JP2002352708A - Fluorescent screen, color cathode-ray tube and forming method of the fluorescent screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a satisfactory fluorescent screen by preventing the occurrence of the overlap and the dot partial or whole missing of a phosphor layer. SOLUTION: In this method, the size of a black matrix hole on which a color in red, green and blue of a light-emitting layer is formed is made larger than the sizes for the other colors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, a phosphor screen used for the same, and a method of forming the same.

[0002]

2. Description of the Related Art At present, the fluorescent screen of a color cathode ray tube has a glass panel treated with a black matrix in the form of a dot or stripe hole, or only the light wavelengths of red, green and blue light emitted on the glass panel. Is formed on the black matrix or the optical filter film, and the corresponding phosphor layer emitting red, green, and blue light in the form of dots or stripes is formed on the black matrix or the optical filter film. Methods of forming are widely known.

[0003] As a method of forming the phosphor layer, a process of applying a phosphor slurry containing a phosphor and a photoresist on a black matrix or an optical filter film and drying the same, mounting a shadow mask, and exposing a light to the substrate. And a step of removing the shadow mask and performing development.

However, in the exposure step, the exposure sensitivity of the green light emitting phosphor coating layer is lower than the exposure sensitivity of the red light emitting phosphor coating layer and the blue light emitting phosphor coating layer. The composition had to be higher in sensitivity than the blue light emitting phosphor slurry. This is because if the body color of the phosphor becomes yellowish due to the copper element contained as an activator in the green light-emitting phosphor, it becomes easier to absorb ultraviolet light used for exposure.

[0005] For this reason, if the green light emitting phosphor slurry has the same composition as the red light emitting phosphor and the blue light emitting phosphor slurry, the sensitivity is lower than that of the red light emitting phosphor and the blue light emitting phosphor at the time of exposure. There was a problem.

FIG. 4 is a graph showing the spectral characteristics of the phosphor. In the figure, 101 indicates a red light-emitting phosphor, 102 indicates a blue light-emitting phosphor, and 103 indicates a graph indicating spectral characteristics of a green light-emitting phosphor. As shown in the graph 103, the green light-emitting phosphor has a wavelength
It can be seen that the reflectance is low, that is, the absorption is large, as compared with 1,102.

Therefore, under the same exposure conditions,
In order to increase the sensitivity of the slurry of the green light-emitting phosphor, the amount of ADC (ammonium dichromate) used as an ultraviolet sensitizer was increased more than in the other two colors to compensate for the exposure sensitivity. However, since the ADC easily causes a thermal crosslinking reaction, a thermal crosslinking reaction is caused by the heat of the heater in a drying step after slurry application. At this time, there is a problem that the minimum adhesion size of the green light-emitting phosphor layer having a large ADC amount becomes large. In the thermal crosslinking reaction, the adhesive force of the dots is weaker than in the photocrosslinking reaction, so that the green light-emitting phosphor layer was liable to drop and sprinkle dots.

FIG. 5 is a graph showing the patterning width of the phosphor slurry using the standard amount and 1/2 amount of the ADC. In the drawing, a graph 201 shows a stable area of the dot size with respect to the panel rising temperature when a standard amount of ADC is used and a graph 203 uses a 1/2 amount of ADC and the exposure amount is fixed. The graph 202 shows the case where the standard amount of ADC is used, and the graph 204 shows １ ／.
Represents the fog area when the amount of ADC is used,
Each of the graphs 202 and 204 indicates that there is no fog on the left side with respect to the boundaries. The fog here means that adjacent dots are connected. From these graphs, it can be seen that when the amount of ADC is large, the thermal crosslinking reaction proceeds, and the dot size becomes large at a relatively low temperature, causing fog. On the other hand, even when the temperature at which the panel rises is high, it can be seen that the smaller the ADC amount, the smaller the minimum adhesion size.

FIG. 6 shows a standard amount and a half amount ADC.
FIG. 4 is a graph showing the exposure sensitivity of a phosphor slurry using the method shown in FIG. In the figure, a graph 207 is a graph showing the relationship between the panel rising temperature of the phosphor slurry using the standard amount of ADC and the relative exposure amount. In addition, the graph 208 shows 1 /
This is the case where two amounts of ADC are used.

The integrated light quantity is generally represented by the product of exposure illuminance and exposure time. The relative exposure amount here is a value obtained by adjusting the exposure illuminance using an ultraviolet filter while the exposure time is constant.
%. As is clear from FIG. 6, the smaller the ADC, the lower the sensitivity, and the higher the temperature at which the panel rises, the smaller the required exposure amount tends to be.

