JP2002343250A - Method of manufacturing cathod-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an amount of extra slurry fixed to a glass panel skirt part and an amount of a phosphor residue fixed to a black matrix, when a phosphor screen is formed on a glass panel of a cathode-ray tube. SOLUTION: A graphite film is formed, and then a water repellent agent is applied onto the graphite film, before phosphor patterns 3a, 3b, 3c for each color are formed by pouring the phosphor suspension liquid, whereby water repellent films 6a, 6b are respectively formed on an upper face of a part 2a formed on the skirt part 1a of the graphite film, and an upper face of a part forming the black matrix 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a cathode ray tube, which includes a step of forming a phosphor screen on an inner surface of a panel of the cathode ray tube.

[0002]

2. Description of the Related Art Generally, a fluorescent screen of a cathode ray tube is formed by the following method. First, a desired resist pattern is formed on the inner surface of a glass panel using a conventionally known method, and then a light-absorbing graphite is applied on the entire surface to form a graphite film. Next, etching is performed using an etching solution containing an oxidizing agent, and the resist pattern and the portion of the graphite coating film formed on the resist pattern are removed by spray development to form a black matrix.

Next, a phosphor suspension containing a photosensitive resin (hereinafter, referred to as a slurry) is injected and applied by an appropriate method onto the inner surface of the glass panel on which the black matrix is formed.
After the excess slurry is removed by shaking off, the slurry is dried to form a fluorescent film, and the excess fluorescent film attached to the inner surface of the skirt portion of the glass panel is washed and removed (hereinafter, referred to as trimming) by an appropriate method. Thereafter, the fluorescent film is cured by exposing through a color selection electrode (shadow mask) having an opening of a predetermined pattern, and the water-soluble fluorescent film in an unexposed portion is removed by spray development, whereby the phosphor of the first color is removed. The pattern is completed. Hereinafter, the same operation is repeated for the second color and the third color to obtain a pattern for three colors of green, blue and red.

FIG. 6 is a diagram schematically showing a cross section near the skirt portion of the glass panel at the stage when the black matrix is formed. FIG. 7 is a diagram in which phosphor patterns for three colors of green, blue and red are formed. It is a figure which shows typically the cross section of the vicinity of the skirt part of the glass panel at the stage which showed. In these figures, reference numeral 1 denotes a glass panel, 1a denotes a skirt portion of the glass panel 1, 2 denotes a black matrix patterned on the inner surface of the glass panel 1 into a desired shape, and 2a denotes a glass panel 1.
Graphite coating formed on skirt portion 1a of
Reference characters a, 3b, and 3c denote green, blue, and red phosphor patterns, respectively.

In the step of shaking off excess slurry,
The slurry injected into the inner surface of the glass panel 1 is spread in a film shape, and the glass panel 1 is rotated at a speed of several hundreds to several hundreds rpm in order to remove the surplus. At this time, a part of the surplus slurry adheres to the graphite film 2a of the skirt 1a. After the shaking-off process, the slurry film becomes a fluorescent film through a drying process. At that time, the excess slurry attached to the graphite film 2a of the skirt portion 1a is fixed.

After the step of drying the slurry film and before the exposure step is performed, a cleaning step of cleaning the skirt by performing trimming such as flowing hot pure water is performed.
Further, the skirt portion is also cleaned in the spray developing process after the exposure process. The excess slurry adhered to the skirt 1a is removed to some extent by such trimming and washing in the spray development process, but it is difficult to completely remove the slurry. In addition, the water-soluble fluorescent film in the unexposed portion that has not been exposed in the exposure step is removed in the spray development step, but cannot be completely removed. Therefore, conventionally, as shown in FIG. 7, the graphite film 2a of the skirt portion 1a is formed.
The excess slurry dried matter 4 remained on the upper surface of the black matrix 2 and the phosphor residue 5 which remained during cleaning by spray development remained on the upper surface of the black matrix 2.

The dried matter 4 and the phosphor residue 5 are fixed to the black matrix of the glass panel and the graphite film of the skirt portion until the high-temperature treatment step of passing through the furnace, but the glass panel is passed through the furnace. If the treatment is carried out at a high temperature, the organic components serving as a substrate for the adhesive force are decomposed and scattered. Therefore, the dried matter 4 and the phosphor residue 5 easily fall off as a powder or a lump due to the impact of the movement of the completed cathode ray tube or the impact during loading. When they fall into the cathode ray tube, they cause clogging of the color selection electrodes,
In addition, if it adheres to the vicinity of the electron gun, the withstand voltage characteristic is reduced.

