JPH10312746A - Fluorescent screen forming method for color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the reduction of white luminance caused by the pigment residue of a green filter layer at a practically nonproblematical level by forming the pattern of a black matrix left with resist at the formation position of the filter layer on the inner face of a panel, forming the pattern of a green filter layer with a green pigment, then forming the pattern of a blue or red filter layers. SOLUTION: The light absorbing layer 12 of the pattern of a black matrix is formed with photo-resist and graphite, and a residual hardened resist layer 13 is left at the expected pigment formation position. A green pigment coat layer 20G of the first color is formed on it, a green pigment layer is obtained, and a blue pigment layer 30B and a red pigment layer are formed on a residual green pigment layer 22G having a slight thickness on the residual hardened resist layer 13 of the other portion. The difference between the peak transmission factor and the transmission factor at other wavelength areas and the pigment concentration of the green filter layer are lower than those of the red or blue filter layer, and the adverse effect on the luminescence of blue and red phosphors by the residue of the green pigment is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a fluorescent screen with a filter of a color cathode ray tube.

[0002]

2. Description of the Related Art Conventionally, in a color cathode ray tube, a filter layer corresponding to the emission color of a phosphor is provided between the front surface of the phosphor layer, that is, the inner surface of the face plate of the panel and the phosphor layer. It is known to be a body layer.

A phosphor layer of red, blue, green dots or stripes is formed on the inner surface of the face plate of a general color cathode ray tube, and an electron beam collides with the phosphor layer to emit a fluorescent light. The body layer emits light to display an image. By providing a filter layer between the face plate and the phosphor layer that transmits light of the same color as the emission color of the phosphor layer, the green and blue components of the incident external light can be converted to green by the red pigment layer. The blue and red component light are absorbed by the blue pigment layer, and the blue and red component light are absorbed by the green pigment layer to improve contrast and color purity.

In such a filter layer, a pattern of a first color filter layer is formed on the inner surface of a face plate on which a black matrix pattern is formed by a photolithography technique, and this is repeated for three colors of red, blue and green. Formed by

[0005]

However, there is a case where the photocured resist remains on the hole portion in the black matrix pattern formed on the inner surface of the face plate, that is, the surface of the filter layer forming position, without being sufficiently peeled. Such a phenomenon appears more remarkably when a water-soluble photosensitive solution containing an azide-based photosensitive agent or a silane coupling agent is used. The first color filter layer is formed by applying the pigment dispersion also on the surface of the remaining photocurable resist layer.

However, after the formation of the pattern of the first color filter layer, the position of the other color pigment layer formation was investigated, and the first color pigment was not completely removed on the surface of the remaining resist. It was confirmed that there was a part. As described above, the residue of the pigment of the first color causes a reduction in the luminance of the emission colors of the other two phosphors, and in some cases, there is a problem in that the white luminance is reduced to a level that does not satisfy practical use.

[0007] The generation of residue due to the adhesion of the first color pigment to the remaining resist surface can be prevented by coating the entire inner surface of the panel including the remaining resist surface with an inorganic material such as colloidal silica. In this case, there is an adverse effect that the manufacturing cost increases because a new process is added.

The present invention has been made in order to solve such a problem, and a fluorescent light of a color cathode ray tube capable of suppressing a decrease in luminance due to a residue of a pigment in a first color filter layer to a practically problematic level. It is intended to provide a surface forming method.

[0009]

In order to achieve the above object, a method for forming a fluorescent screen of a color cathode ray tube according to the present invention comprises applying a resist to the inner surface of a panel, exposing the resist to light, and developing the resist. After forming a pattern of the remaining black matrix, a green pigment is applied to the inner surface of the panel to form a pattern of a green filter layer, and then a pattern of a blue or red filter layer is formed. is there.

FIG. 1 shows, from the top, the spectral transmittance of practical pigments for forming blue, green, and red filters. The line A indicates the relationship between the wavelength and the transmittance of each color pigment, and the line B indicates
The line is the characteristic curve of the phosphor of each color. Here, the difference between the peak transmittance of the green pigment and the transmittance at the emission peak wavelengths of the blue and red phosphors (around 450 nm and 630 nm) is the peak transmittance of the blue pigment and the emission peak of the green and red phosphors. The difference between the transmittance at the wavelength (around 550 nm and 630 nm), the peak transmittance of the red pigment and the emission peak wavelength of the blue / green phosphor (around 450 nm, 550 n)
m (near m).

