JP2000323075A - Cathode ray tube - Google Patents

Abstract

(57) Abstract: A reflective antistatic film that has low reflectance over the entire wavelength range to be displayed, prevents reflection of extraneous light on a panel glass, achieves high contrast, and prevents charging. The present invention provides a cathode ray tube having good visibility and comprising: A vacuum envelope is constituted by a panel glass (1) forming a screen by coating a phosphor layer on an inner surface, a neck for accommodating an electron gun, and a funnel connecting the panel glass and the neck. The porosity of the high refractive conductive ultrafine particles 21 having the antireflection antistatic film 20 composed of the high refractive conductive ultrafine particle layer 20A on the outer surface of the panel glass 1 and constituting the high refractive conductive ultrafine particle layer 20A Was a small value on the panel glass side and a large value on the surface side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube,
In particular, the present invention relates to a cathode ray tube provided with an antireflection antistatic film for preventing reflection of extraneous light to a panel glass to increase contrast and to prevent electrification.

[0002]

2. Description of the Related Art A cathode ray tube used for a television receiver or a personal computer monitor has a vacuum formed by a panel glass constituting an image display surface, a neck for accommodating an electron gun, and a funnel connecting the panel glass and the neck. An envelope is formed, and a desired image is displayed by exciting a phosphor layer formed on the inner surface of the screen with a modulated electron beam emitted from an electron gun.

FIG. 9 is a schematic sectional view illustrating the structure of a shadow mask type color cathode ray tube as an example of this type of cathode ray tube, wherein 1 is a panel glass (face plate), 2 is a neck, 3 is a funnel, 4 is a phosphor layer, 5
Is a shadow mask, 6 is a mask frame, 7 is a suspension mechanism, 8 is a support pin (stud), 9 is a magnetic shield,
0 is an anode button, 11 is an internal conductive film, 12 is a deflecting device, 13 is an electron gun, and 14 is an electron beam (red, green, blue).

In this color cathode ray tube, a vacuum envelope is constituted by a panel glass 1 constituting a screen (screen), a neck 2 accommodating an electron gun 13, and a funnel 3 connecting the panel glass 1 and the neck 2. . An inner conductive film 11 for supplying a high anode voltage applied to the anode button 10 to the electrodes of the electron gun 13 and the screen is applied to the inner surface of the vacuum envelope.

[0005] The shadow mask 5 is welded to the mask frame 6 and is locked by the support pins 8 embedded in the inner wall of the skirt portion of the panel glass 1 by the suspension mechanism 7, and the phosphor layer 4 formed on the inner surface of the panel glass 1 is formed. At predetermined intervals.

The magnetic shield 9 shields an external magnetic field such as a terrestrial magnetism with respect to the electron beam 14, and is held by welding to the mask frame 6.

On the neck 2 side of the funnel 3, a deflecting device 12 for forming a horizontal deflection magnetic field and a vertical deflection magnetic field in the path of the electron beam 14 emitted from the electron gun 13 is mounted. The three electron beams are deflected in two directions, a horizontal direction and a vertical direction, to scan the phosphor layer 4 two-dimensionally.

In general, in such a cathode ray tube, an antireflection antistatic layer for preventing reflection of extraneous light incident on a panel glass as a screen to prevent a decrease in contrast or prevent static electricity from being charged. Are formed.

FIG. 10 is a schematic cross-sectional view of a portion A of FIG. 9 illustrating an example of a structure for preventing reflection of extraneous light of a cathode ray tube and viewed from a direction perpendicular to an arrangement direction of three electron beams. 42 is a black matrix, 43 is a phosphor, 44 is a metal back, 51 is an electron beam passage hole of a shadow mask, R, G, and B are electron beam paths of each color, 20 is an antireflection antistatic film, and 23 is a phosphor. Emission light, 24 is extraneous light,
Reference numerals 25 and 26 indicate reflected light of extraneous light, and the same reference numerals as those in FIG. 9 correspond to the same parts.

In FIG. 1, electron beams R, G, and B emitted from an electron gun are color-selected for each phosphor 43 by an electron beam passage hole 51 of a shadow mask 5 and impinge on the phosphor layer 4. .

