JPH07114877A - Fluorescent screen forming method for color picture tube - Google Patents

Abstract

PURPOSE:To prevent color purity and breakdown voltage from deteriorating in a screen peripheral part. CONSTITUTION:A photoabsorbing layer 11, setting a part of forming a phosphor layer to a cavity part 24, is formed in the internal surface of a panel 1 having a skirt part in a peripheral part, to apply phosphor slurry 27 to the internal surface of the panel formed with this photoabsorbing layer, and the phosphor layers 10B, 10G, 10R are formed in the cavity part by a photoprinting method. After forming the photoabsorbing layer, a water repellent substance is applied to an internal surface of the skirt part before applying the phosphor slurry.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fluorescent screen of a color picture tube.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, a color picture tube has an envelope composed of a panel 1 and a funnel 2 integrally joined to the panel 1, and a fluorescent screen 3 is provided on the inner surface of the panel 1. Is formed, and a shadow mask 4 is disposed inside the phosphor screen 3 so as to face the phosphor screen 3. On the other hand, in the neck 5 of the funnel 2, an electron gun 7 that emits the three electron beams 6 is arranged. Then, the three electron beams 6 emitted from the electron gun 7 are deflected by the magnetic field generated by the deflection yoke 8 mounted on the outer side of the funnel 2, and the fluorescent screen 3 is horizontally and vertically scanned to form a color image. It is formed in a display structure.

As the phosphor screen 3, as shown in FIGS. 4 and 5, a dot-shaped three-color phosphor layer 10B, 1 having a predetermined arrangement.
0G, 10R and the three-color phosphor layers 10B, 10G, 1
Black light absorbing layer 1 provided to be embedded in the 0R gap
Black matrix type phosphor screen consisting of 1 and stripe-shaped three color phosphor layers 10B, 10G and 10R in a predetermined arrangement
And a black stripe type phosphor screen composed of a black light absorption layer 11 provided so as to be embedded in the gaps between the three color phosphor layers 10B, 10G and 10R.

Conventionally, the fluorescent screen 3 of such a color picture tube is formed as follows by a photographic printing method.

As shown in FIG. 6, first, on the inner surface of the panel,
A photosensitive agent containing polyvinyl alcohol (PVA) and ammonium dichromate (ADC) as main components is applied and dried to form a photosensitive film. Next, this photosensitive film is exposed through a shadow mask to print a pattern corresponding to the electron beam passage hole of the shadow mask. Next, the pattern-printed photosensitive film is developed to remove the unexposed portion, and a resist film having a pattern corresponding to the electron beam passage hole of the shadow mask is formed on the inner surface of the panel. Next, a light absorbing paint containing graphite or the like as a main component is applied to the inner surface of the panel having the resist film formed thereon and dried to form a light absorbing paint layer. Next, the inner surface of the panel on which the light absorbing paint layer is formed is treated with hydrogen peroxide solution to remove the resist film and the light absorbing paint layer applied on the resist film.
A light absorbing layer is formed with a space where the color phosphor layer is formed.

[0006] After that, a phosphor slurry of any one color, a phosphor containing PVA and ADC as the main components, is applied to the inner surface of the panel on which the light absorption layer is formed and dried to form a phosphor slurry layer. Next, this phosphor slurry layer is exposed through a shadow mask to print a pattern corresponding to the electron beam passage hole of the shadow mask. Next, the baked phosphor slurry layer of this pattern is developed to remove the unexposed portion, and a phosphor layer of any one color is formed in a predetermined void portion of the light absorption layer. The method for forming the phosphor layer is repeated for the three-color phosphor.

However, when the phosphor screen 3 is formed by such a method, after the exposure, when the phosphor slurry layer is developed to remove the unexposed portion, the light absorbing paint layer formed on the inner surface of the skirt portion of the panel. The unexposed phosphor slurry layer applied on top cannot be removed sufficiently and the phosphor remains.

When the color picture tube is assembled with the phosphor remaining in the skirt portion of the panel as described above, the electron beam reflected by colliding with the shadow mask during operation of the color picture tube is the residual phosphor in the skirt portion. Are excited to emit light, deteriorating the color purity of the peripheral portion of the screen. Further, in the heating process when assembling the color picture tube, the residual fluorescent substance in the skirt part falls off, and the dropped fluorescent substance adheres to the electrodes of the electron gun and the like, which causes a problem that the withstand voltage characteristic is deteriorated.

As a method of removing the residual fluorescent substance from the skirt portion of the panel, there is a method of conventionally adding water to a sponge-like roll mat and pressing the roll mat against the skirt portion of the panel to mechanically remove it. . However, in this method, when the frictional force of the roll mat is large, not only the residual phosphor but also the light absorbing paint layer on the skirt is peeled off. On the contrary, if the frictional force is small, the residual phosphor cannot be removed sufficiently.