Therefore, the present invention first forms a green color filter layer having the smallest difference between the peak transmittance and the transmittance in the other wavelength region among the three color filter layers, and subsequently forms a blue or red color filter layer. By forming the filter layer, even if a residue of the green pigment is present at the position where the blue / red pigment layer is formed, the degree of the adverse effect on the emission of the blue and red phosphors due to the residue of the green pigment. Can be minimized, and a decrease in white luminance can be suppressed to a practically acceptable level. Further, the concentration of the green pigment is lower than that of the blue and red pigments, and from this point, the adverse effect on the emission of the light emitter of another color due to the residue of the green pigment can be minimized. Furthermore, since the surface of the remaining resist is covered with the green pigment, the second color pigment does not remain at the third color pigment formation position. Here, to explain the reason why the concentration of the green pigment is relatively low, the spectral transmittance of the green pigment is close to a so-called luminosity curve. Therefore, if the pigment concentration is too high, the white luminance is significantly reduced. For this reason, the density of the green pigment is selected to be a relatively low value that can correct the body color while minimizing the decrease in white luminance. On the other hand, since the density of the blue pigment has the least effect on white luminance, it is set as high as possible to obtain the maximum contrast effect. Further, the concentration of the red pigment is set to a high value so that the body color does not have a reddish color.

When the body color of the fluorescent screen of the color cathode ray tube is measured by using a Minolta spectral reflectometer CM-2002, a in the CIE1976L * a * b * display system chromaticity diagram
The preferred value ranges of * and b * are as follows.

-1.5> a *>-2.5 -0.2> b *>-1.2 However, this measurement result is based on the observation result of the fluorescent screen by 20 observers. is there.

Table 1 below shows that the green pigment liquid satisfying the above-mentioned conditions a * and b * for each of the phosphor screen on which the green pigment layer is formed first and the phosphor screen on which the blue pigment layer is formed first. The concentration and the blue pigment liquid concentration are shown.

[0015]

[Table 1] As shown in this table, the green pigment liquid concentration of the phosphor screen on which the green pigment layer is formed first may be lower than the green pigment liquid concentration of the phosphor screen on which the blue pigment layer is formed first. The concentration of the blue pigment liquid on the phosphor screen on which the green pigment layer is formed first is higher than the concentration of the blue pigment liquid on the phosphor screen on which the blue pigment layer is formed first. The effect of the phosphor screen on the white luminance is slight, and does not cause a practical problem.

Therefore, according to the method of the present invention, by forming the green pigment layer first, the green pigment liquid concentration can be set low by the green pigment remaining at the position where the filter layer of another color is formed. , White luminance can be improved.

The concentration of the green pigment particles in the green optical filter layer is in the range of 4.0 to 11.0% by weight, preferably in the range of 5.1 to 11.0% by weight.
The reason for this is that when the concentration of green pigment particles is less than 4.0% by weight (preferably when less than 5.1% by weight)
Is because the green component disappears and the body color becomes magenta. On the other hand, when the concentration of the green pigment particles is more than 11.0% by weight, the luminance is significantly reduced due to green and the white luminance is also reduced. It is because.

Table 2 below shows a comparison of the luminance of a single green color, the luminance of a single red color, and the luminance of a white color between the case where the blue pigment layer is formed first and the case where the green pigment layer is formed first.

[Table 2] From this table, the green monochromatic luminance, red monochromatic luminance, and white luminance when the green pigment layer was first formed and formed were all higher than when the blue pigment layer was formed first, and the first color filter layer was formed. It can be seen that the decrease in luminance due to the residue of the pigment can be significantly suppressed.

The pigment used in the present invention may be either inorganic or organic. In particular, the pigment can be uniformly dispersed in the filter layer of the phosphor layer provided with a filter and causes light scattering. Pigments capable of imparting sufficient transparency to the filter layer are preferred. In addition, since a high-temperature treatment is involved in the manufacturing process of the color cathode ray tube, an inorganic material is more preferable. Specifically, the following pigments can be exemplified.

