1. Field of the Invention
The present invention relates to a plasma display panel (PDP) having a mesh-patterned partition, each square of which encloses one or more cells for constituting a display surface and a method for manufacturing the PDP.
A PDP is commercialized for a wall-hung TV set, whose screen size has reached 60 inches. PDP is a digital display device comprising binary light emission cells, so it is suitable for a display of digital data and is expected as a multimedia monitor. In order to increase applications of a PDP, a new panel structure is under development, which can provide a brighter and more stable display and can be manufactured in a high productivity.
2. Description of the Prior Art
An AC type PDP for a color display employs a surface discharge format. The surface discharge format has an arrangement of electrodes in which display electrodes that become anodes and cathodes in a display discharge for ensuring a luminance are arranged in parallel on a front or back substrate, and address electrodes are arranged so as to cross a pair of the display electrodes. In the surface discharge format PDP, a partition is necessary for separating a discharge for each column of a matrix display along the longitudinal direction of the display electrode (hereinafter referred to as the row direction). The partition also works as a spacer for defining a discharge space size in the direction of the panel thickness.
A partition pattern (a shape of the partition in the plan view) is broadly divided into a stripe pattern and a mesh pattern. The stripe pattern divides the discharge space for cells arranged in the row direction (i.e., in each column). In the stripe pattern, the discharge space of cell included in each column is not separated, so that exhausting of inner air and filling of discharge gas are relatively easy in a manufacturing process of a PDP. The mesh pattern divides the discharge space both in the row direction and in the column direction. A typical mesh pattern is a check pattern. A mesh pattern has an advantage in that the discharge is separated for each cell and that a fluorescent material is arranged on a side face of the partition so as to enclose the cell for increasing a light emission area. The mesh pattern, however, has a disadvantage in that a gap generated by subtle unevenness on the upper surface of the partition becomes an air path in the inner air exhaustion, so a resistance of the air exhaustion is large and it takes a long time for the process.
Conventionally, a partition structure of an overlaying form of the mesh-patterned partition and the stripe-patterned partition (this is called a composite pattern structure) is known. In this structure, since the discharge space is continuous as in the case of the stripe pattern, the air exhaustion resistance is smaller than in the case where the stripe-patterned partition is not overlaid. Furthermore, an improved composite pattern structure is disclosed in Japanese unexamined patent publication No. 4-274141, in which a stripe-patterned partition is provided with a hiatus for each cell, so that a grid-shaped air path (air exhaustion path) is formed for the gas to flow not only in the column direction but also in the row direction.
The above-explained partition having the composite pattern structure has a mesh-patterned partition whose banding portion in the column direction or the row direction is raised. There was a problem that the partition forming process becomes complicated for forming the above-mentioned structure on the inner surface of one of the substrate pair. Furthermore, if a mesh-patterned partition is disposed at one of the substrates and if a stripe-patterned partition is disposed on the other partition, the fluorescent material should be arranged on both of the substrates for increasing the area in which the fluorescent material is formed. In addition, a registration of the substrate pair in the assembling process is difficult. Thus, the partition having the composite pattern structure is adverse from the viewpoint of the productivity.
There is a method of forming the air path by cutting a part of the partition. However, this method may increase the number of manufacturing steps for the cutting process and may reduce the manufacturing yield since the partition can be broken by the cutting process.
An object of the present invention is to provide a PDP that has a good productivity of partition formation and air exhaustion process and can display more brightly and more stably than a PDP that has a stripe-patterned partition.
According to the present invention, a mesh-patterned partition is arranged on the inner surface of one of the substrates. The partition has low portions that form a mesh-like air path that travels through all of the gas-filled space enclosed by the partition in a plan view. For example, in a simple check pattern in which a line along the horizontal direction and a line along the vertical direction cross each other, the portion corresponding to the line along the horizontal direction is made low. In this case, the pattern width (the line width) of the portion corresponding to the line along the horizontal direction is made thicker than the pattern width of the portion corresponding to the line along the vertical direction so as to generate a height difference. The shrink quantity in the thick portion is smaller in the width direction but is larger in the height direction than the thin portion.
Hereinafter, the present invention will be explained in detail with reference to embodiments and accompanied drawings.
The PDP 1 comprises a pair of substrate structures (a structure including a substrate on which cell elements are arranged) 10, 20, and the display surface ES comprises m×n cells. In each cell, the display electrodes X, Y constituting an electrode pair for generating the display discharge are extending in the row direction (the horizontal direction) of the matrix display, and the address electrodes A are extending in the column direction (the vertical direction).
