JPH11354054A - Cathode-ray tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep black display the performance of a cathode-ray tube, and at the same time, increase brightness and contrast. SOLUTION: A meniscus layer 3 having continuous fine uneven part is formed on a smooth surface treatment film 2 formed on the outer surface of a face panel 1. The meniscus layer 3 consists of a flat binder layer 3a and a projecting part 3b, the projecting part 3b gives directivity in the face surface normal line direction to transmitted light 4 from the inside of a cathode-ray tube by the difference between refraction indexes and the angle of an inclined part, and effectively increase orientation distribution in the face surface normal line direction. The cathode-ray tube having the meniscus layer 3 increases the luminance in a face surface normal line direction. By making the panel 1 and the transmission factor of the surface treatment film 2 the same as those of the conventional cathode-ray tubes, contrast performance is enhanced without increasing external light reflected intensity without causing decrease in the black display performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 6 is a schematic diagram showing the structure of a conventional cathode ray tube. In the figure, 1 is a face panel, 11 is an envelope, 12 is a fluorescent screen provided on the inner surface of the face panel 1, and 13 is a built-in electron gun (not shown) for irradiating an electron beam for exciting and emitting the fluorescent screen 12. A deflection yoke 14 for electromagnetically deflecting the electron beam from the outside;
5 is a color selection electrode. The brightness and contrast performance of a cathode ray tube provided with a surface treatment film (not shown) on the outer surface of the face panel 1 are determined when the characteristics of the phosphor screen 12 formed on the inner surface of the face panel 1 are constant. It is greatly affected by the transmittance of the surface treatment film, the wavelength dependence of the transmittance, the intensity ratio of the reflected light to the incident light from the outer surface of the face panel 1 (hereinafter, referred to as external light reflectance), and the wavelength dependence of the reflected light. .

[0003]

Conventionally, as a method of improving the contrast of a cathode ray tube by the effect of a surface treatment film, a low reflection film is formed on the outer surface of the face panel 1 or on the surface treatment film to suppress the external light reflectance. There was a way. According to this method, the contrast can be improved by reducing the external light reflectance, but it does not contribute to the luminance. The contrast is defined as a ratio of the luminance of light emitted from the inside of the cathode ray tube to the reflection intensity of external light.

On the other hand, as a method of improving the brightness of the cathode ray tube by the function of the surface treatment film, a glass material having a relatively high light transmittance is used for the face panel 1, and a wavelength selective absorption surface treatment film is provided on the outer surface thereof. There was a way to provide.
With this method, the luminance can be improved, but the external light reflectance increases and the contrast performance decreases. In addition, the black display performance also decreases. in this case,
By enhancing the wavelength selectivity of the surface treatment film, it is possible to reduce the external light reflectance and maintain the contrast performance, but at the same time, the surface of the cathode ray tube is specified by the transmittance spectrum of the surface treatment film. , Which also reduces the black display performance. As described above, in the cathode ray tube including the conventional surface treatment film, there is a problem that when any one of the luminance, the contrast, and the black display performance is improved, the other performance is reduced. .

The present invention has been made to solve the above problems, and has as its object to improve brightness and contrast while maintaining the black display performance of a cathode ray tube.

[0006]

A cathode ray tube according to the present invention comprises a fluorescent screen provided on the inner surface of a face panel, an electron gun for irradiating an electron beam for exciting and illuminating the fluorescent screen, and an electromagnetic gun for emitting the electron beam from the outside. A cathode ray tube provided with a deflection yoke that deflects a light beam, wherein a meniscus layer having continuous fine irregularities is provided on the outer surface of the face panel.
Further, a smooth surface treatment film is provided between the face panel and the meniscus layer.

Further, according to the method of manufacturing a cathode ray tube according to the present invention, polymer beads are dispersed in water or an organic solvent such as alcohol on a face panel outer surface or a smooth surface treatment film provided on the face panel outer surface. The method includes a step of applying the obtained suspension by a spin coating method or a spraying method, and a step of drying a coating film, so that a meniscus layer having continuous fine irregularities is formed on the outermost surface of the face panel. is there. Further, a suspension in which glass beads are dispersed in an alcohol / water mixed solution containing an alkyl silicate on a face panel outer surface or a smooth surface treatment film provided on the face panel outer surface is formed by spin coating or spraying. The method includes a step of applying and a step of baking the applied film, so that a meniscus layer having continuous fine irregularities is formed on the outermost surface of the face panel. Further, a polymer bead or a glass bead having a bead diameter of 1 to 20 μm is used.

