JP2000011903A - Light emitting device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency of light emission by setting the surface roughness of a light emitting surface of a light emitting body film adapted to emit light, according to the excitation ray from an exciting light source to a specified value or less. SOLUTION: When an exciting ray 2 from an excitation source 1A is applied to a light emitting body film 3, the light emitting body film 3 emits light 4, and the light 4 can be observed from the direction where the excitation light source 1A is arranged. When the surface roughness of the light emitting surface of the light emitting body regulated to the maximum height is set at 5 μm or less or twice or less the average particle diameter of the fluorescent powder material, the emitted light 4 is emitted with good directivity hardly undergoing scattering. When the surface roughness is 2 μm or less or the average particle diameter of the fluorescent powder material or less, the increase in light emission intensity due to the minimization of surface roughness reaches a saturation point, so that the emitted light 4 is emitted with good directivity with little scattering. The filling factor of the fluorescent powder material in the light emitting body film is det at 37 or 38-39%. The surface roughness of the light emitting surface can be set comparatively simply to 5 μm or less, 3 μm at average by application of fluorescent body ink with the viscosity of 1,000 cps or less at a cross speed of 10/s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor film, a light emitting device such as a plasma display panel using rare gas discharge light emission used in a color television receiver for character or image display, a display, and the like, and its manufacture. It is about the method.

[0002]

2. Description of the Related Art A conventional plasma display panel (hereinafter, referred to as PDP) will be described with reference to the drawings. FIG. 13 is a sectional view schematically showing an AC surface discharge type plasma display panel.

In FIG. 13, reference numeral 41 denotes a front glass substrate (front cover plate) on which a display electrode 42 is formed. Further, the front glass substrate 41 on which the display electrodes 42 are formed
Are covered with a dielectric glass layer 43 and a dielectric protection layer (magnesium oxide) 44.

[0005] Reference numeral 45 denotes a rear glass substrate (back plate).
6, a partition 47 and a phosphor layer 48 are provided. 4
9 is a dielectric protection layer 44, a rear glass substrate 45, and a partition wall 47.
And a discharge space surrounded by
A discharge gas is sealed in the tube 9. The phosphor layer 48 is red,
Each of the phosphor layers 48r, 48g, 48b of three colors of green and blue is housed and arranged in order in each of the adjacent discharge spaces 49. The phosphor layers 48r, 48g, and 48b of these colors emit and emit light by ultraviolet rays having a short wavelength (147 nm) generated by discharge.

[0005] A schematic configuration of such a PDP is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-342991.

[0006]

When a television having a small area occupied by each pixel, such as a high-definition television, is to be constructed using the PDP thus constructed, the luminance of the PDP is greatly increased. There was a problem that must be raised. This will be described below.

It is known that a display device using a CRT can obtain a luminance of about 500 cd / m ² by the current technology. On the other hand, in the conventional PDP, a 40-inch NTSC panel (the number of cells: 640 × 480, the cell pitch: 0.43 mm × 1.29 mm, the cell area: about 0.1 mm).
55 mm ² ), a luminance of about 250 cd / m ² ,
That is, only about half the luminance of the CRT can be obtained. This is described, for example, in "Functional Materials", February 1996, Vol. 16, No. 2, page 7 [published by CMC Corporation].

On the other hand, a full-spec high-definition television has a very small number of pixels (1920 × 1125), a cell pitch (0.15 mm × 0.48 mm: 42 inch class), and a cell area (0.072 mm ² ). Pixel level. In a PDP, it is known that the radiation efficiency of ultraviolet rays generated from a discharge space becomes worse as the discharge space becomes smaller. That is, as the discharge space becomes smaller, the ratio of the surface area of the discharge space to the discharge space (the area of the side wall or the like in contact with the discharge space) increases, whereby ions and electrons generated by the plasma discharge are reduced. This is considered to be due to the fact that it is easily absorbed by the side walls, which causes a decrease in the amount of ultraviolet radiation.

Therefore, if a 42-inch PDP for a high-definition television is manufactured with a conventional cell configuration, the panel luminous efficiency (= luminance / input power) is 0.15 to 0.17.
lm / W, NTS of the same size (42 inches)
1 compared to plasma display panels for C-TV
/ 7 to 1/8.

As described above, the PDP has a feature that it has structurally lower luminance than the CRT, and also has a characteristic that the radiation efficiency of the ultraviolet ray is reduced in accordance with the miniaturization of the pixel. If a television with a small pixel such as a high-definition television is manufactured using the PDP and the brightness of the television is set to be the same as that of the current NTSC television, the P
Obviously, the brightness of the DP had to be significantly improved.

Accordingly, an object of the present invention is to provide a light emitting device such as a PDP which operates with relatively high luminous efficiency by forming a luminous film having good luminous characteristics.

[0012]

In order to achieve the above object, the present invention provides a light emitting device provided with a light emitting film which emits light based on an excitation line emitted from an excitation source, wherein the light emitting device is defined by a maximum height. The light emitting surface of the light emitting film has a surface roughness of 5 μm.
The features are as follows.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a light emitting device having a light emitting film that emits light based on an excitation ray emitted from an excitation source, and is defined by a maximum height. It is characterized in that the surface roughness of the light emitting surface of the light emitting film is set to 5 μm or less, thereby having the following effects. That is, in the light emitting film, the emitted light is scattered according to the surface roughness of the light emitting surface. In the present invention, by setting the surface roughness of the light emitting surface defined by the maximum height to 5 μm, it is possible to irradiate the light emitted from the light emitting surface forward with good directivity without causing large scattering.

The outline of the operation of the light emitting device of the present invention will be described below.
Description will be made based on the conceptual diagram of FIG. In FIG. 1, reference numeral 1 denotes an excitation source, 2 denotes an excitation line, 3 denotes a light-emitting film such as a phosphor film, and 4 denotes light such as visible light emitted by excitation of the light-emitting film. The luminous film 3 emits light 4 such as visible light, and the maximum height of the surface roughness defined by the maximum height is 5 mm.
It is formed to be less than μm. The excitation beam 2 has a function of causing the luminous film 3 to emit light, and is composed of ultraviolet rays, electron beams, X-rays, and the like. The excitation source 1 performs an operation of generating an excitation ray 2, and includes an ultraviolet light source, an electron beam source, an X-ray source, and the like. Note that the excitation source 1 and the phosphor film 3 are arranged so that the direction in which the light emitting film 3 emits the light 4 is opposite to the direction in which the phosphor film is irradiated with excitation light.

When the excitation light 2 from the excitation source 1 irradiates the light emitting film 3, the light emitting film 3 emits light 4, and the light 4 can be observed from the direction in which the excitation source 1 is arranged. here,
Since the luminous film 3 has a maximum surface roughness of 5 μm or less, the emitted light is radiated with good directivity toward the excitation source 1 without being greatly scattered. On the light source 1 side, light 4 with high emission intensity can be observed.

According to a second aspect of the present invention, in the light emitting device according to the first aspect, the surface roughness of a light emitting surface of the light emitting film defined by a maximum height is set to 2 μm or less. This has the following effects. That is, when the surface roughness of the light emitting surface defined by the maximum height is set to 2 μm or less, the increase in light emission intensity due to miniaturization of the surface roughness reaches the saturation point. Therefore, the emitted light from the light emitting surface can be radiated forward with good directivity without substantially scattering.

