according to the present invention, an antistatic low reflection film consisting of an optical interference two-layer film formed by a sol-gel method is formed on the outer surface of a glass face plate. In such an antistatic low reflection type cathode ray tube, a silica film having a film thickness of 50 to 100 angstroms was formed by a sol-gel method between the outer surface of the face plate and the antistatic low reflection film.

Further, in the method of manufacturing an antistatic low reflection type cathode ray tube in which an antistatic low reflection film consisting of an optical interference two-layer film is formed on the outer surface of a glass face plate by a sol-gel method, the outer surface of the face plate An alcohol solution of a silicon compound soluble in alcohol is applied to and dried to form a silicon compound film, and a conductive high refractive index layer forming liquid is applied onto the silicon compound film and dried to form a two-layer optical interference film. Forming a first layer for forming a conductive high refractive index layer, and applying a low refractive index layer forming liquid on the first layer and drying to form a low refractive index layer of the optical interference two-layer film. After the second layer for forming the film is formed, the silicon compound film, the first layer and the second layer are heated and baked at a predetermined temperature, and light is applied to the outer surface of the face plate through the silica film by the sol-gel method. Form an antistatic low-reflection film consisting of an interference two-layer film Was Unishi.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 (a) shows a color picture tube which is one form thereof. This color picture tube comprises a glass panel 3 (face plate) in which a skirt portion 2 is provided around an effective portion 1 having an outer surface which is a smooth curved surface, and a funnel-shaped funnel 4 joined to the skirt portion 2. Which has a vacuum envelope made of blue, green,
Phosphor screen 5 consisting of a three-color phosphor layer that emits red light
Is provided, and a shadow mask 6 is arranged inside the phosphor screen 5 so as to face the phosphor screen 5. On the other hand, an electron gun 8 that emits three electron beams is sealed in the neck 7 of the funnel 4. Then, the three electron beams emitted from the electron gun 8 are deflected by a magnetic field generated by a deflecting device (not shown) mounted outside the funnel 4, and the phosphor screen 5 is horizontally and vertically scanned. Thus, a structure for displaying a color image is formed.

Further, in this color picture tube, an explosion-proof band 10 is attached to the outer periphery of the skirt portion 2 of the panel 3. Further, the following antistatic low reflection film 11 is formed on the outer surface of the effective portion 1 of the panel 3, and is electrically connected to the explosion-proof band 10. The antistatic low-reflection film 11 is used for the explosion-proof band 10 when the color picture tube is incorporated into the image receiver.
Grounded via.

The antistatic low reflection film 11 is shown in FIG.
As shown in FIG. 3, the conductive high refractive index layer 13 is formed on the outer surface side of the effective portion 1 of the panel 3, and the conductive high refractive index layer 1 is formed.
3 is a two-layer optical interference film in which the low refractive index layer 14 is formed. The conductive high refractive index layer 13 is made of ATO (Antimony
In addition to conductive fine particles such as (Tin Oxide) and ITO (Indium Tin Oxide), a silica in which a light selective absorption dye or an organic pigment for improving the contrast of an image drawn on the phosphor screen 5 is dispersed as necessary. Consists of layers. On the other hand, the low refractive index layer 14 is made of a silica layer. Particularly, in the color picture tube of this example, the effective portion 1 of the panel 3 is
A silica layer 15 having a film thickness of 50 to 100 angstroms is provided between the outer surface of the panel and the conductive high refractive index layer 13 of the antistatic low reflection film 11, and the effective portion 1 of the panel 3 is provided through the silica layer 15. An antistatic low reflection film 11 is formed on the outer surface of the.

The antistatic low reflection film 11 as described above is used as a sol after the color picture tube is manufactured by a known manufacturing method.
It is formed by the gel method.

