JP2002124193A - Plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PDP with high luminous efficiency and brightness for a discharge cell size, in the discharge cells or the like of a PDP of High-Vision type or the like. SOLUTION: Visible light reflecting layer 17 and a barrier rib 18 are installed on a backside glass substrate 15, and phosphor layers 19 to 21 for each color of R, G and B are formed with an average film thickness of about 12 μm of the region H having a face along the visible light reflection layer 17 and about 25 μm for the region V having faces other than the above region H.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma display panel used for a television receiver, a display, and the like.

[0002]

2. Description of the Related Art In recent years, as the demand for higher performance of televisions such as high-quality images and large screens has increased, various displays such as high-definition televisions have been developed. The main types of displays that are being studied are CRT displays and liquid crystal displays (LCs).
D), a plasma display panel (PDP) and the like.

[0003] Among them, the PDP is problematic in that it increases the depth dimension and weight of the CRT when a large screen is assumed,
It is also excellent in that it can avoid problems such as the visual field of view of LCDs, and now large-screen products of the 40-inch class have been developed (Functional Materials, February 1996 V
ol. 16, No. 2, P7). Figure 7 shows an AC type color PDP
FIG. 1 is a cross-sectional view showing an example (see Japanese Patent Application Laid-Open No. 5-342991). As shown in the figure, the AC type PDP has a front glass substrate (front cover plate) 41 and a rear glass substrate (back plate) 45 arranged in parallel with each other. In order from the glass substrate 41 side to the rear glass substrate 45 side, a display electrode 42, a dielectric glass layer 43 covering the display electrode 42, and a dielectric protection layer
44, partition walls 47 arranged perpendicular to the glass substrates 41 and 45 at regular intervals, address electrodes 46 provided on the rear glass substrate 45, and the like are provided. Here, a configuration surrounded by a pair of opposed partition walls 47, the dielectric protection layer 44, and the back glass substrate 45 is called a discharge cell.

[0004] Phosphor layers 50 to 52 are formed on the rear glass substrate 45 and the partition wall 47, and the address electrodes 46 are included in the phosphor layers 50 to 52. The phosphor layers 50 to 52
Contains one phosphor of each of red, green, and blue (R, G, B) color components in order to provide color display on the entire PDP. These are the dielectric protection layer 44, partition walls
47, in a discharge space 49 surrounded by the phosphor layers 50 to 52 and the like, short-wavelength ultraviolet rays (wavelength of about 14) generated by a discharge between the address electrode 46 and the display electrode 42 opposed thereto.
7 nm).

[0005]

The brightness of the PDP depends mainly on the intensity of ultraviolet rays generated in the discharge gas (He-Xe system, Ne-Xe system, etc.). 640 x 480 pixels, cell pitch 0.43 mm x 1.29
In an NTSC type PDP having a unit cell area of 0.55 mm ² mm and a UV of about 147 nm, a luminous efficiency of about 1.0 lm / W is obtained. However, in large-size full-vision high-definition televisions that are expected in recent years, for example, at 42 inches, the number of pixels is 1920 × 1125, the cell pitch is 0.15 mm × 0.48 mm,
In addition, performance such as a unit cell area of 0.072 mm ² is required, and a considerably finer configuration is required as compared with current PDP products.

Here, when the unit cell is miniaturized, the discharge space becomes finer. In general, the intensity of excitation light emitted by ultraviolet rays is proportional to the volume of the discharge space, and the reflection luminance is also increased by the area of the light receiving area of the phosphor layer. Due to such a property, the problem that excitation light emission is weakened and light emission efficiency is deteriorated is likely to occur. It is believed that if a large-sized high-definition PDP is manufactured with the conventional technology, the luminous efficiency will be reduced to about 0.6 lm / W.

SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to provide a PDP capable of obtaining higher luminous efficiency and luminance even in a fine unit cell as compared with the related art.

[0008]

According to the present invention, a front cover plate and a back plate having a partition formed on a surface thereof are arranged in parallel with each other, and a phosphor layer is formed on the partition and the back. A plasma display panel disposed over a plate surface, wherein a visible light reflecting layer is provided between the back plate and the phosphor layer on a back plate, and the phosphor layer has an average thickness on a partition wall. An average film thickness of a region having a surface along the visible light reflecting layer is smaller than that of the visible light reflecting layer.

