JP2677281B2 - Picture tube and picture tube reflection and antistatic treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube, and more particularly to a picture tube having anti-static and anti-reflection of a glass panel and shading of a reflected image, and a reflection and anti-static treatment method for the picture tube. Is.

[0002]

2. Description of the Related Art In a picture tube, the surface of its glass panel is charged when a high voltage is applied as an anode electrode.
Due to this charging, dust is adsorbed on the panel surface and the panel surface becomes dirty, or when a hand is brought close to the panel surface, there is an unpleasant sensation such as an electric shock.

Therefore, an antistatic picture tube having a transparent conductive film formed on the surface of a glass panel and grounded through a valve fixing metal fitting is commercially available. The material of the transparent conductive film used in this antistatic picture tube is tin oxide (SnO ₃ )
In addition to indium oxide (In ₂ O ₃ ) and titanium oxide (TiO ₂ ) as the main component, the transparent conductive film has a refractive index of about 2.0 as compared with glass (n = 1.52). Since the thickness is high, the reflection image on the surface of the glass panel is emphasized as the thickness of the transparent conductive film increases under the condition of the general film thickness.

That is, in the case of vertical incidence, in the Fresnel equation, when the phase angle between the incident light and the reflected light satisfies the condition of the equation (1), the reflected light becomes the strongest. (2m + 1) π = (4π / λ) nd (1) λ ... wavelength, n ... refractive index, d ... film thickness

First, the standard wavelength λ of light is 550 nm.
As a result, the vertical reflectance on the surface of the glass panel is
In ordinary glass is about 4.3%, the antistatic film (hereinafter
Is simply referred to as a charging film) , as shown in FIG.
The reflectance has a maximum value of about 20% near 0 angstrom. When the above-mentioned transparent conductive film material is used to form a charging film by a thermal CVD method suitable for continuous production, if the film thickness becomes thick, the film may crack, and the film may have a thickness of several hundred angstroms. This is the limit when the film thickness is one. In this range of film thickness, it is necessary to reduce the film thickness in order to reduce the reflectance as is clear from FIG. 3, but the conductive resistance of the film will increase.

Therefore, a transparent conductive film having a surface reflectance of about 100 to 150 angstroms, which is set to the upper limit of the allowable range and the conductive resistance of the film is near the lower limit of 10 ¹⁰ Ω / □, is used. Commercialized picture tubes are commercially available.

Next, the surface reflectance may be improved and the contour of the reflected image may be shaded to improve the visibility. This method is a method of spraying a silicon oxide solution using alcohol as a solvent on the charging film to finish the surface of the antistatic film as an uneven surface, and is disclosed in JP-A-2-72549.

According to this conventional method, the average film thickness of the uneven surface is set to 1000 Å, and the height of the uneven surface, that is, the surface roughness of 0.5 μmRz is required. For this reason,
At least 60% of the depth from the top of the convex portion of the surface has a film thickness of 2000 angstroms or more. As shown in FIG. 4, the conventional charging film has a wavelength of 450 to 680 nm.
The antireflection effect hardly occurs in the visibility region of. Therefore,
The antireflection effect can be obtained only in the portion having a film thickness of about 1000 Å in the valley portion of the recess.

[0009]

Conventionally, a multilayer film system in which an antireflection film has an antistatic property is formed by forming a multilayer film by vapor deposition or sputtering in a high vacuum to allow the incidence and reflection of light between layers. The reflectivity is extremely effectively reduced by the phase difference between and. The antireflection property of the multilayer film system is shown in FIG.

This multilayer film is formed by placing a large product such as a picture tube in a vacuum container and stacking it on a glass panel. This multilayer film is formed by alternately stacking high-refractive index layers and low-refractive index layers, and a material required for each layer is formed by repeating vapor deposition or sputtering with an accuracy of 10 angstrom units. is there.

According to this method, in the case of continuous mass production, an extremely large-scale apparatus is required, and there are many difficult problems in improving workability and product yield.

There is also a method of forming the charging film by a thermal CVD method. This method is suitable for mass production and is put into practical use because it does not require a high vacuum atmosphere and the film thickness can be formed accurately.