That is, after the phosphor screen 5 is formed on the inner surface of the panel 3 using the shadow mask 6 as an optical mask by the photo printing method, the shadow mask 6 is mounted on the panel 3 on which the phosphor screen 5 is formed. Then, the panel 3 having the shadow mask 6 attached thereto and the funnel 4 are joined (sealed). Further, the electron gun 8 is sealed in the neck 7 of the envelope obtained by the joining and exhausted. After that, the explosion-proof band 10 is attached to the outer periphery of the skirt portion 2 of the panel 3.

The antistatic low-reflection film 11 first cleans the outer surface of the panel 1 to which the explosion-proof band 10 is attached, and heats the cleaned panel 1 to about 30.degree. Then, the outer surface of the heated panel 3 is coated with a coating solution such as a spraying method, a spin coating method or a dipping method, preferably a spraying method, with a silica film forming solution comprising an alcohol solution of a silicon compound soluble in alcohol. And then dried, Fig. 2
As shown in (a), a silicon compound film 17 is formed on the outer surface of the panel 3.

Next, on the outer surface of the panel 3 having the silicon compound film 17 formed thereon, ATO or IT is applied by a coating method such as a spray method, a spin coating method or a dipping method.
A high-refractive-index layer-forming liquid consisting of an alcohol solution of a silicon compound soluble in alcohol, to which conductive fine particles such as O are dispersed and optionally a photoselective absorption dye or an organic pigment is applied, is dried, As shown in (b), a first layer 18 for forming a high refractive index layer of a two-layer optical interference film is formed on the silicon compound film 17. Next, on the outer surface of the panel 3 on which the first layer 18 is formed, the spray method,
A low refractive index layer forming liquid comprising an alcohol solution of a silicon compound soluble in alcohol is applied by a coating method such as a spin coating method or a dipping method and dried, and then, as shown in (c), the first layer A second layer 19 for forming a low refractive index layer of the optical interference two-layer film is formed on 18. Thereafter, the silicon compound film 17 formed on the outer surface of the panel 3, the first layer 18 for forming the high refractive index layer and the second layer 19 for forming the low refractive index layer are heated to about 200 ° C. By heating and baking, the outer surface side of the effective surface of the panel 3 is made into a high refractive index layer, and an antistatic low reflection film consisting of an optical interference two-layer film having a low refractive index layer formed on this high refractive index layer is formed. Along with the formation, a silica film is formed between the outer surface of the effective surface of the panel 3 and the high refractive index layer.

By the way, as described above, the film thickness by the sol-gel method is provided between the outer surface of the panel 3 and the antistatic low-reflection film 11 consisting of the optical interference two-layer film formed thereon by the sol-gel method. 50-100 Angstrom silica film 15
By providing, the conductive high refractive index layer 13 formed on the outer surface side of the panel 3 can be adhered to the outer surface of the panel 3 with sufficient strength. Moreover, there is an effect that the silica film 15 can be formed between the outer surface of the panel 3 and the antistatic low reflection film 11 formed of the light interference two-layer film by a spray method simple in manufacturing.

That is, when an antistatic low reflection film composed of a light interference multilayer film for suppressing reflection of external light due to the interference effect of light is formed on the outer surface of the panel, the strength of the adhesion to the glass panel causes It is desired that the same or similar substance as the above. This is because if the materials are structurally the same, the bonding surface can have a structure with less strain, and good bonding strength can be obtained. However, when the antistatic low-reflection film is formed of a two-layer optical interference film, a conductive high refractive index layer having a higher refractive index than that of the panel must be formed on the outer surface side of the panel. In order to form by coating conductive alcohol fine particles such as a light selective absorption dye or an organic pigment with an alcohol solution of a silicon compound dispersed therein, a decomposition product of the silicon compound obtained as a result of heating and firing is used. The SiO ₂ network structure of certain silica is distorted and has a stable network structure, but even if a film is formed on the outer surface of a lath panel, the structure of the bonding surface becomes unstable, and the required bonding strength cannot be obtained.