According to a third aspect of the present invention, there is provided a light-emitting device including a light-emitting film which emits light based on an excitation line emitted from an excitation source, wherein the light emission is defined by a ten-point average roughness. It is characterized in that the surface roughness of the light emitting surface of the body film is set to 3 μm or less, thereby having the following effects. That is, the emitted light is scattered according to the surface roughness of the light emitting surface. According to the present invention, by setting the surface roughness of the light emitting surface defined by the ten-point average roughness to 3 μm, it is possible to irradiate the light emitted from the light emitting surface forward with good directivity without causing large scattering. it can.

According to a fourth aspect of the present invention, there is provided the light emitting device according to the third aspect, wherein the surface roughness of the light emitting surface of the light emitting film defined by the ten-point average roughness is 1 μm or less. Thus, it has the following effects. That is, when the surface roughness of the light emitting surface defined by the ten-point average roughness is set to 1 μm or less, the increase in the light emission intensity due to the miniaturization of the surface roughness reaches the saturation point. Therefore, the emitted light from the light emitting surface can be radiated forward with good directivity without substantially scattering.

According to a fifth aspect of the present invention, there is provided a light emitting device including a light emitting film containing a phosphor powder material that emits visible light based on an excitation ray emitted from an excitation source, It is characterized in that the light emitting surface of the light emitting film has a surface roughness of twice or less the average particle diameter of the phosphor powder material, thereby having the following effects. That is,
The emitted light is scattered according to the surface roughness of the light emitting surface. According to the present invention, the surface roughness of the light emitting surface is set to be not more than twice the average particle diameter of the phosphor powder material, so that the emitted light of the light emitting surface is not scattered largely and has good directivity toward the front. Can be irradiated.

According to a sixth aspect of the present invention, there is provided the light emitting device according to the fifth aspect, wherein a surface roughness of a light emitting surface of the light emitting film is not more than an average particle diameter of the phosphor powder material. This has the following effects. That is, when the surface roughness of the light emitting surface is set to be equal to or less than the average particle diameter of the phosphor powder material, the increase in the light emission intensity due to the miniaturization of the surface roughness reaches the saturation point. Therefore, the emitted light from the light emitting surface can be radiated forward with good directivity without substantially scattering.

According to a seventh aspect of the present invention, there is provided the light emitting device according to any one of the first to sixth aspects, wherein the surface roughness is defined by a sectional curve from which a frequency component of 10 μm or less is removed. Is characterized by the fact that
This has the following effect. In other words, the surface roughness of the light-emitting surface includes a fine unevenness component that cannot be reduced even by a method of the manufacturing method, and a waviness component of a relatively long wavelength that can be reduced by the method of the manufacturing method and that mainly affects light scattering. Exists. In the present invention, the above-mentioned minute unevenness component can be eliminated by removing the frequency component of 10 μm or less in the definition of the surface roughness.

According to an eighth aspect of the present invention, in the light emitting device according to any one of the first to sixth aspects, the surface roughness is defined by a sectional curve from which a frequency component of 2 μm or less is removed. It has the characteristic that it has the following effects. In other words, the surface roughness of the light emitting surface is caused by the microscopic unevenness component that is caused by the particle size of the phosphor powder material and cannot be reduced by the method of the manufacturing method, and that the surface roughness can be reduced by the method of the manufacturing method and is mainly light scattering. And a swell component having a relatively long wavelength which influences the wavelength. In the present invention, in the definition of the surface roughness, 2 μm
By removing frequency components below m, the above-mentioned minimal unevenness component can be eliminated.

According to a ninth aspect of the present invention, there is provided a light emitting device comprising a light emitting film containing a phosphor powder material that emits visible light based on an excitation ray emitted from an excitation source, The filling rate of the phosphor powder material in the light emitting film is set to 3
It is characterized in that it is set to 7 or more than 38 to 39%, thereby having the following effects. That is, since the filling rate of the phosphor powder material in the light emitting film is 37 or 38 to 39% or more, light emitted toward the inside of the light emitting film is reflected by the phosphor powder material inside. The rate toward the front, that is, the internal reflectance increases.

According to a tenth aspect of the present invention, there is provided the light emitting device according to the ninth aspect, wherein the filling rate of the phosphor powder material in the luminous film is 45% or more. This has the following effects. That is, the filling rate of the phosphor powder material in the light emitting film is 45%.
% Or more, almost all the light emitted toward the inside of the phosphor film is reflected by the phosphor powder material inside and travels forward.

According to an eleventh aspect of the present invention, there is provided the light emitting device according to the ninth or tenth aspect, wherein the phosphor powder in the luminous body film is cut at a cut surface when the luminous body film is cut. It is characterized in that the 3/2 power of the area ratio occupied by the material is defined as the filling rate of the phosphor powder material in the luminous film, thereby having the following effect. That is, the filling rate of the phosphor powder material can be accurately measured by a relatively simple method.

According to a twelfth aspect of the present invention, in the light emitting device according to the ninth or tenth aspect, the volume ratio occupied by the phosphor powder material in the luminous body film is determined. Is characterized in that it is defined as the filling rate of the phosphor powder material in the above, and has the following effects. That is, the filling rate of the phosphor powder material can be accurately measured by a relatively simple method.

According to a thirteenth aspect of the present invention, there is provided the light emitting device according to any one of the first to twelfth aspects, wherein the light emitting device is a plasma display panel, and the light emitting film is a plasma display panel. Is characterized in that it is a phosphor film provided in a discharge space possessed by the above, and thereby has the following operation. That is,
The plasma display panel has a problem that it is necessary to increase the luminous efficiency by increasing the brightness. If the present invention is applied to the plasma display panel having such a problem, the luminous efficiency of the present invention is increased. The effect becomes effective.

According to a fourteenth aspect of the present invention, there is provided a method of manufacturing a light emitting device according to the first or third aspect, wherein the viscosity of the phosphor ink is 1000 cps or less at a shear rate of 10 / s. The feature is that the luminous body film is formed by the method described above, thereby having the following effects. That is, the surface roughness of the light emitting surface of the light emitting film can be relatively easily set to 5 μm or less (maximum height) and 3 μm (ten-point average roughness).

According to a fifteenth aspect of the present invention, there is provided a method for manufacturing the light emitting device according to the second or fourth aspect, wherein the viscosity of the phosphor ink is 200 cps or less at a shear rate of 10 / s. The feature is that the luminous body film is formed by the method described above, thereby having the following effects. That is, the surface roughness of the light emitting surface of the light emitting film can be relatively easily set to 2 μm or less (maximum height) and 1 μm (ten-point average roughness).

According to a sixteenth aspect of the present invention, there is provided the method for manufacturing a light emitting device according to the fourteenth aspect, wherein the phosphor contains phosphor powder material at a weight ratio of 70% or less as the phosphor ink. It is characterized by using ink, and has the following effects. That is, a phosphor ink having a viscosity of 1000 cps or less at a shear rate of 10 / s can be easily prepared.

According to a seventeenth aspect of the present invention, there is provided the method for manufacturing a light emitting device according to the fifteenth aspect, wherein the phosphor contains phosphor powder material at a weight ratio of 60% or less as the phosphor ink. It is characterized by using ink, and has the following effects. That is, a phosphor ink having a viscosity of 200 cps or less at a shear rate of 10 / s can be easily prepared.