The phosphor 43 is excited by the electron beam impingement and emits light.
As shown in FIG. An antireflection antistatic layer 20 is formed on the outer surface of the panel glass. The external light 24 incident on the panel glass 1 is reflected toward the inside of the antireflection antistatic layer 20, and the light 25 is absorbed or interfered with by the antireflection antistatic layer 20, and energy is suppressed to the phosphor layer side. The penetration is suppressed and the reflected light is also reduced.

Although such an antireflection antistatic layer is formed by various methods, most of them are generally formed by a so-called sol-gel method. As a typical example, a conductive material and a high- and low-refractive index material are alternately sputtered on the outer surface of the panel glass. Each of the above substances is vapor-deposited on a polyethylene terephthalate (PET) film. Attached to the
It is known that a colloid of ultrafine particles of a noble metal is directly coated on the outer surface of a panel glass, and a transparent silica compound having a low refractive index is coated thereon.

As a material which discloses the above-mentioned prior art, there is, for example, Japanese Patent Application Laid-Open No. 10-69866.

[0014]

Among the above conventional techniques, the technical content is different from that of the present invention.
Considering the antireflection antistatic layer, the following problems were encountered.

Usually, the antireflection antistatic film is formed by spin-coating a dispersion of conductive ultrafine particles on the outer surface of a glass panel of a cathode ray tube to form a first layer, and a silica compound as a main component on the first layer. (Usually a hydrolyzed solution of silicon alkoxide) is formed by spin coating,
It is obtained by forming a second layer having an antireflection function with a refractive index lower than the refractive index of the layer.

The second layer is coated with a solution containing a silica compound as a main component, and the silica compound is infiltrated between the conductive ultrafine particles of the first layer to have the function of the binder of the first layer.

However, this antireflection antistatic film is
(1) If the conductive layer is formed densely to reduce the resistance, the reflection curve becomes V-shaped because the antireflection antistatic film is a two-layer type antireflection layer, and the reflection is the lowest. Rate (usually called bottom reflectance) is 0.1 to 0.2
%, As shown in FIG. 11, there is a problem that the reflectance sharply increases at wavelengths other than the wavelength corresponding to the bottom reflectance (around 550 nm) and the reflection color becomes strong.

(2) A film having a low transmittance (usually 50
(-75%), there is a problem that if there is a film formation error such that the transmittance of the film is too low, the contrast becomes strong and the yield rate decreases.

An object of the present invention is to solve the above-mentioned problems of the prior art, to reduce the reflectance in the entire wavelength range to be displayed, to prevent the reflection of extraneous light on the panel glass, and to improve the contrast. It is another object of the present invention to provide a cathode ray tube having good visibility having a reflective antistatic film for preventing electrification.

[0020]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a high refractive index conductive ultrafine particle having a refractive index of 1.7 to 2.2 in visible light which constitutes a reflective antistatic film. , That is, the filling rate of the high-refractive-index conductive ultrafine particles in the layer constituting the reflective antistatic film is different between the panel glass side and the surface side. A typical configuration of the present invention is described as follows.

(1) A vacuum envelope is constituted by a panel glass forming a screen by coating a phosphor layer on an inner surface, a neck for accommodating an electron gun, and a funnel connecting the panel glass and the neck. An anti-reflection anti-static film composed of a high-refractive conductive ultrafine particle layer having a refractive index of 1.7 to 2.2 on visible light on an outer surface of the panel glass; The porosity of the high refraction conductive ultrafine particles constituting the above was set to a small value on the panel glass side and a large value on the surface side.

(2) The antireflection antistatic layer in (1) is composed of a plurality of layers, and the porosity of the high refractive conductive ultrafine particles is small in the layer on the panel glass side, and the porosity is in the direction away from the panel glass. Then, the value was gradually increased.

By changing the porosity of the high refractive conductive ultrafine particles constituting the antireflection antistatic layer in the above (1) continuously as in the above (2), the reflectivity shown in FIG. The V-shaped slope of the wavelength dependence graph becomes gentle, the reflectance of the entire visible light wavelength region required decreases, and the degree of coloring of the reflected light is reduced.

