JPH03133048A - Direct-current type plasma display panel - Google Patents

Abstract

PURPOSE:To make a light green monochromatic plasma display panel (PDP) by representing the average grain size of phosphor as -D and a paint film thickness of phosphor as to and specifying the ratio of the film thickness to the average grain size of phosphor (t/-D). CONSTITUTION:When PDP is manufactured from Zn2SiO4 : Mn phosphor whose Mn density is within more than 0.2, but less than 1.0 wt.%, the average grain size of the phosphor is represented by -D and the paint film thickness of the phosphor, by t, and -D is within the range of more than 2.0 mu, but less than 8.0mu, and the ratio of the film thickness to the average grain size (t/-D) is adjusted to the range of more than 2.5, but less than 6.0. The Mn density of Zn2SiO4 : Mn phosphor 7 used as its green component is made to an optimal constant value and also phosphor is painted by limiting the ratio of the paint film thickness to the grain size so that it is possible to prevent lowering of emission-luminance due to the body color of the phosphor 7. A light green monochromatic PDP can thereby be made.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a plasma display panel (PDP) that mainly excites phosphors and emits light using vacuum ultraviolet rays emitted by gas discharge. Z n2s
i Oa: Related to DC type plasma display panels coated with Mn phosphor [Conventional technology and its problems] In recent years, flat display panels have been actively developed. Among them, DC type PDPs have advantages in display capacity, display screen quality, response speed, step display, etc., are resistant to vibration and shock, are lightweight, and are suitable for large screens, so they are used in laptop computers. It has been put into practical use.

A typical DC type PDP will be explained with reference to FIG. Figure 1-a is a perspective view of a structural model of a PDP display panel, which consists of two electrodes constituting an anode 1 and a cathode 2, which are arranged in a madnox shape on two glass plates to form individual display dots. are doing. The anode electrode on the front glass side 3 is formed by etching a deposited transparent conductive film, and the cathode electrode on the back glass side 4 is formed by thick film printing. Further, a partition wall 5 is provided so that a wide viewing angle can be obtained by thick film printing, and each display dot is separated and independent. In addition, FIG. 1-a is a diagram showing the cross-sectional structure of FIG. 1-a, and inside the discharge space 6 surrounded by the partition wall 5,
The anode 1 is filled with a mixed gas such as e, Xe-Ar, etc., and a phosphor 7 is coated on the anode 1.

In conventional PDPs, there is a large amount of N in the discharge space of the PDP.
It is an orange monochrome type that is filled with a mixed gas such as e-Ar and utilizes light emission from Ne glucose discharge. On the other hand, monochrome or multicolor PDPs that coat the anode with phosphor and use the 147 μm vacuum ultraviolet rays emitted by Xe glow discharge to excite the phosphor and emit light are still at the prototype stage and have yet to be put into practical use. has not yet been reached.

However, among these, the green monochrome type PDP that is being put into practical use uses Z as a phosphor with high luminance at 147 μm.
n2s i O4: Made using Mn. The amount of Mn activated in the phosphor is also about 1.6% by weight based on the phosphor matrix, and the literature also states that the optimal amount of Mn in the Z n2s i O4:Mn phosphor used for FDP is 0.
．． 06g atm/mole (J, Koike et al.: J, Elec
torochem, soc, , +26[6], 1
008 (1979)) When this is converted into a weight percent of Mn based on the phosphor matrix, it is approximately 1.5 weight percent.

The brightness of conventional PDPs is expressed in terms of brightness per unit light emitting surface (point brightness), and in the case of the former orange monochrome PDP, it is 80 cd/
m2, and the latter green monochrome PDP is 110 cd/m2, both of which are within the practical range, but compared to backlit LCD displays, the brightness of the power consumption ratio is not necessarily high, and in order to reduce heat loss, Furthermore, a PDP using a green phosphor with higher brightness is strongly desired.

Therefore, in view of the above circumstances, the present invention is intended to provide a brighter green monochrome type PDP by optimally using a high-brightness phosphor for the green component of the PDP.

