JPH10199441A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube with no remaining photosensitive agent and high color purity by forming a stripe-shaped carbon layer on panel glass, depositing a white-base metal in the carbon layer by plating, forming a wall with the carbon layer and the white base metal layer, and applying a phosphor to the gap between the stripe-shaped walls. SOLUTION: A photosensitive film is formed on the inner surface of panel glass, exposure is performed with ultraviolet rays, a photosensitive agent is washed out, and resist is left. Carbon is applied to the panel glass, dried, then the resist is decomposed and peeled off together with carbon, a carbon layer 2 is left, and a carbon stripe is formed. A white base metal such as nickel is deposited on the carbon stripe by plating to form a white base metal layer 3, a mixed solution of a green phosphor and a photosensitive agent is applied to a gap between the stripe-shaped walls to form a phosphor stripe. Green, red, blue phosphor layers 5, 6, 7 are formed to constitute the phosphor stripe, and color purity and color reproducibility are enhanced.

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 more particularly, to a cathode ray tube having a feature in a phosphor screen formed on a panel glass.

[0002]

2. Description of the Related Art As a cathode ray tube, a cathode ray tube using a single electron gun, a three-beam type electron gun in which cathodes are arranged in-line, and using an aperture grill is known.

In this cathode ray tube, an electron beam emitted from an electron gun passes through an aperture grill having a plurality of slits and irradiates a fluorescent screen formed on a panel glass.
Display the image on the panel glass. The phosphor screen includes a phosphor stripe in which a phosphor is applied in a stripe shape, and a carbon stripe formed of carbon that fills a gap adjacent to the phosphor stripe.

In the case of a color cathode ray tube, the phosphor stripe is composed of red, green, and blue phosphors, and each of the phosphors emits light when irradiated with an electron beam emitted from an electron gun. The carbon stripe is for absorbing light and reducing the reflectance of ambient light to the screen, whereby the contrast ratio, which is the ratio of the highlight of the screen to the brightness of the black level, is relatively improved.

[0005] A method of manufacturing the phosphor screen will be described.

In the carbon stripe forming step, first, a photosensitive agent is uniformly applied to the inner surface of the panel glass. Next, the applied photosensitive agent is dried to form a photosensitive film. On the panel glass on which the photosensitive film is formed, an aperture grill is mounted at a predetermined position as an exposure mask, and exposure with ultraviolet light is performed. Thereafter, the aperture grill is removed, and the unexposed portion of the photosensitive agent on the inner surface of the panel glass is washed away with pure water, leaving a stripe of the exposed photosensitive agent (hereinafter referred to as a resist). Then, after the carbon is applied and dried, the carbon on the resist is removed together with the resist by a chemical that decomposes the photosensitive agent. As a result, a carbon stripe is formed on the inner surface of the panel glass in a portion where the photosensitive agent was not exposed in the exposure process.

[0007] Next, in the phosphor stripe forming step, one surface is formed on the inner surface of the panel glass on which the carbon stripe is formed.
A mixed liquid of the phosphor of the color and the photosensitive agent is applied and dried to form a mixed film. Next, an aperture grill is mounted at a predetermined position on the panel portion on which the mixed film is formed, and exposure is performed by a light source of the color of the phosphor. The panel glass is then developed. By this development, the phosphor and the photosensitizer in the unexposed portion are eluted, and a phosphor stripe of the first color is formed on the inner surface of the panel portion. These steps correspond to red, green and blue.
By being repeated several times, on the inner surface of the panel glass,
Red, green and blue phosphor stripes are formed.

Further, as shown in FIG.
A metal layer 11 is provided thereon to form a wall 12 and the wall 12
It is known that the thickness of the phosphor stripes is increased by applying a phosphor to the gaps, and the color purity indicating the accuracy of color reproducibility of a color image is improved.

In the above-mentioned carbon stripe forming step, the wall 12 is coated with carbon and dried,
It is formed by depositing a metal oxide on the surface of carbon by spraying and then removing the photosensitive agent.