Further, in the present invention, the phosphor layer has a thickness of 20 in a region having a surface along the visible light reflecting layer.
It may be less than μm. Here, it is desirable that the phosphor layer on the back plate surface has a thickness that is at least 2 times and not more than 7 times the average particle diameter of the phosphor forming the phosphor layer. Furthermore, the particle shapes of the phosphors forming all the phosphor layers are such that when the longest distance from the center point of the particles to the surface is L ₁ and the shortest distance is L ₂ , 0.8 ≦ L ₂ / L ₁ ≦ 1.0. It is desirable that the shape be satisfactory.

A particle having a particle size distribution, in which the cumulative value of the particle size distribution is 10%, is A ₁₀ , and the particle size, in which the cumulative value is 90%, is A ₉₀ , x
= 100A / x (%) represented by (A + A ₉₀ -A ₁₀₎ when the defined as the particle径集moderate particle径集moderate phosphors forming the phosphor layer 50% to 100% It is preferred that here,
The concentration of the phosphor particles forming the phosphor layer is 80% or more and 100%.
% Is more desirable.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Overall Configuration of PDP) Hereinafter, a PDP according to an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view schematically showing an AC surface discharge type PDP which is one application example of the present invention. As shown in the figure, the PDP has a display electrode (discharge electrode) 12, a dielectric glass layer 13, a protective layer 14, and the like sequentially arranged on a front glass substrate 11, while an address electrode 16, a visible electrode The light reflecting layers 17 and the like are arranged in this order, and the protective layer 14 and the visible light reflecting layer 17 are arranged at a fixed interval via a plurality of partitions 18 perpendicular to the respective surfaces. This partition
Numeral 18 is to form a discharge cell by joining with the protective layer 14 and the visible light reflecting layer 17. In each discharge cell, a phosphor layer of each of R, G, and B colors is formed on the partition wall surface and the visible light reflecting layer, and a discharge gas is sealed. The display electrodes 12 and the address electrodes 16 are both striped silver electrodes, and are arranged so as to form an orthogonal matrix.

The dielectric glass layer 13 is a layer made of lead-containing glass having a thickness of about 20 μm, and is uniformly formed on the surface of the front glass substrate 11 while covering the display electrodes 12. The protective layer 14 laminated on the dielectric glass layer 13 is a thin layer of magnesium oxide (MgO) having a thickness of about 1.0 μm. Visible light reflective layer 17 contains titanium fine particles about 20 μm thick
And thereby has both the reflectivity for visible light and the function as a dielectric layer.

The partition wall is made of alumina-containing glass, and has a height and a pitch between adjacent partition walls of 0.15 mm, and protrudes from the surface of the visible light reflecting layer. Books with this configuration
The PDP size is set to a 42-inch high-definition television display, with 1920 x 1125 pixels and a cell pitch of 0.
The size is 15 mm × 0.48 mm and the unit cell area is 0.072 mm ² . This PDP was produced by the following production method.

(Manufacturing Method of PDP) A paste for the address electrodes 16 was screen-printed on one main surface of the rear glass substrate 15 at a pitch of 0.15 mm in a stripe shape, and then fired to form the address electrodes 16. Next, a slight amount of titanium oxide (TiO ₂ ) was added to a lead-containing glass paste composed of 75% by weight of lead oxide (PbO), 15% by weight of boron oxide (B ₂ O ₃ ), and 10% by weight of silicon oxide (SiO ₂ ). ) The particles were mixed, screen-printed on the main surface of the rear glass substrate 15 so as to cover the address electrodes 16, and baked to form a visible light reflective layer 17 having a thickness of about 20 µm.

Subsequently, a glass paste containing alumina is screen-printed on the visible light reflecting layer 17 at a pitch of 0.15 mm in the form of stripes, and the glass paste is laminated several times, fired and fired to a height of 0.15 mm. The partition 18 was formed. The above-mentioned visible light reflecting layer 17 and the partition wall 18 are provided with a phosphor ink 29 described later.
The contact angle becomes larger on the visible light reflective layer 17 than on the partition 18 surface (specifically, the contact angle becomes about 13 ° on the visible light reflective layer 17 and about 8 ° on the partition 18) In this case, the composition ratio is set.

