JPH09120776A - Plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the efficiency of utilizing the output light from a phosphor layer of a plasma display panel and heighten the brightness to a great extent. SOLUTION: A front plate 16 has a front glass 1 on which a display electrode 5 is installed while a back plate 18a has a back glass 11 on which a trigger electrode 12 and/or address electrode 14 are installed, and a bulkhead 17a to partition the cell spatially is furnished between the front plate 16 and the back plate 18a, wherein a phosphor layer 10 is furnished at the bulkhead 17a on the surface confronting the front discharge space 19 of a bulkhead plate 8 through a mirror face 9a made of aluminum. When ultraviolet rays are generated by electric discharge in the front discharge space 19, the phosphor layer 10 generates visible rays, which are emitted to outside through the front plate 16, when also the visible rays generated from the phosphor layer 10 on the bulkhead plate 8 side will be reflected by the mirror face 9a and emitted to the outside from the front plate 16. Thereby the visible rays from the phosphor layer 10 can be utilized effectively, and the brightness be heightened to a great extent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device used as various thin display panels,
In particular, it relates to a plasma display panel in which the phosphor layer is excited by the energy of ultraviolet rays to obtain visible light.

[0002]

2. Description of the Related Art Plasma display panels (PDPs)
In order to improve the brightness of the, the technology of changing the color of the substance used for the partition walls forming the cells from black to white so as to minimize the absorption of the emitted light of the phosphor layer excited by ultraviolet rays, For example, it is disclosed in Japanese Patent Laid-Open No. 61-24126. This is to increase the reflectance of light and effectively reflect the light emitted from the phosphor layer by using a material that does not contain a black pigment as a material forming the partition wall or the like.

[0003]

However, in the above-mentioned prior art, the reflected light becomes diffused (scattered) light, and the reflectance at one time is about 50%, which is a plurality of times from the inside of the cell to the observer. However, even if the reflectance is substantially improved, the effect of improving the brightness was remarkably reduced.

An object of the present invention is to provide a plasma display panel which solves such a problem and can significantly improve the brightness.

[0005]

In order to achieve the above object, the present invention forms a mirror surface on the inner wall surface of a cell and forms a phosphor layer on the mirror surface.

Further, according to the present invention, the address electrode itself serves as the mirror surface also as the address electrode.

The phosphor is excited by the energy of ultraviolet rays generated by the discharge between the display electrodes and emits visible light. The visible light travels in all directions of the display space, but according to the above configuration of the present invention, visible light directed in a direction other than the viewer side (front glass plate side) is also provided on the inner wall surface of the cell. -To the viewer side (front plate side) by being efficiently reflected by the surface. Further, since the mirror surface has a high reflectance, the amount of reflected light does not significantly decrease even if the light is reflected multiple times. That is, the visible light from the phosphor layer is efficiently extracted to the observer side by the mirror surface, so that the brightness is remarkably improved.

Further, since the mirror surface is made of aluminum or the like, it can also be used as an address electrode, which simplifies the structure.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part showing a first embodiment of a plasma display panel according to the present invention.
One of the cells, which is a light emitting region (discharge space that is the minimum unit of light emission) spatially separated for each light emission color, is shown.
Is a front glass plate, 5 is a display electrode, 6 is an insulating layer, 7 is a protective layer, 8 is a partition plate, 9a is a mirror surface, 10 is a phosphor layer, 1
1 is a back glass plate, 12 is a trigger electrode, 13 is an insulating layer,
14 is an address electrode, 15 is a protective layer, 16 is a front plate, 1
7a is a partition wall, 18a is a back plate, 19 and 20 are discharge spaces,
21 is a through hole.

In FIG. 1, a display electrode 5 is formed on a front glass plate 1, a transparent insulating layer 6 is provided so as to cover the display electrode 5, and a transparent protective layer 7 is further provided to provide the front plate 1.
6 are constituted. Although not shown, the display electrode 5 is composed of a transparent electrode made of a nesa film or ITO and a bus electrode made of Cr—Cu—Cr or the like in parallel therewith. The protective layer 7 is made of MgO or the like.

A back plate 18a is provided across the front plate 16 and the partition wall 17a.

The partition wall 17a spatially separates the cell rows by the partition plate 8, and a discharge space 19 on the display side and a discharge space 20 for priming and address are formed in the separated cells. And these discharge spaces 1
9 and 20 are connected by a through hole 21 for moving charged particles. On the discharge space 19 side, a reflective film made of aluminum or the like having a mirror surface 9a is formed on the surface of the partition plate 8, and the mirror surface 9 is formed.
A phosphor layer 10 is provided on a. On the side of the discharge space 20, the surface of the partition plate 8 is exposed as it is.