[0010]

In the above-described method of applying a metal oxide by spraying to the surface of carbon, the height of the metal oxide is 10 μm due to a problem such as a particle size of the metal oxide.
Only about a wall can be formed. The phosphor stripe cannot be made higher than the height of the wall formed by the carbon stripe and the metal layer. Therefore, there are limitations on the particle size of the phosphor used for the phosphor screen and the thickness of the phosphor stripe. Further, as described above, since the metal oxide is attached to the carbon during the formation of the carbon stripe, there is a problem in that the photosensitive agent is hardly peeled off, and that the photosensitive agent is apt to remain.

Therefore, the present invention has solved the problem of the remaining of the photosensitive agent, and has improved the color purity by providing a higher wall than the conventional one by using a carbon stripe and a metal layer, and applying a phosphor to the gap between the walls. The purpose is to provide a cathode ray tube.

[0012]

In view of the above-mentioned problems, a cathode ray tube according to the present invention forms a stripe-shaped carbon layer on a panel glass at the time of manufacturing a panel surface, and then adds a white metal to the carbon layer. A wall is formed of a carbon layer and a white metal layer by plating and vapor deposition, and a phosphor is applied to a gap between the formed stripe-shaped walls.

[0013] As a result, there is no residual photosensitive agent,
Further, a cathode ray tube having high color purity is provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cathode ray tube to which the present invention is applied
A single-electron gun with three cathodes arranged inline is used. Each cathode emits an electron beam corresponding to red, green, and blue based on a color signal supplied to the electron gun. I do. The emitted electron beam passes through an aperture grill, which is a color selection mechanism having a plurality of slits, irradiates a fluorescent screen formed on the inner surface of the panel glass, and projects an image on the panel glass.

As shown in FIG. 1, the phosphor screen has a carbon layer 2 applied to a panel glass 1 in a stripe shape,
The red, green, and blue layers 3 are deposited on the carbon layer 2 and are applied to a gap between a white metal layer 3 such as nickel and a wall 4 formed by the carbon layer 2 and the white metal layer 3. Phosphors 5, 6, and 7 are provided.

The carbon layer 2 absorbs light, reduces the reflectance of the panel glass 1 with respect to ambient light, and improves the contrast ratio, which is the ratio of the luminance of the highlight to the black level, of the image projected on the screen. is there. The white metal layer 3 is formed by plating and depositing nickel on the carbon layer 2.

In the gap between the carbon layer 2 and the wall 4 formed by the white metal layer 3, red, green, and blue phosphors 5, 6, and 7 are repeatedly arranged. The red, green, and blue phosphors 5, 6, and 7 are emitted from the above-described electron gun, are irradiated with electron beams corresponding to the respective colors, which pass through the aperture grille, emit light, and emit a color image on a screen. Project.

Here, a method for manufacturing the phosphor screen will be described in detail with reference to FIG.

First, in step S1, a photosensitive agent is evenly applied to the inner surface of the panel glass 1. Next, the applied photosensitive agent is dried to form a photosensitive film.

In step S2, an aperture grill is mounted at a predetermined position as an exposure mask on the panel glass on which the photosensitive film has been formed, and exposure is performed using ultraviolet rays.
Thereafter, in step S3, the aperture grill is removed, and the unexposed portion of the inner surface of the panel glass 1 is washed away with pure water. As a result, the exposed photosensitive agent stripe (hereinafter referred to as a resist) remains.

In step S4, the panel glass 1
Then, after carbon is applied and dried, in step S5, the carbon applied on the resist is removed together with the resist using a chemical that decomposes the photosensitive agent. As a result, the inner surface of the panel glass 1 is exposed to the exposure process step S
2, the carbon layer 2 remains in the unexposed portion, and a carbon stripe is formed.

In step S6, a white metal such as nickel is plated and deposited on the carbon stripe formed by the carbon layer 2 to form a white metal layer 3.

After the stripe-shaped wall 4 is formed by the carbon layer 2 and the white metal layer 3 in this manner, in step S7, the first color, for example, a green phosphor and a photosensitive agent are formed on the inner surface of the panel glass 1. Is applied and dried to form a mixed film. Next, in step S8, an aperture grill is attached to a predetermined position on the panel glass 1 on which the mixed film is formed, and exposure is performed using a light source of the color of the phosphor. Thereafter, in step S9, the panel glass 1 is washed with pure water and developed. With this development,
The phosphor and the photosensitizer in the unexposed portion elute, and the first color phosphor stripe is completed on the inner surface of the panel glass 1.

