JPH08329852A - Color picture tube and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Structure] The widths of the electron beams 13B, 13G, 13R which strike the filter layers 2B, 2G, 2R are made smaller than the widths of the filter layers 2B, 2G, 2R between the light absorption layers 6. [Effect] The whiteness uniformity can be improved as compared with the conventional case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube provided with a phosphor layer with a filter having, for example, a two-layer structure and a method for manufacturing the same.

[0002]

2. Description of the Related Art On the inner surface of a face plate of a cathode ray tube or a color image receiver, red, blue and green phosphor layers having a dot shape or a stripe shape are formed. When the electron beam collides with the phosphor layer, the phosphor layer emits light to display an image. A light absorption layer made of, for example, graphite fine particles is formed in the boundary region of each color phosphor layer. This light absorption layer is formed by forming a resist layer having a predetermined pattern at a position corresponding to each color on the inner surface of the panel, applying a dispersion liquid of graphite fine particles on the entire surface including the resist layer, and drying the resist layer together with the resist layer. It is generally performed by removing the graphite fine particles. To form the resist layer at the position corresponding to each color, apply the resist material to the inner surface of the panel, then install the light source at the position where the electron gun of each color is located, and expose the inner surface of the panel through the shadow mask. Then, a predetermined position of the resist material may be cured.

[0003]

By the way, when the light absorption layer is formed, the light exposure on the inner surface of the panel is performed three times by the light sources at different positions for each color. The size of dot-shaped or stripe-shaped matrix holes of the layer, that is, holes of the light absorption layer may vary. As a result, the size of the red, blue, and green pixels provided between the light absorption layers varies, the size of the light emitting region of each color phosphor due to electron beam bombardment differs, and the whiteness uniformity of the image deteriorates. The present invention has been made to address such problems, and an object thereof is to provide a color picture tube having improved whiteness uniformity and a method for manufacturing the same.

[0004]

According to the present invention, there is provided a phosphor screen comprising a plurality of laminated structures of a filter layer and a phosphor layer formed on the inner surface of a panel and a light absorption layer formed between the laminated structures. And an electron gun which is arranged so as to face the fluorescent screen and emits a plurality of electron beams, and a shadow mask which is arranged between the fluorescent screen and the electron gun and closely faces the fluorescent screen and has a plurality of electron beam passage holes. The width of the electron beam that passes through the electron beam passage hole of the shadow mask and strikes the filter layer is smaller than the width of the filter layer between the light absorption layers. The width of the electron beam can be adjusted by, for example, setting the hole diameter of the shadow mask to a predetermined value in advance.

Further, according to the present invention, there is provided a phosphor screen comprising a plurality of laminated structures of a filter layer and a phosphor layer formed on the inner surface of the panel, and a light absorption layer formed between the laminated structures, and the phosphor screen. Of a color picture tube including an electron gun which is disposed to face each other and emits a plurality of electron beams, and a shadow mask which is disposed between the fluorescent screen and the electron gun in close proximity to the fluorescent screen and has a plurality of electron beam passage holes. Regarding the manufacturing method, the manufacturing process of the phosphor screen is a step of forming a plurality of laminated structures of a filter layer and a resist layer on the inner surface of the panel, and a resist layer is applied after applying a material for forming the light absorption layer on the inner surface of the panel. The method includes a step of filling the filter layers with a light absorbing layer by peeling, and a step of forming a phosphor layer on the filter layers.

[0006]

The most important factor affecting whiteness uniformity is the difference in hole size (Hr, Hg, Hb) of the black matrix. If these differences are locally different on the screen, the white uniformity is deteriorated. Conventionally, when the black matrix is formed, each color is separately exposed.
It is difficult to form a uniform g and Hb size over the entire surface, and it is usually ± 3 μm for 100 μm.
There will be a difference in degree.