In the rear plate 18a, the trigger electrode 12 is formed on the rear glass plate 11 in parallel with the display electrode 5, and the insulating layer 13 is provided so as to cover the trigger electrode 12. An address electrode 14 is formed on the insulating layer 13 so as to intersect the display electrode in a three-dimensional orthogonal manner.
An insulating layer 13 is provided so as to cover 4 and a protective layer made of MgO or the like is further provided thereon.

In such a structure, the discharge is selectively performed for each cell, but this selection is performed by the trigger electrode 12 and the address electrode 14.

That is, if it is desired to discharge in the illustrated cell, the trigger electrode 12 and the address electrode 14 passing through this cell
And a potential difference is applied between them and causes a preliminary discharge in the discharge space 20 on the back side. The charged particles generated by this preliminary discharge pass through the through holes 21 and are accumulated on the protective layer 7 of the front plate 16. The accumulated charged particles serve as a memory, and a discharge occurs in the discharge space 19 on the front side when a voltage difference occurs in the display electrode 5. This discharge generates ultraviolet rays, and the ultraviolet rays excite the phosphor layer 10 to generate visible light having a spectrum peculiar to this phosphor. This visible light is output to the viewer side through the front plate 16 and used as display light.

On the other hand, the same visible light is also output from the phosphor layer 10 to the partition plate 8 side, and this visible light is reflected by the mirror surface 9a or the mirror surface 9a and the phosphor layer 1 are also reflected.
It is repeatedly reflected at 0 and output to the front plate 16 side.

In this way, the output light from the phosphor layer 10 is efficiently extracted to the outside (observer side).

When the partition wall 17a having the double space structure is used as described above, addressing (cell designation) is performed by the trigger electrode 12 and the address electrode 14 of the rear plate 18a, so that the phosphor layer 10 of the phosphor layer 10 is formed. It was possible to optimize the thickness independently from the viewpoint of brightness or color purity without being restricted by discharge voltage and the like.

When the partition plate 8 is formed by processing a transparent glass material and the phosphor layer 10 is directly formed on the partition plate 8, visible light generated from the phosphor layer 10 is generated by the partition wall. Since there is a problem that the three colors of visible light are mixed with each other and the color purity is lowered because they pass through the plate 8 and enter the adjacent cell, in this embodiment, the partition plate 8 is formed with the mirror surface 9a. By forming the phosphor layer 10 on this, it was possible to prevent such color mixture and improve the color purity.

In this embodiment, stripe-shaped partition walls 17a are provided along the address electrodes 14 to spatially divide the light emitting regions forming the cell rows, but the partition walls 17a are also orthogonal to the partition walls 17a. By providing barrier ribs for each cell, the periphery of each cell is covered with the barrier ribs, and the phosphor layer 10 is provided on the surface of the peripheral barrier ribs on the discharge space 19 side via the mirror surface. Often,
This further improves the brightness.

FIG. 2 is a cross-sectional view of an essential part showing a second embodiment of the plasma display panel according to the present invention,
b is a mirror surface, 17b is a partition wall, 18b is a back plate,
Portions corresponding to those in FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 3 is a front view showing the partition wall 17b on which the phosphor layer 10 is not formed.

2, in this embodiment, instead of providing the address electrode 14 on the back plate 18b side as in the first embodiment shown in FIG. 1, the mirror surface 9b made of aluminum or the like is also used as the address electrode. It is also used.

For this reason, the mirror surface 9b extends in the direction of the cell columns in the same row perpendicular to the paper surface. Hereinafter, the mirror surface 9b will be referred to as a mirror surface that also serves as an address electrode.

In the above structure, when the cell shown in the figure is selected as the cell to be discharged, a potential difference is applied between the trigger electrode 12 and the mirror surface 9b also serving as the address electrode, and a preliminary discharge is generated in the rear discharge space 20. Let The charged particles generated by this preliminary discharge pass through the through holes 21 and are accumulated on the protective layer 7 of the front plate 16. The accumulated charged particles serve as a memory, and a discharge occurs in the discharge space 19 on the front side when a voltage difference occurs in the display electrode 5. Ultraviolet rays are generated by this discharge, and the phosphor layer 10 is generated by the ultraviolet rays.
Are excited to generate visible light having a spectrum peculiar to this phosphor.

Also in this case, as in the case of the first embodiment shown in FIG. 1, the visible light traveling from the phosphor layer 10 to the partition plate 8 is reflected by the mirror surface 9b also serving as the address electrode. Therefore, the output light of the phosphor layer 10 can be efficiently extracted to the outside (observer side).