Next, on the surface of the partition wall 18 and on the visible light reflecting layer 17
R, G, B phosphors of each color are applied and fired as follows,
Phosphor layers 19 to 21 were formed. In the present invention, each color phosphor
Can be used in general PDP
However, in the present embodiment, the red phosphor (Y_xGd_1-x) BO_Three:EU
³⁺, Green phosphor (Zn_TwoSio_Four: Mn), blue phosphor (BaMgAl
_TenO₁₇:EU²⁺) Was prepared. Each phosphor has an average particle size
About 3 μm was used.

Next, the phosphor ink is applied, and a screen printing method can be used as the application method. However, in the present invention, when performing high-definition coating, problems such as color mixing may occur, which is not preferable.
Therefore, in the present embodiment, the following method is adopted. A solvent containing 45% by weight of the phosphor and 1.8% by weight of the binder was adjusted so that the viscosity at a shear rate of 200 S ^-1 was 50 centipoise at 25 ° C., and this was used as a phosphor ink. Here, the organic binder is ethyl cellulose and the solvent is α-
Terpineol was used.

Subsequently, as shown in FIG.
30 (nozzle diameter 80μ) connected to a tank 28
m, pressure 0.5 kgf / cm) on the visible light reflecting layer 17, scan along the longitudinal direction of the partition 18 at a speed of 50 mm / s, and determine the distance between the tip of the nozzle 30 and the visible light reflecting layer 17. 100μm
The phosphor ink 29 was continuously injected between the partition walls 18 while the meniscus of the phosphor ink 29 (crosslinking by surface tension) was applied to the two opposing partition walls 18.
At this time, about 90% of the phosphor ink 29 was filled for each cell pitch.

Here, the viscosity of the phosphor ink 29 is a numerical value set to continuously and smoothly discharge the phosphor ink 29 from the nozzle 30 and to form the meniscus of the phosphor ink 29 well. The preferred numerical range is considered as follows.
That is, it is desirable that the viscosity at a shear rate of 200 S ⁻¹ be not more than 1000 centipoise at 25 ° C.

Further, by setting the contact angles of the partition walls 18 and the visible light reflecting layer 17 with the phosphor ink as described above, the following problems were suppressed. FIG. 4 is a cross-sectional side view of the back glass showing a state in which the phosphor ink 29 is injected between the conventional partitions 18. Conventionally, the phosphor ink 29 is used for partition walls.
When injected during 18, there is a risk that after a while, as shown in the cross-sectional view of the rear glass in FIG. On the other hand, in the present embodiment, since the contact angle is larger on the surface of the visible light reflecting layer 17 than on the surface of the partition wall 18, the phosphor ink 29 is formed as shown in the rear glass side sectional view of FIG. The above-mentioned shift was improved by being strongly adsorbed on the partition wall 18 surface. The phosphor ink 29
In order to form a phosphor layer having an appropriate film thickness on the surface of the partition wall 18, a composition having a slightly lower fluidity than ink used in screen printing or the like is preferable. That is, it is desirable that the phosphor contains 20% by weight to 60% by weight of phosphor and 0.1% by weight to 7% by weight of ethyl cellulose. Also, in the above, the phosphor ink is 90
Although an example of injecting% is shown, the range considered preferable for forming a phosphor layer having a large area is 80% or more.

After the phosphor ink 29 has been dried,
Baking at 0 ° C. for 10 minutes. Then, as shown in the partition wall cross-sectional view of FIG. 6, a region H having a surface along the visible light reflection layer 17 is formed.
The average thickness of the phosphor layer is approximately 12 μm, and the average thickness of the region V having a surface other than the surface along the visible light reflection layer 17 is approximately 25 μm.
19-21 were obtained. Here, each phosphor layer described below will be described using the above-described region H and region V. The thicknesses of the phosphor layers 19 to 21 were actually confirmed by a scanning electron microscope (SEM).

On the other hand, a display electrode 12 is provided on a front glass substrate 11.
Paste for screen printing and firing to display electrodes
12 formed. 75% by weight of lead oxide (PbO)
20 μm-thick lead-based dielectric glass layer 13 composed of 10% by weight of boron oxide (B ₂ O ₃ ) and 10% by weight of silicon oxide (SiO ₂ )
Was formed by screen printing and firing. The thickness of the dielectric glass layer 13 is reduced by CVD (chemical vapor deposition).
A protective layer 14 of 1.0 μm magnesium oxide (MgO) was laminated. Here, the CVD method is a method in which a gas of a reaction system molecule or a mixed gas of a reaction system molecule and an inert gas is reacted on a heated substrate to deposit a reaction product. In this embodiment uses acetylacetone magnesium as a source _{[Mg (C 5 H 7 0} 2) 2], the other cyclopentadienyl magnesium _{[Mg (C 5 H 5)} 2] , etc. may be used .