The invention according to claim 18 of the present invention is the manufacturing method for manufacturing a light emitting device according to claim 9, wherein the light emitting device is formed by applying a phosphor ink containing a resin component in a weight ratio of 3% or less. It is characterized by forming a film, and thereby has the following effects. That is, by using the phosphor ink containing the resin component at a low ratio of 3% or less by weight, the filling ratio of the phosphor powder material is reduced to 40%.
The luminous film having such a high value can be easily and reliably formed.

According to a nineteenth aspect of the present invention, there is provided a method for manufacturing the light emitting device according to the tenth aspect, wherein the phosphor is formed by applying a phosphor ink containing a resin component in a weight ratio of 1% or less. It is characterized by forming a film,
This has the following effect. That is, by using the phosphor ink containing the resin component at a particularly low ratio of 1% or less by weight, the filling rate of the phosphor powder material can be increased to a substantially saturated state. This gives 4
A light-emitting film having a high filling rate of the phosphor powder material such as 5% or more can be easily and reliably formed.

Hereinafter, a plasma display panel according to an embodiment of the present invention will be described with reference to the drawings.

Embodiment 1 FIG. 2 is a sectional view schematically showing an AC surface discharge type plasma display panel (hereinafter, referred to as PDP) according to Embodiment 1 of the present invention. Although only one cell is shown in FIG. 2, it goes without saying that a PDP is configured by arranging a large number of cells that emit red, green, and blue light.

This PDP has a front panel 20 and a back panel 21. The front panel 20 is configured such that a display electrode 12, a dielectric glass layer 13, and a protective layer 14 are sequentially formed on a front glass substrate (front cover plate) 11. The rear panel 21 has an address electrode 16 on a rear glass substrate (back plate) 15.
, A visible light reflecting layer 17, a partition wall 18, and a phosphor film (corresponding to a light emitting film in the claims) 19A are sequentially formed. Then, after the front panel 20 and the rear panel 21 having such a configuration are adhered to each other, a discharge gas is sealed in a discharge space 22 formed between the front panel 20 and the rear panel 21 to form a PDP. Have been.

The present embodiment is characterized in that the surface roughness of the light emitting surface 19a of the phosphor film 19A is set as follows. That is, the surface roughness of the light emitting surface 19a of the phosphor film 19A is set to 2 μm at the maximum height (see JIS G0601).
m, whereby the light emitted by the phosphor film 19A can be extracted from the light emitting surface 19a to the front with high directivity with maximum directivity. Hereinafter, the reason will be described with reference to FIGS.

In general, light emission of the phosphor film occurs on the outermost surface and is scattered by irregularities on the surface of the phosphor film. As a result,
The intensity of visible light traveling in front of the phosphor film depends on the surface roughness of the phosphor film. By reducing the surface roughness, the generated light can be effectively extracted to the front of the phosphor film.

FIGS. 3 and 4 show a light emitting device shown in FIG. 1 using the same phosphor film 19A as that of the first embodiment, which is generated by an excitation source 1A composed of a Xe excimer lamp. Vacuum ultraviolet light (wavelength: 172 nm)
2 shows the surface roughness dependence of the relative luminance of the reflected visible light when the phosphor film 19A emits light. 3 and 4, the horizontal axis represents the surface roughness defined by the maximum height, and the vertical axis represents the relative luminance of the phosphor film 19.
Here, the relative luminance is a value in which each luminance value is expressed as a percentage, with the luminance value when the luminance fluctuating due to the change in the surface roughness is saturated as 100%.

In a PDP, the phosphor film 19A
Is also formed on the side surface of the partition wall 18, so that the phosphor film 19
The surface A has a large undulation at the side wall of the partition wall. Therefore, when a cross-sectional curve of the phosphor film 19A is formed along a direction orthogonal to the wall surface of the partition wall 18, the cross-sectional curve is formed to include large undulation components at both ends, and this undulation component is formed on the surface. It can be a noise component in roughness measurement. On the other hand, if the cross-sectional curve of the phosphor film 19A is formed along a direction parallel to the wall surface of the partition wall 18, the noise component need not be picked up. When forming a cross-sectional curve of the phosphor film 19A along a direction orthogonal to the wall surface of the partition wall 18, the cross-sectional curve may be formed excluding the waviness component.

The phosphor film 19A used for the measurement was a green phosphor (Zn ₂ Si) having a thickness of 20 μm and an average particle size of 2 μm.
O ₄ : Mn ²⁺ ) is used as a main component. In the measurement, the phosphor film 19A is set in a nitrogen atmosphere. FIG. 3 shows that the reference length is 2
The figure shows the result of measuring the surface roughness from the cross-sectional curve from which the frequency component of 10 μm or less was removed, with 50 μm. FIG. 4 shows a result of measurement from a cross-sectional curve from which a reference length is set to 30 μm and a frequency component of 2 μm or less is removed.

As apparent from FIGS. 3 and 4, when the surface roughness defined by the maximum height is about 2 μm or less, the relative luminance is saturated (100%), but the surface roughness becomes 2 μm or more. Thus, the relative luminance decreases as the surface roughness increases. Therefore, in order to extract the visible light emitted from the phosphor film 19A as effectively as possible, it is understood that the surface roughness specified by the maximum height needs to be 2 μm or less. In view of this, in the present embodiment, by setting the surface roughness of the light emitting surface 19a defined by the maximum height to 2 μm or less, the visible light emitted from the phosphor film 19A can be effectively used as much as possible. From the front with good directivity.

Embodiment 2 This embodiment is basically similar to Embodiment 1 shown in FIG.
And the structure will be described with reference to FIG. The same or similar parts as in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment is characterized in that the surface roughness of the light emitting surface 19a of the phosphor film 19B is set to a maximum height of 5 μm or less. Hereinafter, the reason will be described.

In the first embodiment, the visible light emitted from the phosphor film 19A is subjected to surface roughness so that the relative luminance that fluctuates with the surface roughness of the light emitting surface 19a becomes relatively 100%. By defining this, it is considered that visible light can be effectively extracted. However, if the visible light emitted from the phosphor film can extract at least about 90% of the relative luminance, it can be considered that the light can be extracted almost effectively. Based on this point, in the present embodiment, the visible light emitted from the phosphor film 19B is reduced to the relative luminance of about 9%.
The surface roughness of the light emitting surface 19a is defined so that 0% or more can be extracted. That is, as is clear from FIGS. 3 and 4, when the surface roughness specified by the maximum height is about 5 μm or less, the relative luminance shows about 90%, and the visible light emitted from the phosphor film 19B is It can be seen that the surface roughness specified by the maximum height needs to be 5 μm or less in order to take out almost effectively. In the present embodiment, based on this, the surface roughness of the light emitting surface 19a defined by the maximum height is set to 5 μm or less, and the phosphor film 19 is formed.
The light emitted in B is effectively extracted with good directivity forward from the light emitting surface 19a.

Embodiment 3 This embodiment is basically similar to Embodiment 1 shown in FIG.
And the structure will be described with reference to FIG. The same or similar parts as in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the light emitting surface 1 of the phosphor film 19C is used.
The feature is that the surface roughness of 9a is set as follows. That is, the surface roughness of the light emitting surface 19a of the phosphor film 19C is set to 1 μm as a ten-point average roughness (see JIS G0601).
m, whereby the light emitted by the phosphor film 19C can be extracted from the light emitting surface 19a to the front with high directivity with maximum directivity. Hereinafter, the reason will be described with reference to FIGS.