(3) A vacuum envelope is constituted by a panel glass forming a screen by coating a phosphor layer on the inner surface, a neck for accommodating an electron gun, and a funnel connecting the panel glass and the neck. Having an antireflection antistatic film composed of a high refractive index conductive ultrafine particle layer on the outer surface of the panel glass, and defining the porosity of the high refractive index conductive ultrafine particles constituting the antireflection antistatic layer as a panel. An intermediate value was set on the glass side, a small value on the intermediate side, and a large value on the surface side.

(4) The antireflection and antistatic layer in (3) is composed of a plurality of layers, and the porosity of the high refractive conductive ultrafine particles has an intermediate value in the layer on the panel glass side and a large value on the surface side. In the middle layer, the value was smaller than that of the adjacent layer.

By changing the porosity of the high refractive conductive ultrafine particles constituting the antireflection antistatic layer in the above (3) in multiple stages as in the above (4), the wavelength of the reflectance shown in FIG. Since the slope of the V-shape of the dependence graph becomes gentle and approaches the W-shape, the reflectance of the entire required wavelength region decreases, and the degree of coloring of the reflected light is reduced.

Further, instead of setting the porosity in the above configuration to an intermediate value, other conductive ultrafine particles having a higher refractive index than the above conductive ultrafine particles may be provided. A mixture of the conductive ultrafine particles and other conductive ultrafine particles having a refractive index can also be used.

(5) The low refractive index covering the antireflection antistatic layer in (1) to (4) and having a refractive index of 1.4 to 1.5 and lower than the refractive index of the high refractive index conductive ultrafine particles. Was formed.

The transparent ultrafine particle layer having a low refractive index scatters external light to reduce the penetration of the reflected light into the antireflection antistatic layer, thereby improving the visibility. As transparent ultrafine particles having a low refractive index, silica compounds (for example, SiO 2
_X H _Y ) is preferred.

The conductive ultrafine particles include gold,
Platinum, silver, palladium, rhodium, iridium, and mixtures of these ultrafine particles, or alloy particles of two or more thereof, and mixtures thereof can be employed. Further, colloidal silica (trade name “Snowtex” manufactured by Nissan Chemical Industries, Ltd.) may be mixed.

As described above, according to the present invention, the reflection color density is reduced, the slope of the reflection characteristic curve is reduced, and the visibility of the cathode ray tube is improved.

Further, the present invention is not limited to the above configuration, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples. Hereinafter, in the present invention, visible light means light in the range of 380 nm to 760 nm.

FIG. 1 is a schematic partial sectional view for explaining the structure of a panel glass portion of a first embodiment of a cathode ray tube according to the present invention, wherein 1 is a panel glass, 20 is an antireflection antistatic film, and 20A is a refractive index. A layer of high refractive index conductive ultrafine particles having a refractive index of 1.7 to 2.2, 20B is a transparent ultrafine particle layer having a low refractive index of 1.4 to 1.5, and 21 is a conductive ultrafine particle. Then, the porosity is stepwise adjusted so that the porosity is small on the glass panel 1 side of the layer 20A of the high refractive index conductive ultrafine particles and large on the surface side, that is, on the side of the transparent ultrafine particle layer 20B having a low refractive index. Has been changed.

The high-refractive-index conductive ultrafine particle layer 20A penetrates the silica compound of the low-refractive-index transparent ultrafine particle layer 20B formed in the upper layer between silver (Ag) and palladium (Pd) mixed ultrafine particles. Has become a binder.

By forming the antireflection antistatic film having such a structure, it is possible to obtain a cathode ray tube with good visibility by suppressing reflection of external light and suppressing charging.

Next, a method of forming the antireflection antistatic film of the above embodiment will be described with reference to FIGS. FIG. 2 is a process chart for explaining one embodiment of the forming method of the embodiment shown in FIG. In the following:
The particle size of the fine particles is an average particle size measured by "N4 type manufactured by Coulter".