FIG. 7 is a graph showing film loss of a phosphor slurry using a standard amount and a half amount of ADC. In the figure, a graph 205 shows film loss in a phosphor slurry using a standard amount of ADC. When the temperature at which the panel rises is changed, the dot thickness of a dot size of 150 μm changes with respect to the coating thickness. It is a check that only the number has decreased. The dot film thickness is a value obtained by converting the film thickness (coating weight) after patterning into a solid value. Further, a graph 206 represents a film edge in the phosphor slurry using a 1/2 amount of the ADC. Graph 207
Indicates a coating film thickness.

FIG. 7 shows that when the ADC amount is small, the dot film thickness is stable even when the panel rising temperature is high. However, it can be seen that when the ADC amount is large, film thinning is good at a low panel rising temperature, but the film thinning becomes extremely bad when the panel rising temperature is high. This is because the thermal cross-linking reaction progresses, the adhesive force weakens,
This is due to the occurrence of film loss during development.

Thus, it can be seen that the amount of ADC has a great influence on the formation of the phosphor layer.

When the amount of ADC of the green light-emitting phosphor slurry is increased, the green light-emitting phosphor dot size or stripe size becomes larger, for example, as shown in FIG. 5, despite the same manufacturing conditions. As a result, overlap with other colors occurs.

On the other hand, if the exposure time is shortened or the integrated illuminance is reduced by reducing the exposure illuminance in order to make the dot size or stripe size of the green phosphor the same as before the increase in the ADC, dot spots and dot breaks are likely to occur. This has been a serious problem in manufacturing.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to prevent the occurrence of fogging, doting, and dot dropping of a phosphor layer, and To obtain an excellent phosphor screen.

It is a second object of the present invention to provide a method of manufacturing a phosphor screen which can provide a good phosphor screen without causing fogging, doting, and dropping of a phosphor layer.

Further, a third object of the present invention is to provide a color cathode ray tube having a good phosphor screen without fogging, doting and dropping of a phosphor layer.

[0019]

According to the present invention, there is provided a method for forming a fluorescent screen, comprising the steps of forming a black matrix having dot-shaped or stripe-shaped holes on the inner surface of a glass panel for a color cathode-ray tube, red, green, and blue. Using the light-emitting phosphor and the photoresist, red, green, and blue light-emitting phosphor slurries are respectively prepared, and at least the red, green, and blue light-emitting phosphor layers are formed in the hole portion in the form of dots or stripes, respectively. In the method of forming a phosphor screen, the size of the hole in which the phosphor layer of one color of the red, green, and blue light emitting phosphor layers is to be formed is determined by the size of the phosphor layer of the other two colors. Is larger than the size of the hole to be formed.

The phosphor screen of the present invention comprises a black matrix having holes in the form of dots or stripes formed on a glass panel, and at least red, green and blue light-emitting phosphor layers respectively formed in the holes. On the phosphor screen provided, the size of the hole portion in which a phosphor layer of one color among the red, green, and blue light-emitting phosphor layers is to be formed,
It is characterized in that it is larger than the size of the hole in which the other two color phosphor layers are to be formed.

A color cathode ray tube according to the present invention is provided with a neck tube, a funnel extending from the neck tube in a funnel shape, and a dot or stripe shape formed on a glass panel so as to seal an opening of the funnel. A black matrix having a hole portion, a vacuum envelope having a glass panel on which a phosphor screen including at least red, green, and blue light-emitting phosphor layers respectively formed in the hole portion,
An electron gun provided in the neck tube facing the glass panel, wherein one of the red, green, and blue light-emitting phosphor layers is provided;
The size of the hole in which the phosphor layers of the colors are to be formed is larger than the size of the hole in which the phosphor layers of the other two colors are to be formed.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The phosphor screen of the present invention comprises a black matrix having holes in the form of dots or stripes formed on a glass panel, and at least red, green and blue light emitted respectively in the holes. The size of the hole having the phosphor layer and in which the phosphor layer of one color is to be formed is larger than the size of the hole in which the phosphor layers of the other two colors are to be formed.