It was confirmed by X-ray analysis that the MgO layer formed by the chemical vapor deposition method had a crystal structure oriented in the (100) plane. Next, while facing the surface on the rear glass substrate 15 side on which the partition wall 18 is disposed, and the surface on the front glass substrate 11 side on which the protective layer 14 is disposed, they are bonded together with sealing glass, A discharge space 22 was formed. The inside of the discharge space 22 was evacuated to a degree of vacuum of 8 × 10 ⁻⁷ Torr,
Helium (He) gas containing 50% xenon (Xe) gas was sealed as a discharge gas at 500 Torr. The PDP of the present embodiment was manufactured by the above method.

(Detailed Description of Phosphor Layer and Visible Light Reflecting Layer) The PDP manufactured as described above was charged with a discharge maintaining voltage of 1
When energized at 50V / frequency 30kHz, the brightness is about 400cd /
m ² , and the luminous efficiency was about 0.7 lm / W. As a comparative example, when the thickness of the phosphor layer was uniformly formed at about 25 μm in both the regions H and V, the luminance was about 350 cd / m ² and the luminous efficiency was about 0.6 lm
/ W. Further, the thickness of the phosphor layer is set to 1 in region V.
When formed at 2 μm and about 25 μm in region H, the luminance was about 340 cd / m ² and the luminous efficiency was about 0.58 lm / W.

From these results, it is understood that the luminous efficiency and the luminance are improved by setting the thickness of the region H of the phosphor layer to be smaller than the conventional thickness of about 20 μm. On the other hand, using a blue phosphor (BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ) having an average particle diameter of 3 μm, phosphor layers having an average film thickness set in steps of approximately 5 μm are respectively formed, and ultraviolet rays of the same intensity are formed thereon. (About 147 nm), and the change of the luminance (reflection luminance) of the fluorescence obtained by irradiation was tracked. FIG. 2 summarizes the results of the investigation on the relationship between the reflection luminance and the thickness of the phosphor layer. Curve 23 in FIG.
Is the curve when the visible light reflective layer is provided under the phosphor layer.
Reference numeral 24 denotes a case where no visible light reflecting layer is provided (that is, it corresponds to a phosphor layer on the partition wall surface).

As shown in the figure, when the visible light reflecting layer is not provided, the reflection luminance is proportional to the increase in the thickness of the phosphor layer until the thickness of the phosphor layer reaches about 20 μm. Approximately reaches saturation luminance. On the other hand, when the visible light reflecting layer is provided, the reflection luminance is proportional to the film thickness of the phosphor layer to some extent, but reaches the saturation luminance as soon as the film thickness is about 12 μm or more. Here, the saturated luminance indicates a constant luminance value in which the phosphor layer asymptotically approaches regardless of the film thickness.
This confirms that the reflection luminance can be secured on the visible light reflecting layer even if the thickness of the phosphor layer is set to be small.

Further, from the results of the graph of FIG. 2, when the visible light reflecting layer is provided in the phosphor layer having the same thickness, a slightly higher reflection luminance is obtained as a whole than when the visible light reflecting layer is not provided. You can see that These results indicate that the phosphor particles in the phosphor layer are
Visible light emitted in 15 directions, visible light reflective layer 17 is front glass
It also suggests that reflection in 11 directions contributes to brightness improvement.