In the present invention, since the size of the light emitting region of the phosphor is determined not by the hole size of the black matrix but only by the hole diameter of the same shadow mask, there is no difference in principle between the light emitting regions of the respective colors, which is extremely good. White uniformity can be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a manufacturing process of a phosphor screen in an embodiment of the present invention. First, as a pigment dispersion liquid and a photoresist liquid for forming blue, green and red filters, those having the following compositions were prepared. <Blue pigment dispersion> Blue pigment particles: Cobalt aluminate 30% by weight (trade name: Cobalt Blue X (particle size 0.01 to 0.02 µm, manufactured by Toyo Pigment Co., Ltd.) Dispersant: ammonium salt of polyacrylic acid copolymer 0.7% by weight (manufactured by Dispec GA-40 (Allied colloids, Inc.)) dispersed in pure water each <green pigment dispersion> green pigment _{particles: TiO 2 -NiO-CoO-ZnO} 30 % by weight (trade name die Pyroxide TM-Green # 3320 (particle diameter 0.01 to 0.02 μm, manufactured by Dainichiseika) Dispersant: sodium salt of acrylic acid 0.7% by weight (Despec N-40) in pure water. distributed <red pigment dispersion> red pigment particles: Fe ₂ O ₃ fine particles 20% by weight of (particle size 0.01～0.02Myuemu) dispersant: a polyoxyethylene alkyl ether sulfate Monium salt (Hitenol 08 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)) 0.7% by weight Dispersed in pure water <Photoresist solution> Polyvinylpyrrolidone 3% by weight Bisazide crosslinking agent 0.20% by weight Surfactant 0. 01% by weight Silane-based adhesion aid 0.01% by weight Pure water Remainder Next, the panel was held at a temperature of 30 ° C. to apply the blue pigment dispersion liquid, the panel was rotated at 100 to 300 rpm,
The excess pigment dispersion was shaken off. Heater temperature 120 ℃
And dried for 3-4 minutes. Then, after coating and drying a photoresist solution, a predetermined pattern was exposed using a high pressure mercury lamp through a shadow mask, for example. Subsequently, a developing solution made of, for example, an alkaline aqueous solution is immersed in the panel for development, and then atomized water, for example, is sprayed at a liquid pressure of ² to 10 kg / cm ² .
As shown in (a), a laminated structure of a blue pigment layer 2B and a resist layer 3 was formed on the panel 1. Then, as shown in FIG. 1 (a), a green pigment layer is formed on a panel 1 made of, for example, face glass by the same process as the above except that the blue pigment dispersion is replaced with a green pigment dispersion and a red pigment dispersion. A laminated structure of 2G and resist layer 4 and a laminated structure of red pigment layer 2R and resist layer 5 were formed.

Next, when forming the light absorption layer, a solution containing the first pigment particles and a solution containing the second pigment particles are prepared.
The following composition was prepared. <Solution Containing First Pigment Particles> First pigment particles: graphite (average particle size 0.05 μm) Dispersant: ammonium salt of polyacrylic acid copolymer (Despec GA-40 (manufactured by Allied Colloid Co.)) Dispersion in pure water <Solution containing second pigment particles> Second pigment particles: Graphite (average particle diameter 1 μm) Dispersant: Ammonium salt of polyacrylic acid copolymer (Despec GA-40 (made by Allied Colloid Co., Ltd. )) Dispersion in pure water Next, a solution containing the first pigment particles is applied and dried on the panel, and subsequently, a solution containing the second pigment particles is applied and dried.
Next, by applying a resist decomposition solution containing 10% sulfamic acid and peeling off the resist layers 3, 4, and 5,
As shown in FIG. 1B, the light absorption layer 6 has a film thickness of 0.1.
A first pigment layer 6a having a thickness of 2 μm and a second pigment layer 6b having a thickness of 2 μm are formed.

Next, as shown in FIG. 1C, the blue phosphor layer 7B, the green phosphor layer 7G, and the red phosphor layer 7R are respectively subjected to a blue pigment layer 2B, a green pigment layer 2G, and a green pigment layer 2G by an ordinary method. It was formed so as to correspond to the red pigment layer 2R. Thus, the filter layer 2B formed on the inner surface of the panel 1
A phosphor screen composed of a plurality of laminated structures of 2G, 2R and phosphor layers 7B, 7G, 7R and a light absorption layer 6 formed between the laminated structures was obtained.

In this embodiment, since the light absorbing layer 6 is formed by peeling the resist layers 3, 4, and 5, the exposing step and the developing step in forming the light absorbing layer 6 which have been conventionally required. Is no longer needed. The resist layer 3 covers the blue pigment layer 2B when applying the green pigment dispersion, and the resist layers 3 and 4 cover the blue pigment layer 2B and the green pigment layer 2G when applying the red pigment dispersion. Since the resist layers 3 and 4 will be finally removed while covering with, the color mixture between blue, green and red could be prevented. Further, since the light absorption layer 6 has the first pigment layer 6a containing the first pigment particles having a very small average particle diameter, it is possible to prevent irregular reflection or internal reflection with respect to external light and to make the black matrix completely black. it can.

Next, as shown in FIG. 2, a shadow mask 11 having a plurality of electron beam passage holes is arranged inside the panel 1 on which the fluorescent screen is formed so as to closely face the fluorescent screen. The panel 1 on which 11 is mounted and the glass funnel 12 are integrally joined (sealed) to form a valve composed of the panel 1 and the funnel 12. Next, a plurality of pre-assembled electron beams 13B, 13G, 13R are provided in the neck of the integrally joined bulb.
The electron gun 14 with a stem that injects
Manufactured by venting.