The method further includes a step of applying an alcohol / water solution containing water glass to the outer surface of the face panel or a smooth surface treatment film provided on the outer surface of the face panel by a spray method, and a step of firing the applied film. A meniscus layer having continuous fine irregularities is formed on the outermost surface of the panel. Further, the method includes a step of applying an organic polymer solution by a spray method on the outer surface of the face panel or a smooth surface treatment film provided on the outer surface of the face panel, and a step of drying the coating film. This is to form a meniscus layer having various irregularities.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Since the main configuration of the cathode ray tube in the present embodiment is the same as that of the conventional cathode ray tube, the description will be made with reference to FIG. In the figure, 1 is a face panel, 11 is an envelope, 12 is a fluorescent screen provided on the inner surface of the face panel 1, and 13 is a built-in electron gun (not shown) for irradiating an electron beam for exciting and emitting the fluorescent screen 12. Reference numeral 14 denotes a deflection yoke for electromagnetically deflecting the electron beam from outside, and 15 denotes a color selection electrode. FIG.
Is a face panel 1 of the cathode ray tube in the present embodiment.
It is a partial expanded sectional view which shows a part. In the figure, reference numeral 2 denotes a surface treatment film formed of several layers of smooth films provided on the outer surface of the face panel 1, and 3 denotes a meniscus layer provided on the surface treatment film 2 and having continuous fine irregularities. Has a function as an uneven lens. Although the surface treatment film 2 is provided between the face panel 1 and the meniscus layer 3 in the present embodiment, the meniscus layer 3 may be provided directly on the outer surface of the face panel 1.

The operation of the meniscus layer 3 according to the present embodiment will be described with reference to FIG. The meniscus layer 3 is formed on the surface treatment film 2 formed on the outer surface of the face panel 1,
The structure comprises a flat binder layer 3a and a projection 3b. The projection 3b is formed by the difference in refractive index and the angle of the inclined portion with respect to the transmitted light 4 from the inner surface of the face panel 1,
It has the effect of giving directivity to the face surface normal direction and increasing the orientation distribution in the face surface normal direction. In FIG. 2, 4a
Indicates a path of transmitted light in the conventional cathode ray tube, and 4b indicates a path of transmitted light in the cathode ray tube on which the meniscus layer 3 according to the present embodiment is formed. For this reason, in the cathode ray tube according to the present embodiment, the brightness in the normal direction of the face surface, that is, the brightness from the viewpoint of the observer located in front of the cathode ray tube is improved.

FIG. 3 is a diagram for explaining the effect of the meniscus layer 3 according to the present embodiment on the orientation distribution of the transmitted light from the inner surface of the face panel 1, and 6 indicates the outermost surface of the cathode ray tube. Conventionally, the transmitted light from the inner surface of the face panel 1 radiated from the outermost surface 6 of the cathode ray tube has an orientation distribution as shown by 7a in FIG. 3, but the cathode ray tube on which the meniscus layer 3 according to the present embodiment is formed. In this case, since the orientation distribution in the normal direction of the face surface is increased, the transmitted light has the orientation distribution shown by 7b in FIG. For this reason, from the viewpoint of an observer located in the normal direction of the face surface, an effect of improving luminance can be obtained. In this case, by making the transmittance of the face panel 1 the same as that of the related art, it is possible to improve the luminance without increasing the external light reflection intensity, and therefore, without lowering the black display performance. Further, the contrast performance, which is a ratio of the luminance of light emitted from the inside of the cathode ray tube to the reflection intensity of external light, is improved.

As described above, according to the present embodiment, the meniscus layer 3 having continuous fine irregularities is provided on the surface treatment film 2 on the outer surface of the face panel 1 of the cathode ray tube. Directivity is given to the transmitted light from the inner surface, the orientation distribution of the transmitted light in the normal direction of the face surface is increased, and the luminance and the luminance in the normal direction of the face surface are reduced without lowering the black display performance and the external light reflectance performance. It is possible to improve the contrast.