Therefore, the thermal CVD method is used to form the first layer of the charging film, and the second layer is sprayed (Japanese Patent Laid-Open No. 2-72).
No. 549), a concave portion of the scattering surface has an antireflection effect when formed as a thin film having antireflection and scattering functions, but the convex portion has a thick film of the formula (1). Since the condition is not satisfied, there is no antireflection effect. When the above-mentioned methods are comprehensively evaluated, there is a problem that the antireflection effect is small, and further, it is difficult to form a uniform film thickness by spraying, and a film thickness difference of several hundred angstroms is generated. However, there is a problem that unevenness of the reflection color occurs.

Further, in the example of Japanese Patent Laid-Open No. 60-39744, mechanical particles are formed on the glass panel surface by using brittle particles even on the polishing pace, and the antireflection film is formed in a vacuum system. It was manufactured by vapor phase growth or sputtering.

The method disclosed in Japanese Patent Application Laid-Open No. 60-39744 requires a step of reinforcing glass by chemical treatment with a salt solution after mechanical unevenness. Further, in the reference, it is necessary to perform chemical activation by glow discharge for 15 minutes in a vacuum container, which is the same as the above-mentioned multilayer antireflection film formation, and it is necessary to obtain workability necessary for mass production. Requires a very large scale equipment. Further, a step of manufacturing the antireflection film by vapor phase growth or sputtering in a vacuum is required, and since a complicated vacuum device is added, the antireflection film cannot be formed by a simple method, resulting in a low manufacturing cost. There was a problem that it would lead to a rise.

Further, as for the picture tube disclosed in JP-A-59-98442, in which a transparent conductive film is attached to the surface of a glass panel having a roughened surface, the conductive layer is vacuumed, as is apparent from the description of the publication. It is realized by a method of forming by vapor deposition, and as described above, it is a method that causes a high manufacturing cost. Therefore, in order to improve the cost, in the case where the conductive film is realized by the thermal CVD method, the reflectance increases as the film thickness increases, as described in the section of the related art. That is, even if the glass panel surface is roughened, if the antireflection film having a film thickness of about 100 to 150 angstrom is formed, the gloss value (6
In the case of a rough surface which is conventionally about 60, the value of 0 degree (according to the specular gloss method) is increased by about 10 to approach a mirror surface as a visual feeling, and the scattering effect due to the rough surface cannot be sensed.

Therefore, since the film thickness of the antistatic film is fixed within the above-mentioned range, there is a limit to lowering the reflectance and the conductive resistance, and further improvement is required.

An object of the present invention is to provide a picture tube having a multi-layered antistatic film formed by a CVD method and a spin coating method, and a reflection and antistatic treatment method for the picture tube.

[0019]

In order to achieve the above object, a picture tube according to the present invention comprises a scattering surface, a transparent conductive film , and
A picture tube having a transparent thin film and having a structure for irradiating the phosphor on the inner surface of the panel with an electron beam to cause the phosphor to emit light,
Scattering surface, a panel outer surface uneven pattern is attached, before
The height of the unevenness is in the range of 0.6 μm Rz to 0.8 μm Rz .
Are those having a homogeneous surface roughness is囲内, transparent
The electric film is laminated on the scattering surface, has an uneven pattern on the surface, and is grounded. The electric film has a refractive index of about 2 and a film thickness of about 300 angstroms. The transparent thin film was laminated on the transparent conductive film , had an uneven pattern on its surface, had a refractive index of about 1.5, and had an average film thickness of 1100 to 1500 angstroms. It is a thing.

[0020]

[0021]

Further, the reflection and antistatic treatment method for a picture tube according to the present invention has a physical treatment step, a chemical treatment step, a transparent conductive film forming step, and a transparent thin film forming step. Reflective and antistatic treatment is applied to the outer surface of the panel
A method of reflection and antistatic treatment of the picture tube, the physical treatment step, by spraying ultra-hard particles on the panel outer surface of the picture tube, to perform a pretreatment to give unevenness to the panel outer surface, In the chemical treatment step, the outer surface of the panel that has been physically treated is further subjected to a chemical etching treatment to give an uneven pattern to finish as a scattering surface, and the transparent conductive film forming step is performed on the scattering surface. by CVD is intended to form a transparent conductive film having an uneven pattern on the surface, a transparent thin film forming step, before the alcoholic solution
The transparent thin film having an uneven pattern on the surface is applied and formed on the conductive film by rotating the panel while dropping the conductive film .