As another method of removing the residual phosphor on the skirt portion of this panel, there is a method of increasing the spray pressure (water pressure) when developing the phosphor slurry layer. The required dot-shaped or stripe-shaped phosphor layer is easily damaged.

[0011]

As described above, in the black matrix type or black stripe type phosphor screen having the three-color phosphor layer and the light absorption layer, the light absorption layer is first formed on the inner surface of the panel, Then, the phosphor slurry is applied to the inner surface of the panel on which the light absorption layer is formed, and the phosphor slurry is exposed and developed to form the phosphor layer.

However, when the phosphor screen is formed by this method, the phosphor slurry layer applied on the light absorbing paint layer formed on the inner surface of the skirt portion of the panel cannot be sufficiently removed, and the phosphor remains, When the color picture tube is assembled as it is, the electron beam reflected by colliding with a shadow mask excites the residual phosphor in the skirt portion to emit light, thereby deteriorating the color purity in the peripheral portion of the screen. Further, in the heating process when assembling the color picture tube, the residual fluorescent substance in the skirt part falls off, and the dropped fluorescent substance adheres to the electrodes of the electron gun and the like, which causes a problem that the withstand voltage characteristic is deteriorated.

As a method of removing the residual fluorescent substance from the skirt portion of the panel, there is a method of conventionally adding water to a sponge-like roll mat and pressing the roll mat against the skirt portion of the panel to mechanically remove it. . However, in this method, when the frictional force of the roll mat is large, not only the residual phosphor but also the light absorbing paint layer on the skirt is peeled off. On the contrary, if the frictional force is small, the residual phosphor cannot be removed sufficiently. Another method is to increase the spray pressure when developing the phosphor slurry layer. In this method,
There is a problem that the dot-shaped or striped phosphor layer on the inner surface of the panel is easily damaged.

The present invention has been made in order to solve the above-mentioned problems, and prevents the phosphor from remaining on the inner surface of the skirt portion of the panel after development, and even if the phosphor remains, it absorbs light. An object of the present invention is to obtain a phosphor screen forming method that can be easily removed without damaging the paint layer.

[0015]

A light absorbing layer having a space for forming a phosphor layer is formed on an inner surface of a panel having a skirt portion on a peripheral portion, and the inner surface of the panel on which the light absorbing layer is formed is formed. In the method for forming the fluorescent screen of the color picture tube, in which the fluorescent substance slurry is applied to and the fluorescent substance layer is formed in the voids by the photo printing method. The material was applied.

[0016]

As described above, when the water-repellent substance is applied to the inner surface of the skirt after the light absorption layer is formed and before the phosphor slurry is applied,
Since the phosphor slurry is hydrophilic, it is hard to be attached to the inner surface of the skirt portion, and therefore can be removed by development so as not to remain on the inner surface of the skirt portion. Even if it remains, it can be easily removed without damaging the light absorption layer on the inner surface of the skirt portion.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows the manufacturing steps of the phosphor screen forming method as one embodiment of the present invention, and FIG. 2 shows the main steps thereof.

First, as shown in FIG. 2A, the panel 1
The inner surface of the panel is cleaned, and the PVA and ADC are applied to the inner surface of this panel 1.
A photosensitizer containing as a main component is applied and dried to form a photosensitive film 20. Next, as shown in FIG.
0 is exposed through the shadow mask 4, and a pattern corresponding to the electron beam passage hole 21 of the shadow mask 4 is printed. Next, the photosensitive film 20 having the above-mentioned pattern printed thereon is developed to remove the unexposed portion, and as shown in (c), the electron beam passage hole 21 of the shadow mask 4 is formed on the inner surface of the panel 1.
A dot-shaped or stripe-shaped resist film 22 having a pattern corresponding to is formed. Then, a light absorbing paint containing graphite or the like as a main component is applied to the inner surface of the panel 1 on which the resist film 22 is formed and dried to form a light absorbing paint layer 23 as shown in FIG. In this case, panel 1
The light absorbing paint is applied to the inner surface of the skirt portion to form a light absorbing paint layer. Next, the inner surface of the panel 1 is treated with a hydrogen peroxide solution to peel off the resist film 22 and the light absorbing paint layer 23 applied on the resist film 22, and as shown in FIG. The light absorbing layer 11 having a dot shape or a stripe shape is formed with the voids 24 in the portion forming the phosphor layer. In this case, the light absorbing paint layer applied and formed on the inner surface of the skirt portion of the panel 1 remains without being removed even if treated with hydrogen peroxide solution.