As a red pigment, ferric oxide-based product name Sicotrans Red 1-2817 (particle size 0.01 μm)
m-0.02 μm, manufactured by ASF) and Chromopha Tar Red A2B (trade name: Anthraquinone, particle size: 0.01 μm, manufactured by Ciba Geigy). As the blue pigment, cobalt aluminate (Al ₂ O ₃ —C
oO) -based trade name Cobalt Blue X (particle size 0.0
1 μm to 0.02 μm, manufactured by Toyo Pigment Co., Ltd.) 8000 (particle size 0.03 μm, manufactured by Daiichi Kasei Co., Ltd.), and phthalocyanine blue-based product name Lionol Blue FG-7370 (particle size 0.01 μm, manufactured by Toyo Ink Co., Ltd.). As the green pigment, TiO ₂ —NiO—ZnO-based product name Dilopoxide TM-Green # 3320 (particle size 0.01
μm to 0.02 μm, manufactured by Dainichi Seika Co., Ltd.), CoO—Al ₂
O ₃ is a -Cr ₂ O ₃ system product name die Piroki side TM
-Green # 3420 (particle size 0.01 μm to 0.02
μm, Dainichi Seika Co., Ltd.), trade name of a Cr ₂ O ₃ system D-
801 (particle size 0.35 μm, manufactured by Nippon Denko), chlorinated phthalocyanine green-based product name First Gen Green S (particle size 0.01 μm, manufactured by Dainippon Ink Co., Ltd.), and brominated phthalocyanine green-based product name Fast Gen Green 2YK (particle size: 0.01 μm, manufactured by Dainippon Ink and Chemicals) can be exemplified.

Further, as a method for forming the filter layer,
For example, the following method can be mentioned. First, a pigment dispersion mainly containing pigment particles and a polymer electrolyte pigment dispersant is applied to the inner surface of a face plate having a black matrix. The application method may be appropriately selected in consideration of the shape and size of the face plate, and a spin coating method, a roller method, an immersion method, or the like can be used. In particular, spin coating is desirable as a method for obtaining a uniform and predetermined film thickness. Next, the pigment coating layer is dried. As a drying method in this case, while evaporating water,
As long as a part of the salt in the polymer electrolyte salt can be dissociated, various methods can be adopted without particular limitation.
For example, drying by a heater, drying by hot air, or drying for a long time at room temperature can be performed. Thereafter, a photoresist layer is formed on the pigment layer, exposed to a predetermined pattern using a high-pressure mercury lamp or the like, and developed to obtain a predetermined filter pattern. By repeating the above-described filter layer forming process in the order of green, blue, and red, filter layers of three colors can be obtained.

Further, by applying a pigment dispersion containing a photoresist to the inner surface of a face plate having a black matrix, a filter pattern can be obtained without a step of forming a photoresist layer.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment will be described with reference to FIGS.

As shown in FIG. 2A, a light absorbing layer 12 having a predetermined pattern as a black matrix is formed on the inner surface of the panel 10 of the color cathode ray tube. This light absorbing layer 12
Is formed, for example, by the following method. That is,
A photoresist comprising at least an azide-based photosensitive group and polyvinylpyrrolidone is applied on the panel 10, exposed through a shadow mask, developed, and dried to form a stripe or dot on the portion where the pigment layer and the phosphor layer are to be formed. The photocured film is left. After applying and binding a light absorbing material, for example, graphite, 15% sulfamic acid is applied thereon to embrittle the photocured film, and the light absorbing layer thereon is also removed with the light absorbing material. The patterned light-absorbing layer 12 is formed by exposing a hole portion where a pigment layer and a phosphor layer are to be formed. At this time, as shown in (a) of an enlarged cross-sectional view of the position where the blue pigment layer is formed in FIG. 3, the cured resist layer 13 having a thickness of about 200 Å is considered to remain on the surface of the hole. It is.

Next, the following compositions were prepared as green, blue and red pigment dispersions.