The effect of improving the brightness by making the phosphor layer thinner on the visible light reflecting layer is that the phosphor layer can be clearly obtained in a thickness range of about 12 μm to about 20 μm using the visible light reflecting layer. This can be seen from FIG. However, the thickness of the phosphor layer is 6μ.
In the vicinity of m, the reflection luminance is almost the same as when there is no visible light reflection layer, but in the discharge cell of the PDP, the discharge space is about 20 μm to about 30 μm in the case of the conventional phosphor layer having an average thickness of about 30 μm. As compared with the case where the thickness of the phosphor layer in the region H is in the range of about 6 μm to about 12 μm, high luminance can be obtained as a result. In the case of phosphor particles having an average particle size of about 3 μm, this range is approximately 2 μm.
It is expected that the phosphor layer needs to be composed of two or more phosphor particles. In order to improve the brightness when the thickness of the phosphor layer in the region H is in the range of about 6 μm to about 20 μm while securing the discharge space with a fine discharge cell like a PDP for HDTV, it is necessary to use visible light reflection. It is desirable to form a phosphor layer having as a region H a film thickness of about 12 μm to about 20 μm, at which reflection luminance is higher than when no layer is provided. Here, when actually manufacturing a PDP, if the phosphor layer in the region H is formed to be thicker than about 20 μm, almost only the discharge space of the conventional discharge cell can be secured. Since the effect of the reflective layer is weakened, it is not preferable to use a phosphor layer having a thickness greater than this value.

Although detailed numerical values are not displayed,
By a method as described in 62-201989 or JP-A-7-268319, an average particle diameter of 3 μm originally having a hexagonal plate shape
The blue phosphor (BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ) is processed into a shape that satisfies the formula 1, that is, a spherical or nearly spherical shape,
A survey similar to that of FIG. 2 was conducted. As a result, when compared to those using phosphors that are not spherically processed, the reflective brightness and luminous efficiency for a given film thickness are further improved for those with a phosphor layer of spherically processed phosphors laminated on the visible light reflective layer. I found out.

[0030]

(Equation 1)

Here, L ₁ is the longest distance from the center of gravity of the particle to the surface, and L ₂ is the shortest distance. Further, the particle size concentration x of the average particle size A having a particle size distribution x (%) = 100 A / (A + A ₉₀ -A ₁₀ ) is defined, and while changing the x value for the phosphor particles of A = 3 μm, The relationship between the reflection luminance and the thickness of the phosphor layer was examined as shown in FIG. 2 for each phosphor particle having a particle size distribution having a different x value. Here, A ₁₀ is the cumulative value of 10% of the particle diameter of the particle size distribution, A ₉₀ is a particle size cumulative value of 90% of the particle size distribution.

As a result, when x = 50 (%), the thickness of the phosphor layer reaching the saturation luminance is about 12 μm, and x = 80 (%).
Above (%), the film thickness was about 9 μm. This x = 80
(%) Using a phosphor having a particle size concentration
When a PDP having a phosphor layer with a thickness of about 25 μm in region V and about 9 μm in region H is manufactured by the manufacturing method of
Im / W could be obtained. Such a result was obtained because the particle size became more uniform as the value of the particle size concentration increased, the gap between the phosphor particles in the phosphor layer became larger, and the visible light transmittance was increased. This is probably because the reflection effect of the visible light reflecting layer was increased. Further, the use of a thin phosphor layer contributes to increasing the luminous intensity of the excitation light emission itself by increasing the discharge space. Therefore, in order to obtain a high luminous efficiency and brightness in a small discharge cell is to minimize the difference between A ₁₀ and A _90, it is desirable to form the phosphor layer by uniform phosphor particles.

The phosphor used in the present embodiment is:
The present invention is not limited to the above-described phosphor, and other general ones may be used. For the combination of the solvent and the binder, an organic solvent such as diethylene glycol methyl ether or water can be used as the solvent, and PMMA (polymethyl methacrylate) or PV
A synthetic polymer such as A (polyvinyl alcohol) can be used.

By the way, in this embodiment, in order to adjust the adsorbing force of the phosphor ink on the partition walls and the visible light reflecting layer,
Although the example in which the contact angle between the partition wall surface and the phosphor ink is set to be smaller than the contact angle with the visible light reflective layer has been described, the roughness of the surface that contacts the phosphor ink is also used. You may do so. When the surface roughness is about 5 μm on the partition and about 0.5 μm on the visible light reflecting layer, there is an example in which a thicker phosphor layer can be formed on the partition.

In this embodiment, an example in which the visible light reflecting layer is uniformly laminated on the surface of the rear glass plate has been described. However, the present invention is not limited to this. First, a partition is provided on the surface of the plate, and then a glass paste containing a visible light reflecting material such as titanium oxide is applied on the back glass plate surface between the partitions, whereby a visible light reflecting layer is provided. Is also good. Further, in the present embodiment, an example in which the phosphor ink contains 45% by weight of the phosphor is used. However, in practice, it is sufficient that the phosphor ink contains 20% to 60% by weight of the phosphor. It has been found that almost the same result can be obtained in the range. Further, in the present embodiment, the phosphor particles having an average particle diameter of 3 μm are used, but the present invention is not limited to this, and it is sufficient if the average particle diameter is 5 μm or less. Phosphor particles significantly larger than 5 μm are not preferable when used as a phosphor ink, because they may settle between application of the ink and subsequent drying.