FIGS. 5 and 6 correspond to FIGS. 3 and 4, in which the phosphor film 19C according to the third embodiment is taken out to constitute the light emitting device shown in FIG. 1 and comprises a Xe excimer lamp. It shows the surface roughness dependence of the relative luminance of reflected visible light when the phosphor film 19B emits light with vacuum ultraviolet rays (wavelength: 172 nm) generated by the excitation source 1. The phosphor film 19C used for the measurement uses a green phosphor (Zn ₂ SiO ₄ : Mn ²⁺ ) having a thickness of 20 μm and an average particle size of 2 μm, similarly to the phosphor film 19A of the first embodiment. . In the measurement, the phosphor film 19C is set in a nitrogen atmosphere. FIG. 5 shows that the reference length is 250 μm.
m, the surface roughness was measured from the cross-sectional curve from which the frequency component of 10 μm or less was removed. FIG.
Shows the measurement result from the cross-sectional curve from which the reference length is 30 μm and the frequency component of 2 μm or less is removed.

As is clear from FIGS. 5 and 6, when the surface roughness specified by the ten-point average roughness is about 1 μm or less, saturated relative luminance (100%) is exhibited, but the surface roughness is reduced. At 1 μm or more, the relative luminance decreases as the surface roughness increases. Therefore, the phosphor film 1
It can be seen that in order to extract the visible light emitted at 9C as effectively as possible, the surface roughness specified by the ten-point average roughness must be 1 μm or less. In the present embodiment, based on this, the light emitting surface 19 defined by the ten-point average roughness is used.
The light emitted by the phosphor film 19C is extracted from the light emitting surface 19a to the front with good directivity with the surface roughness of a set to 1 μm or less.

Embodiment 4 This embodiment is basically similar to Embodiment 1 shown in FIG.
And the structure will be described with reference to FIG. The same or similar parts as in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment is characterized in that the surface roughness of the light emitting surface 19a of the phosphor film 19D is set to 3 μm or less in ten-point average roughness. Hereinafter, the reason will be described.

In the third embodiment, the relative luminance, which fluctuates with the fluctuation of the surface roughness of the light emitting surface 19a, is relatively about 10%.
The surface roughness of the light emitting surface 19a is defined so as to be 0%. However, if the visible light emitted from the phosphor film can extract at least about 90% of the relative luminance described above, it can be considered that the light can be extracted almost effectively.
Based on this point, in the present embodiment, the surface roughness of the light emitting surface 19a is defined so that approximately 90% or more of the visible light emitted from the phosphor film 19D can be extracted. That is, as is clear from FIGS. 5 and 6, the surface roughness defined by the ten-point average roughness shows about 90% of the relative luminance when the surface roughness is about 3 μm or less.
In order to extract the visible light emitted by 9D almost effectively,
It is understood that the surface roughness specified by the ten-point average roughness needs to be 3 μm or less. In the present embodiment, based on this, the surface roughness of the light emitting surface 19a defined by the ten-point average roughness is set to 3 μm or less, and the light emitted by the phosphor film 19D is effectively removed from the light emitting surface 19a. It is taken out with good directivity toward the front.

FIG. 3 referred to in Embodiments 1 to 4
In the measurement of FIG. 4, the reason for measuring the surface roughness from the cross-sectional curve from which the frequency component of 10 μm or less is removed is as follows. That is, as shown in FIG. 7 (a), the measured cross-sectional curve f includes a waviness component (long wavelength component) f1 and a fine unevenness component (short wavelength component) f2 on the surface. Of these surface roughness components f1 and f2, the minute unevenness component f2 is difficult to adjust its size (reduce the unevenness), whereas the long wave component waviness component f1 is difficult to adjust. It is possible to adjust the size (reduce the undulation) by devising the manufacturing method. Further, light scattering can be controlled by adjusting the size of the swell component f1. By removing the frequency component of 10 μm or less from the cross-sectional curve, the minute unevenness f
2 can be selectively removed.

Therefore, in the measurement results shown in FIGS. 3 and 4,
After removing the frequency component of 10 μm or less from the cross-sectional curve, the relationship between the remaining undulation component (long wavelength component) f1 and the relative luminance is graphed. As a result, FIG.
As shown in (b), the fine unevenness component f which is a noise component for the relationship between the adjustable waviness component f1 and the relative luminance.
2. A measurement result (cross-sectional curve) f ′ obtained by selectively removing 2 is obtained, and the detection accuracy of the relative relationship between the light scattering and the adjustment of the surface roughness is increased to further enhance the effect of preventing the light scattering. Can be.

FIGS. 5 and 5 referred to in the first to fourth embodiments.
The reason why the surface roughness is measured from the cross-sectional curve from which the frequency component of 2 μm or less is removed in the measurement of FIG. 6 is as follows. That is, when the above-mentioned minute unevenness component f2, which is a noise component for the relationship between the undulation component f1 and the relative luminance, is analyzed, it can be seen that most of the components are constituted by the following. That is, the phosphor films 19A to 19D
Are formed using a phosphor powder material as a main raw material. Therefore, as shown in FIG. 8A, the shape (particle size) of the particles r of the phosphor powder material is included in the frequency component of the cross-sectional curve f on the cross-sectional curve f obtained by measuring the surface of the light emitting surface 19a. , And the minimal unevenness component f2 ′ resulting from this is mixed. Since such an extremely small unevenness component f2 ′ is generated due to the shape (grain size) of the particles r of the phosphor powder material, it is difficult to adjust (decrease) the size thereof. f2 is mainly composed of such minimal unevenness component f2 '.

Observation of the minimum unevenness component f2 'revealed that it was composed of frequency components of 2 μm or less. Therefore, it can be seen that the frequency component of 2 μm or less should be removed from the sectional curve in order to selectively remove the minimal unevenness component f2 ′. Therefore, in the measurement results shown in FIGS. 5 and 6, after removing the frequency component of 2 μm or less from the cross-sectional curve, the relationship between the remaining undulation component (long wavelength component) f1 and the relative luminance is graphed. .
As a result, as shown in FIG. 8B, a measurement result (cross-sectional curve) is obtained in which the minimal unevenness component f2 ′, which is a noise component for the relationship between the adjustable waviness component f1 and the relative luminance, is selectively removed. . Therefore, the detection accuracy of the relative relationship between the light scattering and the adjustment of the surface roughness is improved, and the effect of preventing the light scattering can be further enhanced.

In FIG. 8, in order to clarify that the minimal unevenness component f 2 ′ is generated due to the shape (particle size) of the particles r of the phosphor powder material, FIG. The scale is increased.

In the first to fourth embodiments, the present invention is implemented by defining the surface roughness of the phosphor film 19 by an absolute value such as a maximum height and a ten-point average roughness. However, the surface roughness of the light emitting surface 19a in the present invention can be relatively defined by the average particle diameter rh of the particles r of the phosphor powder material constituting the phosphor film 19.