On the other hand, the film formation by the sol-gel method is carried out by forming a gel while hydrolyzing and condensing the sol, but it does not completely gel and is not condensed without heating and baking. Many OH groups remain. Therefore, when films having different structures are laminated in a state where they are not completely gelled, they are structurally unstable with respect to each other, and the contact surfaces thereof become structurally more stable. As a result, when the laminated films are heated and baked at a predetermined temperature, the bonding strength to the panel can be increased as compared with the case where a film having a structure different from that of the panel is directly formed on the outer surface of the panel.

That is, a sol-gel film of a silicon compound that provides good adhesion to the outer surface of a glass panel is provided, and the sol-gel film does not become a complete gel film, and the sol-gel film and the panel are formed thereon. When a film (first layer) for forming a conductive high refractive index layer having a different structure is formed, the adhesion strength of this film to the outer surface of the panel can be dramatically increased.

Further, a conductive high refractive index layer is formed by forming a second layer for forming a low refractive index layer made of silica on the first layer for forming the conductive high refractive index layer. Since the structure is sandwiched between silica layers, the structurally weak conductive high refractive index layer is covered with a strong film, and the antistatic low reflection film can be strengthened.

Next, an embodiment of the antistatic low reflection film composed of the above-mentioned optical interference two-layer film will be described.

[0026]

【Example】

Example 1. After washing the outer surface of the glass panel and heating it to 30 ° C., an alcohol solution (silica film forming solution) of a silicon compound having the composition shown in Table 1 was applied to the outer surface of the panel by spin coating and dried. As a result, a silicon compound film having a film thickness of 90 angstrom was formed. Next, after heating the panel having the silicon compound film formed thereon to 30 ° C.,
A high-refractive-index layer forming liquid having the composition shown in Table 2 was applied onto the silicon compound film by a spin coating method and dried to form a first layer for forming the high-refractive index layer. A low refractive index layer forming liquid having the composition shown in Table 3 was applied onto one layer and dried to form a second layer for forming the low refractive index layer. Thereafter, the silicon compound film formed on the outer surface of these panels, the first layer for forming the high refractive index layer and the second layer for forming the low refractive index layer are heated and baked at a temperature of 200 ° C. Then, the optical interference two-layer film was formed on the outer surface of the panel, and the silica film was formed between the optical interference two-layer film and the high refractive index layer constituting the optical interference two-layer film.

[0027]

Table 1 (Silica film forming liquid) Ethyl silicate solution (solid content 4% by weight) 20% Isopropyl alcohol 40% n-Butyl alcohol 40%

(Table 2) High refractive index layer forming liquid ATO-dispersed ethyl silicate solution (solid content 3% by weight) 20% Photoselective absorption dye 5% Ethyl alcohol 15% Isopropyl alcohol 30% n-Butyl alcohol 30%

(Low refractive index layer forming liquid) Ethyl silicate solution (solid content 4% by weight) 30% Isopropyl alcohol 35% n-Butyl alcohol 35% Example 2. After washing the outer surface of the glass panel and heating it to 30 ° C., an alcohol solution (silica film forming solution) of a silicon compound having the composition shown in Table 4 was applied to the outer surface of the panel by a spray method and dried. A silicon compound film having a film thickness of 70 angstrom was formed. Next, after heating the panel having the silicon compound film formed thereon at 30 ° C., a high refractive index layer-forming liquid having the composition shown in Table 2 was applied onto the silicon compound film by a spin coating method and dried, A first layer for forming the high refractive index layer is formed, and Table 3 is formed on the first layer.
A low refractive index layer forming liquid having the composition shown in (4) was applied and dried to form a second layer for forming the low refractive index layer. afterwards,
The silicon compound film formed on the outer surfaces of these panels, the first layer for forming the high refractive index layer and the second layer for forming the low refractive index layer are heated and baked at a temperature of 200 ° C.,
While forming a two-layer optical interference film on the outer surface of the panel,
A silica film was formed between the optical interference two-layer film and the high refractive index layer.