In the present embodiment, an AC type PDP capable of color display has been described. However, the present invention is not limited to this, and may be applied to a monochrome type PDP or a DC type PDP.

[0037]

As described above, according to the present invention, it is possible to effectively extract the fluorescence emitted from the phosphor layer in the discharge cell. Further, the discharge space with respect to the discharge cell volume can be made wider than before, and the intensity of the ultraviolet excitation light emission can be increased. As a result, the efficiency of the fluorescent light emission can be improved. Therefore, when the present invention is applied to a high-definition type fine discharge cell, there is an effect that a PDP having relatively high luminance and luminous efficiency can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main configuration of an AC surface discharge type plasma display panel which is an application example of the present invention.

FIG. 2 is a diagram illustrating a relationship between reflection luminance and a thickness of a phosphor layer.

FIG. 3 is a schematic view showing a phosphor ink injection step.

FIG. 4 is a schematic diagram showing a state between partition walls into which a conventional phosphor ink is injected.

FIG. 5 is a schematic view showing a state between partition walls after a phosphor ink is conventionally injected and dried.

FIG. 6 is a schematic diagram illustrating a drying process of the phosphor ink when the adsorbing force of the phosphor ink on the visible light reflecting layer with the phosphor ink is smaller than that of the partition wall surface.

FIG. 7 is a cross-sectional view of a main configuration of a conventional AC surface discharge type plasma display panel.

[Explanation of symbols]

 11, 41 Front glass substrate (front cover plate) 12, 42 Silver electrode 13, 43 Dielectric glass layer 13, 44 Dielectric protection layer 15, 45 Rear glass substrate (back plate) 16, 46 Address electrode 17 Visible light reflective layer 18, 47 Partition wall 19, 50 Phosphor layer (red) 20, 51 Phosphor layer (green) 21, 52 Phosphor layer (blue) 22, 49 Discharge space 29 Phosphor ink 30 nozzle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Aoki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Shigeru Horii 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 1006 Kadoma, Kadoma City Matsushita Electric Industrial Co., Ltd. F term (reference) 5C028 FF12 FF16 5C040 FA01 FA04 GB03 GG03 GG09 GG10 JA04 MA03

Claims (6)

[Claims] 1. A front cover plate and a back plate having a partition formed on a surface thereof are arranged in parallel with each other,
A plasma display panel in which a phosphor layer is disposed over the partition wall and the back plate surface, wherein a visible light reflection layer is provided between the back plate and the phosphor layer on the back plate; The plasma display panel according to claim 1, wherein an average thickness of a region having a surface along the visible light reflecting layer is smaller than an average thickness of the partition walls. 2. The plasma display panel according to claim 1, wherein the phosphor layer has a thickness of 20 μm or less in a region having a surface along the visible light reflecting layer. 3. The phosphor layer on the back plate surface,
3. The plasma display panel according to claim 1, wherein the plasma display panel has a thickness corresponding to at least two times and at most seven times the average particle diameter of the phosphor forming the phosphor layer. 4. The particle shape of the phosphor forming all the phosphor layers is such that when the longest distance from the center of gravity of the particle to the surface is L ₁ and the shortest distance is L ₂ , 0.8 ≦ L ₂ / L ₁ ≦ 4. The plasma display panel according to claim 1, wherein the plasma display panel has a shape satisfying 1.0. 5. A phosphor particle having a particle size distribution and having an average particle size of A, the particle size at which the cumulative value of the particle size distribution becomes 10%.
A ₁₀ , the particle size value at which the cumulative value becomes 90% is A _90, and x = 100 A /
When x (%) represented by (A + A ₉₀ -A ₁₀ ) is defined as the particle size concentration, the particle size concentration of the phosphor forming the phosphor layer is 50%.
The plasma display panel according to any one of claims 1 to 4, wherein the content is not less than 100% and not more than 100%. 6. The plasma display panel according to claim 5, wherein the phosphor forming the phosphor layer has a particle concentration of 80% or more and 100% or less.