JP2000040468A - Photosensitive film, its manufacture, cathode ray tube fluorescent screen and its forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive film for forming a cathode ray tube fluorescent screen having excellent productivity and uniformity, and its forming method, further to provide a cathode ray tube fluorescent screen having high quality of display using the photosensitive film, and its manufacture. SOLUTION: Photosensitive films 1 formed by sequentially laminating fluorescent layers 2 and color filter layers 3 on a base film 1a are respectively formed for the colors of blue, green and red. The photosensitive films 1 are bonded to the internal surface of a face panel patterned with a blackbody absorption layer so that the color filter layer side is contacted, then they are exposed through a light shading mask, to be processed and patterned. This process is repeated, to form a laminated structural pattern of the fluorescent layers 1 and the color filter layers 3 of blue, green and red on the internal surface side of the face panel. The thickness of the color filter layers 3 and the fluorescent layers 2 can be uniformized at the stage of the formation of the photosensitive films 1, further two kinds of layers are patterned at a time, which prevents displacement of them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive film for forming a cathode ray tube fluorescent screen and a method for forming the same, and a cathode ray tube fluorescent screen using the photosensitive film and a method for forming the same.

[0002]

2. Description of the Related Art Various methods have been proposed to improve the display characteristics of a cathode ray tube, for example, the contrast. For example, a commonly practiced method is to use dark glass having a light transmittance of about 40 to 50% for a face panel, that is, a panel holding a phosphor layer. In this case, the external light is absorbed by the dark glass, so that the contrast can be improved. However, since the light emitted from the fluorescent screen is also absorbed by the dark glass, there is a problem that the luminance is reduced. In addition, a method of using a phosphor with a pigment in a phosphor layer is also well known. However, in this method, when the pigment concentration is high, a part of the phosphor emission is absorbed by the pigment, and the luminance is also lowered. There was a problem.

In recent years, as a method of minimizing the decrease in luminance and increasing the contrast, a light selective absorption method containing a pigment of the same color as each color phosphor between the inner surface of the face panel and the phosphor layer has recently been used. A method of providing a layer for each phosphor color has been considered. In this method, the effect of reducing the reflection of external light is very large as compared with the reduction in luminance, and this method is very effective for increasing the contrast. Further, when this light selective absorption layer is combined with a face panel having a high light transmittance, it is very effective for increasing the luminance.

However, in order to provide a pigment filter layer (hereinafter, referred to as a color filter layer) serving as a light selective absorption layer for each color phosphor layer, an aqueous dispersion containing a pigment and a photosensitive resin has conventionally been used. Was applied and a color filter layer was formed by the exposure-development method, and then the phosphor layer was formed by the same method. Therefore, the number of steps was doubled compared to the case where the color filter layer was not formed. However, significant additional equipment was required, and the production cost and throughput were affected.

Further, in the above-mentioned production method, since the spin coating method is used to apply the pigment dispersion, coating unevenness is likely to occur, and after forming a color filter layer of three colors corresponding to the three primary colors, When the layer is formed, the phosphor layer and the color filter layer are misaligned, the color filter layer is dropped off by development in the phosphor layer formation step, or the color filter layer swollen by the development step causes the phosphor particles of another color to swell. Adhesion of the phosphor causes poor cleaning of the phosphor and the like, which causes a decrease in the non-defective product rate, and has a drawback that the manufacturing cost is significantly increased.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a color filter which can ensure good display quality and does not increase the manufacturing cost. An object of the present invention is to provide a cathode ray tube fluorescent screen including a layer and a method for forming the same, a photosensitive film used for forming the cathode ray tube fluorescent screen, and a method for forming the same.

[0007]

The photosensitive film according to the present invention is for forming a fluorescent screen of a cathode ray tube, and is formed by sequentially laminating a phosphor layer and a color filter layer on a base film. The phosphor layer and the color filter layer are each formed to have a uniform thickness.

The phosphor layer, which is a component of the photosensitive film according to the present invention, comprises a paste in which the phosphor is dispersed in a high-viscosity aqueous solution of a water-soluble resist polymer having photocurability. It is.

Further, the color filter layer, which is a component of the photosensitive film according to the present invention, comprises a paste in which an inorganic pigment is dispersed in a high-viscosity aqueous solution of a photosensitive curable water-soluble resist polymer. It is.

Further, the photosensitive film according to the present invention comprises:
The solid content ratio of the water-soluble resist polymer to the phosphor in the phosphor layer and the inorganic pigment in the color filter layer is 1 to 10 in volume ratio.