[0023]

[Function] After the physical pretreatment of spraying ultra-hard particles on the surface of the glass panel of the picture tube, the surface roughness is 0.6 μm by chemical etching with high-pressure acid and alkali.
Rz to 0.8 μm Rz uneven surface is formed, and antimony-doped tin oxide or tin-doped indium oxide is deposited on the surface of the uneven surface by the CVD method with accuracy of about 300 angstroms. Form the first layer of the membrane. Further, an extremely dilute alcohol-based solution containing silicon oxide is dropped thereon, and a thin film second layer is formed on the uneven surface by a spin coating method. With the above-described structure, two layers of films are laminated on the scattering surface, and the effects of preventing charging, reducing the amount of reflected light, and blurring the contour of the reflected image are obtained.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1A is a sectional view showing a picture tube according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view showing a glass panel.

In FIG. 1, a phosphor layer 2 and an aluminum film layer 3 are laminated on the inner surface of a glass panel of a picture tube. Then, the phosphor layer 2 and the aluminum film layer 3 are irradiated with the electron beam 4 emitted from the electron gun by applying a high voltage, and the phosphor emits light. In this transient of high voltage application, the glass panel surface 1 facing the laminate of the phosphor layer 2 and the aluminum film layer 3 is charged.

Therefore, as shown in FIG. 2, a charging film 5 for preventing charging is formed on the surface of a conventional glass panel, and this film 5 is grounded, and the outline of the reflected image is further formed on the charging film 5. In some cases, a scattering thin film (or an antireflection film) 6 was formed in order to improve the brightness.

The lower transparent charging film 5 shown in FIG.
As shown in, the reflectance tends to increase until the product (n × d) of the refractive index and the film thickness becomes equal to ¼ of the dominant wavelength of light. For example, the refractive index is 2.0 and the dominant wavelength of light is 550n.
In the case of m, the reflectance increases until the film thickness reaches about 700 Å, so it is necessary to suppress the film thickness.

On the other hand, in order to improve the antistatic effect, it is necessary to increase the film thickness to reduce the conductive resistance, and practically, there was no choice but to find a compromise in the film thickness range. For example,
Since tin oxide doped with antimony as the charging film has a refractive index (n) of 2.0 as described above, the film thickness is set to 100 to 150 angstroms and the reflectance is set to the lower limit of the practical range from the above conditions. As a result of suppressing, the conductive resistance value is 10
^{It is 9} to 10 ¹⁰ Ω / □, which is the limit of the antistatic effect, but it has been put to practical use as a product. In order to suppress the increase in reflectance even if the conductive resistance is further reduced, a multilayer film may be formed. However, as described above, there are many difficult aspects in manufacturing, and instead, a method of using a two-layer film with good productivity is used. Is disclosed in JP-A-2-72549.

According to this method, it is intended to simultaneously obtain the suppression of the increase in reflectance that occurs when the conductive resistance is lowered and the effect of blurring the reflected image. First, a practical method for lowering the conductive resistance will be described. Since the present invention also employs the same manufacturing method, an explanation will be given based on an example implemented in the present invention.

The thicker the charging film, the lower the conductive resistance, and therefore it is necessary to increase the thickness to a film thickness at which a desired resistance value can be obtained. In general, a resistance value of 10 ⁶ Ω / □ or less is ideal.

On the other hand, the practical practical limit of the film thickness that can be formed by thermal CVD method, for example, antimony-doped tin oxide or tin-doped indium oxide by one-time film formation is almost in consideration. It is 300 Å, and the conductive resistance at this film thickness is 10 ⁵ to 10 ⁶ Ω / □.
It is.

Therefore, under the above conditions, a charging film 5 having a refractive index (n) of 2.0 and a film thickness of 300 Å is formed as a first layer on a smooth glass panel surface, and then silicon oxide (SiO ₂ ) is mainly used. FIG. 4 shows the results of actually measuring the reflectance with respect to the wavelength of light by forming the transparent thin film having various thicknesses by a spin coating method.