Several methods have been proposed to address such problems. For example, Japanese Patent Application Laid-Open No. 57-19935 discloses that the skirt is wetted before the slurry is injected so that the slurry is uniformly spread on the skirt when the excess slurry is shaken off. I have. Japanese Patent Application Laid-Open No. 2000-228144 discloses that the slurry is not directly attached to the inner surface of the glass panel.
It is disclosed that a resist film is formed on a skirt portion before slurry injection. However, according to these methods, the ease with which the excess slurry adheres to the skirt portion is equal to or higher than that of the conventional method, and the workability of cleaning and removing is not much different from the conventional method.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to provide a cathode ray tube having good display quality.
An object of the present invention is to prevent the deterioration of the characteristics of a cathode ray tube, which is caused by the excess slurry adhered to a skirt portion or a black matrix of a panel when forming a phosphor screen.

[0010]

According to the first aspect of the present invention, a step of forming a desired resist pattern on an inner surface of a panel, a step of forming a light absorbing film on an inner surface of a panel on which a register pattern is formed, Forming a phosphor slurry film on the inner surface of the panel on which the black matrix is formed through a process of removing the resist pattern and a portion of the light absorbing film formed on the upper surface of the resist pattern; Removing the portion of the phosphor slurry film formed on the inner surface of the skirt portion of the panel, exposing a portion of the phosphor slurry film to be left as a phosphor pattern, Removing the exposed portion, in a method of manufacturing a cathode ray tube including repeating the phosphor slurry film of each color, the step of forming the light absorbing film, Forming a water-repellent film by applying a water-repellent agent to at least a portion of the light-absorbing film formed on the panel skirt portion between the step of forming the phosphor slurry film. And

According to a second aspect of the present invention, in the first aspect of the present invention, the water repellent contains fine silicon dioxide.

According to a third aspect of the present invention, in the second aspect of the present invention, the content of the fine particle silicon dioxide contained in the water repellent is from 0.01% by mass to the total amount of the water repellent. It is characterized by being in the range of 10.0% by mass.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the water-repellent film is formed on a portion formed on a panel skirt portion of the light absorbing film and on an upper surface of the black matrix. It is characterized in that it is formed on both of the formed portions.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the step of forming the water-repellent film is performed after the step of forming the light-absorbing film. In the step of removing the portion of the absorbent film formed on the upper surface of the resist pattern, the portion formed on the upper surface of the removed portion of the light-absorbing film of the formed water-repellent film is removed. It is characterized by that.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. Embodiment 1 FIG. Embodiment 1 of the present invention will be described with reference to FIGS. In FIGS. 1 and 2, FIG.
The same elements as those shown in FIG. 7 are denoted by the same reference numerals.

In the conventional fluorescent screen forming process for a cathode ray tube, a slurry (phosphor suspension) is injected after a black matrix is formed on the inner surface of the glass panel of the cathode ray tube. After the black matrix 2 is formed, the excess slurry adhered to the skirt portion 1a of the panel 1 is sufficiently removed in a subsequent cleaning step.
Before injecting the slurry, a water-repellent film 6 is formed on the upper surface of the graphite coating 2a of the skirt 1a.

Therefore, as a water repellent, a water repellent solution (composition 1) in which fine particles of silicon dioxide having a particle size of several to several tens nm are uniformly dispersed in a solvent containing methyl ethyl ketone and toluene as main components is prepared. deep. (Composition 1) Fine particle silicon dioxide 5% by mass Acrylic resin 5% by mass Ethylene glycol 5% by mass Methyl ethyl ketone 40% by mass Toluene balance

The solution of the above composition 1 is discharged from the discharge nozzle toward the skirt portion 1a while the entire inner surface of the glass panel 1 is masked except for the skirt portion 1a. Thereafter, a water-repellent film indicated by reference numeral 6 in FIG. 2 is formed on the upper surface of the graphite coating film 2a of the skirt portion 1a of the glass panel 1 by evaporation to dryness.

Since the adhesive force of the slurry to the water-repellent film is lower than the adhesive force to the graphite coating film, the formation of such a water-repellent film improves the cleaning efficiency of the cleaning step, and the skirt of the glass panel 1 Since the amount of the slurry adhered to the portion 1a is greatly reduced, it is possible to prevent the color selection electrode from being clogged and the withstand voltage characteristics from being lowered.

In the present embodiment, methyl ethyl ketone and toluene are used as the solvent, but the solvent is not particularly limited as long as the solvent can uniformly disperse the fine silicon dioxide particles. In addition, an aqueous solution can be used if dispersed by using an appropriate surfactant.In this case, in order to obtain a uniform film, the drying conditions are set and the boiling point is controlled for controlling the drying speed. It is necessary to appropriately select different additives and set the amount of additives to be added.

It is desirable to control the thickness of the water-repellent film so that the formed water-repellent film does not peel off. The film thickness can be controlled by adjusting the content of the finely divided silicon dioxide, controlling the drying speed by adding an additive having a different boiling point such as ethylene glycol shown in the above composition 1, and selecting a coating method of the solution. .