[0013]

[Embodiment 1] Hereinafter, a method for forming a meniscus layer of a cathode ray tube which is Embodiment 1 of the present invention will be described. First, a suspension is prepared by dispersing polymer beads serving as nuclei for forming a meniscus layer in an organic solvent such as water or alcohol. In the present example, in an aqueous solution containing polyvinyl alcohol (hereinafter referred to as PVA) shown in Composition 1 of Table 1 as a binder, acrylic resin beads having a particle diameter of 1 to 20 μm have a weight ratio of beads to water of 1: 1. Disperse evenly so that

(Table 1) Composition 1 PVA 3% by weight Ammonium polycarboxylate 1% by weight Pure water balance

Next, the above-mentioned bead suspension is uniformly applied to the outer surface of the face panel or the surface treatment film provided on the outer surface of the face panel by a known spin coating method. At this time, it is important to control the film thickness by the number of rotations so that the beads form one or two layers. Thereafter, the coating film is evaporated to dryness by heating and drying. In this embodiment, the acrylic resin is used for the beads. However, the same effect can be expected as long as the beads are highly transparent polymer. For example, a styrene resin may be used. As the binder, a water-soluble emulsion or the like can be used in addition to a water-soluble polymer such as PVA.

FIG. 4 is a schematic diagram showing the structure of the meniscus layer formed in this embodiment. Meniscus layer 3
Is composed of a binder layer 3a, a projection 3b made of core beads 5, and a slope 3c formed by the surface tension of the binder. As described above, in the meniscus layer 3 having the beads 5 as nuclei, the shape and size of the protrusions 3b can be controlled by the shape and particle diameter of the beads 5, and the shape of the slope 3c can be controlled by the surface tension and viscosity of the solvent. Also,
When a conventionally used spin coater is diverted, only the composition of the suspension needs to be changed, so that no significant additional equipment is required, and an increase in manufacturing cost is suppressed.

Embodiment 2 FIG. Hereinafter, a method for forming a meniscus layer of a cathode ray tube which is Embodiment 2 of the present invention will be described.
First, a suspension is prepared by dispersing glass beads serving as nuclei for forming a meniscus layer in an alcohol / water mixed solution containing an alkyl silicate. In this embodiment,
An alcohol / water mixed solution containing water glass shown in Composition 2 of Table 2 was prepared, and glass beads having a particle diameter of 1 to 20 μm were uniformly dispersed in the solution so that the weight ratio of beads to water was 1: 1. Let it.

(Table 2) Composition 2 Silica solid content 3% by weight Ethanol 80% by weight Silicon oil 1% by weight Hydrochloric acid Trace amount Pure water Remainder

Next, the above-mentioned bead suspension is uniformly applied to the outer surface of the face panel or a surface treatment film provided on the outer surface of the face panel by a known spin coating method.
At this time, it is important to control the film thickness by the number of rotations so that the beads form one or two layers. Thereafter, the coating film is evaporated to dryness by heating and drying, and then baked at 150 ° C. or higher.

In this embodiment, the composition 2 was used as an example of the suspension necessary for forming the meniscus layer. However, when determining the composition of the suspension, the dispersion state of the beads and the surface tension of the solution were determined. By controlling the drying speed, etc.
It is important to determine the conditions under which a meniscus layer as shown in FIG. 4 can be formed. A surfactant such as polycarboxylic acid can be used to control the surface tension, and an additive having a different boiling point such as 2-propyl alcohol or ethylene glycol can be used to control the drying rate.

Embodiment 3 FIG. Hereinafter, a method for forming a meniscus layer of a cathode ray tube which is Embodiment 3 of the present invention will be described.
First, a suspension is prepared by dispersing polymer beads serving as nuclei for forming a meniscus layer in an organic solvent such as water or alcohol. In this example, acrylic resin beads having a particle size of 1 to 20 μm are uniformly dispersed in an aqueous solution containing PVA shown in Composition 1 of Table 1 as a binder such that the weight ratio of beads to water is 1: 1. .