[0028]

Table 4 (Silica layer forming liquid) Ethyl silicate solution (solid content 4% by weight) 50% Isopropyl alcohol 15% n-Butyl alcohol 15% n-Pentyl alcohol 20% Comparative Example 1. After washing the outer surface of the glass panel and heating it to 30 ° C., an alcohol solution of the silicon compound (silica film forming solution) having the composition shown in Table 5 was applied to the outer surface of the panel by spin coating and dried. As a result, a silicon compound film having a film thickness of 40 Å was formed. Next, after heating the panel having the silicon compound film formed thereon at 30 ° C., a high refractive index layer-forming liquid having the composition shown in Table 2 was applied onto the silicon compound film by a spin coating method and dried to obtain a high temperature. A first layer for forming a refractive index layer is formed, and a low refractive index layer forming liquid having the composition shown in Table 3 is applied onto the first layer and dried to form a low refractive index layer. The second layer for forming was deposited. After that, the silicon compound film formed on the outer surface of these panels, the first layer forming the high refractive index layer and the second layer forming the low refractive index layer are heated and baked at a temperature of 200 ° C. An optical interference two-layer film was formed on the outer surface, and a silica film was formed between the optical interference two-layer film and the high refractive index layer forming the optical interference two-layer film.

[0029]

(Table 5) Silica layer forming liquid Ethyl silicate solution (solid content 4% by weight) 10% Isopropyl alcohol 45% n-Butyl alcohol 45% Comparative example 2. After washing the outer surface of the glass panel and heating it to 30 ° C., an alcohol solution (silica film forming solution) of a silicon compound having the composition shown in Table 6 was applied to the outer surface of the panel by a spin coating method and dried. As a result, a silicon compound film having a film thickness of 300 Å was formed. Next, after heating the panel having the silicon compound film formed thereon at 30 ° C., a high refractive index layer-forming liquid having the composition shown in Table 2 was applied onto the silicon compound film by a spin coating method and dried, A low refractive index layer is formed by forming a first layer for forming a high refractive index layer, further applying a low refractive index layer forming liquid having the composition shown in Table 3 on the first layer, and drying. A second layer for forming the film was formed.
After that, the silicon compound film formed on the outer surface of these panels, the first layer forming the high refractive index layer and the second layer forming the low refractive index layer are heated and baked at a temperature of 200 ° C. An optical interference two-layer film was formed on the outer surface, and a silica film was formed between the optical interference two-layer film and the high refractive index layer forming the optical interference two-layer film.

[0030]

(Table 6) Silica layer forming liquid Ethyl silicate solution (solid content 4% by weight) 40% Isopropyl alcohol 30% n-Butyl alcohol 30%

The film characteristics (luminous reflectance,
The film strength of the eraser due to friction is shown in Table 7 in comparison with Comparative Examples 1 and 2 and the case where a direct optical interference two-layer film is formed without forming a silica layer on the outer surface of the panel.

[Table 7] As shown in Table 7, the antistatic low-reflection films of Examples 1 and 2 have silica films of 90 Å and 70 Å in thickness formed between the outer surface of the panel and the antistatic low-reflection film. However, the luminous reflectance is 0.85, 0.
90, which is comparable to the luminous reflectance of 0.80 when the antistatic low reflection film is directly formed without forming the silica film on the outer surface of the panel. In addition, regarding the film strength of the eraser due to friction, when the silica film having a film thickness of 40 Å was formed as in Comparative Example 1 and when the antistatic low reflection film was directly formed on the outer surface of the panel without forming the silica film. In the case of 100, the strength of Examples 1 and 2 is 200, which is about twice the strength.
The panel was able to be adhered to the outer surface with sufficient strength. Further, even if the silicon compound film is formed by the spray method as in Example 2, the characteristics are not so affected, and the antistatic low reflection film composed of the optical interference two-layer film can be formed by a simple manufacturing method. it can.

In the above embodiment, the case where the antistatic low reflection film consisting of the optical interference two-layer film is formed on the outer surface of the panel of the color picture tube has been described.
It can also be applied to the case of forming an antistatic low reflection film on the outer surface of the face plate of another cathode ray tube.