Embodiment 2 FIG. Embodiment 2 of the present invention will be described with reference to FIGS. 3 and 4, the same elements as those shown in FIGS. 6 and 7 are denoted by the same reference numerals.

In the second embodiment, a water-repellent film is formed before forming a black matrix. That is, after the graphite is applied to the inner surface of the glass panel on which the desired resist pattern is formed, a water-repellent solution is evenly applied to the upper surface of the graphite coating before the etching solution is injected to remove the resist pattern. A water film is formed and excess solution is discharged.
Next, the resist pattern, the graphite film on the resist pattern upper surface, and the water-repellent film formed thereon are removed by etching and spray development. At this time, it is important to control the thickness of the water-repellent film so as not to impair the permeability of the etching solution. The film thickness can be controlled, for example, by shaking off at an appropriate number of revolutions for uniform coating, adjusting the content of fine silicon dioxide particles, and the like.

Thus, as shown in FIG. 3, a black matrix 2 having a water-repellent film 6b formed on the upper surface is formed on the inner surface of the glass panel 1, and its skirt portion 1a is formed.
Is a graphite film 2a having a water-repellent film 6a formed on the upper surface.
Is formed. In the second embodiment, since the water-repellent film is formed not only on the graphite film 2a of the skirt portion 1a but also on the graphite constituting the black matrix 2, not only the dried slurry 4 of excess slurry remaining on the skirt portion 1a but also Also, the efficiency of the cleaning process is improved for the phosphor residue 5 on the upper surface of the black matrix, and as shown in FIG. 4, it is possible to form a phosphor screen on which the excess slurry is not fixed on either the black matrix or the skirt. . As a result, color mixing and fogging, which occur at the edges of the phosphor stripes or the phosphor dots due to the separation of the fixed slurry, are greatly suppressed.

FIG. 5 shows whether a black matrix can be formed and whether the excess slurry in the skirt portion is dried when the method of the second embodiment is performed using solutions having different compositions (compositions 2 to 10). And the amount of the phosphor residue in the black matrix portion. The amount of the phosphor residue is represented by the number of phosphor particles per unit area observed on the graphite film constituting the black matrix.

In the case of the solution of the composition 2, the etching ability is reduced due to the excessive content of the fine silicon dioxide particles, so that the black matrix is not formed normally and should be the opening of the black matrix pattern. A phenomenon was observed in which the resist pattern and the graphite film remained in portions. Also, due to the excessive thickness of the water-repellent film, portions where the graphite film was peeled off together with the water-repellent film were scattered, and therefore, the number of phosphor residues on the graphite film constituting the black matrix could be confirmed. However, it was confirmed that the excess slurry dried matter adhering to the inner surface of the skirt portion of the glass panel was significantly reduced.

Similarly, the solutions of compositions 3 to 10 were subjected to the method of Embodiment 2 to determine whether a black matrix could be formed, the amount of excess slurry dried matter, and the amount of phosphor residue. The results are as shown in FIG. The solutions of compositions 3 to 10 are obtained by diluting the solution of composition 2 with toluene.

By gradually changing the content of the fine particle silicon dioxide as in compositions 2 to 10, the content of the fine silicon dioxide can be adjusted to determine whether or not a black matrix can be formed.
The effect of the excess slurry on the amount of the dried matter and the amount of the phosphor residue could be confirmed.

That is, if the content of the fine silicon dioxide particles is too large, formation of a black matrix becomes difficult, and peeling of the water repellent film and the graphite film occurs. Conversely, if the content of the finely divided silicon dioxide is too small, the formation of the black matrix will not be a problem, but the expected effect of reducing the excess slurry and phosphor residue will not be obtained.

If the content of the fine silicon dioxide particles is less than 0.01% by mass based on the total amount of the solution as a water repellent, water repellency is hardly obtained. Since it was confirmed that the film thickness was too large and peeling occurred partially, the content of the fine particle silicon dioxide had to be set between 0.01% by mass and 10.0% by mass.

The method of the second embodiment is different from the conventional method in that a water-repellent film is formed, but the other points are not different from the conventional method. That is, in order to obtain the effect of the second embodiment, it is only necessary to add the step of forming the water-repellent film to the conventional step, and the surplus of the glass panel skirt portion can be obtained without a significant capital investment or a change in the process conditions. Not only the dried slurry, but also the phosphor residue on the upper surface of the black matrix can be reduced.

In the first and second embodiments of the method of the present invention described above, fine particles of silicon dioxide are used as a material for obtaining a water-repellent action, so that a fluororesin material having a fluorocarbon chain such as polytetrafluoroethylene is used. Unlike the case of using the electron gun, the emission characteristic of the electron gun inside the cathode ray tube does not deteriorate.