The display electrodes X, Y are arranged on the inner surface of the glass substrate 11 of the front substrate structure 10 as a pair for each row. Herein, the “row” means a set of cells whose positions in the column direction are the same, and the number of the cells is equal to the number of columns (m). Each of the display electrodes X and Y includes a transparent conductive film 41 that forms a surface discharge gap (a discharge slit) and a metal film (a bus conductor) 42 that is overlaid on the edge in the column direction. The display electrodes X, Y are covered with a dielectric layer 17 having the thickness of approximately 20-40 μm, and the surface of the dielectric layer 17 is coated with a protection film 18 made of magnesia (MgO). The electrode gap between rows (that is called a reverse slit) is provided with a dark color layer 65 that is called a black stripe by applying a paint on the outer surface of the glass substrate 11 or by forming a colored glass layer including fillers such as manganese, iron oxide, chromium and other colorant so as to increase contrast (see FIG. 2).
The address electrodes A are arranged on the inner surface of the glass substrate 21 of the back substrate structure 20 as one for each column and are covered with a dielectric layer 24. On the dielectric layer 24, the partition 29 is disposed, which has a grid pattern with partially low profile structure that is unique to the present invention. The partition 29 is made of a baked material of a low melting point glass and includes a portion for dividing the discharge space into columns (hereinafter referred to as a vertical wall) 291 and a portion for dividing a discharge space into rows (hereinafter referred to as a horizontal wall) 292. The intersection of the vertical wall 291 and the horizontal wall 292 is a common part of them. The horizontal wall 292 is lower in height (i.e., is shorter) than the vertical wall 291 by approximately 10 μm. The upper surface of the dielectric layer 24 and the side face (i.e., side walls) of the partition 29 are covered with red, green and blue colors of fluorescent material layers 28R, 28G and 28B for color display. The italic letters (R, G and B) in
As shown in
The PDP 1 having the above-mentioned structure can be manufactured by the following process.
As shown in
In the PDP 1 of this embodiment, the inter-row portion 293 of the partition 29 is made approximately 10 μm lower than other portions, i.e., made approximately 7% lower, relative to the maximum height (140 μm) of the partition 29. Thereby, an air exhaustion path 90 is formed which has a grid shape in the plan view for enabling air exhaustion both in the column direction and in the row direction. The width W20 of the inter-row portion 293 is substantially large, and the inter-row portion 293 is substantially lowered, relative to the other portions, and therefor, the air exhaustion conductance is substantially the same as the stripe pattern. Concrete dimension of the partition 29 is as follows.
It is important that the width W20 of the inter-row portion 293 is substantially larger than the width W11 of the vertical wall 291, so that the difference between the widths makes a height difference between the inter-row portion 293 and other portions. Namely, in a baking process of a material such as a general low melting point glass having a heat shrink property, as shown schematically in
The composition of the low melting point glass that is a material of the partition 29 is shown in Table 1.
Concerning optical characteristics of the partition 29, it is desirable that it is semitransparent having the absorptance of visual light at approximately 80% per 30 μm of film thickness. If it is semitransparent, light rays generated at the vicinity of the top of the partition pass the partition and contribute to improvement of the luminance, while external rays that entered the partition are reflected by the bottom surface of the partition and are absorbed by the partition before reaching the front surface. Therefore, a display having a good contrast can be realized.
The process of forming the partition 29 is as follows.
The partition 29b shown in
Each of the display electrodes Xb and Yb shown in
In the example shown in FIG. 11 and in the example shown in
In
In
In the above-mentioned embodiment, the dimension and the material of the partition 29 are not limited to the examples. The plan-view pattern of the partitions 29, 29b-29e is not limited to that enclosing a cell. It can be a mesh pattern enclosing plural cells as a unit.
According to the present invention, a PDP that has a good productivity of partition formation and air exhaustion process and can display more brightly and more stably than a PDP that has a stripe-patterned partition can be realized.
While the presently preferred embodiments of the present invention have been shown and described, it will be understood that the present invention is not limited thereto, and that various changes and modifications may be made by those skilled in the art without departing from the scope of the invention as set forth in the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
2000-269569 | Sep 2000 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
3953756 | Monfroy et al. | Apr 1976 | A |
5352478 | Miyake et al. | Oct 1994 | A |
5754003 | Murai et al. | May 1998 | A |
5909083 | Asano et al. | Jun 1999 | A |
5990616 | Lee et al. | Nov 1999 | A |
6249264 | Sano et al. | Jun 2001 | B1 |
6313580 | Makino | Nov 2001 | B1 |
Number | Date | Country |
---|---|---|
0 920 048 | Jun 1999 | EP |
4-206126 | Jul 1992 | JP |
4-274141 | Sep 1992 | JP |
4-277439 | Oct 1992 | JP |
5-094772 | Apr 1993 | JP |
9-115452 | May 1997 | JP |
9-190768 | Jul 1997 | JP |
11-213896 | Aug 1999 | JP |
11-297211 | Oct 1999 | JP |
Number | Date | Country | |
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Parent | 09778879 | Feb 2001 | US |
Child | 11113337 | US |