[Means for Solving the Problems] The present inventor has developed the conventionally known Z n2s i Oa:
By using Mn phosphor for PDP, we selected the optimal value of M n +51 degrees, and discovered the optimal values for the coating thickness and particle size of the phosphor when coating the phosphor on FDP.
We were able to create a better green component for PDP.

First, in order to investigate the relationship between the amount of Mn and the emission brightness of the phosphor, the concentration of Mn in the Zn2s i Oa:Mn phosphor was varied in many ways with respect to the phosphor matrix (Zn2SiO4), and the average particle size was 4μ. I made a prototype to make it look like this. The relative luminance of the powder when these phosphors are excited at 253.7 μm is shown in FIG. 2-a, with the luminance of the reference phosphor being 100%.

Further, after coating the FDP with the phosphor at a thickness of 15 μm,
Filled with a mixed gas of 1% Xe and 99% He to emit light.
The brightness at that point was measured. The results are shown in Figure 2-b.

As can be seen from these results, in the case of 253.7 μm excitation, the brightness increases as the amount of MnO activation increases, but when the phosphor is mounted on an FDP, in the case of 147 μm excitation with Xe, the brightness increases. A peak is seen in the brightness with respect to the amount of Mn activation, and the optimum value of the amount of Mn activation is clearly different.

Second, the Mnfi degree is 0.13.0 from among the phosphors.
45.1. Figure 3 shows the results of examining the relationship between the excitation wavelength and relative emission intensity of 5.3.5% by weight powders.

From this, the emission intensity near 253 nm is 3.5>1.5>
0.45>0. 20 compared to 13 l1lli high
Near Onm, 0.45>1.5>3.5>0.13.

By the way, it is known that when the amount of Mn activated in the phosphor increases, the body color of the phosphor changes to yellow.

The phosphor that has turned yellow absorbs its own emitted light with its body color, resulting in a decrease in brightness. However, the second result shows that the phosphor does not emit light unless Mn is activated. Therefore, there are conditions that the activation amount of Mn must be as small as possible and that the phosphor must have high luminance.

Therefore, thirdly, in order to determine the optimum value of the body color of the phosphor, the spectral reflectance of the four types of phosphors was measured, setting the reflectance of the barium sulfate diffuser plate as 100%. The results are shown in FIG.

From FIG. 4, as M n 8 degrees increases, the reflectance of the phosphor in the ultraviolet to visible range decreases, and M n
f! There is a big difference in body color between those with 0.13 weight percent of 4 degrees and those with 3.5 percent by weight. As a result, since the conventional phosphor has a large amount of Mn activation, it is thought that the luminescence of the conventional phosphor is reduced by self-absorption.

From these results, the optimum Mn concentration of Zn25iOa:Mn phosphor for PDP is 0. It can be understood that the content is 2% by weight or more and less than 1.0% by weight.

Fourth, Figure 5 shows the relationship between the film thickness when the phosphor is applied to a PDP with varying film thickness and the brightness of the unit light emitting surface of the PDP when the FDP is actually made to emit light afterwards. .

As is clear from this figure, when the coating film has a large M n of 8 degrees, the luminance is relatively high where the coating film is thin, but as the thickness increases, the point luminance decreases rapidly. Compared to this, M
For those with a small n9 degree, even if the film thickness is increased, the rate of decrease is small. This is due to the influence of the body color of the phosphor. In other words, for those with a large M n of 11 degrees, the thicker the film, the more the emitted light is self-absorbed due to the color of the body.

Therefore, the following points are the most distinctive features of the present invention, and based on the above results, the Mn concentration is 0.2 or more and 1.
When an FDP is manufactured using a Zn25ion:Mn phosphor in a range of less than 0% by weight, if the average particle size of the phosphor is ■ and the coating thickness of the phosphor is t, then ■
is in the range of 2.0μ or more and 8°0μ or less, and the ratio (t/D) of the film thickness to the average particle diameter is adjusted to be in the range of 2.5 or more and 6.0 or less. It is t/″r:i
If it is less than 2°5, the amount of phosphor is small, so naturally the luminance will decrease, and if it is greater than 6.0, the luminance will increase as mentioned above, but self-absorption will occur due to the body color. It is.