[0033]

According to the first aspect of the present invention, when a fluorescent screen is formed on a panel of a cathode ray tube, it is possible to greatly reduce the amount of excess slurry solidified on a skirt portion. Thus, it is possible to prevent clogging of the opening of the color selection electrode and deterioration of withstand voltage characteristics due to peeling of the dried matter.

According to the invention described in claim 2, according to claim 1
In the invention described in the above, since a fluororesin material having a fluorocarbon chain such as polytetrafluoroethylene is not used as a material for forming a water-repellent film for preventing the excessive slurry from adhering to the graphite film, the electron gun inside the cathode ray tube is not used. Deterioration of emission characteristics can be avoided.

According to the invention described in claim 3, according to claim 2
In the invention described in (1), a water-repellent effect can be obtained while preventing the water-repellent film from peeling off.

According to the fourth aspect of the present invention, the first aspect is provided.
In the invention described in (1), both the adhesion of the excess slurry to the upper surface of the black matrix and the adhesion to the skirt portion can be significantly suppressed.

According to the invention of claim 5, according to claim 1,
The water-repellent film can be easily formed on the upper surface of the black matrix and the upper surface of the graphite coating film on the skirt.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a cross section near a skirt portion of a glass panel of a cathode ray tube in which a water-repellent film is formed on an upper surface of a graphite coating film of a skirt portion in Embodiment 1 of the present invention.

FIG. 2 is a diagram schematically showing a cross section near a glass panel skirt of a cathode ray tube on which a phosphor screen is formed by the method according to the first embodiment of the present invention.

FIG. 3 is a diagram schematically showing a cross section near a skirt portion of a glass panel of a cathode ray tube in which a water-repellent film is formed on an upper surface of a graphite coating film on a skirt portion and an upper surface of a black matrix in a second embodiment of the present invention. It is.

FIG. 4 is a diagram schematically showing a cross section near a skirt portion of a glass panel of a cathode ray tube on which a phosphor screen is formed by the method according to the second embodiment of the present invention.

FIG. 5 is a diagram showing, for various compositions of a solution used as a water repellent in Embodiment 2 of the present invention, whether a black matrix can be formed, the amount of excess slurry dried matter, and the amount of phosphor residue. is there.

FIG. 6 is a diagram schematically showing a cross section near a skirt portion of a cathode ray tube glass panel on which a black matrix is formed.

FIG. 7 is a view schematically showing a cross section near a skirt portion of a glass panel of a cathode ray tube on which a phosphor screen composed of phosphor patterns of green, blue and red is formed.

[Explanation of symbols]

1 glass panel, 1a glass panel skirt, 2 black matrix, 2a graphite coating, 3a green phosphor pattern, 3b blue phosphor pattern, 3c red phosphor pattern, 4
Dried slurry, 5 phosphor residue, 6, 6a, 6
b Water repellent film.

Claims (5)

[Claims] A step of forming a desired resist pattern on an inner surface of the panel, a step of forming a light absorbing film on an inner surface of the panel on which the register pattern is formed, the resist pattern, and the resist pattern of the light absorbing film. Forming a phosphor slurry film on the inner surface of the panel on which the black matrix has been formed through the step of removing the portion formed on the upper surface of the panel, and the inner surface of the panel skirt portion of the formed phosphor slurry film Removing a portion formed in the phosphor slurry film, exposing a portion to be left as a phosphor pattern of the phosphor slurry film, and removing an unexposed portion of the phosphor slurry film, the phosphor of each color In a method for manufacturing a cathode ray tube including repeating a slurry film, a step of forming the light absorbing film and a step of forming the phosphor slurry film The cathode ray tube manufacturing method characterized by including the step of at least the panel portion formed skirt portion of the light-absorbing film is applied water repellent agent to form a water-repellent film. 2. The method according to claim 1, wherein the water repellent contains fine silicon dioxide. 3. The method according to claim 1, wherein the content of the fine particle silicon dioxide contained in the water repellent is in the range of 0.01% by mass to 10.0% by mass based on the total amount of the water repellent. 2
3. The method for manufacturing a cathode ray tube according to item 1. 4. The light-repellent film is formed on both a portion formed on a panel skirt portion of the light-absorbing film and a portion formed on an upper surface of the black matrix. 2. The method for manufacturing a cathode ray tube according to 1. 5. The step of forming the water-repellent film is performed after the step of forming the light-absorbing film, wherein the step of forming the resist pattern and the portion of the light-absorbing film formed on the upper surface of the resist pattern are performed. 2. The cathode ray tube according to claim 1, wherein the removing step removes a portion of the formed water-repellent film formed on an upper surface of the removed portion of the light absorbing film. Method.