Further, in the photosensitive film according to the present invention, the inorganic pigment contained in the color filter layer has the same color as the emission color of the phosphor contained in the phosphor layer.

Further, the method of forming a photosensitive film according to the present invention is a step of forming a first paste by dispersing a phosphor in a high-viscosity aqueous solution of a water-soluble resist polymer having photocurability by kneading or the like. Stretching the first paste on a flexible thin film base film to have a uniform thickness, and drying to obtain a thin film phosphor layer, a water-soluble resist polymer having photocurability A step of forming a second paste by dispersing an inorganic pigment by kneading or the like in a high-viscosity aqueous solution of, spreading the second paste on the phosphor layer so as to have a uniform film thickness, and drying. And obtaining a thin film color filter layer.

[0013] Further, the cathode ray tube fluorescent screen according to the present invention comprises:
The photosensitive film, or the photosensitive film obtained by the above forming method, pressure-bonded so that the color filter layer is in contact with the inner surface side of the face panel, after peeling the base film constituting the photosensitive film, The color filter layer and the phosphor layer are left on the inner surface of the face panel, and only a region that is selectively required is left by patterning a multilayer film including the color filter and the phosphor layer.

Further, the method for forming a fluorescent screen of a cathode ray tube according to the present invention is characterized in that the above-mentioned photosensitive film or the photosensitive film obtained by the above-mentioned forming method is so formed that the color filter layer is in contact with the inner surface of the face panel. Pressure bonding step, peeling off the base film constituting the photosensitive film, leaving the color filter layer and the phosphor layer on the inner surface of the face panel, the color filter layer and the phosphor through a light shielding mask The method includes a step of selectively patterning a multilayer film composed of the color filter layer and the phosphor layer by selectively exposing the layer to light and removing an unexposed portion with water.

Further, according to the method of forming a fluorescent screen of a cathode ray tube according to the present invention, the color of the inorganic pigment contained in the multilayer film composed of the color filter layer and the phosphor layer is the same as the emission color of the phosphor. The above-mentioned multilayer films, which emit light of any one of the three primary colors, are sequentially formed on a face panel to obtain a phosphor screen.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Next, Embodiment 1 of the present invention will be described. The photosensitive film 1 according to the present invention has a structure in which a phosphor layer 2 and a color filter layer 3 are sequentially laminated on a base film 1a as shown in the sectional view of FIG. When the phosphor is attached to the inner surface of the face panel serving as the substrate, the upper surface of the photosensitive film 1 in FIG. 1, that is, the surface of the color filter layer 3 is used by being pressed against the inner surface of the face panel.

An outline of how to use the photosensitive film 1 in forming a cathode ray tube fluorescent screen according to the present invention will be described. First, after the black body absorbing layer is formed on the inner surface of the face panel, the photosensitive film 1 is pressure-bonded to the inner surface of the face panel including the surface of the black body absorbing layer so that the color filter layer is in contact with the base film 1a. After that, an exposure-development process is performed, and necessary portions of the phosphor layer 2 and the color filter layer 3 are formed.
Are simultaneously patterned and the others are removed. By repeating this step, it is possible to obtain a cathode ray tube fluorescent screen.

Next, a method for forming the photosensitive film 1 shown in FIG. 1 will be described. The base film 1a on which the phosphor layer 2 and the color filter layer 3 are laminated is made of a flexible thin film such as PET (polyethylene terephthalate), polyethylene, or polyacryl. The thickness of the base film 1a is not particularly limited, but when the photosensitive film 1 is pressure-bonded, even if unevenness is formed on the pressure-bonded surface, the photosensitive film 1 is adhered without depending on the surface shape. What is necessary is just to have the degree of flexibility which is possible.

The phosphor layer 2 is composed of a phosphor paste obtained by kneading and dispersing a phosphor having an average particle size of about 5 to 15 μm in an aqueous solution of a photosensitive resist polymer. It can be obtained by elongating uniformly to a film thickness of about 5 to 50 μm on the upper la and then evaporating the water. During the formation of the phosphor paste, the amount of the phosphor to be added and the amount of the photosensitive resist polymer are adjusted so that the solid content volume ratio of the phosphor and the photosensitive resist polymer is in the range of 1: 1 to 10,
Further, for the purpose of improving dispersibility, an appropriate amount of a suitable dispersant such as a polycarboxylic acid or an acrylic may be added.

Next, a color filter layer 3 is laminated on the phosphor layer 2. The color filter layer 3 is formed of an inorganic pigment having an average particle diameter of 0.1 μm or less.
And a pigment dispersion paste obtained by performing the same treatment as in the formation of the phosphor layer 2.
It is obtained by evaporating water after uniformly spreading to a film thickness of about 1 to 10 μm on the surface of the substrate, and it is possible to obtain the photosensitive film 1 having a multilayer structure through such steps.

