JPH05290744A - Color plasma display panel - Google Patents

Abstract

PURPOSE:To provide a display panel having high brightness, and allowing only low risk of wire breaking by forming a line like cathode made on a glass plate of at least two line segments parallel to a line and plural arm lines combining this combination. CONSTITUTION:A line-like cathode 3 made on a front glass plate is formed of at least two line segments parallel to a line and plural arm lines combining the line segments. The arm lines are set on the center portions of discharge cells and on the upper portions of barriers. When the cathode is formed of plural line segments as securing a definite cathode area, the line width of one line becomes small, so that the risk of wire breaking increases, although brightness increases. However, by setting the arm lines, it is possible to secure reliability equivalent to that of the thick line or more. By setting the arm lines on the upper portions of the barriers 5, no discharge cells are shaded, and by setting the arm lines on the center portions of the discharge cells, the arm lines also become parts of the cathode so as to take part in exciting fluorescent substance. Thereby it is possible to increase brightness and avoid the risk of the wire breaking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a direct current type color plasma display of a reflection type. More specifically, the linear cathode formed on the front glass plate is composed of a plurality of thin line segments, and is broken at high brightness. The present invention relates to a direct current type color plasma display panel having a small amount.

[0002]

2. Description of the Related Art Various types of color plasma display panels (hereinafter abbreviated as color PDP) have been proposed. The direct current type (DC type) color PDP is one of them, and so-called reflection type, which directly sees the emission of the phosphor by ultraviolet excitation, and so-called transmission type, which sees the emission through the phosphor, are known. There is.

FIG. 1 is a partial schematic sectional view of a reflection type DC color PDP. In addition, the reference numerals of the respective drawings shown below are common, and the same reference numerals indicate similar components.

A linear cathode 3 is attached to the inner surface of the front glass plate 1 in the vertical direction. A line-shaped anode 4 is formed on the back plate 2 in a direction intersecting with the cathode. The discharge space 7 formed at the intersection of the cathode 3 and the anode 4 is surrounded by the partition walls 5 that partition adjacent discharge cells. The phosphor 6 is adhered to the back plate and the inner surface of the partition wall except for a part of the anode.

Although not shown in the figure, a light-shielding dielectric layer for improving contrast, a trigger electrode or an auxiliary anode for assisting discharge initiation, a current limiting resistor or a dielectric layer for coating or multilayer wiring, etc. Sometimes used. Since these have no direct relation to the present invention, they are omitted in FIG.

For the front glass plate and the back plate, inexpensive soda lime glass is commonly used. Various circuits and partitions are formed on these substrates. Also a phosphor is deposited. These are generally performed using a film forming technique. Thin film technology is applied to fine patterns, and thick film technology with high mass productivity is applied to other cases. Instead of forming a partition on the substrate,
Alternatively, the partition plate may be separately formed.

In a high-definition color PDP, it is convenient to form a discharge cell at a position where a line cathode and a line anode intersect.

The color PDP thus constructed is completed by hermetically sealing the periphery with glass and enclosing a predetermined gas.

As can be seen from the figure, a reflection type color PDP
In the case where the cathode is formed on the front glass plate and the cathode material is usually light-shielding, the cathode blocks light emission inside the discharge cell. Therefore, it is preferable that the cathode area is small for light transmission. However, the luminance is higher when the discharge amount, that is, the cathode area is larger. Therefore, for a given discharge cell area, there is a proper cathode area, which is actually designed.

The closer the phosphor is to the cathode, the stronger the light emission. Therefore, even if the cathode area and the phosphor coating amount are the same, high brightness can be obtained if many phosphors close to the cathode can be arranged.

2 and 3 are schematic plan views showing a conventional cathode structure. In FIG. 2, the cathode 3 crosses the opening of the discharge cell and has a line shape that also serves as a wiring. In FIG. 3, the wiring 3a is formed in a line above the partition wall 5, and the cathode 3 is formed in the center of the cell opening. The cathode part is shaded.

Comparing FIG. 2 and FIG. 3, the formation of the cathode is easier in FIG. Also, assuming that the cathode area is the same, the phosphor area (dotted portion) surrounded by line segments equidistant from the cathode is
3 is larger and the brightness is higher. In order to further improve the brightness, it is possible to divide the cathode into thin line segments. For example, in FIG. 3, a plurality of comb-shaped cathodes are formed from the wiring.