First, after a color cathode ray tube of 51 cm size is manufactured by a well-known ordinary method, the outer surface of the panel glass is lightly polished with fine powder of cerium oxide, and water and a nonionic surfactant (for example, "Emulgen 8 made by Kao"
10 "(trade name)), rinse with pure water and rinse thoroughly. ... Step 1 A color cathode ray tube having the panel glass cleaned is charged into a heating furnace and heated to 35 ± 1 ° C. Step 2 Next, using a spray gun (for example, a type A two-fluid spray gun manufactured by Binks, USA), the following “Composition 1”
100m distance from panel glass with conductive ultra-fine particle solution
m, moving speed 400 mm / S, liquid flow rate 2 liter /
h, the entire surface of the panel glass is sprayed with a single spray at the first concentration at an air flow rate of 150 l / m, as shown in FIG. Step 3 "Composition 1" Ultrafine particles of silver (Ag) / palladium (Pd) mixed 0.5 wt% (Ag / Pd = 4/6, average particle size = 4-6 nm) Alcohols・ ・ 70wt% pure water ・ ・ ・ ・ ・ Remainder After that, supply of the conductive ultrafine particle solution to the spray gun is stopped, and drying is performed by spraying only air. ... Step 4 After drying, the liquid flow rate of the conductive ultrafine particle solution is 1.8 liter /
h, spraying the second concentration in the same manner as described above at an air flow rate of 150 liter / m, Step 5: Stop supplying the conductive ultrafine particle solution to the spray gun,
Dry by spraying with air only. ... Step 6 After drying, the liquid flow rate of the conductive ultrafine particle solution is 1.5 liter /
h, spraying the second concentration in the same manner as described above at an air flow rate of 150 L / m, Step 7: Stop supplying the conductive ultrafine particle solution to the spray gun,
Dry by spraying with air only. Step 8: Reheat the dried panel glass of the color cathode ray tube to
After adjusting the temperature to 0 ± 1 ° C. Step 9 Set the panel glass on a spin coater so that the convex surface faces upward, 1% ethoxysilane hydrolyzate, 40% ethyl alcohol, 40% methyl alcohol, water 10
%, About 9% of diacetone alcohol and nitric acid are added to adjust the pH to 3.5, and spin-coated at 150 rpm. ... Step 10 After spin coating, heat at 180 ° C for 20 minutes.・ ・
Step 11 As described above, the porosity of the conductive ultrafine particle layer of Ag / Pd is 40%, 65%, and 80% from the panel glass side, and the silica compound is added to the layer having a multilayer structure having a thickness of 25 nm, 10 nm, and 5 nm. (SiO _X H _Y ) was permeated, and an antireflection antistatic film having a low refractive index transparent ultrafine particle layer made of a silica compound having a thickness of about 85 nm was obtained thereon. In addition,
The porosity is a value determined from the ratio of the occupied area of the void in an image obtained by observing the cross section of the produced antireflection antistatic film with a scanning electron microscope (SEM).

FIG. 4 is an explanatory diagram of the reflection characteristics of the antireflection antistatic film formed by the above method, and FIG. 5 is an explanatory diagram of the transmission characteristics. As shown in FIG. 4, V shown in FIG.
The inclination of the graph in the shape of a letter becomes gentle, the reflectance of the entire required wavelength range decreases, and the color change of the reflected light is reduced.

Further, the transmittance of the panel glass becomes substantially flat over the entire required wavelength region as shown in FIG. 5, and the visibility is improved.

In the above-described forming method, the conductive ultrafine particle layer is composed of three layers.
By increasing the process up to and further reducing the porosity of the conductive ultrafine particle layer, the conductive ultrafine particle layer can be formed in a multilayer structure of four or more layers. By reducing the number of layers, it is possible to obtain a structure in which the porosity changes almost continuously from the panel glass side to the surface side.