In addition, it is known that in Z n2s i Oa:Mn phosphors, the larger the particle size, the higher the luminance. However, when the phosphor is used in a PDP, one having an average particle size of 2.0 to 8.0 microns is used. This is because if it is less than 2.0μ, the luminance of the entire phosphor will be low even if the film thickness is increased, and if it is more than 8.0μ, the light emitting surface will become uniform and rough, which will conversely cause a decrease in brightness. .

In addition, the average particle size specifically means the specific surface area sphere equivalent diameter,
This is a value measured using a Fisher subsieve sizer as a measuring device.

[Function] As mentioned above, the PDP of the present invention uses Mn111 of Z n2s i O4:Mn phosphor used as its green component.
It has become possible to prevent a decrease in luminance due to the body color of the phosphor by setting the coating density to an optimum value and limiting the ratio of coating film thickness to particle size.

[Example 1] First, the Mna degree was 0.45% by weight with respect to the phosphor matrix, 'r
Zn25 ioa which is 54μm: 12 to Mn90g
．． 160g of 5wt% PVA aqueous solution and 1ml of Octatool
, and 3 ml of a 20% ammonium dichromate aqueous solution were mixed to form a phosphor slurry.

The slurry was then applied to the anode side of the panel using a roll coating method to a thickness of 15 μm.

Next, after firing the binder, the panel arrives and He99
A mixed gas of 1% and 1% of Xe was sealed, and after a getter flash with Hg, Hg was diffused to obtain a PDP of the present invention. As a comparative example, the Mn concentration was 1. PDPs were manufactured in the same manner using 5% by weight and 3.5% by weight.

When those PDPs were turned on and the point brightness was measured, the PDP of the present invention had a brightness of 125 cd/m2 and an Mn of 1.5.
The weight percent was 110 cd/m2, and the 3.5 weight percent was 100 cd/m2.

[Effects of the Invention] The FDP of the present invention is brighter than the conventional PDP using a phosphor that is said to have an optimal Mn concentration.

Further, even when the phosphor used in the PDP of the present invention is used in a multicolor FDP under the same coating conditions, the brightness of white color increases.

[Brief explanation of the drawing]

FIG. 1-a and FIG. 1-A are perspective views and cross-sectional views of a structural model of a display panel of a typical DC plasma display;
Figure 2-a is Z n2s i Oa: M of Mn phosphor
A diagram showing the relationship between n 8 degrees and relative brightness, Figure 2-b is Z
n2s i Oa: Mn fl of Mn phosphor! The factor expressing the relationship between degree and point brightness, Figure 3 is Z n2s i O
a: A diagram showing the relationship between the excitation wavelength and relative emission intensity of the Mn phosphor, Figure 4 is a diagram showing the body color of the Zn2s i Oa: Mn phosphor using a spectral reflectance curve, and Figure 5 is the coating film. FIG. 3 is a diagram comparing a PDP according to an embodiment of the present invention and a conventional FDP in terms of the relationship between thickness and point brightness. 1 fist fight, 7 nodes, 2... cathode, 3... front glass, 4... back glass, 5... bulkhead, 6...
-Discharge space, 7...phosphor.

Claims (1)

[Claims] (1) Manganese-activated silicic acid with an average particle diameter of 2.0 μm or more and 8.0 μm or less, activated with Mn of 0.2% by weight or more and less than 1.0% by weight based on the base amount of zinc silicate (Zn_2SiO_4) In a plasma display panel coated with zinc phosphor (Zn_2SiO_4:Mn), where the average particle diameter of the phosphor is @D@ and the coated film thickness is t, the ratio (t/@D@) is is in a range of 2.5 or more and 6.0 or less.