Further, as in the first embodiment shown in FIG. 1, since addressing (cell designation) is performed by the trigger electrode 12 on the rear plate 18b and the mirror surface 9b also serving as the address electrode, the partition plate. The thickness of the phosphor layer 10 in 8 can be optimized independently from the viewpoint of brightness or color purity without being restricted by discharge voltage and the like.

FIG. 4 is a cross-sectional view of an essential part showing a third embodiment of the plasma display panel according to the present invention.
c is a mirror surface also serving as an address electrode, 22 is a partition plate,
The parts corresponding to those in the above drawings are designated by the same reference numerals and duplicate description will be omitted.

In FIG. 4, the front plate 16 is the above-mentioned first and first plates.
A partition plate 2 having the same structure as the front plate 16 in the second embodiment but spatially separating the front plate 16 and cells.
A rear glass plate 11 is provided so as to sandwich 2 and a mirror surface 9c also serving as an address electrode is provided between partition walls 22 on the rear glass plate 11. And this rear glass plate 11
The phosphor layer 10 is provided on the surface of the partition wall 22 and the side surface of the partition plate 22 so as to cover the mirror surface 9c that also serves as the address electrode.

In the above structure, when the cell shown in the figure is selected as the cell to be discharged, a potential difference is applied between the trigger electrode 12 and the mirror surface 9b also serving as the address electrode to cause the preliminary discharge. The charged particles generated by this preliminary discharge are accumulated on the protective layer 7 of the front plate 16. The accumulated charged particles serve as a memory, and a discharge occurs in the discharge space 19 on the front side when a voltage difference occurs in the display electrode 5.
This discharge generates ultraviolet rays, and the ultraviolet rays excite the phosphor layer 10 to generate visible light having a spectrum peculiar to this phosphor.

In this case, the visible light traveling from the phosphor layer 10 to the rear glass plate 11 is the mirror surface 9b also serving as the address electrode.
It is reflected by and goes toward the front plate 16.

As described above, also in the third embodiment, the output light from the phosphor layer 10 can be efficiently extracted to the outside (observer side), but as shown in FIG. 5, it also serves as an address electrode. By further extending the mirror surface 9b to the side surface of the partition plate 22, the effect can be further enhanced.

Further, in the case of the three-electrode structure as described above, since the address electrode itself is formed also as the mirror surface, the structure is simplified and the brightness can be improved.

By the way, in each of the embodiments described above, the external light incident on the front plate 16 side is reflected by the insulating layer 6, the protective layer 7, the phosphor layer 10, etc., and the visible light generated in the cell is observed by the observer. In some cases, the contrast is lowered. In order to prevent this, in the embodiment shown in FIGS. 6 to 9, a color filter is provided on the front plate 16 side to cut off external light, and its reflection is reduced to improve the contrast.

Here, the embodiment shown in FIG. 6 is obtained by providing a color filter to the first embodiment shown in FIG. 1. Similarly, the embodiment shown in FIG. 7, FIG. 8 and FIG. Color filters are provided in the embodiments shown in FIGS. 2, 4 and 5, respectively, and the configurations of the front plate 16 in these embodiments are all the same, so the embodiment shown in FIG. explain.

In FIG. 6, 2 is a color filter and 3 is a color filter.
Is a black matrix, 4 is a protective flat layer, and FIG.
Are assigned the same reference numerals.

On the front plate 16, a color filter 2, a black matrix 3, and a protective flat layer 4 are provided between the front glass plate 1 and the display electrodes 5. That is, in each cell, a color filter 2 formed of an inorganic material or an organic material on the front glass plate 1 facing the discharge space 19 to select the wavelength of output light is provided between the cells, and a color filter 2 is provided on the other portion between the cells. Black matrixes 3 for dividing and absorbing light are respectively provided, and a protective flat layer 4 for covering these and protecting the color filters 2 and the black matrix 3 and for ensuring flatness is provided. ing. Then, as described above, the display electrode 5, the insulating layer 6, and the protective layer 7 are laminated on the protective flat layer 4.

The color filter 2 has a pass wavelength range through which light having a wavelength to be generated from this cell is passed, and therefore, a component of the outside light having a wavelength outside the pass wavelength range of the color filter 2 is generated. Be cut. Therefore, the amount of external light reflected by the insulating layer 6, the protective layer 7, the phosphor layer 10, etc. is sufficiently reduced, and the contrast is significantly improved.