The method for forming a phosphor screen according to the present invention is an example of a method for obtaining such a phosphor screen, and the size of a hole in which a phosphor layer of one color is to be formed is different from that of the other two colors. Forming a black matrix having a plurality of dot-shaped or stripe-shaped holes on the inner surface of the glass panel for a color cathode-ray tube, so that the size of the holes is larger than the size of the holes in which the phosphor layer is to be formed; and A step of preparing red, green, and blue light-emitting phosphor slurries each containing a photoresist and forming red, green, and blue light-emitting phosphor layers in at least a dot shape or a stripe shape, respectively, in these holes.

Further, the color cathode ray tube of the present invention is provided with a neck tube containing an electron gun, a funnel extending in a funnel shape from the neck tube, and an opening for opening the funnel. A vacuum envelope having a panel on which the phosphor screen is formed.

According to the present invention, a black matrix having a plurality of dot-like or stripe-like holes is provided.
Since the size of the hole in which the phosphor layer of one certain color is to be formed is larger than the size of the hole in which the phosphor layers of the other two colors are to be formed, the other two phosphor layers are formed.
Even when a phosphor slurry containing a large amount of an ultraviolet sensitizer, for example, ADC, is used as compared with the color, under the same drying and exposure conditions, no fogging, doting, and dot dropping occur on the phosphor layers of the other two colors. And a good phosphor screen can be obtained.

As the phosphor used in the phosphor layer that can be formed so as to be larger than the size of the dots or stripes of the phosphor layers of the other two colors, a green light-emitting phosphor is preferable.

The green light-emitting phosphor tends to have lower UV exposure sensitivity than the other two colors, and tends to increase the ADC amount of the phosphor slurry. Thus, by using the present invention, it is possible to prevent fogging, doting, and dot dropping on the phosphor layers of the other two colors, and obtain a good phosphor screen.

FIG. 1 is a diagram schematically showing an example of the configuration of a black matrix used in the present invention. In the figure, 1
0 indicates a black matrix, 1 indicates a portion where a blue light emitting phosphor layer is to be formed, 2 indicates a portion where a green light emitting phosphor layer is to be formed, and 3 indicates a portion where a red light emitting phosphor layer is to be formed. As shown, in this example, the size of the hole portion of the black matrix is smaller in the portion 2 where the green light emitting phosphor layer is to be formed than in the portions 1 and 3 where the phosphor layers of the other two colors are to be formed. It is formed large. As a method for forming the black matrix, a known method can be appropriately applied.

In the phosphor screen of the present invention, a glass panel,
An optical filter film that can selectively transmit light having a wavelength corresponding to the wavelength of the emission color of each phosphor layer can be further formed between the red, green, and blue light emitting phosphor layers. This optical filter film is red, green,
And a step of forming a blue light emitting phosphor layer. As a method of forming the optical filter, a known method can be appropriately applied.

FIG. 2 is a partially cutaway view showing an example of the configuration of a color cathode ray tube according to the present invention.

The cathode ray tube 60 has a vacuum envelope 61 whose inside is evacuated. The vacuum envelope 61 includes the neck tube 6.
2 and a cone 63 continuously extended from the neck tube 62
Having. Further, the vacuum envelope 61 has a glass panel 64 sealed with frit glass. The metal explosion-proof tension band 65 is wound around the periphery of the glass panel 64. Three electron guns 66 for irradiating electron beams corresponding to the blue light emitting phosphor layer, the green light emitting phosphor layer, and the red light emitting phosphor layer are provided in the neck tube 62. The fluorescent screen 67 is formed on the inner surface of the glass panel 64.

FIG. 3 is a sectional view showing an example of the configuration of the phosphor screen of the present invention. As shown, the fluorescent screen 67
Holes 1, 2, 2 provided on the glass panel 64 and in which the red, green, and blue light emitting phosphor layers 5, 6, 7 are to be formed.
A black matrix 10 in which the size of the hole 2 in which the phosphor layer of one color is to be formed is larger than the size of the holes 1 and 3 in which the phosphor layers of the other two colors are to be formed. And optical filter layers 11, 12, 1 that are provided in accordance with the emission colors of the phosphor layers and selectively transmit light having wavelengths corresponding to the wavelengths of the red, green, and blue emission colors, respectively.
3 and a blue light emitting phosphor layer 5, a green light emitting phosphor layer 6, and a red light emitting phosphor layer 7 which emit light when excited by an electron beam from an electron gun. As a method of forming the phosphor screen,
As long as the size of the hole portion 2 of the black matrix can be made larger than the hole portions 1 and 3, a known method can be appropriately applied.

[0033]

The present invention will be described below in detail with reference to examples.