"Embodiment 2 of Forming Method"
The process up to the step 4 described in the above is the same. As the alcohol dispersion solution of the Ag / Pd mixed ultrafine particles sprayed in the step 5, the solution of the composition 1 (first concentration) is composed of the alcohol 7 and the pure water 3
(The second concentration), which is diluted with a solvent having a ratio of 0.3% to make the ratio of the Ag / Pd mixed ultrafine particles 0.3%.・
In the same manner as in Step 5, as the alcohol dispersion solution of the Ag / Pd mixed ultrafine particles sprayed in Step 7, the solution of the composition 1 (second concentration) was diluted with a solvent having a ratio of alcohol 7 and pure water 3 to Ag / Pd. The Pd-mixed ultrafine particles having a ratio of 0.2% (second concentration) are sprayed. Hereinafter, an anti-reflection antistatic film having the same function as that of the first embodiment of the forming method is obtained through the same steps as in FIG.

FIG. 6 is a schematic partial sectional view for explaining the structure of a panel glass part of another embodiment of the cathode ray tube according to the present invention, and the same reference numerals as those in FIG. 1 correspond to the same functional parts. In the figure, 2a is a layer on the panel glass side of the conductive ultrafine particle layer, 2a
0b indicates an intermediate layer, and 20c indicates a surface-side layer.

In this embodiment, the porosity of the conductive ultrafine particles in the high refractive conductive ultrafine particle layer 20A constituting the antireflection antistatic layer 20 is an intermediate value on the panel glass side 20a, and the porosity of the intermediate layer 20b on the intermediate glass layer 20b. It has a small value and a large value on the front side 20c.

When the high-refractive conductive ultrafine particle layer 20A has a multilayer structure of four or more layers, each intermediate layer has a smaller value than an adjacent layer.

By forming the antireflection antistatic film having such a structure, it is possible to obtain a cathode ray tube having good visibility by suppressing reflection of external light and suppressing charging.

[Third Embodiment of Forming Method] Next, a method of forming the antireflection antistatic film of the second embodiment will be described with reference to FIGS. FIG. 7 is a process chart for explaining an embodiment of the forming method of the other embodiment shown in FIG.

First, similarly to FIG. 2, a color cathode ray tube having a size of 51 cm is manufactured by a well-known ordinary method.
The outer surface of the panel glass is lightly polished with a fine powder of cerium oxide, and washed with a 0.05% mixture of water and a nonionic surfactant (for example, “Emarc 810” (trade name) manufactured by Kao), Rinse well with pure water and clean. ... Step 1 A color cathode ray tube having the panel glass cleaned is charged into a heating furnace and heated to 35 ± 1 ° C. Step 2 Next, using a spray gun (for example, a type A two-fluid spray gun manufactured by Binks, USA), the following “Composition 2”
100m distance from panel glass with conductive ultra-fine particle solution
m, moving speed 400 mm / S, liquid flow rate 2 liter /
h, the entire surface of the panel glass is sprayed with a single spray at the first concentration at an air flow rate of 150 l / m, as shown in FIG. Step 3 "Composition 2" Ultrafine particles of silver (Ag) / palladium (Pd) mixed 0.4 wt% (Ag / Pd = 4/6, average particle size = 4 to 6 nm) Snowtex 20 ( Nissan Chemical's trade name) 0.1 wt% Alcohols ... 70 wt% Pure water ... The remainder After that, supply of the conductive ultrafine particle solution to the spray gun was stopped, and only air was sprayed. To dry. ... Step 4 After drying, the liquid flow rate of the conductive ultrafine particle solution is 1.8 liter /
h, a solution of the following “Composition 3” is sprayed at a flow rate of 150 L / m in the same manner as described above.

Step 5 “Composition 3” Ultrafine mixed particles of silver (Ag) and palladium (Pd) 0.46 wt% (Ag / Pd = 4/6, average particle size = 4 to 6 nm) Titanium oxide Ultrafine particles 0.04 wt% Alcohols 70 wt% pure water Remainder Stop supplying the conductive ultrafine particles solution to the spray gun,
Dry by spraying with air only. ... Step 6 After drying, the liquid flow rate of the conductive ultrafine particle solution is 1.5 liter /
h, spraying a solution of the following "Composition 4" at a flow rate of 150 L / m in the same manner as above.