As shown in FIG. 4, the wavelength 5 having the highest luminosity factor is used.
The film thickness of the transparent thin film which becomes the minimum around 50 nm is 1100.
Angstrom. This wavelength range (500-55
Since the reflectance of 0 angstroms) was extremely small, the reflected image was felt to be darker, and the reflected color was bluish purple, which was perceived as a visually pleasing color.

However, the reflection image shows 0.4% in comparison with the surface reflectance of 4.3% of the glass in the visible region, as shown in the reflectance characteristic of the multilayer antireflection film formed on the smooth glass panel surface shown in FIG. %, Which has a significant antireflection effect, but when this is a two-layer film, the reflectance in the luminosity region is 0.8, as can be seen from the reflectance characteristic diagram shown in FIG.
%. This shows the antireflection effect compared to the reflection on the glass surface, but the contour of the reflection image is clear to the eyes when the reflection image whose contour is blurred by the scattering surface is seen,
Need to improve.

Therefore, for example, in Japanese Unexamined Patent Publication (Kokai) No. 2-72549, it is proposed to spray silicon oxide onto the charging film 5 by a spray so that the average film thickness of the scattering thin film 6 becomes 1000 angstrom at which the reflectance is minimized. ing. However, the surface roughness of the scattering thin film 6 is 0.5 μmRz.
Therefore, the convex portion of the uneven surface has little antireflection effect, and the antireflection effect of the concave surface portion generally increases the reflectance when the film thickness of the antistatic film 5 is increased. Although the reflectance could be suppressed to 5.3% by suppressing the above, the effect that was significantly lower than the reflectance of glass of 4.3% was not obtained.

Therefore, in the present invention, first, the first charging film 7
Before forming the layer, the glass panel surface 1 is subjected to a physical pretreatment by spraying ultra-high particles from a high-pressure nozzle.
Next, the glass scattering surface 9 having a uniform unevenness is formed by chemical etching in which an acidic liquid and an alkaline liquid are alternately sprayed at high pressure or low pressure.

According to the present invention, when the shape and particle size of the particles to be sprayed on the glass panel surface 1 are adjusted and pre-treatment is carried out, the conditions for the subsequent spraying of the acidic and alkaline liquids are adjusted so that the glass panel It is possible to form a uniform scattering surface as a whole.

In the embodiment, the surface roughness is 0.4 μm.
A prototype was made by changing the range from mRz to 1.0 μmRz, and antimony-doped tin oxide was atomized and sprayed onto this scattering surface at a high temperature of over 400 ° C. The charging film 7 having a film thickness of 300 angstroms, that is, the belt, is almost uniformly formed on the uneven surface.
A transparent conductive film as an antistatic film is formed. In this state, the surface resistance is 10 ⁶ Ω / □, which is a sufficient conductive resistance. Furthermore, the viscosity on the charging film 7 is extremely low (2-4C).
The glass panel is rotated by dropping the alcohol diluted solution containing silicon oxide (PS) as the main component and rotating the glass panel at a combination of the rotational speeds so that the film thickness becomes uniform.
A transparent thin film 8 having a thickness of about angstrom is formed.

The results of measuring the reflectance of the antireflection film of the present invention are shown in FIG. As is apparent from FIG. 7, the minimum value of the reflectance is increased to 0.8% as compared with that of FIG. 6, but the change of the reflectance with respect to the wavelength change of light is suppressed to about 4% or less. Due to the small number, the bluish purple color of the reflected color is slightly faint.
Furthermore, the reflectance in the luminosity region is 1.3%, which is slightly higher than the reflectance in the luminosity region of the reflection characteristics (FIG. 6) when applied to the smooth glass panel surface described above. However, the same or better effect was obtained due to the blurring effect.
Regarding the surface roughness of the prototype under these conditions, in the OA work, the blurring of the contour of the reflected image due to the reflection of the ceiling light in the room where the OA work is performed, and the high-density display image used for this evaluation are: Although it is an alphabetic character formed by 1024 dots (horizontal direction) x 768 lines (number of scanning lines), this displayed character was evaluated by the reverse display (black character on white background) which has been increasing recently. A so-called glare phenomenon occurred due to the interference between the scanning lines on the white background and the surface roughness. Therefore, the faintness and the glare phenomenon are opposite characteristics, and appropriate values are obtained. Therefore, FIG. 8 shows the results of evaluation by making a prototype with a surface roughness of the glass panel surface 1 from 0.4 μm Rz to 1.0 μm Rz, and laminating a two-layer film on the prototype.