Next, a water-repellent substance is applied to the inner surface of the skirt portion of the panel 1 on which the light absorption layer 11 is formed and dried to form a water-repellent substance film. As the water-repellent substance, a substance that effectively repels a hydrophilic phosphor slurry described later is preferable, and for example, Toshiba Silicone TSW8251 made of a dimethyl silicone oil solution is effective.
As a coating method, a simple method such as roll coating with a sponge roller containing a water-repellent substance is used.

After that, on the inner surface of the panel 1 on which the light absorption layer 11 is formed, a phosphor of any one color, for example, a blue phosphor,
A phosphor slurry containing PVA and ADC as the main components is applied and dried, and as shown in FIG.
Form 7. Next, as shown in (g), the phosphor slurry layer 27 is exposed through the shadow mask 4, and a pattern corresponding to the electron beam passage hole 21 of the shadow mask 4 is printed. Next, the baked phosphor slurry layer 27 of this pattern is developed to remove the unexposed portion, and as shown in (h), a dot-shaped or stripe-shaped pattern is formed in a predetermined void portion of the light absorption layer 11. A blue phosphor layer 10G is formed. By repeating the method of forming the blue phosphor layer 10B for the green and red phosphors, as shown in (i), the three color phosphor layers 10B, 10G, 10R are formed in the predetermined gaps of the light absorption layer 11. To form.

By the way, after the light absorption layer 11 is formed as described above and before the phosphor slurry is applied, a water repellent substance is applied to the inner surface of the skirt portion of the panel 1 and dried to form a water repellent substance film. As a result, the hydrophilic phosphor slurry is less likely to adhere to the inner surface of the skirt portion, and will not remain on the inner surface of the skirt portion after the phosphor slurry layer 27 is developed. Even if it remains, the amount thereof is very small and can be easily removed so as not to damage the light absorbing paint layer on the inner surface of the skirt portion.

Therefore, by forming the phosphor screen as described above, the phosphor remains on the inner surface of the conventional skirt,
It is possible to prevent the deterioration of the color purity of the peripheral portion of the screen caused by the emission of the phosphor and the deterioration of the withstand voltage due to the fall of the phosphor.

The water-repellent substance film on the inner surface of the skirt portion is formed in the process of assembling the color picture tube after the fluorescent screen is formed.
450 when sealing (joining) the panel and funnel
Decomposes by heating at ℃, for example Toshiba Silicone TSW
In the case of 8251, it becomes a very small amount of SiO 2 and does not affect the characteristics of the color picture tube at all.

[0025]

In the method for forming a fluorescent screen of a color picture tube, when the water-repellent substance is applied to the inner surface of the skirt after the light absorption layer is formed and before the cloth for applying the phosphor slurry, the phosphor slurry is formed on the inner surface of the skirt. It is less likely to be adhered, and thus can be prevented from remaining on the inner surface of the skirt after development. Even if it remains, it can be easily removed without damaging the light absorption layer on the inner surface of the skirt, and the conventional phosphor remains on the inner surface of the skirt. It is possible to prevent the deterioration of the color purity and the deterioration of the withstand voltage due to the fall of the phosphor.

[Brief description of drawings]

FIG. 1 is a flowchart showing manufacturing steps of a method for forming a fluorescent screen of a color picture tube according to an embodiment of the present invention.

2 (a) to 2 (i) are diagrams showing the main steps thereof.

FIG. 3 is a diagram showing a configuration of a color picture tube.

FIG. 4 (a) is a plan view showing the structure of a black matrix type phosphor screen, and FIG. 4 (b) is a sectional view thereof.

5 (a) is a plan view showing the structure of a black stripe type phosphor screen, and FIG. 5 (b) is a sectional view thereof.

FIG. 6 is a flowchart showing manufacturing steps of a conventional phosphor screen forming method for a color picture tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 4 ... Shadow mask 10B, 10G, 10R ... 3-color phosphor layer 11 ... Light absorption layer 20 ... Photosensitive film 22 ... Resist film 23 ... Light absorption paint layer 24 ... Void part 27 ... Phosphor slurry layer

Claims (1)

[Claims] 1. A light-absorbing layer having a space for forming a phosphor layer as a void is formed on an inner surface of a panel having a skirt portion at a peripheral portion, and a phosphor slurry is formed on the inner surface of the panel having the light-absorbing layer formed. In the method for forming a fluorescent screen of a color picture tube, in which a phosphor layer is formed in the void by a photo printing method, the inner surface of the skirt is water repellent after the light absorption layer is formed and before the phosphor slurry is applied. A method for forming a fluorescent screen of a color picture tube, which comprises applying a substance.