[0033]

EFFECT OF THE INVENTION In an antistatic low reflection type cathode ray tube in which an antistatic low reflection film composed of an optical interference two-layer film by a sol-gel method is formed on the outer surface of a glass face plate, the outer surface of the face plate If a silica film having a film thickness of 50 to 100 angstroms formed by the sol-gel method is provided between the antistatic low-reflection film formed by the sol-gel method and the antistatic low-reflection film formed on the surface of the face plate, The conductive high refractive index layer formed on the outer surface side of the face plate can be adhered to the surface with sufficient strength, and the conductive high refractive index layer is directly formed on the outer surface of the conventional face plate. Therefore, the antistatic low-reflection film composed of the optical interference two-layer film, which could not be adhered to the outer surface of the face plate with sufficient strength, can be adhered with sufficient strength.

Further, in a method of manufacturing an antistatic low reflection type cathode ray tube in which an antistatic low reflection film composed of an optical interference two-layer film is formed on the outer surface of a glass face plate by a sol-gel method, the outside of the face plate is used. An alcohol solution of a silicon compound soluble in alcohol is applied on the surface and dried to form a silicon compound film, and a conductive high refractive index layer forming liquid is applied on the silicon compound film and dried to form two layers of optical interference. The first layer for forming the conductive high refractive index layer of the film is formed, and the low refractive index layer forming liquid is applied onto the first layer and dried to form the optical interference 2
After forming the second layer for forming the low refractive index layer of the layer film, for forming the silicon compound film, the first layer for forming the conductive high refractive index layer and the low refractive index layer When the second layer is heated and baked at a predetermined temperature, the silica film obtained by baking the silicon compound film has sufficient adhesion to the outer surface of the face plate made of glass, while the silica film and the first layer The conductive high refractive index layer obtained by firing can be bonded with sufficient strength. Therefore, as a result, since the conductive high-refractive index layer is directly formed on the outer surface of the face plate, it is impossible to adhere the outer surface of the face plate with sufficient strength.
An antistatic low-reflection film composed of a layer film can be adhered with sufficient strength.

[Brief description of drawings]

FIG. 1 (a) is a diagram showing a configuration of a color picture tube which is an embodiment of the present invention, and FIG. 1 (b) is a diagram showing a configuration of an antistatic low reflection film on an outer surface of the panel. is there.

2A to 2C are views for explaining a method of forming an antistatic low reflection film on the outer surface of the panel of the color picture tube.

[Explanation of symbols]

 3 ... Panel 5 ... Phosphor screen 8 ... Electron gun 10 ... Explosion-proof band 11 ... Antistatic low reflection film 13 ... High refractive index layer 14 ... Low refractive index layer 15 ... Silica film 17 ... Silicon compound film 18 ... First layer 19 ... second layer

Claims (2)

[Claims] 1. An antistatic low reflection type cathode ray tube comprising an antistatic low reflection film comprising a light interference two-layer film formed by a sol-gel method on the outer surface of a glass face plate. An antistatic low reflection type cathode ray tube, characterized in that a silica film having a film thickness of 50 to 100 angstrom is provided between the antistatic low reflection film and the antistatic low reflection film by a sol-gel method. 2. A method of manufacturing an antistatic low reflection type cathode ray tube, which comprises forming an antistatic low reflection film consisting of an optical interference two-layer film on the outer surface of a glass face plate by a sol-gel method. An alcohol solution of a silicon compound soluble in alcohol is applied on the surface and dried to form a silicon compound film, and a conductive high refractive index layer forming liquid is applied on the silicon compound film and dried to produce the optical interference 2 The first layer for forming the conductive high refractive index layer of the layer film is formed, and the low refractive index layer forming liquid is applied onto the first layer and dried to form the low refractive index of the optical interference two-layer film. After forming the second layer for forming the layer, the silicon compound film, the first layer and the second layer are heated and baked at a predetermined temperature to form a silica film on the outer surface of the face plate by the sol-gel method. Through an anti-static low reflection film consisting of two layers of optical interference Method for producing antistatic low reflection type cathode ray tube, characterized by forming.