Generally, the average particle diameter of the particles r of the phosphor powder material is about 2 μm. Therefore, the surface roughness of the phosphor film 19 according to the above-described first to fourth embodiments is defined as follows based on the phosphor powder material having the particles r having an average particle diameter of 2 μm. . That is, when the surface roughness of the light emitting surface 19a of the phosphor film 19 is set to be not more than twice the average particle diameter rh of the particles r of the phosphor powder material constituting the phosphor film 19, the phosphor film 19 emits light. About 90% or more of the emitted light can be extracted from the light emitting surface 19a forward with good directivity. In this case, the surface roughness may be defined by the maximum height or the ten-point average roughness.

Further, when the surface roughness of the light emitting surface 19a of the phosphor film 19 is set to be equal to or less than the average particle size rh of the particles r of the phosphor powder material constituting the phosphor film 19, the phosphor film 19 emits light. Almost 100% or more of the emitted light can be extracted from the light emitting surface 19a forward with good directivity.

Embodiment 5 This embodiment is basically similar to Embodiment 1 shown in FIG.
And the structure will be described with reference to FIG. The same or similar parts as in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The PDP of the present embodiment has a phosphor film 19E
A blue phosphor (BaMgAl ₁₀ O) having an average particle size of 2 μm
₁₇ : 20 μm thick mainly containing powder material of Eu ²⁺ )
m, and the filling rate of the blue phosphor powder material in the phosphor film 19E is set to 45% or more. Thus, the light emitted by the phosphor film 19E is extracted from the light emitting surface 19a to the front as efficiently as possible. Hereinafter, the reason will be described with reference to FIG.

In general, in the phosphor film, the visible light emitted from the outermost surface also enters the inside of the phosphor film, and a part of the visible light is reflected by the phosphor powder material contained in the phosphor film. From the phosphor film surface toward the front of the panel. Therefore, the intensity of light traveling forward of the phosphor film depends on the filling rate of the phosphor powder material in the phosphor film, and by increasing the filling rate of the phosphor powder material, the reflection of the phosphor film is increased. The effect is enhanced, and the emitted light can be effectively extracted from the front.

FIG. 9 shows a phosphor film 1 according to the fifth embodiment.
9E is taken out to constitute the light emitting device shown in FIG. 1, and the relative luminance of the reflected visible light when the phosphor film 19E emits light with vacuum ultraviolet rays (wavelength: 254 nm) generated by the excitation source 1B composed of a mercury lamp. This shows the charging rate dependency of the phosphor powder material. In FIG. 9, the horizontal axis indicates the filling rate of the phosphor powder material, and the vertical axis indicates the relative luminance of the phosphor film 19E. Here, the relative luminance is the same as that described in the first embodiment, and the filling rate of the phosphor powder material is (volume of phosphor powder material / volume of phosphor film 19E). Say. In the measurement, the phosphor film 19E is set in a nitrogen atmosphere.

As apparent from FIG. 9, when the filling rate of the phosphor powder material is about 45% or more, the relative luminance is saturated (becomes 100%), but when the filling rate becomes less than 45%, the filling rate becomes lower. The relative luminance decreases with the decrease. Therefore, in order to extract the visible light emitted from the phosphor film 19E as effectively as possible, it is understood that the filling rate of the phosphor powder material is required to be 45% or more. In the present embodiment, based on this, by setting the filling rate of the phosphor powder material to 45% or more, the visible light emitted from the phosphor film 19E can be effectively and forwardly directed from the light emitting surface 19a. Out.

Embodiment 6 This embodiment has basically the same configuration as that of Embodiment 5, and its structure will be described with reference to FIG. Furthermore, the same or similar parts as in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

The present embodiment is characterized in that the phosphor powder material filling rate of the phosphor film 19F is set to 37% or more. Hereinafter, the reason will be described.

In the fifth embodiment, the visible light emitted from the phosphor film 19E is changed so that the relative luminance that fluctuates with the difference in the filling ratio of the phosphor powder material becomes relatively 100%.
It is considered that by defining the filling rate of the phosphor powder material, visible light can be effectively extracted. However, if the visible light emitted from the phosphor film can extract at least about 90% of the relative luminance, it can be considered that the light can be extracted almost effectively. Based on this point, in the present embodiment, the filling ratio of the phosphor powder material is defined so that the visible light emitted from the phosphor film 19F can be extracted at about 90% or more of the relative luminance. That is, as is apparent from FIG. 9, the filling rate of the phosphor powder material is 37%.
In the above description, the relative luminance indicates approximately 90%, and it can be seen that in order to effectively extract the visible light emitted from the phosphor film 19F, the phosphor powder material filling rate needs to be 37% or more. . In the present embodiment, based on this, the filling rate of the phosphor powder material is set to 37% or more, and the light emitted by the phosphor film 19F is effectively extracted forward from the light emitting surface 19a.

In this embodiment, the blue phosphor (Ba
This is an embodiment in which a phosphor film 19E mainly containing a powder material of MgAl ₁₀ O ₁₇ : Eu ²⁺ ) is provided, but the feature of this embodiment (the filling rate of the phosphor powder material is 37% or more). To increase the efficiency of forward light emission), it is also possible to apply to a green phosphor such as Zn ₂ SiO ₄ : Mn ²⁺ . However, (Y _X Gd _1-X ) B
In a phosphor film containing a powder material of a red phosphor such as O ₃ : Eu ³⁺ , the current filling rate of the phosphor powder material is about 37%. In the current PDP having the above, the relative luminance secures 90%. Therefore, in order to effectively extract light forward from the light emitting surface 19a in the phosphor film 19F 'containing the powder material of the red phosphor, the filling ratio of the phosphor powder material is set to 40.
It needs to be%.

Hereinafter, a method of manufacturing the PDP according to the first to sixth embodiments will be described.

Manufacturing of Front Panel 20 The front panel 20 has a display electrode 1 on a front glass substrate 11.
2 is formed, and is covered with a lead-based dielectric glass layer 13, and a protective layer 14 is formed on the surface of the dielectric glass layer 13.

The display electrode 12 is, for example, a silver electrode. In this case, the display electrode 12 is formed by a method in which a paste for a silver electrode is screen-printed and then fired. The dielectric glass layer 13 of the lead system, lead oxide [PbO] 70 wt%, boron oxide [B ₂ O _3] 15 wt%, silicon oxide [SiO _2] 15 wt%
And is formed to a thickness of about 20 μm by screen printing and baking.

Next, CVD is performed on the dielectric glass layer 13 described above.
A protective layer 14 of magnesium oxide (MgO) having a thickness of 1.0 μm is formed by a chemical vapor deposition method. Thereby, the front panel 20 is completed.

Manufacturing of Back Panel 21 First, the address electrodes 16 are formed on the back glass substrate 15 by a method of screen-printing a silver electrode paste and then firing the paste. A visible light reflecting layer 17 made of TiO ₂ particles and dielectric glass is formed thereon by screen printing and baking. Further, the glass partition walls 18 having a height are formed at a predetermined pitch by repeating the same screen printing and then firing.

Then, in each space sandwiched by the partition walls 18,
One phosphor film 19A to 19F among the red phosphor, the green phosphor, and the blue phosphor is formed. This phosphor film 19A-
The method of forming 19F and the phosphor material and ink used therefor will be described in detail later, but the phosphor ink is applied by a method of scanning while continuously ejecting the phosphor ink from the nozzles, and the phosphor ink is applied and baked. Form.