Next, a method for forming a cathode ray tube fluorescent screen using the photosensitive film formed as described above will be described. FIG. 2 is a cross-sectional view of a cathode ray tube fluorescent screen formed according to the present invention. In this drawing, reference numeral 4 denotes a face plate, and reference numeral 5 denotes a pattern formed on an inner surface (an upper surface side in the drawing) of the face plate 4. This is a black body absorbing layer, and the black body absorbing layers 5 are arranged at a constant opening width and at the same pitch.

Blue, green, and red fluorescent portions 6B, 6G, and 6R are disposed between adjacent black body absorbing layers 5, and these three color fluorescent portions are repeatedly disposed on the upper surface of the face plate 4. Have been. The blue, green, and red fluorescent portions 6B, 6G, and 6R are provided on the blue, green, and red color filter layers 3b, 3g, and 3r provided on the inner surface of the face plate 4, respectively. This shows a multilayer film in which red phosphor layers 2b, 2g, and 2r are stacked.

In order to obtain a cathode ray tube fluorescent screen as shown in FIG. 2, first, as shown in FIG.
On the inner surface side of the substrate, a film forming a material constituting the black body absorbing layer 5 is formed, and is patterned to form the fluorescent portions 6B, 6B of the respective colors.
An opening serving as an effective arrangement region for G and 6R is formed, and the other portion is left as the black body absorbing layer 5. Black body absorption layer 5
The size of the pattern and the size of the opening are each made uniform, so that finally the white uniformity is good.
A fluorescent screen with high display quality can be obtained.

Next, as shown in FIG. 4, the blue photosensitive film 1B is pressed on the surface of the face plate 4 including the surface of the black body absorbing layer 5. The blue photosensitive film 1B is a film in which a blue phosphor layer 2b and a blue color filter layer 3b are sequentially laminated on a base film 1a, and the color filter layer side is adhered to the inner surface side of the face plate 4. Thereafter, the base film 1a is peeled off, leaving the blue phosphor layer 2b and the blue color filter layer 3b. A specific method for forming the blue photosensitive film 1B will be described in a second embodiment.

After that, as shown in FIG. 5, for example, through a light-shielding mask used when forming the black body absorbing layer 5,
By selectively exposing the region where the blue fluorescent portion 6B is arranged, curing the exposed portion, and performing development processing, the blue fluorescent layer 2b and the blue color filter layer 3b are simultaneously patterned, and the blue fluorescent portion 6B is patterned. 6B is obtained. The light-shielding mask used in this patterning step is a mask used for forming an opening between the black body absorbing layers 5 that determines an effective arrangement area of the fluorescent portion of each color, and is usually a separate mask for each color. Has been created and used for patterning.

Next, as shown in FIG. 6, the green photosensitive film 1 G is pressed against the inner surface of the face plate 4.
Thereafter, as shown in FIG. 7, patterning is performed by the same processing as in the case of the blue fluorescent portion 6 </ b> B, and a green color filter layer 3 g and a green phosphor layer 2 g are sequentially laminated on the inner surface of the face plate 4. The fluorescent part 6G is obtained.

Further, as shown in FIG. 8, the red photosensitive film 1 R is pressed against the inner surface of the face plate 4.
By performing patterning in the same manner as in the case of the blue and green photosensitive films 1B and 1G, the red color filter layer 3r is formed.
Red fluorescent portion 6 having a laminated structure of
R can be obtained, and a cathode ray tube fluorescent screen having the structure shown in FIG. 2 can be obtained. Needless to say, the order of forming the blue, green, and red fluorescent portions 6B, 6G, and 6R is not limited to the above example, and there is no problem even if the order is different.

As described above, a photosensitive film of each color is formed in advance, and the photosensitive film of each color is pressed on the inner surface of the face panel on which the black body absorbing layer is patterned to leave only necessary portions. Since the color filter layer and the phosphor layer are patterned into a predetermined shape, each layer constituting the photosensitive film can have a uniform thickness. Furthermore, since the color filter layer and the phosphor layer are simultaneously patterned, there is no displacement between them.
Also, there is no problem of the color filter layer falling off.

In the case where the phosphor layer is formed after the patterning of the color filter layer, color mixing failure due to the remaining washing of the other color phosphor may occur on the color filter layer. By using a photosensitive film in which a phosphor layer is previously laminated on a filter layer, such a defect does not occur, and the yield can be improved.