Next, the above-mentioned bead suspension is sprayed on the outer surface of the face panel or on a surface treatment film provided on the outer surface of the face panel by a known spray method to have a nozzle diameter of 1 to 25 μm.
m using a discharge nozzle of m. Thereafter, the coating film is evaporated to dryness by heating and drying. In this example, the suspension of the composition 1 was used. However, the suspension is not particularly limited as long as the composition satisfies the above-described conditions for forming the meniscus layer. In addition, when a conventionally used spray machine is used, only the composition of the suspension needs to be changed, so that no significant additional equipment is required, and an increase in production cost is suppressed.

Embodiment 4 FIG. Hereinafter, a method for forming a meniscus layer of a cathode ray tube which is Embodiment 4 of the present invention will be described.
First, a suspension is prepared by dispersing glass beads serving as nuclei for forming a meniscus layer in an alcohol / water mixed solution containing an alkyl silicate. In this embodiment,
An alcohol / water mixed solution containing water glass shown in Composition 2 of Table 2 was prepared, and glass beads having a particle diameter of 1 to 20 μm were uniformly dispersed in the solution so that the weight ratio of beads to water was 1: 1. Let it.

Next, the above-mentioned bead suspension is sprayed on the outer surface of the face panel or on a surface treatment film provided on the outer surface of the face panel by a known spray method to form a nozzle having a diameter of 1 to 25 μm.
m using a discharge nozzle of m. Thereafter, the coating film is evaporated to dryness by heating and drying, and then baked at 150 ° C. or higher. In this example, the suspension of the composition 2 was used. However, the composition is not particularly limited as long as the composition satisfies the above-described conditions for forming the meniscus layer.

Embodiment 5 FIG. Hereinafter, a method for forming a meniscus layer of a cathode ray tube which is Embodiment 5 of the present invention will be described.
First, alcohol containing water glass shown in composition 3 of Table 3
Prepare the water mixture.

Table 3 (Composition 3) Silica solid content 5% by weight Ethanol 80% by weight Ethylene glycol 5% by weight 2-propyl alcohol 10% by weight Hydrochloric acid Trace amount Pure water Remainder

Next, the above-mentioned mixed solution is applied to the outer surface of the face panel or a surface treatment film provided on the outer surface of the face panel by a known spray method using a discharge nozzle having a nozzle diameter of 0.5 to 1 μm. Thereafter, the coating film is evaporated to dryness by heating and drying, and then baked at 150 ° C. or higher.

In this embodiment, the droplets ejected from the nozzle collide with the face surface, so that each droplet becomes the meniscus layer 3 as shown in FIG. For the formation of such a meniscus layer 3, the viscosity of the mixed liquid and the drying speed are very important. Control of the shape and size of the meniscus layer 3 includes the content or viscosity of silica solids and the drying rate,
It can be performed continuously depending on the manufacturing process conditions such as the nozzle diameter. In this example, the mixed liquid of composition 3 was used. However, when the meniscus layer 3 was formed with another composition, the viscosity was controlled by changing the silica solid content or PV.
Addition of a high viscosity polymer such as A is conceivable.

Embodiment 6 FIG. Hereinafter, a method for forming a meniscus layer of a cathode ray tube which is Embodiment 6 of the present invention will be described.
First, an organic polymer solution shown in Composition 4 of Table 4 was prepared.

Table 4 (Composition 4) 8% by weight of PVA 80% by weight of ethanol 5% by weight of ethylene glycol 10% by weight of 2-propyl alcohol Ammonium polycarboxylate Trace amount of pure water Remainder

Next, the above-mentioned mixed solution is applied to the outer surface of the face panel or the surface treatment film provided on the outer surface of the face panel by a known spray method using a discharge nozzle having a nozzle diameter of 0.5 to 1 μm. Thereafter, the coating film is evaporated to dryness by heating and drying. Also in this embodiment, a meniscus layer as shown in FIG. 5 is formed. Meniscus layer 3
The shape and size of can be controlled continuously depending on the production process conditions such as the polymer content or viscosity, the drying speed, and the nozzle diameter. In this example, the mixed solution of the composition 4 was used. However, when the meniscus layer 3 is formed with another composition, the viscosity can be controlled by changing the PVA concentration or adding another high-viscosity polymer. is there. The drying rate can be controlled by changing the alcohol concentration or by adding an additive having a different boiling point, such as 2-propyl alcohol or ethylene glycol.