Step 7 “Composition 4” Ultra-fine particles of silver (Ag) / palladium (Pd) 0.25 wt% (Ag / Pd = 4/6, average particle size = 4 to 6 nm) Titanium oxide Ultrafine particles 0.04 wt% Snowtex 20 (trade name of Nissan Chemical) 0.15 wt% Alcohol 70 wt% pure water Remaining solution of conductive ultrafine particles to spray gun Stop the supply,
Dry by spraying with air only. Step 8: Reheat the dried panel glass of the color cathode ray tube to
After adjusting the temperature to 0 ± 1 ° C. Step 9 Set the panel glass on a spin coater so that the convex surface faces upward, 1% ethoxysilane hydrolyzate, 40% ethyl alcohol, 40% methyl alcohol, water 10
%, About 9% of diacetone alcohol and nitric acid are added to adjust the pH to 3.5, and spin-coated at 150 rpm. ... Step 10 After spin coating, heat at 180 ° C for 20 minutes.・ ・
Step 11 As described above, the porosity of the conductive ultrafine particle layer of Ag / Pd is 65%, 40%, and 80% in order from the panel glass side, and the silica compound is added to the layer having a multilayer structure having a thickness of 25 nm, 10 nm, and 5 nm. (SiO _X H _Y ) was permeated, and an antireflection antistatic film having a low refractive index transparent ultrafine particle layer made of a silica compound having a thickness of about 85 nm was obtained thereon.

It is needless to say that the present invention can be applied not only to a cathode ray tube but also to a screen of a liquid crystal panel, a plasma panel, an EL panel, or another display device.

As described in the above embodiments of the cathode ray tube, according to the present invention, the reflection characteristics (low reflectance and low reflection color) of the panel glass are excellent, and the transmission characteristics are flat.
As shown in FIG. 8, an antireflection antistatic film having a W-shaped reflectance is obtained.

The surface resistance of this antireflection antistatic film is 30
0 to 600 Ω / cm ^2, which can meet even the strictest regulations on leakage of electromagnetic waves from a color cathode ray tube. Also,
In the present invention, since the layer for decreasing the transmittance is formed by spraying in multiple stages, even if a defect occurs in each layer, the contrast is low and inconspicuous, so that the yield rate is improved.

The transparency of this type of film is represented by haze (diffuse transmittance / total light transmittance). However, if the surface temperature is too high or the amount of air during spraying is large, the transparency is lost. . However, the antireflection antistatic film according to the present invention has a transmittance of at most 0.5% or less, and the transparency is not impaired from human eyes.

In the embodiment of the above-described forming method, the case where the anti-reflection antistatic film is formed by three-step spraying has been described. However, the reflectivity can be lowered by further increasing the number of steps. However, the further increase in the number of stages involves the switching of the solution by the valve of the spray gun and the complexity of the solution supply device, so that the number of stages is limited.

In the above-described embodiment of the forming method, the film is formed by spraying, but a spin coater may be used.

Table 1 shows the comparison between the cathode ray tube according to the present invention and the conventional cathode ray tube.

[0058]

[Table 1]

Further, recently, a flat panel type cathode ray tube in which the outer surface of the panel glass is flat and the inner surface has a slight curvature has been commercialized. Such a cathode ray tube is different from a conventional cathode ray tube. When the so-called tint glass is used, where the thickness difference between the panel glass of the central part and the peripheral part is about twice as large and the light absorption is large, the difference in transmittance between the central part and the peripheral part becomes large, resulting in a difference in brightness. Therefore, a method of performing surface treatment with low transmittance using glass with high transmittance has been adopted. The present invention is also effective for such a cathode ray tube.

[0060]

As described above, according to the present invention,
It is possible to reduce the required average reflectance of the required wavelength of visible light (380 nm to 780 nm) by reducing the darkness of the reflection color and flattening the reflection curve, which are the drawbacks of the conventional reflection antistatic film. Thus, a cathode ray tube with improved visibility can be provided.

Further, by adopting the method of spray coating the high refractive index layer, the amount of expensive solution used can be reduced by half, the manufacturing process can be simplified, and the maintenance cost of the manufacturing equipment is greatly reduced. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view illustrating a configuration of a panel glass portion of a first embodiment of a cathode ray tube according to the present invention.