According to the evaluation result of FIG. 8, 0.6 μmRz
From this, it was found that the use of a glass panel having a surface roughness of 0.8 μmRz is suitable.

[0041]

As described above, the present invention improves the antireflection effect by mutually adjusting the film thickness of the two-layer transparent charging film and the transparent thin film, so that the reflectance in the luminosity region is 1.3. %, The reflection on the panel surface can be suppressed to about 1/3. Moreover, by improving the opacity effect of the reflected image by the glass scattering surface, the reflected color is a slightly pale bluish purple, and it is possible to obtain a visually pleasing color tone. Therefore, the light amount of the bluish-purple reflected image is suppressed, the contour thereof can be blurred, the reflected image of ambient light does not hinder the observation of the surface image, and an easily viewable screen can be realized. Furthermore, the conductive resistance of the conductive film is 10 ⁶ Ω / □,
It has the effect of improving the antistatic property.

[Brief description of the drawings]

1A is a sectional view showing a picture tube according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view.

2A is a sectional view showing a conventional picture tube, and FIG. 2B is an enlarged sectional view.

FIG. 3 is a diagram showing a film thickness and a reflectance of an antistatic film.

FIG. 4 is a diagram showing a wavelength and a reflectance with respect to a change in film thickness of a transparent film.

FIG. 5 is a diagram showing a wavelength and a reflectance of a multilayer antireflection film.

FIG. 6 is a diagram showing the wavelength and reflectance of a two-layer antireflection film.

FIG. 7 is a diagram showing a wavelength and a reflectance when a two-layer antireflection film is formed on a scattering surface.

FIG. 8 is a diagram showing the relationship between the degree of reflection image reflection due to surface roughness and the image glare.

[Explanation of symbols]

 1 glass panel surface 5,7 charging film 6 scattering thin film 8 transparent thin film 9 glass scattering surface

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masayuki Okiyama 5-7-1 Shiba, Minato-ku, Tokyo Within NEC Corporation (72) Inventor Tsutomu Banno 5-7-1 Shiba, Minato-ku, Tokyo Japan Electric Co., Ltd. (56) Reference JP-A-63-34840 (JP, A) JP-A-4-74568 (JP, A) Actual development Sho-63-133049 (JP, U)

Claims (2)

(57) [Claims] 1. A picture tube having a scattering surface, a transparent conductive film, and a transparent thin film, and having a structure for irradiating the phosphor on the inner surface of the panel with an electron beam to cause the phosphor to emit light. , a panel outer surface uneven pattern is attached, before
The height of the unevenness is in the range of 0.6 μm Rz to 0.8 μm Rz .
The transparent conductive film has a uniform surface roughness inside, is laminated on the scattering surface, has an uneven pattern on the surface, and is grounded, and has a refractive index of about 2
, And the and is intended film thickness is set to about 300 angstroms in substantially uniform, transparent thin film is laminated on the transparent conductive film has an uneven pattern on its surface, a refractive index of about 1.5 And the average film thickness is set to 1100 to 1500 angstroms. 2. A physical treatment step and a chemical treatment step,
A transparent conductive film forming step, a transparent thin film forming step, the reflection and antistatic treatment applied to the outer panel surface of the CRT claims
The reflection and antistatic treatment method for a picture tube according to 1 , wherein the physical treatment step is a pretreatment for imparting irregularities to the outer surface of the panel by spraying ultrafine particles on the outer surface of the panel of the picture tube. There, the chemical treatment step, the physical treatment panels outer surface, denoted by the uneven pattern by further chemical etching treatment, which finished as a scattering surface, the transparent conductive film forming step, the scattering surface A transparent conductive film having a concavo-convex pattern on the surface is formed on the conductive film by a CVD method. In the transparent thin film forming step, the alcohol-based solution is dropped onto the conductive film and the panel is rotated to rotate the conductive film.
Reflection and antistatic treatment method of the picture tube, characterized in that the transparent thin film having an uneven pattern on the surface on the film coating, and forms.