Example 1 and Comparative Example 1 100 first panels for a 17-inch color display tube having dot-shaped black matrices and optical filters corresponding to each color of phosphor were formed.

In the first panel, the holes for the green light emitting phosphor layer had a diameter of 110 μm, and the holes for the red and blue light emitting phosphor layers had a diameter of 102 μm.

Next, the following phosphor slurries were prepared.

Blue light-emitting phosphor slurry Blue light-emitting phosphor (ZnS: Ag, Al) 400 g Pure water 420 g Polyvinyl alcohol 130 g Ammonium dichromate 8 ml Other additives 40 ml Green light-emitting phosphor slurry Green light-emitting phosphor (ZnS: Cu, al) 400 g of pure water 350g polyvinyl alcohol 170g ammonium bichromate 14ml other additives 50ml red light-emitting phosphor slurry red-emitting phosphor _{(Y 2 O 2 S: Eu} ) 400g of pure water 330g polyvinyl alcohol 160g bichromate ammonium 8ml other First, the blue light-emitting phosphor slurry was applied to the inner surface of the first panel on which the optical filter and the black matrix were formed, and the obtained coating film was heated with a heater. It was 燥.

At this time, the M / C index was 10 seconds, and the heater drying after the phosphor slurry was applied was blue, green,
And both the red light emitting phosphor slurry and 4Pos. Met. Therefore, the heater drying time was 40 seconds.

Next, the shadow mask is positioned on the first panel on which the coating film is formed, and the exposure illuminance is set to 0.054.
(MW / cm ² ) for 36 seconds.

Thereafter, development was performed using warm pure water (about 40 ° C.) to form a blue light emitting phosphor layer on the blue light emitting phosphor layer hole.

Next, the first blue light-emitting phosphor layer is applied.
The green light-emitting phosphor slurry was applied to the inner surface of the panel. The obtained coating film was dried, exposed, and developed in the same manner as the blue light emitting phosphor layer except that the exposure time was changed to 50 seconds,
A green light emitting phosphor layer was formed on the green light emitting phosphor layer hole.

Thereafter, the green light-emitting phosphor slurry was applied to the inner surface of the first panel on which the blue and green light-emitting phosphor layers were applied. The obtained coating film is dried, exposed, and developed in the same manner as the blue light emitting phosphor layer except that the exposure time is set to 34 seconds to form a red light emitting phosphor layer on the red light emitting phosphor layer hole. did.

Thus, phosphor layers of three colors were formed.

In the above exposure step, the target dot size with respect to the hole size was set as follows.

Black matrix phosphor Hole size: 102 μm → Target dot size: 140 μm Hole size: 110 μm → Target dot size: 155 μm The yield at this time is shown in Table 1 below.

Comparative Example 1 In the second panel, the hole diameters of the blue, red and blue light emitting phosphor layers were all 105 μm, the exposure time of the blue light emitting phosphor slurry was 42 seconds, and the exposure time of the green light emitting phosphor slurry was Three phosphor layers were formed in the same manner as in Example 1 except that the exposure time of the red light emitting phosphor layer slurry was 38 seconds and the target dot size was 145 μm.

The yield at this time is shown in Table 1 below.

[0048]

[Table 1]

As shown in Table 1 above, the green light-emitting phosphor layer (G)
In the first panel of Example 1 having a hole size of 110 μm, the hole size of the red light emitting phosphor layer (R), G, and the blue light emitting phosphor layer (B) was 0% while the G dot spot was 0%. In the second panel of Comparative Example 1 having a dot size of 105 μm, as much as 6% of G dot spots were generated. This is because the target G dot size was smaller than the minimum size under these conditions as a result of trying to attach the G dot size in accordance with the hole size, and the dot adhesion was apt to occur due to insufficient adhesion. it is conceivable that.

The average dot size of each color at this time was as follows.

First Panel Second Panel B: 141 μm B: 145 μm G: 155 μm G: 145 μm R: 140 μm R: 144 μm Comparative Example 2 Further, a second panel similar to that of Comparative Example 1 was used. The exposure time for G was extended to 47 seconds in the panel No. 2 until there was no dot spot, the exposure time for B was 42 seconds, and R
A phosphor layer was formed in the order of B, G, and R in the same manner as in Example 1 except that the exposure time was 38 seconds. Table 2 shows the yield at this time.