In the case of the embodiment shown in FIG. 6, as in the case of the first embodiment shown in FIG. 1, each cell is surrounded by partition walls, and a mirror is provided on the surface of the partition wall on the discharge space 19 side. The phosphor layer may be provided through the surface, which can further increase the brightness.

Next, a method of forming the mirror surface (film) 9a and the mirror surfaces 9b and 9c also serving as the address electrodes (hereinafter, these are collectively referred to as the mirror surface 9) will be described.

Aluminum was used as the metal material of the mirror surface 9, and a film was formed by electron beam vacuum evaporation. When an organometallic compound was used, gold was the main component, and a film was formed by screen printing.

The conditions for electron beam vacuum evaporation of aluminum are that the ultimate vacuum is 5 × 10 ⁶ Torr and the substrate temperature is 30.
The temperature is 0 ° C. and the vapor deposition rate is 4Å / sec. A metal mask was used as the pattern. However, a normal phosphor material needs to be fired at 400 to 450 ° C., and this heating causes the aluminum material forming the mirror surface 9 to be thermally deteriorated. For this reason, when the above-mentioned phosphor material that requires high temperature firing is used, a transparent inorganic insulating material is formed on the mirror surface 9 to prevent heat deterioration of the mirror surface 9. When a phosphor material such as an alkoxide-based material that can be formed at a low temperature (400 ° C. or less) is used, the problem of heat deterioration of the mirror surface 9 does not occur even if the above-mentioned inorganic insulating material is not used. It was

The film formation conditions of the screen printing of the metal organic compound containing gold as a main component were as follows: a mesh # 200 screen was used, and after printing, leveling was performed for 10 minutes.
After drying at 0 ° C for 15 minutes, it was baked at a peak temperature of 580 ° C for 15 minutes. Further, in this case, since the mirror surface 9 is not thermally deteriorated due to the formation of the phosphor layer, the above-mentioned inorganic insulating material is not necessary. However, it goes without saying that it is effective to form the inorganic insulating material from the viewpoint of life and the like.

As a method for forming the mirror surface 9, in addition to the above electron beam vacuum vapor deposition, there are methods such as sputter vapor deposition, ion plating, electroplating and electroless plating. It is also possible to use metal alkoxides.

When the mirror surface 9c is provided in the three-electrode structure shown in FIG. 5, the mirror surface 9c can be formed more accurately on the side surface of the partition plate 22 by screen printing of a metal organic compound. Therefore, the mirror surface 9c was also formed using both electron beam vacuum evaporation of aluminum and screen printing of a metal organic compound containing gold as a main component.

That is, after the partition plate 22 is formed on the rear glass plate 11 by the sandblast method, the metal organic compound film is printed and baked by the screen which is patterned so that the mirror surface 9c can be formed only on the side surface of the partition plate 22. After that, an aluminum film was formed on the rear glass plate 11 by electron beam vacuum evaporation.

Although not shown, the terminal lead-out portion of the electrode is formed by screen printing using a silver-based paste material prior to the formation of the partition plate 22 to form the terminal portion with high accuracy. We were able to.

Regarding members other than the mirror surface 9,
It goes without saying that the film is formed by a general method (thin film process, thick film process, etc.).

Further, as the panel size increases, the resistance of the electrodes increases, which may cause problems such as discharge variations. In such a case, as shown in FIGS. 10 to 13, the bus electrode 2 made of nickel, aluminum or the like is used.
By providing 3 on the mirror surface 9c that also serves as an address electrode, good conductivity could be ensured. It goes without saying that it is effective to provide the bus electrode 23 on the mirror surface 9b also serving as the address electrode in the embodiment shown in FIGS.

Regarding the phosphor, in the case of monochrome use,
A single phosphor or a mixture of R, G and B phosphors was used. Also, in the case of color applications, R ・ G ・
The B phosphors may be painted separately for each cell, or a single phosphor or a white phosphor mixed with the R, G, and B phosphors may be uniformly applied, and each color may be applied by a color filter. Even if they were separated, color display was possible. Of course, R
It goes without saying that color display is possible even if the G and B phosphors are separately coated for each cell and further separated by color filters.

[0051]

As described above, according to the present invention,
By providing the phosphor layer of the cell on the mirror surface, the utilization efficiency of the output light of the phosphor layer can be increased and the brightness can be significantly improved.

Further, in the present invention, since the mirror surface is also used as the address electrode, the structure is simplified.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an essential part showing a first embodiment of a plasma display panel according to the present invention.

FIG. 2 is a sectional view of an essential part showing a second embodiment of the plasma display panel according to the present invention.