FIG. 2 is a process chart for explaining one embodiment of the forming method of the embodiment shown in FIG. 1;

FIG. 3 is an explanatory diagram of a moving state of a spray gun.

FIG. 4 is an explanatory diagram of a reflection characteristic of an antireflection antistatic film formed by the method described in FIG. 2;

FIG. 5 is an explanatory diagram of transmission characteristics of an antireflection antistatic film formed by the method described in FIG. 2;

FIG. 6 is a schematic partial sectional view illustrating a configuration of a panel glass portion of another embodiment of the cathode ray tube according to the present invention.

FIG. 7 is a process chart for explaining an embodiment of the forming method of another embodiment shown in FIG.

FIG. 8 is an explanatory diagram of the reflectance of the antireflection antistatic film formed by the method described in FIG. 7;

FIG. 9 is a schematic sectional view illustrating the structure of a shadow mask type color cathode ray tube as an example of a cathode ray tube to which the present invention is applied.

FIG. 10 is a schematic cross-sectional view of a portion A of FIG. 9 illustrating an example of a structure for preventing reflection of extraneous light of a cathode ray tube and viewed from a direction perpendicular to an arrangement direction of three electron beams.

FIG. 11 is an explanatory diagram of the reflectance in a conventional cathode ray tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Panel glass 4 Phosphor layer 20 Antireflection antistatic film 20a Layer on the side of panel glass of conductive ultrafine particle layer 20b Intermediate layer 20c Layer on the surface side 20A Layer of high refractive index conductive ultrafine particle 20B Low refractive index transparent Ultrafine particle layer 21 Conductive ultrafine particles.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Norikazu Uchiyama 3300 Hayano, Mobara-shi, Chiba Prefecture, Hitachi, Ltd.Display Group (72) Inventor Maki Taniguchi 3300, Hayano, Mobara-shi, Chiba Prefecture, Hitachi, Ltd. (72) Inventor Toshio Tojo 3681 Hayano Mobara-shi, Chiba F-term in Hitachi Device Engineering Co., Ltd. (reference) 5C032 AA02 DD02 DE01 DF01 DG01 DG02

Claims (5)

[Claims] A vacuum envelope is constituted by a panel glass forming a screen by coating a phosphor layer on an inner surface, a neck for accommodating an electron gun, and a funnel connecting the panel glass and the neck. An anti-reflection antistatic film composed of a high-refractive conductive ultra-fine particle layer on the outer surface of the panel glass; and a high-refractive conductive super-fine particle in the high-refractive conductive ultra-fine particle layer constituting the anti-reflective anti-static layer. A cathode ray tube wherein the porosity of the fine particles has a small value on the panel glass side and a large value on the surface side. 2. The antireflection antistatic layer is composed of a plurality of layers, and the porosity of the high refractive conductive ultrafine particles has a small value in the layer on the panel glass side and a gradually increasing value in the layer away from the panel glass. The cathode ray tube according to claim 1, wherein the cathode ray tube has: 3. A vacuum envelope comprising a panel glass forming a screen by coating a phosphor layer on an inner surface thereof, a neck accommodating an electron gun, and a funnel connecting the panel glass and the neck. An antireflection antistatic film composed of a high refractive conductive ultrafine particle layer on the outer surface of the panel glass, wherein the porosity of the high refractive conductive ultrafine particles constituting the antireflective antistatic layer is a panel glass. A cathode ray tube characterized by having a middle value on the side, a small value on the middle, and a large value on the front side. 4. The antireflection antistatic layer is composed of a plurality of layers, and the porosity of the high-refractive conductive ultrafine particles has an intermediate value in the layer on the panel glass side, a large value on the surface side, and an intermediate layer. 4. The cathode ray tube according to claim 3, wherein the cathode ray tube has a smaller value than an adjacent layer. 5. The cathode ray tube according to claim 1, wherein a transparent ultrafine particle layer having a low refractive index is formed so as to cover said antireflection antistatic layer.