Further, it is possible to cut the photosensitive film to a required area in accordance with the size of the face panel to be used, to suppress the generation of surplus material, and to reduce the material cost. It is possible to keep it low.

Embodiment 2 Next, a method for forming the blue photosensitive film 1B will be described in detail. First, Zn
S: Ag, Cl phosphor (blue, average particle size 5 μm, 30% by weight), polycarboxylic acid dispersant (3% by weight), sodium dichromate (crosslinking agent, 1% by weight) as a photosensitive resist polymer, For example, polyvinyl alcohol (10% by weight)
To obtain a phosphor paste. The solid content volume ratio of the phosphor of the phosphor paste to the photosensitive resist polymer is approximately 1: 1.3.

The above-mentioned blue phosphor paste is coated with 10 μm
The film is laminated on a base film 1a having a thickness of about 10 μm, for example, a PET film so as to have a uniform thickness by stretching, and dried to obtain a blue phosphor layer 2b having a thickness of about 10 μm.

Then, cobalt aluminate (blue, average particle size 0.05 μm, 7% by weight) as a pigment, polycarboxylic acid dispersant (1% by weight), sodium dichromate (crosslinking agent, 0.3% by weight) %) Is kneaded and dispersed in an aqueous solution of a photosensitive resist polymer, for example, polyvinyl alcohol (3% by weight) to obtain a pigment-dispersed paste. The solid content volume ratio between the pigment of the pigment dispersion paste and the photosensitive resist polymer is approximately 1: 1.

The blue pigment-dispersed paste is spread on the dried and dried blue phosphor layer 2b so as to have a uniform film thickness, and then dried to form a film of about 1.5 μm. It is possible to obtain the thick blue color filter layer 3b and obtain the blue photosensitive film 1B, and obtain the green and red photosensitive films 1G and 1R by the same manufacturing method by using different phosphors and pigments. It is possible.

FIG. 9 shows an example of the composition of the paste constituting the blue photosensitive film 1B and the composition of each paste constituting the green and red photosensitive films 1G and 1R.

In the second embodiment, as a photosensitive resist for forming a color filter layer and a phosphor layer, polyvinyl alcohol using hexavalent chromium in sodium dichromate as a crosslinking agent is used. However, the present invention is not limited to this, and another photosensitive resist having a similar effect can be applied. For example, a polyvinyl alcohol derivative having a photosensitive sensitive group in a polymer, a water-soluble photosensitive resist using an azide compound as a crosslinking agent, or the like can be used.

FIG. 10 shows the luminance, external light reflection intensity and contrast characteristics of a cathode ray tube (test tube) having a phosphor screen formed by using the photosensitive film shown in the second embodiment. The results of evaluation with those values as 100 for conventional pipes that have not been performed are shown. In the cathode ray tube obtained according to the embodiment of the present invention, the luminance was 10% lower than that of the conventional tube, but the contrast performance was able to be improved by 50% as compared with the conventional tube.

As can be seen from the above, providing a color filter layer of the same color as the phosphor emission for each color phosphor is very effective for improving the contrast performance.
It can be seen that by forming the cathode-ray tube fluorescent screen by the forming method described in Embodiment 1, a fluorescent screen with higher display quality can be obtained.

[0039]

The effects of each claim of the present invention will be described below. According to the present invention, since a photosensitive film in which a phosphor layer and a color filter layer are sequentially laminated on a base film is used for forming a cathode ray tube fluorescent screen,
In addition to the effect of improving the contrast performance by forming the color filter layer, the color filter layer and the phosphor layer can be patterned on the inner surface side of the face panel in a single exposure and development step. It is not necessary to introduce a large facility for forming the filter layer, and the increase in the number of manufacturing steps can be suppressed.

Further, according to the present invention, the positional deviation between the phosphor layer and the color filter layer, the dropping of the color filter layer, the color filter layer, and the like can occur when the color filter layer and the phosphor layer are sequentially formed. It is possible to prevent poor color mixing due to remaining phosphor washing on the layer,
The display quality of the finally obtained cathode ray tube fluorescent screen can be improved.

Further, according to the present invention, a multi-layer photosensitive film comprising a phosphor layer and a color filter layer is provided.
Since it is possible to cut and use only a required area in accordance with the size of the face panel to be applied, it is possible to suppress the material cost without generating excess material.

[Brief description of the drawings]

FIG. 1 is a diagram showing a photosensitive film used for describing Embodiment 1 of the present invention.