When a 40-inch class high-definition television is manufactured, the height of the partition 18 is 0.1 to 0.1 mm.
0.15 mm, the pitch of the partition walls 18 is 0.15 to 0.3 m
m. The thickness of the phosphor film 19 formed on the side surfaces of the rear glass substrate 15 and the partition wall 18 is 5 to 50 μm.

Production of PDP by Laminating Panels Next, the front panel 20 and the rear panel 21 produced in this manner are laminated using sealing glass. At this time, the display electrodes 12 and the address electrodes 16 are attached so as to be orthogonal to each other. Further, at this time, after the inside of the discharge space 22 partitioned by the partition wall 18 is evacuated to a high vacuum (about 8 × 10 ⁻⁷ Torr), a discharge gas having a predetermined composition is sealed at a predetermined pressure. Thus, the PDP is completed.

In this manufacturing method, X in the discharge gas
e content is 5% by volume, and the sealing pressure is 500-800.
It is set in the range of Torr.

Phosphor Material and Ink As the phosphor powder material constituting the phosphor ink used when forming the phosphor film, those generally used as the phosphor film of PDP may be used. it can. Specific examples thereof include a blue phosphor: BaMgAl ₁₀ O ₁₇ : Eu ²⁺ green phosphor: Zn ₂ SiO ₄ : Mn ²⁺ , or BaAl ₁₂ O ₁₉ :
Mn ²⁺ red phosphor: YBO ₃ : Eu ³⁺ or (Y _X Gd _1-X ) BO
₃ : Eu ³⁺ or Y ₂ O ₃ : Eu ³⁺ . Further, the phosphor powder material of each color can be produced as follows.

[0080] As blue phosphor powder material feed, barium carbonate (BaCo _3), magnesium carbonate (MgCO _3), aluminum oxide (α-Al ₂ O ₃₎
Is blended so that the atomic ratio of Ba, Mg, and Al is 1: 1: 1: 10. Then adding a predetermined amount of europium oxide (Eu ₂ 0 ₃₎ with respect to the mixture. Further, the mixture was mixed with an appropriate amount of flux (AlF ₂ , BaCl ₂ ) in a ball mill,
By firing at 1400 ° C. to 1650 ° C. for a predetermined time (for example, 0.5 hour) in a weak reducing atmosphere (in H ₂ and N ₂ ), a blue phosphor powder material is obtained.

Yttrium hydroxide Y ₂ (OH) ₃ , boric acid (H ₃ BO ₃ ), and Y and B are used as a red phosphor powder material raw material in an atomic ratio of Y and B of 1: 1.
It is blended so that it becomes. Next, a predetermined amount of europium oxide (Eu ₂ O ₃ ) was added to this mixture, and the mixture was mixed with an appropriate amount of flux using a ball mill.
By firing at 〜1450 ° C. for a predetermined time (for example, 1 hour), a red phosphor powder material is obtained.

[0082] Zinc oxide as a green phosphor powder material feed (ZnO), silicon oxide (Si0 ₂₎
Is blended so that the atomic ratio of Zn and Si is 2: 1.
Next, a predetermined amount of manganese oxide (Mn ₂ O ₃ ) was added to the mixture, and the mixture was mixed in a ball mill.
The green phosphor powder material is obtained by firing at 50 ° C. for a predetermined time (for example, 0.5 hour).

The phosphor ink can be prepared by mixing the above-mentioned phosphor material powder of each color, a solvent component, and if necessary, a binder resin, a surfactant, silica and the like so as to have an appropriate viscosity.

Production of Phosphor Film In general, a phosphor film to be incorporated in a PDP is produced by a screen printing method or a photolithography method.
In this case, since the viscosity of the phosphor ink used is high and the fluidity is low, the surface roughness of the produced phosphor film is 5 μm or more at the maximum height and 3 μm or more at the ten-point average roughness.

On the other hand, if the fluidity of the phosphor ink is increased, the surface roughness of the phosphor film to be produced can be reduced. The inventor of the present application has conducted various experiments, and as a result, if the fluidity of the phosphor ink is set as follows,
It has been found that the surface roughness of the phosphor film can be set to a value required in the present invention. That is, a shear rate of 10 / s
In the case of using phosphor ink having a viscosity of 1000 cps or less, phosphor films 19B and 19D having surface roughness (maximum height of 5 μm or less, or ten-point average roughness of 3 μm or less) as in Embodiments 2 and 4 are formed. Can be made. Further, when a phosphor ink having a viscosity of 200 cps or less at a shear rate of 10 / s is used, the tendency of decreasing the surface roughness is almost saturated, and as in Embodiment 1.3, the surface roughness (maximum height 2 μm or less) Or 10-point average roughness 1 μm or less)
Can be produced.

To produce each of the low-viscosity phosphor inks described above, for example, the following method may be used. That is,
The weight of the phosphor powder material is 70 times the weight of the entire phosphor ink.
% Or less, 1000 c at a shear rate of 10 / s
A low-viscosity ink of ps or less can be produced. If the weight of the phosphor powder material is set to 60% or less of the weight of the entire phosphor ink, 200% at a shear rate of 10 / s.
A low-viscosity ink of cps or less can be produced.

On the other hand, when a phosphor film is produced by a screen printing method or a photolithography method, it is necessary to contain a resin component in the phosphor ink to be used. Generally, the phosphor film is formed by a screen printing method. In the case of manufacturing, at least 5% or more by weight of a binder resin is contained in the phosphor ink. When a phosphor film is formed by photolithography, the photosensitive resin is contained in an amount of about 20 to 40%. In such a configuration of the conventional phosphor ink, the binder resin and the photosensitive resin are about 0.3 to 2 times as much as the phosphor powder material in terms of volume, and when the phosphor films 19A to 19F are fired, Since these resin components evaporate, voids corresponding to the volume thereof are formed, and the filling rate of the phosphor powder material with respect to the entire phosphor film becomes less than 40%.

Therefore, if the amount of the binder resin and the amount of the photosensitive resin in the phosphor ink can be reduced, the filling rate of the phosphor powder material in the phosphor film to be produced can be increased. However, it is difficult to reduce the amount of a photosensitive resin or a binder resin to be added in a photolithography method or a screen printing method. Therefore, in the present invention, the amount of the binder resin to be added was reduced by improving the ink coating method, and thereby, the phosphor films 19E and 19F of the fifth and sixth embodiments were manufactured.

That is, the inventor of the present application performs various experiments to reduce the phosphor powder material weight to 3% or less of the entire phosphor ink weight, as in the sixth embodiment. It has been found that the filling rate of the phosphor powder material can be increased to 40% or more. Furthermore, if the weight of the phosphor powder material is set to 1% or less of the total weight of the phosphor ink, as in Embodiment 5, the filling rate of the phosphor powder material in the phosphor film 19E is almost the saturation point 45. %
I found that I could do more.

However, if the amount of the binder resin is reduced in this manner, it becomes difficult to produce a phosphor film by a normal screen printing method. Therefore,
In the present invention, it is possible to produce a phosphor film with a phosphor ink in which the amount of the binder resin is reduced by using the following ink coating device.

FIG. 10 shows a phosphor film 19 according to the fifth and sixth embodiments.
It is a schematic block diagram of the ink application apparatus 30 used when producing E and 19F. In the ink application device 30, a phosphor ink I is stored in a server 31, and a pressure pump 32 pressurizes the phosphor ink I and supplies the phosphor ink I to a header 33. The header 33 is provided with an ink chamber 33a and a nozzle 34.
Is supplied from the nozzle 34 continuously. This ink application device 3
In the case of 0, the phosphor ink I is continuously ejected from the nozzle 34, thereby making it possible to produce a phosphor film with the phosphor ink in which the amount of the binder resin is reduced.