As the green pigment dispersion, TiO ₂ —NiO—CoO—ZnO (trade name: Tyroxidide TM Green # 3320 (particle size: 0.01 μm)
m-0.02 μm, manufactured by Dainichi Seika Co., Ltd.) 6.4% by weight, ADC + PVA as a photoresist 2% by weight, and sodium salt of acrylic acid (trade name Dispek N-40) as a polymer electrolyte 0.15% %, Each prepared by dispersing in pure water. At this time, the polymer electrolyte concentration / pigment concentration ratio was 0.023, the resist concentration /
The polymer electrolyte concentration was 13.33, and the resist concentration / pigment concentration was 0.313.

As the blue pigment dispersion liquid, cobalt aluminate (trade name: Cobalt Blue X (particle size: 0.01 μm to 0.02 μm, manufactured by Toyo Pigment Co., Ltd.)) was used as blue pigment particles.
8.0% by weight, 0.5% by weight of ammonium bichromate (ADC) + polyvinyl alcohol (PV #) as a photoresist, and ammonium salt of a polyacrylic acid copolymer as a polymer electrolyte (Dispec GA-40, Allied) And 0.414% by weight (made by Colloid Co., Ltd.) in pure water. At this time,
The polymer electrolyte concentration / pigment concentration ratio was 0.023, the resist concentration / polymer electrolyte concentration was 1.208, and the resist concentration /
The pigment concentration is 0.028.

As the red pigment dispersion, fine particles of Fe ₂ O ₃ (particle size: 0.01 μm to 0.0
2 μm) 3.0 wt%, ADC as photoresist
+ PVΑ is 2% by weight, and polyoxyethylene alkyl ether sulfate ammonium salt (Hytenol 08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is 0.069 as a polymer electrolyte.
%, Each prepared by dispersing in pure water. At this time, the polymer electrolyte concentration / pigment concentration ratio was 0.023, and the resist concentration / polymer electrolyte concentration was 29.
0, resist concentration / pigment concentration was 0.67.

Using the green, blue, and red pigment dispersions, patterns of individual filter layers were formed as follows in accordance with the process shown in FIG.

First, a green pigment dispersion for forming a first color filter layer was applied to the inner surface of the panel 10 of the color cathode ray tube maintained at a temperature of 30 ° C. (step A).
Next, the panel 10 was rotated at 100 to 150 rpm to shake off excess pigment dispersion, and the film thickness of the green pigment dispersion was kept constant. Then, at a heater temperature of 120 ° C,
Dry for 4 minutes (step B), FIG. 2 (b) and FIG.
As shown in (b), a green pigment coating layer 20G was obtained.

Next, as shown in FIG. 2C, the green pigment coating layer 20G was exposed to a predetermined pattern using a high-pressure mercury lamp through a shadow mask (not shown) (step C). Subsequently, development is carried out by spraying a mist of, for example, P # 9 with a developer consisting of an aqueous alkali solution containing NaOΗ at a developer pressure of ² to 10 kg / cm ² (step D) and drying (step D). Step E), FIG.
As shown in (d), a green pigment layer 30G having a predetermined pattern was formed. The green pigment at the blue pigment layer forming position and the red pigment layer forming position is not completely removed from the surface of the remaining cured resist layer 13 as shown in FIG. The layer 22G is left on the remaining cured resist layer 13.

Next, a blue pigment layer 30B and a red pigment layer 30R were formed in the same manner as in the green pigment layer forming step described above.
At this time, the developer is composed of the blue pigment layer 30B and the red pigment layer 3B.
An alkaline aqueous solution containing LiCl for both 0R was used. Thus, as shown in FIG.
A desired filter pattern including a green pigment layer 30G, a blue pigment layer 30B, and a red pigment layer 30R was obtained on the inner surface. That is, at the position where the blue pigment layer is formed, FIG.
As shown in (d), the blue pigment layer 30B is laminated on the remaining green pigment layer 22G. The same applies to the position where the red pigment layer is formed.

Next, as shown in FIG. 2 (f), the green phosphor layer 40G, the blue phosphor layer 40B and the red phosphor layer 40R are formed by a usual method, respectively, into a green pigment layer 30G, a blue pigment layer 30B and a blue pigment layer 30B. It was formed so as to correspond to the red pigment layer 30R.