FIG. 2 is a sectional view of a cathode ray tube phosphor screen according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a flow of manufacturing a cathode ray tube fluorescent screen according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a flow of manufacturing a cathode ray tube phosphor screen according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a manufacturing flow of the cathode-ray tube fluorescent screen according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a manufacturing flow of the cathode-ray tube phosphor screen according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a manufacturing flow of the cathode ray tube fluorescent screen according to the first embodiment of the present invention.

FIG. 8 is a diagram showing a manufacturing flow of the cathode ray tube fluorescent screen according to the first embodiment of the present invention.

FIG. 9 is a diagram used for describing Embodiment 2 of the present invention.

FIG. 10 is a diagram used for describing Embodiment 2 of the present invention.

[Explanation of Codes] Photosensitive film 1a. Base film 1B. Blue photosensitive film 1G. Green photosensitive film 1R. 1. Red photosensitive film Phosphor layer 2b. Blue phosphor layer 2g. Green phosphor layer 2r. Red phosphor layer 3. Color filter layer 3b. Blue color filter layer 3g. Green color filter layer 3r. Red color filter layer 4. Face plate 5. Black body absorption layer 5a, 5b, 5c. Resist pattern 6B. Blue fluorescent section 6G. Green fluorescent part 6R. Red fluorescent part

 ──────────────────────────────────────────────────の Continuing on the front page F term (reference) 4F100 AK01B AK01C AK04 AK25 AK42 AR00B AR00C AT00A AT00D BA03 BA07 BA10A BA10C BA10D BA25B BA25C CA13C CA30B DE01B DE01C EH462 EJ862 EJ911 GB41 JB10B JB10B JB10 JB10J JB09J YY00C 5C028 HH09 HH14

Claims (9)

[Claims] 1. A photosensitive material comprising: a phosphor layer and a color filter layer sequentially laminated on a base film, wherein the phosphor layer and the color filter layer are each formed to have a uniform thickness. Film. 2. A phosphor layer comprising a paste in which a phosphor is dispersed in a high-viscosity aqueous solution of a water-soluble resist polymer having photocurability.
The photosensitive film as described in the above. 3. The photosensitive film according to claim 1, wherein the color filter layer is composed of a paste obtained by dispersing an inorganic pigment in a high-viscosity aqueous solution of a water-soluble resist polymer having photocurability. . 4. The solid content ratio of the water-soluble resist polymer to the phosphor in the phosphor layer and the inorganic pigment in the color filter layer is 1 to 10 in volume ratio. The photosensitive film according to any one of the above. 5. The color filter according to claim 2, wherein the inorganic pigment contained in the color filter layer has the same color as the emission color of the phosphor contained in the phosphor layer. Photosensitive film. 6. A step of forming a first paste by dispersing a phosphor in a high-viscosity aqueous solution of a water-soluble resist polymer having photocurability by kneading or the like, and forming the first paste into a thin film having flexibility. A process of stretching to a uniform film thickness on a base film and drying to obtain a thin phosphor layer, kneading an inorganic pigment in a high-viscosity aqueous solution of a water-soluble resist polymer having photocurability, etc. Forming a second paste by dispersing, the second paste is spread on the phosphor layer so as to have a uniform film thickness,
A method for forming a photosensitive film, comprising a step of drying to obtain a thin color filter layer. 7. The photosensitive film according to any one of claims 1 to 5, or the photosensitive film obtained by the forming method according to claim 6, wherein a color filter layer is provided on the inner surface side of the face panel. After the base film constituting the photosensitive film is peeled off, the color filter layer and the phosphor layer are left on the inner surface of the face panel, and the multilayer comprising the color filter and the phosphor layer is formed. A cathode ray tube fluorescent screen characterized in that only a region that is selectively required is left by patterning a film. 8. The photosensitive film according to any one of claims 1 to 5, or the photosensitive film obtained by the method according to claim 6, wherein a color filter layer is provided on the inner surface side of the face panel. Step of pressure bonding to contact, peeling the base film constituting the photosensitive film,
A step of leaving the color filter layer and the phosphor layer on the inner surface of the face panel, selectively exposing the color filter layer and the phosphor layer through a light-shielding mask, and washing away unexposed portions with water. A step of simultaneously patterning a multilayer film composed of the color filter layer and the phosphor layer. 9. The color of the inorganic pigment contained in the multilayer film composed of the color filter layer and the phosphor layer and the color of the phosphor emitted are the same, any one of the three primary colors, and correspond to the above three primary colors. 9. The method for forming a fluorescent screen of a cathode ray tube according to claim 8, wherein said multilayer films emitting light of each color are sequentially formed on a face panel to obtain a fluorescent screen.