Next, a PD incorporating the light emitting device of the present invention is described.
The result of measuring the panel luminance of P will be described with reference to Table 1.

The PDPs of Panel Nos. 1 to 7 are PDPs manufactured based on the above-described embodiment, and the viscosity of the phosphor ink or the binder resin concentration is set to various values so that the surface roughness of the phosphor film is reduced. Or the phosphor filling rate is changed. As an example of the PDP of the present invention, a cross-sectional SEM image of the blue phosphor film of panel number 4 is shown in FIG. The PDP of panel number 8 is the PDP according to the comparative example.
A DP having a phosphor film manufactured using a conventional screen printing method. FIG. 1 shows a cross-sectional SEM image of the blue phosphor film of the PDP of this comparative example (panel number 10).
It is shown in FIG.

In each of the above PDPs, the phosphor film thickness was set at 20 μm, the discharge gas pressure was set at 500 Torr, and the main wavelength of the ultraviolet light generated in the discharge space 22 was 146.
nm. The panel luminance of each PDP was measured under a discharge condition of a discharge sustaining voltage of 150 V and a frequency of 30 kHz. Further, in each PDP, the luminance of the light emitting layer of each color was set so that the white balance of the panel could be obtained at the time of light emission, and the luminance was measured with white lighting on the entire surface.

The surface roughness in the table indicates that the partition wall 18 (4
7) From the cross-sectional curve prepared along the vertical direction,
8 (47) is the surface roughness measured from the cross-sectional curve prepared by removing the undulation component generated near the partition wall 18 (4).
Even if the surface roughness is measured from the cross-sectional curve prepared along the direction parallel to 7), the phosphor film 19 (at the intermediate position between the two partition walls 18 (47) opposed to each other with the discharge space 22 (49) interposed therebetween. It has been confirmed that the surface roughness measured from the cross-sectional curve prepared from the section 48) was almost the same.

The surface roughness measured at a reference length of 250 μm is measured from a cross-sectional curve from which a frequency component of 10 μm or less has been removed. The surface roughness measured at a reference length of 30 μm has a frequency component of 2 μm or less removed. It was measured from the cross section curve.

The phosphor materials used were blue phosphor: BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , green phosphor: Zn ₂ Si.
O ₄ : Mn ²⁺ , red phosphor: (Y _X Gd _{1 -X} ) BO ₃ : Eu ³⁺
Is used. The average particle size of these phosphor powder materials is 2
μm. Terpineol is used as a solvent for the ink. Ethyl cellulose having a molecular weight of 40,000 is used as the binder resin. The binder resin concentration in the table is a weight ratio to the phosphor ink. The phosphor concentration in the table is the weight ratio of the phosphor powder in the phosphor ink.

The filling rate is determined by calculating the amount of the applied phosphor and the actual volume of the phosphor film.
The volume ratio occupied by the phosphor powder material therein was determined. However, the cross section of the prepared phosphor film was observed with a scanning electron microscope (SEM: see FIGS. 11 and 12), and the area ratio of the phosphor powder material in the phosphor film was determined. Even the same filling factor can be obtained by raising to the power of 3/2.

[0099]

[Table 1]

As is clear from Table 1, the light emission luminance (panel luminance) of the PDP is affected by the surface roughness and the filling factor of the phosphor film, and the surface roughness of the reference length 250 μm and the reference length 3
The surface roughness and the filling factor of 0 μm depend on the characteristics of the ink used when producing the phosphor film, and it was difficult to control each parameter independently, but the panel brightness of panel numbers 1 to 7 and 10 was reduced. As is clear from the comparison, it can be confirmed that as the surface roughness is reduced and the filling rate is increased, the panel luminance is improved, and a remarkable effect is obtained by adopting the configuration of the present invention. That was confirmed. Specifically, it was confirmed that the adoption of the configuration of the present invention improved the luminance by about 10 to 30% as compared with the conventional PDP.

In the measurement results shown in Table 1, Zn ₂ SiO ₄ : Mn ²⁺ was used as the green phosphor, and (Y _X Gd _{1 -X} ) BO ₃ : Eu ³⁺ was used as the red phosphor. However, even if BaAl ₁₂ O ₁₉ : Mn ²⁺ is used as the green phosphor, furthermore, YBO ₃ : Eu ³⁺ or Y ₂ O ₃ : Eu is used as the red phosphor.
^It has been confirmed that even when ³⁺ is used, the same effect of improving luminance can be obtained.

Further, it has been confirmed that the same luminance improving effect can be obtained by using not only terpineol but also a solvent such as butyl carbitol (BCA) as a solvent for the ink. Furthermore, it has been confirmed that the same luminance improving effect can be obtained by using acrylic as well as ethyl cellulose as the binder resin.

In the measurement of the surface roughness dependence of the relative luminance of the reflected visible light in the first to fourth embodiments, the main wavelength
The data are obtained when the phosphor films 19A to 19D emit light with 2 nm ultraviolet light. In the measurement of the surface roughness dependence of the relative luminance of the reflected visible light in the fifth and sixth embodiments, the fluorescent light is emitted with the ultraviolet light having the main wavelength of 254 nm. The data is obtained when the body films 19E and 19F emit light. In the PDPs of panel numbers 1 to 7 measured for comparison of panel luminance, the data is obtained when the phosphor film emits light with ultraviolet light having a main wavelength of 146 nm. Data. As described above, in each example, the main wavelength of the ultraviolet light is slightly different, but the same effect can be obtained even when the ultraviolet light of any wavelength is irradiated. This is because the phosphor film emits light unique to the phosphor film irrespective of the wavelength of the ultraviolet light to be received.

In each of the embodiments described above, the present invention is implemented in a PDP. However, the present invention is not limited to this, and a luminous film that emits light based on an excitation line emitted from an excitation source is provided. Any type of light emitting device can be used. The light emitting device that can implement the present invention includes the AC surface discharge type P described above.
In addition to the DP, a direct current surface discharge type PDP, and further, a reflection type light emitting device can be cited as examples.

[0105]

According to the present invention, the following effects can be obtained. According to the first, third, and fifth aspects, the radiated light from the light-emitting surface has good directivity toward the front without being greatly scattered. Since the irradiation is performed, the luminous efficiency of the light emitting device is improved.

According to the second, fourth, and sixth aspects, the light emitted from the light emitting surface can be irradiated forward with little directivity and with good directivity, so that the light emitting efficiency of the light emitting device is further improved.

According to the seventh aspect, by removing the frequency component of 10 μm or less, it is possible to selectively take out only the waviness component of the surface roughness which has a great effect on the light scattering. Roughness detection accuracy is increased.

According to the eighth aspect, by removing the frequency component of 2 μm or less, only the waviness component of the surface roughness which has a great influence on the light scattering can be selectively taken out. Roughness detection accuracy is increased.

According to the ninth aspect, since the internal reflectance is increased, the luminous efficiency of the light emitting device is improved.

According to the tenth aspect, the internal reflectance is further increased, and the luminous efficiency of the light emitting device is further improved.