FIG. 3 is a diagram for explaining the function and effect of the present invention. FIG. 3 (a) shows an electron beam on the phosphor screen on which the light absorption layer 22 and the phosphor layers 23R, 23G and 23B are formed on the panel 21. In the case of the conventional example in which 24R, 24G and 24B hit, FIG. 3B shows the case of the embodiment shown in FIG. In FIG. 3, the width M of the electron beam passage hole of the shadow mask, the width E of the electron beam impinging on the phosphor layer, and the width of the phosphor layer are shown following the cross-sectional view and the plan view of the phosphor screen in the conventional example and the example. P, the width F of the filter layer (only in FIG. 3B),
The width H between the light absorption layers, the width B of the light emitting portion, the width G of the guard band portion, and the magnitude of the contrast (black level) are sequentially shown. As can be seen from FIG. 3, in this embodiment, the width of the electron beam passage hole of the shadow mask is made smaller than in the conventional case, so that the width of the electron beam hitting the filter layer is made smaller than the width of the filter layer between the light absorption layers. There is. As a result, since the width of the electron beam is determined only by the hole diameter of the shadow mask, it is possible to obtain an extremely good white uniformity quality.

On the other hand, the contrast is deteriorated in proportion to the area ratio of the phosphor, but is deteriorated, but it can be made slight due to the effect of reducing the reflectance by using the filter. For example, in the case of a slit tube, the screen pitch Ph
In the design of = 0.6 mm, when the conventional design method is H = 0.13 mm and the phosphor reflectance is 1, the overall reflectance is 75%, but in this embodiment, H = 0.17.
If only 12% reduction in reflectance by the filter can be achieved in mm, at least equivalent black can be obtained.

In this embodiment, the light absorption layer has a two-layer structure of the first pigment layer and the second pigment layer, but the present invention is not limited to this, and for example, a single layer containing the first pigment particles and the second pigment particles. It may be a structure. Further, in this embodiment, the structure in which the light absorption layer is buried between the filter layers is provided, however, the light absorption layer may be formed before the filter layer so that the end portion of the filter layer overlaps with the light absorption layer. .

[0016]

As described above, the present invention provides a fluorescent screen including a plurality of laminated structures of a filter layer and a phosphor layer formed on the inner surface of a panel, and a light absorption layer formed between the laminated structures, and the fluorescent screen. A cathode ray tube having a plurality of electron beams which are arranged to face each other and which emits a plurality of electron beams; and a shadow mask which is arranged between the fluorescent screen and the electron gun in close proximity to the fluorescent screen and has a plurality of electron beam apertures. Since the width of the electron beam hitting the filter layer is smaller than the width of the filter layer between the light absorption layers, the whiteness uniformity can be improved as compared with the conventional case.

The present invention also relates to the method for manufacturing the above-described color picture tube, wherein the phosphor screen manufacturing process comprises a step of forming a plurality of laminated structures of a filter layer and a resist layer on the inner surface of the panel, and a light absorbing layer on the inner surface of the panel. Since the step of filling the filter layer with the light absorption layer by peeling the resist layer after applying the forming material and the step of forming the phosphor layer on the filter layer are performed, the light absorption layer is formed more easily than before. can do.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a phosphor screen forming process in the present invention.

FIG. 2 is a schematic view showing an embodiment of the present invention.

FIG. 3 is a diagram for explaining the function and effect of the present invention.

[Explanation of symbols]

 1 ... Panel 2B, 2G, 2R ... Filter layer 3, 4, 5 ... Resist layer 6 ... Light absorption layer 7B, 7G, 7R ... Phosphor layer 11 ... Shadow mask 13B, 13G, 13R. Electron beam 14 ... Electron gun

Front Page Continuation (72) Takako Kubo, Inventor Takako Kubo, 9-2, Harara-cho, Fukaya City, Saitama Prefecture Fukaya Electronics Factory, Toshiba Corporation (72) Tetsuhisa Nakao 1-9, Harara-cho, Fukaya, Saitama Prefecture Stock Company Toshiba Fukaya Electronics Factory

Claims (3)

[Claims] 1. A phosphor screen comprising a plurality of laminated structures of a filter layer and a phosphor layer formed on the inner surface of the panel, and a light absorption layer formed between the laminated structures, and a phosphor face opposed to the phosphor face. In a color picture tube comprising an electron gun for emitting a plurality of electron beams, and a shadow mask having a plurality of electron beam passage holes arranged between the phosphor screen and the electron gun in close proximity to and facing the phosphor screen, A color picture tube characterized in that a width of the electron beam passing through the electron beam passage hole and hitting the filter layer is smaller than a width of the filter layer between the light absorption layers. 2. The color picture tube according to claim 1, wherein the light absorption layer has a structure that fills the filter layers. 3. A fluorescent surface comprising a plurality of laminated structures of a filter layer and a fluorescent material layer formed on the inner surface of the panel, and a light absorption layer formed between the laminated structures, and arranged so as to face the fluorescent surface. Manufacture of a color picture tube including an electron gun for emitting a plurality of electron beams, and a shadow mask disposed between the fluorescent screen and the electron gun in close proximity to and facing the fluorescent screen and having a plurality of electron beam apertures. In the method, the step of manufacturing the phosphor screen includes a step of forming a plurality of laminated structures of the filter layer and a resist layer on the inner surface of the panel, and a resist layer after applying a material for forming the light absorption layer on the inner surface of the panel. And a step of filling the filter layer with the light absorption layer by peeling off, and a step of forming the phosphor layer on the filter layer. Build method.