However, when the line width becomes smaller, the resistance value increases and the problem of disconnection occurs. The resistance value is determined by the line width and the material and thickness of the cathode and wiring, and if properly selected, it is possible to achieve a practical value even with a line width of about 10 μm. The disconnection is a problem when the length and the number of lines are large in addition to the line width. For example, in the case of a color PDP having a length of 200 mm or more and 200 or more cathodes, it is 100 in thick film technology.
If the line width is less than 50 μm in the thin film technology, the problem of disconnection occurs.

Therefore, in the conventional cathode structure, there is no problem of disconnection and it is difficult to improve the brightness.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art and to provide a color PDP having high brightness and free from disconnection.

[0016]

The above object of the present invention is to provide a linear cathode comprising at least two line segments parallel to the line and a plurality of line segments connecting the two line segments. It is achieved by

That is, the present invention provides a direct current color PDP in which a plurality of discharge display cells are formed at positions where the linear first electrode group and the linear second electrode group intersect.
A color PDP, in which a line-shaped cathode formed on the front glass plate is composed of at least two line segments parallel to the line and a plurality of line segments connecting the two line segments. is there.

The present invention will be described in more detail below. The color PDP of the present invention is different only in the shape of the cathode structure, and other known PDP techniques can be applied. For example, various construction methods, forming materials, forming techniques, and the like. However, a more preferable example will be described below.

The cathode material is preferably A1 or a conductive oxide. This is because the discharge starting voltage can be lowered and an air atmosphere can be used in the firing process. As the conductive oxide, one containing a group Ia, IIa, or IIIa element of the periodic table of elements is preferable, and, for example, JP-A-2-276180, JP-A-2-284217, JP-A-2-284218,
It is described in detail in JP-A-2-288400, JP-A-2-288401, JP-A-2-288402, and the like. When a conductive oxide containing any of the above elements is used as the cathode, the discharge starting voltage is further reduced, and it has the characteristics of being resistant to sputtering. A conductive oxide having a perovskite type or K ₂ NiF ₄ type crystal structure is stable and particularly preferable in terms of characteristics.

When the cathode material is a conductive oxide, it often has a high resistance, and therefore a metal base is preferably used.

If the metal cathode or wiring is formed on the front glass plate and has a metallic luster, the contrast may be harmful. In this case, Cr, Ti on the metal base
Alternatively, Mn or the like may be vapor-deposited and slightly oxidized to blacken the display surface to improve the contrast.

The width of the line segment forming the cathode line is 80 μm.
m or less is preferable. As described above, the brightness can be improved by reducing the line width. 50 μm by normal thick film printing
A line width of a certain degree can be formed. When the thick film ink is made to have photosensitivity, a width of about 20 μm is possible. With the thin film technology, it is possible to easily form even a width of 10 μm.

The cathode line width is harmful even if it is too thin because the frequency of occurrence of disconnection increases. Also, if the discharge is concentrated due to non-uniformity of the cathode formation, the thin cathode has a risk of disconnection during operation. If the line width is 30 μm or more, there is usually no problem.

In the present invention, the cathode line is composed of a plurality of line segments parallel to the cathode line and a plurality of line portions connecting the parallel line segments. If the cathode is composed of a plurality of line segments while securing a constant cathode area, the larger the number of lines, the smaller the line width of one line and the risk of disconnection increases. However, by providing a line segment (arm line) corresponding to an arm connecting parallel line segments, it is possible to secure reliability equal to or greater than that of a thick line. Since the parallel lines are formed, even if there is a partial disconnection, it is unlikely that the entire line will be disconnected.

The number of arm lines is preferably as large as possible within the range where the light-shielding area does not become large and where the line width does not become too thin. One or more per discharge cell is preferable.

The position where the arm line is formed is most preferably above the partition because it does not shield the discharge cell. Another preferred location is the center of the discharge cell. In this case, the arm line also serves as the cathode, which is a convenient place for exciting the phosphor. Furthermore, the central part of the discharge cell is a convenient place for discharging, and an exposed anode is formed on the back side. Since this anode portion does not emit light, even if a light-shielding cathode is placed on this anode portion, light emission is not wasted.