According to the eleventh and twelfth aspects, the filling rate of the phosphor powder material can be accurately measured by a relatively simple method.

According to the thirteenth aspect, the plasma display panel has a problem that it is necessary to increase the luminance. If the present invention is applied to the plasma display panel having such a problem, the luminous efficiency increases. In particular, the effect of the present invention of performing the operation is particularly effective.

According to the fourteenth aspect, the surface roughness of the light emitting surface of the light emitting film can be relatively easily reduced to 5 μm or less (maximum height), 3 μm or less.
m (ten-point average roughness).

According to the fifteenth aspect, the surface roughness of the light emitting surface of the light emitting film defined by the maximum height can be relatively easily set to 2 μm.
m or less.

According to claim 16, the viscosity is set at a shear rate of 10
It is possible to easily prepare a phosphor ink having a cps / s of 1000 cps or less.

According to the seventeenth aspect, the viscosity is set at a shear rate of 1
It is possible to easily produce a phosphor ink at 200 cps or less at 0 / s.

According to the eighteenth aspect, by using the phosphor ink containing the resin component at a low ratio of not more than 3% by weight, the light emission having a high filling factor of the phosphor powder material of not less than 40% is used. The body membrane can be easily and reliably formed.

According to the nineteenth aspect, by using the phosphor ink containing the resin component at a particularly low ratio of 1% or less by weight, the filling rate of the phosphor powder material can be increased to a substantially saturated state. . Thereby, a luminous film having a high filling rate of the phosphor powder material such as 45% or more can be obtained.
It can be created easily and reliably.

As described above, according to the present invention, it is possible to efficiently extract the light emitted from the luminous body film to the front of the luminous body film, and to construct a light emitting device with high luminance and luminous efficiency. Became possible.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a light emitting device of the present invention.

FIG. 2 is a sectional view showing a configuration of an AC surface discharge type plasma display panel according to Embodiments 1 to 6 of the present invention.

FIG. 3 is a diagram showing surface roughness dependence of relative luminance in the first embodiment.

FIG. 4 is a diagram showing surface roughness dependence of relative luminance in the second embodiment.

FIG. 5 is a diagram showing surface roughness dependence of relative luminance in the third embodiment.

FIG. 6 is a diagram showing surface roughness dependence of relative luminance in the fourth embodiment.

FIG. 7 is a diagram for explaining a measured cross-sectional curve.

FIG. 8 is a diagram for explaining a measured cross-sectional curve.

FIG. 9 is a diagram showing the dependency of the relative luminance on the filling rate of the phosphor powder material in the fifth and sixth embodiments.

FIG. 10 is a cross-sectional view showing a schematic configuration of an ink application device used when carrying out the present invention.

FIG. 11 is a cross-sectional SEM image of the phosphor film of the present invention.

FIG. 12 is a cross-sectional SEM image of a conventional phosphor film.

FIG. 13 is a schematic sectional view of a conventional AC surface discharge type plasma display panel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Excitation source 2 Excitation line 3 Light emitting film 4 Light 11 Front glass substrate 12 Display electrode 13 Dielectric glass layer 14 Protective layer 15 Back glass substrate 16 Address electrode 17 Visible light reflecting layer 18 Partition walls 19A to 19G Phosphor film 19a Light emitting surface Reference Signs List 20 front panel 21 rear panel 22 discharge space

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaki Aoki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Hiroyuki Kawamura 1006 Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Shigeo Suzuki 1006 Odaka, Kadoma, Kadoma, Osaka Pref. FF12 5C040 AA01 DD13

Claims (19)

[Claims] 1. A light-emitting device comprising a light-emitting film that emits light based on an excitation ray emitted from an excitation source, wherein a light-emitting surface of the light-emitting film defined by a maximum height has a surface roughness of 5 μm or less. A light-emitting device, comprising: 2. The light emitting device according to claim 1, wherein a surface roughness of a light emitting surface of the light emitting film defined by a maximum height is 2 μm or less. 3. A light-emitting device comprising a light-emitting film that emits light based on excitation light emitted from an excitation source, wherein the light-emitting surface of the light-emitting surface is defined by a ten-point average roughness. A light emitting device having a thickness of 3 μm or less. 4. The light emitting device according to claim 3, wherein a surface roughness of a light emitting surface of the light emitting film defined by a ten-point average roughness is 1 μm or less. 5. A light-emitting device comprising a light-emitting film containing a phosphor powder material that emits visible light based on excitation light emitted from an excitation source, wherein the light-emitting surface of the light-emitting film has a rough surface. A light-emitting device characterized in that the average diameter of the phosphor powder material is twice or less. 6. The light emitting device according to claim 5, wherein a surface roughness of a light emitting surface of the light emitting film is set to be equal to or less than an average particle diameter of the phosphor powder material. 7. The light emitting device according to claim 1, wherein the surface roughness is defined by a sectional curve from which a frequency component of 10 μm or less is removed. apparatus. 8. The light emitting device according to claim 1, wherein the surface roughness is defined by a sectional curve from which a frequency component of 2 μm or less is removed. apparatus. 9. A light emitting device comprising a phosphor film containing a phosphor powder material that emits visible light based on an excitation ray emitted from an excitation source, wherein the phosphor powder material in the phosphor film is provided. A light emitting device characterized in that the filling factor of the material is 37 or 38 or 39% or more. 10. The light emitting device according to claim 9, wherein the filling rate of the phosphor powder material in the light emitting film is 45%.
A light-emitting device characterized by the above. 11. The light emitting device according to claim 9, wherein the area ratio occupied by the phosphor powder material in the luminous body film at the cut surface when the luminous body film is cut is 3/2. Is defined as a filling rate of the phosphor powder material in the luminous film. 12. The light emitting device according to claim 9, wherein a volume ratio occupied by the phosphor powder material in the luminous body film is:
A light emitting device characterized in that the filling rate of the phosphor powder material in the light emitting film is defined. 13. The light-emitting device according to claim 1, wherein the light-emitting device is a plasma display panel, and the luminous film is a fluorescent light provided in a discharge space of the plasma display panel. A light-emitting device, which is a body film. 14. The method for manufacturing a light emitting device according to claim 1, wherein the light emitting device film is formed by applying a phosphor ink having a viscosity of 1000 cps or less at a shear rate of 10 / s. A method for manufacturing a light-emitting device. 15. The method for manufacturing a light emitting device according to claim 2, wherein the phosphor film is formed by applying a phosphor ink having a viscosity of 200 cps or less at a shear rate of 10 / s. A method for manufacturing a light-emitting device. 16. The method for manufacturing a light emitting device according to claim 14, wherein a phosphor powder material is used as the phosphor ink in a weight ratio of 70%.
A method for manufacturing a light emitting device, comprising using a phosphor ink contained below. 17. The method for manufacturing a light emitting device according to claim 15, wherein a phosphor powder material is used as the phosphor ink at a weight ratio of 60%.
A method for manufacturing a light emitting device, comprising using a phosphor ink contained below. 18. A method for manufacturing a light emitting device according to claim 9, wherein a light emitting film is formed by applying a phosphor ink containing a resin component at a weight ratio of 3% or less. Device manufacturing method. 19. A method for manufacturing a light emitting device according to claim 10, wherein the light emitting film is formed by applying a phosphor ink containing a resin component at a weight ratio of 1% or less. Device manufacturing method.