FIG. 3 is a front view showing a partition wall in FIG.

FIG. 4 is a cross-sectional view of an essential part showing a third embodiment of the plasma display panel according to the present invention.

FIG. 5 is a cross-sectional view of essential parts showing a fourth embodiment of a plasma display panel according to the present invention.

FIG. 6 is a cross-sectional view of essential parts showing a fifth embodiment of the plasma display panel according to the present invention.

FIG. 7 is a cross-sectional view of essential parts showing a sixth embodiment of the plasma display panel according to the present invention.

FIG. 8 is a cross-sectional view of essential parts showing a seventh embodiment of the plasma display panel according to the present invention.

FIG. 9 is a sectional view of an essential part showing an eighth embodiment of the plasma display panel according to the present invention.

FIG. 10 is a cross-sectional view of essential parts showing a ninth embodiment of the plasma display panel according to the present invention.

FIG. 11 is a cross-sectional view of essential parts showing a tenth embodiment of a plasma display panel according to the present invention.

FIG. 12 is a sectional view of an essential part showing an eleventh embodiment of a plasma display panel according to the present invention.

FIG. 13 is a cross-sectional view of essential parts showing a twelfth embodiment of the plasma display panel according to the present invention.

[Explanation of symbols]

 1 Front Glass Plate 2 Color Filter 3 Black Matrix 4 Protective Flat Layer 5 Display Electrode 6 Insulating Layer 7 Protective Layer 8 Partition Plate 9a Mirror Surface 9b, 9c Address Electrode Mirror Surface 10 Fluorescent Material Layer 11 Back Glass Plate 12 Trigger Electrode 13 Insulation Layer 14 Address electrode 15 Protective layer 16 Front plate 17a, 17b Partition wall 18a, 18b Rear plate 19 Discharge space on the front side 20 Discharge space on the back side 21 Through hole 22 Partition plate 23 Bus electrode

Front page continuation (72) Inventor Takashi Sasaki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.Multimedia Systems Development Division, Hitachi, Ltd. (72) Inventor Yuji Sano 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ceremony Company Hitachi, Ltd. Multimedia System Development Headquarters (72) Inventor Hiroshi Otaka 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hitachi Ltd. Multimedia System Development Headquarters (72) Inventor Nobuyuki Ushifusa Yokohama, Kanagawa Prefecture (2) 292 Yoshida-cho, Totsuka-ku, Yokohama, Ltd. In the production technology research institute of Hitachi, Ltd. (72) Inventor Eiji Matsuzaki 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa

Claims (9)

[Claims] 1. A plasma display device in which a phosphor layer is excited by energy of ultraviolet rays generated by discharge to obtain visible light in each light emitting region, and a surface on which the phosphor layer is formed and the phosphor layer. A plasma display panel, characterized in that a reflective film for reflecting the light emitted from the phosphor layer is provided between the body layer and the phosphor layer. 2. The reflective film according to claim 1, wherein the reflective film is made of aluminum, titanium, chromium, cobalt, nickel, copper, zirconium, molybdenum, rhodium, palladium, silver, hafnium, tungsten, iridium, platinum, gold, or a single substance. A plasma display panel comprising a plurality of metal materials and / or a metal organic compound or a metal alkoxide containing these. 3. The light emitting region according to claim 1, wherein the light emitting region is spatially separated by a stripe-shaped partition wall or an electrode wiring, and the surface of the partition wall and / or the bottom surface of the light emitting region. Is a surface on which the phosphor layer is formed. 4. The light emitting region according to claim 1, wherein the light emitting region is spatially separated for each cell by a stripe-shaped first partition wall and a second partition wall intersecting with the stripe-shaped first partition wall. A plasma display panel, wherein a front surface and / or a bottom surface of the light emitting region is a surface on which the phosphor layer is formed. 5. The structure according to claim 4, wherein at least the first barrier rib has a double space structure that forms a discharge space on the front side and the rear side, respectively, and is formed on at least the front side of the first barrier rib. A plasma display panel, wherein a surface facing the discharge space is a surface on which the phosphor layer is formed. 6. The plasma display panel according to claim 3, wherein the reflective film is also used as an address electrode. 7. The plasma display panel according to claim 1, wherein the phosphor layer is separately coated for each emitted light. 8. The plasma display panel according to claim 1, wherein the phosphor layer emits light of a single color or white light. 9. The color filter according to claim 1, wherein a color filter is provided for each of a large number of cells forming the light emitting region, and the emitted light from the cell is dispersed by the color filter to the outside. Plasma display panel characterized by taking out.