Table 5 shows the luminance improvement ratio and the contrast improvement ratio of the cathode ray tube in which the meniscus layer 3 was formed in Examples 1 to 6. The luminance was measured in the normal direction of the face surface of the cathode ray tube. The cathode ray tube provided with the meniscus layer 3 formed in Examples 1 to 6 of the present invention has improved luminance in the normal direction of the face surface. The effect was remarkable.

Table 5 Brightness and Contrast Improvement Rate Example 1 Approx. 17% Example 2 Approx. 18% Example 3 Approx. 16% Example 4 Approx. 15% Example 5 Approx. 12% Example 6 Approx. 13%

[0034]

As described above, according to the present invention, by providing a meniscus layer having continuous fine irregularities on the outer surface of the face panel, directivity is imparted to the transmitted light from the inner surface of the face panel, and the face surface is provided. Since the orientation distribution of transmitted light in the normal direction can be increased, it is possible to improve the luminance in the normal direction of the face surface without lowering the black display performance and the contrast performance.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view showing a face panel portion of a cathode ray tube according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation of a meniscus layer formed on the surface of the cathode ray tube according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing the effect of the meniscus layer on the orientation distribution of light transmitted from the inner surface of the face panel of the cathode ray tube according to the first embodiment of the present invention.

FIG. 4 is a schematic view showing a meniscus layer formed in Examples 1 to 4 of the present invention.

FIG. 5 is a schematic view showing a meniscus layer formed in Example 5 and Example 6 of the present invention.

FIG. 6 is a schematic view showing a structure of a conventional cathode ray tube of the present invention.

[Explanation of symbols]

Reference Signs List 1 face panel, 2 surface treatment film, 3 meniscus layer, 3a binder layer, 3b protrusion, 3c slope, 4 transmitted light from inside face panel, 4a path of transmitted light of conventional cathode ray tube, 4b meniscus layer formed Path of the transmitted light of the cathode ray tube, 5 beads, 6 outermost surface of the cathode ray tube, 7a orientation distribution of the transmitted light of the conventional cathode ray tube, 7b orientation distribution of the transmitted light of the cathode ray tube provided with the meniscus layer, 11 , 12 phosphor screen, 13 neck, 14 deflection yoke, 15 color selection electrode

Claims (7)

[Claims] 1. A cathode ray tube having a fluorescent screen provided on an inner surface of a face panel, an electron gun for irradiating an electron beam for exciting and emitting the fluorescent screen, and a deflection yoke for electromagnetically deflecting the electron beam from outside. A cathode ray tube, wherein a meniscus layer having continuous fine irregularities is provided on the outer surface of the face panel. 2. The method according to claim 1, wherein the face panel and the meniscus layer are
2. The cathode ray tube according to claim 1, wherein a smooth surface treatment film is provided. 3. A suspension obtained by dispersing polymer beads in an organic solvent such as water or alcohol on a face panel outer surface or on a smooth surface treatment film provided on the face panel outer surface, by spin coating or A step of applying by a spray method, including a step of drying the coating film,
A method for manufacturing a cathode ray tube, comprising: forming a meniscus layer having continuous fine irregularities on the outermost surface of the face panel. 4. A spin-coating method comprising the steps of spin-coating a suspension in which glass beads are dispersed in an alcohol / water mixed solution containing an alkyl silicate on the outer surface of a face panel or on a smooth surface treatment film provided on the outer surface of the face panel. Alternatively, a method for producing a cathode ray tube, comprising a step of applying by a spray method and a step of baking the coating film, wherein a meniscus layer having continuous fine irregularities is formed on the outermost surface of the face panel. 5. The method for producing a cathode ray tube according to claim 3, wherein the polymer beads or glass beads having a bead diameter of 1 to 20 μm are used. 6. A step of applying an alcohol / aqueous solution containing water glass to the outer surface of the face panel or a smooth surface treatment film provided on the outer surface of the face panel by a spray method, and a step of firing the applied film. Forming a meniscus layer having continuous fine irregularities on the outermost surface of the face panel. 7. The face panel including a step of applying an organic polymer solution by a spray method on an outer surface of the face panel or a smooth surface treatment film provided on the outer surface of the face panel, and a step of drying the applied film. A method for manufacturing a cathode ray tube, comprising: forming a meniscus layer having continuous fine irregularities on the outermost surface.