Further, the same processes as those in steps S7 to S9 are repeated twice for the panel glass 1 for the remaining red and blue phosphors.
The phosphor stripes in which red, green, and blue phosphors 5, 6, and 7 are alternately repeated are formed on the inner surface of.

As described above, according to the method of plating and depositing a white metal after the formation of the carbon stripe, the height of the wall 4 can be increased to a height of 20 μm to 30 μm. Phosphors 5, 6,
7, the thickness of the stripe can be increased, and furthermore, the wall 4 prevents each phosphor 5, 6, 7 from wrapping around to the next color,
Color purity is improved, and a color image with high color reproducibility can be obtained.

According to the method of forming a wall by applying a metal oxide by spraying before forming a carbon stripe, only a wall of about 10 μm is formed, so that only a phosphor having a particle size of about 6 μm or less can be used. However, in the above-mentioned cathode ray tube, a phosphor having a particle size of up to about 15 μm can be used.

In the conventional method of spraying a metal oxide onto a carbon film before forming a carbon stripe,
Although there was a problem such as the remaining of the photosensitive agent, according to the above-described method, since the carbon stripe was already formed before the white metal was plated and deposited, the problem of the remaining photosensitive agent did not occur.

Further, a primal liquid is further applied to the phosphor screen completed through the above-described steps to form a primal intermediate layer, and a thin film of a metal having a high electron transmittance such as aluminum is formed on the primal intermediate layer. May be formed. The metal back improves the brightness of the phosphor screen by transmitting electrons and reflecting light. In the phosphor screen obtained by the above-described method, the height of the wall 4 and the phosphors 5, 6, and 7 can be made uniform, and as a result, the primal intermediate layer is formed flat, and a cathode ray tube with good luminance can be provided.

In the above description, the white metal to be plated and deposited is described using nickel, but a metal such as zinc may be used instead of nickel.

[0030]

In the cathode ray tube according to the present invention, after forming a striped carbon layer on the panel glass, a white metal is plated and deposited on the carbon layer, and the wall is formed by the carbon layer and the white metal layer. A phosphor screen is formed and a phosphor is applied to a gap between the formed striped walls.

Since the carbon stripes are formed before the white metal is deposited by plating, problems such as the remaining of the photosensitive agent do not occur, and a high wall is formed by the carbon layer and the white metal layer. Therefore, the thickness of each phosphor layer can be increased, the wraparound to the next color can be prevented, and a cathode ray tube with high color purity can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a fluorescent screen of a cathode ray tube to which the present invention is applied.

FIG. 2 is a diagram showing a process of manufacturing a phosphor screen.

FIG. 3 is a diagram showing a conventional phosphor screen.

[Explanation of symbols]

1 Panel glass, 2 carbon layers, 3 layers of white metal, 4 walls, 5 phosphors, 6 phosphors, 7 phosphors

Claims (7)

[Claims] 1. A carbon layer applied to a panel glass in a stripe pattern, a white metal layer plated and deposited on the carbon layer, and a carbon layer and the white metal layer. A cathode ray tube comprising: a phosphor stripe applied to a gap between walls. 2. The cathode ray tube according to claim 1, wherein the phosphor stripes are stripes in which red, green, and blue phosphors are alternately arranged. 3. The cathode ray tube according to claim 1, wherein the white metal layer is a nickel layer. 4. The cathode ray tube according to claim 1, wherein the white metal layer is a zinc layer. 5. A method of manufacturing a phosphor screen formed on a panel glass of a cathode ray tube, comprising: forming a striped carbon layer on the panel glass; and depositing and depositing a white metal on the carbon layer. A phosphor screen, comprising: a step of forming a white metal layer; and a step of applying a phosphor to a gap between stripe-shaped walls formed by the carbon layer and the white metal layer. Manufacturing method. 6. The method according to claim 4, wherein the white metal layer is a nickel layer. 7. The method according to claim 4, wherein the white metal layer is a zinc layer.