A simple example of the cathode line having such a structure is a ladder line. It is also possible to arrange multiple ladders side by side. As a more complicated structure, a halftone dot-shaped opening may be provided in the cathode line.

In the above structure, the number of phosphors close to the cathode can be increased, so that the brightness can be improved.

[0029]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 FIG. 4 is a schematic plan view showing a first example of the cathode constitution of the color PDP of the present invention. 4 is a color PDP having the same configuration as that of FIG. Compared to Fig. 2, the width of the cathode is about 1/2
It consists of two line segments and the arm line connecting them. One arm line is formed on the cathode, one arm line is formed in the center of the discharge cell, and two arm lines are formed in each cell. Other conditions such as cathode area are
It is similar to FIG.

As a result, as compared with the cathode structure shown in FIG. 2, the rate of occurrence of wire breakage was equal to or less than that, and the brightness was about twice.

Example 2 FIG. 5 is a schematic plan view showing a second example of the cathode constitution of the color PDP of the present invention. FIG. 5 is a color PDP having the same configuration as that of FIG. Compared to Fig. 3, the width of the cathode is about 1/2
It consists of three line segments and the arm line connecting them. One arm line is formed in the center of each discharge cell. Other conditions such as the cathode area are the same as those in FIG.

As a result, as compared with the cathode structure shown in FIG. 3, the rate of occurrence of wire breakage was about half and the brightness was about 1.4 times.

Embodiment 3 FIG. 6 is a schematic plan view showing a third example of the cathode constitution of the color PDP of the present invention, showing a vertically long display cell.
This feature is as follows.

That is, in a full-color display or the like, for example, pixels are composed of red, green, and blue discharge cells. Typical configurations include a so-called paddle-shaped array in which one cell is composed of four cells and a so-called three-color flag array in which three vertically long cells are arranged.
Usually, the pixels are close to a square.

At this time, the number of scanning lines required to drive the pixels is two in a square shape and one in a three-color flag type. Therefore, the vertically long cell has an advantage of facilitating driving of full color display. This scan line is usually the cathode.

In the figure, the cathode line is composed of three line segments parallel to the line and an arm line connecting them at the center of the discharge cell.

It can be seen that the arrangement of the phosphors is advantageous as compared with the structure having the same cathode area and the structure shown in FIG.

Embodiment 4 FIG. 7 is a schematic plan view showing a fourth example of the cathode constitution of the color PDP of the present invention. Since the wiring portion is formed on the partition wall, the design is advantageous.

[0040]

As is apparent from the above, in the color PDP of the present invention, the cathode and the phosphor can be arranged close to each other, and the brightness can be increased. Even if the line segment is composed of thin line segments, there is an arm line connecting the plurality of line segments, so that the risk of disconnection is small. Therefore, a high-luminance color PDP can be easily provided.

[Brief description of drawings]

FIG. 1 is a partial schematic cross-sectional view of a conventional reflection type DC color PDP.

FIG. 2 is a schematic plan view showing an example of a cathode configuration of a conventional color PDP.

FIG. 3 is a schematic plan view showing another example of the cathode configuration of a conventional color PDP.

FIG. 4 is a schematic plan view showing a first example of the cathode configuration of the color PDP of the present invention.

FIG. 5 is a schematic plan view showing a second example of the cathode configuration of the color PDP of the present invention.

FIG. 6 is a schematic plan view showing a third example of the cathode configuration of the color PDP of the present invention.

FIG. 7 is a schematic plan view showing a fourth example of the cathode configuration of the color PDP of the present invention.

[Explanation of symbols]

1: front glass plate, 2: rear plate, 3: cathode, 3a: cathode wiring, 4: anode, 5: partition wall, 6: phosphor, 7: discharge space.

Claims (2)

[Claims] 1. A line-shaped first electrode group and a line-shaped second electrode group
In a direct current color plasma display panel in which a plurality of discharge display cells are formed at positions where the electrode groups intersect, a linear cathode formed on the glass plate has at least two line segments parallel to this line. And a plurality of line segments connecting the two line segments, a color plasma display panel. 2. The color plasma display panel according to claim 1, wherein the line segment forming the linear cathode has a width of 80 μm or less.