The phosphor suspension used had the following composition. As the green phosphor suspension, a green phosphor (Zn)
S: Cu, Αl) 100 g, polyvinyl alcohol 8
g, 0.40 g of ammonium bichromate, 0.01 g of a surfactant and 160 g of pure water were mixed and stirred. The blue phosphor suspension was a blue phosphor (ZnS: Ｓ).
g, Cl) 100 g, polyvinyl alcohol 5 g, ammonium dichromate 0.30 g, surfactant 0.0 l
g of pure water and 140 g of pure water were mixed and stirred, and the red phosphor suspension was a red phosphor (Y ₂ O ₂ S: Eu) 1
00g, polyvinyl alcohol 10g, ammonium bichromate 0.50g, surfactant 0.0lg, pure water 19
Each prepared by mixing and stirring 0 g was used.

The remaining hardened resist layer 13 was removed by burning in a later step.

Next, a second embodiment according to the present invention will be described mainly with reference to FIGS.

First, as shown in FIG.
The panel 10 on which the black matrix is formed is prepared in the same manner as in the embodiment. Of course, the cured resist layer 13 having a thickness of about 200 Å remains on the surface of the hole of the panel 10 as shown in FIG. I have.

In the present embodiment, a blue, green, and red pigment dispersion having the following composition and containing no photoresist was prepared.

As the green pigment dispersion, TiO ₂ —NiO—CoO—ZnO (trade name: Tyroxidide TM Green # 3320 (particle diameter 0.01 μm) was used as green pigment particles.
m-0.02 μm, manufactured by Dainichi Seika Co., Ltd.), and 6.4% by weight of a sodium salt of acrylic acid (trade name: Dispeck N-40) as a polymer electrolyte were dispersed in pure water. What was produced by making it do was prepared. At this time,
The polymer electrolyte concentration / pigment concentration ratio is 0.023.

As the blue pigment dispersion, 1 blue pigment particles of cobalt aluminate (trade name: cobalt blue X (particle size: 0.01 μm to 0.02 μm, manufactured by Toyo Pigment Co., Ltd.)) was used.
8.0% by weight, and 0.414% by weight of an ammonium salt of a polyacrylic acid copolymer (Dispec GA-40, manufactured by Allied Colloids) as a polymer electrolyte, each of which was prepared by dispersing in pure water. Was prepared. At this time,
The polymer electrolyte concentration / pigment concentration ratio is 0.023.

As a red pigment dispersion, fine particles of Fe ₂ O ₃ (particle diameter: 0.01 μm to 0.0
2 μm) and 0.1% of a polyoxyethylene alkyl ether sulfate ammonium salt (Hytenol 08, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a polymer electrolyte.
What prepared by disperse | distributing each in 05 wt% and pure water was prepared. At this time, the polymer electrolyte concentration / pigment concentration ratio is 0.035.

Using the green, blue and red pigment dispersions, a pattern of each filter layer was formed as follows in accordance with the process shown in FIG.

First, similarly to the first embodiment, a green pigment dispersion for forming a first color filter layer was applied to the inner surface of the panel 10 of the color cathode ray tube maintained at a temperature of 30 ° C. (step F). ). Then, the panel 10
By rotating at 150 rpm, the excess pigment dispersion was shaken off to make the thickness of the green pigment dispersion constant. Thereafter, drying was performed at a heater temperature of 120 ° C. for 3 to 4 minutes to obtain a green pigment coating layer 21G (step B).

Next, 3% by weight of polyvinyl alcohol
A photoresist solution having a composition of 0.20% by weight of ammonium bichromate, 0.01% by weight of a surfactant and the balance of pure water is prepared and applied in the same manner as in the formation of a pigment layer (step). G1), dried (step H), FIG.
As shown in (b), a photoresist layer 25 was laminated on the green pigment coating layer 21G.

Next, as shown in FIG. 5C, the photoresist layer 25 was exposed to a predetermined pattern using a high-pressure mercury lamp through a shadow mask (not shown) (step C). In the present embodiment, the exposure time is only about 1/5 as compared with the method of mixing the dye and the resist as in the first embodiment.