[0052]

[Table 2]

As shown in Table 2, in Comparative Example 2, the overlap of G was as large as 14%. This is because, since the G exposure time was extended, the dot size of the G phosphor became larger in all panels than the dot size of the B and R phosphors, and the tendency of G overlap was confirmed in all panels. Was done. At this time, the average dot size of each color was B: 145 μm G: 152 μm R: 144 μm.

[0054]

According to the present invention, compared with the other two colors, the working width at the time of patterning is increased by increasing the size of the hole for applying the phosphor slurry containing a large amount of the ultraviolet sensitizer, for example, ADC. And under the same drying and exposure conditions, a good phosphor screen can be obtained without fogging, doting, and dot dropping on the phosphor layers of the other two colors.

Further, according to the present invention, it is possible to obtain a color cathode ray tube having a good phosphor screen, high definition and good image quality.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating an example of a configuration of a black matrix used in the present invention.

FIG. 2 is a partially cutaway view showing an example of a configuration of a color cathode ray tube of the present invention.

FIG. 3 is a cross-sectional view illustrating an example of a configuration of a phosphor screen according to the present invention.

FIG. 4 is a graph showing spectral characteristics of a phosphor.

FIG. 5 is a graph showing a width of a phosphor slurry patterning operation;

FIG. 6 is a graph showing the exposure sensitivity of a phosphor slurry using a standard amount and a half amount of ADC.

FIG. 7 is a graph showing film loss of a phosphor slurry.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hole for blue light emitting phosphor, 2 ... Hole for green light emitting phosphor, 3 ... Hole for red light emitting phosphor, 5 ... Blue light emitting phosphor layer, 6 ... Green light emitting phosphor layer, 7 ... Red light emitting phosphor layer ,
DESCRIPTION OF SYMBOLS 10 ... Black matrix, 11, 12, 13 ... Optical filter layer, 60 ... Cathode ray tube, 61 ... Vacuum envelope, 62
... Neck tube, 63 ... cone, 64 ... glass panel, 66
… Electron gun, 67… phosphor screen

Claims (8)

[Claims] 1. An inner surface of a glass panel for a color cathode ray tube,
Step of forming a black matrix having a dot-shaped or stripe-shaped hole, red, green, and using a blue light-emitting phosphor and a photoresist, red, green, and blue light-emitting phosphor slurry respectively prepared, at least A method for forming a phosphor screen, comprising the steps of forming red, green, and blue light-emitting phosphor layers in a dot shape or a stripe shape, respectively, in the hole portion, wherein one color of the red, green, and blue light-emitting phosphor layers is provided. Wherein the size of the hole in which the phosphor layer is to be formed is larger than the size of the hole in which the phosphor layers of the other two colors are to be formed. 2. Prior to the step of forming the red, green, and blue light emitting phosphor layers, an optical filter film capable of selectively transmitting light having a wavelength corresponding to the wavelength of the emission color of each phosphor layer is provided. The method of claim 1, further comprising the step of forming. 3. A phosphor layer having a hole portion size larger than that of the phosphor layers of the other two colors has a higher content of the ultraviolet sensitizer than the phosphor layers of the other two colors. Claim 1
The method described in. 4. The method of claim 1, wherein only the green light-emitting phosphor layer of the red, green and blue light-emitting phosphor layers is larger than the red light-emitting phosphor layer and the blue light-emitting phosphor layer. Item 4. The method according to any one of Items 1 or 3. 5. A black matrix having a dot-shaped or stripe-shaped hole formed on a glass panel, and a phosphor screen having at least red, green, and blue light-emitting phosphor layers respectively formed in the hole. The size of the hole in which the phosphor layer of one of the red, green, and blue light emitting phosphor layers is to be formed is larger than the size of the hole in which the phosphor layers of the other two colors are to be formed. A phosphor screen, characterized in that: 6. An optical filter capable of selectively transmitting light having a wavelength corresponding to the wavelength of the emission color of each phosphor layer between the glass panel and the red, green, and blue light emitting phosphor layers. The phosphor screen according to claim 5, further comprising a film. 7. The red, green and blue light emitting phosphor layers, wherein only a green light emitting phosphor layer is larger in size than the red light emitting phosphor layer and the blue light emitting phosphor layer. 7. The fluorescent screen according to 5 or 6. 8. The phosphor screen according to claim 5, wherein the phosphor screen is formed so as to seal a neck tube, a funnel extending in a funnel shape from the neck tube, and an opening of the funnel. A color cathode ray tube comprising: a vacuum envelope having a glass panel; and an electron gun provided in the neck tube so as to face the glass panel.