Subsequently, in the case of, for example, PΗ9 in the form of a mist, Na
Developing is performed by spraying a developing solution composed of an alkaline aqueous solution containing ₂ CO ₃ at a developing solution pressure of ² to 10 kg / cm ² (Step D), and drying (Step E), and FIG. As shown in FIG.
And a photoresist layer 25 to form a laminated pattern.
The green pigment at the blue pigment layer forming position and the red pigment layer forming position is not completely removed from the surface of the remaining cured resist layer 13 as shown in FIG. The layer 22G is left on the remaining cured resist layer 13.

Next, a blue pigment layer 31B and a red pigment layer 31R were formed in the same manner as the green pigment layer forming step. At this time, an alkaline aqueous solution containing Na ₂ CO ₃ was used for both the blue pigment layer 31B and the red pigment layer 31R. Thus, as shown in FIG. 5E, the green pigment layer 31G and the blue pigment layer 31B are formed on the inner surface of the panel 10.
And a filter pattern comprising the red pigment layer 31R. That is, at the position where the blue pigment layer is formed, FIG.
As shown in (d), the blue pigment layer 31B is laminated on the remaining green pigment layer 22G. The same applies to the position where the red pigment layer is formed.

Next, after the resist layer 25 on each of the blue, green and red pigment layers is peeled off, the phosphor layers 41G, 41B and 41 are formed by a usual method as shown in FIG.
R was formed. The phosphor suspension used had the same composition as that of the first embodiment.

The cured resist layer 13 remaining on the inner surface of the hole in the panel 10 was removed by burning in a later step.

[0051]

As described above, according to the method for forming a fluorescent screen of a color cathode ray tube according to the present invention, even if the pigment of the first color remains at the position where the second and third pigment layers are formed, the first color remains. Can minimize the degree of adverse effects on the emission of the other two color phosphors due to the residual pigment, and can suppress the reduction in white luminance to a practically acceptable level. Therefore, it is possible to obtain a color cathode ray tube in which luminance and contrast are greatly improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the spectral transmittance of practical pigments for forming blue, green, and red filters.

FIG. 2 is a cross-sectional view corresponding to each step of a illuminant layer forming section with a filter in the method for forming a phosphor screen of a color cathode ray tube according to the first embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view corresponding to each step of a blue pigment layer forming position in the first embodiment.

FIG. 4 is a diagram showing a procedure for forming a filter pattern of each color according to the first embodiment;

FIG. 5 is a cross-sectional view corresponding to each step of a illuminant layer forming portion with a filter in a method of forming a phosphor screen of a color cathode ray tube according to a second embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view corresponding to each step of a blue pigment layer forming position in the second embodiment.

FIG. 7 is a diagram showing a procedure for forming a filter pattern of each color in the second embodiment.

[Explanation of symbols]

 10 Panel 12 Light absorbing layer 13 Residual cured resist layer 20G, 21G Green pigment coating layer 30G, 31G Green pigment layer 30B, 31B Blue pigment layer 30R, 31R Red pigment layer 40G, 41G... Green phosphor layer 40B, 41B... Blue phosphor layer 40R, 41R... Red phosphor layer 22G... Remaining green pigment layer

Claims (3)

[Claims] A step of applying a resist to the inner surface of the panel, exposing and developing the same to form a pattern of a black matrix in which the resist remains at a position where an optical filter layer is formed; A step of forming a pattern of a green optical filter layer by applying a pigment, and a step of forming a pattern of a blue or red optical filter layer after forming the pattern of the green optical filter layer. A method for producing a phosphor screen of a color cathode ray tube. 2. The method for producing a fluorescent screen of a color cathode ray tube according to claim 1, wherein the resist used in the black matrix forming step is a water-soluble photosensitive solution containing at least an azide-based photosensitive agent or a silane coupling material. A method for producing a phosphor screen of a color cathode ray tube, characterized by comprising: 3. The method according to claim 1, wherein each of said optical filter layers has a dot-shaped or stripe-shaped pattern. Production method.