JPS6298534A - Plasma display panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a plasma display panel, and more particularly, to the structure of a plasma display panel, and in particular to a dielectric layer covering the inner surface of the plasma display panel. be.

BACKGROUND OF THE INVENTION Plasma display panels are devices that display textual, numerical or graphical data. Therefore, the data display is two-dimensional.

Data is displayed by causing areas or dots on the surface to emit light in combination using suitable control means.

A plasma display panel is a matrix-like screen consisting of a network of unit cells arranged along intersecting rows and columns.

This screen is controlled by two intersecting electrode networks. Each unit cell is filled with ionized gas and can be selectively addressed. When a sufficient voltage is applied across the terminals of a unit cell, the gas emits light and
This is one of the bright spots or light emitting dots mentioned above.

AC plasma display panels have the simplest structure.

According to one embodiment, the plasma display panel is constructed from two plates or sheets of insulating material.

At least one of the plates is transparent so that the bright spots or dots are visible. These plates are placed in mutually parallel planes and are provided with an electrode network on their respective inner surfaces.

These two electrode networks are opposite and orthogonal to each other. These plates are set in place and sealed to confine a gas mixture at a predetermined pressure. The electrode network is made of metal and is insulated from the gas by a dielectric layer. The dielectric layer is mainly made of dielectric and has a thickness of 1
They often consist of a 5 to 30 micron film coated with a vapor-deposited film of magnesium oxide less than about 1 micron thick. The dielectric layer thus formed is transparent.

Plasma display panels emit orange-red light. However, its luminosity remains relatively low for now. The brightness is moderate, up to several tens of candelas per l m'.

In such a state, if the surrounding illuminance exceeds several hundred lux, the contrast between the ignited region and the extinguished region may be small, making it difficult to see the display panel display.

Various methods have been proposed to increase this contrast.

The simplest method is to deposit a layer of black paint or black camellia (grease) on the back side of the plasma display panel (this back side is not visible to anyone looking at the panel). In this way, Excess light reflecting off the backside of the display panel can be eliminated without reducing the amount of useful light emitted.

It is also possible to attach an anti-reflection filter to the front of the display panel. Using this anti-reflection filter, the light reflected by the display panel can be significantly reduced without unduly reducing the useful light.

It is also conceivable to use metal electrodes to reduce reflections. In this regard, aluminum or chromium electrodes, for example, are less reflective than gold electrodes. This is a matter of basic technology choice, and the result is more than just contrast improvement.

Another solution is based on the concept of color contrast and has nothing to do with luminosity. It is well known that it is theoretically preferable to provide a green background, or even a green electroluminescent light background, at the back of a plasma display panel, since red contrasts strongly with green.

PROBLEM TO BE SOLVED BY THE INVENTION The solution described above makes it possible to obtain a plasma display panel whose display can be read even under illuminance of more than 1000 lux. However, these solutions have the disadvantage that they complicate the manufacturing process of the display panel by adding extra operations such as painting, coating with resin, installing filters or plates for electroluminescent light, etc.

The purpose of the present invention is to use a simple manufacturing method as in the past,
The goal is to increase the contrast of a plasma display panel.

SUMMARY OF THE INVENTION The present invention comprises first and second plates of insulating material arranged in planes parallel to each other, with an ionized gas layer between the first and second plates. This invention relates to a sealed plasma display panel. The first provision comprises at least one first electrode on the surface in contact with the ionized gas.

The second plate includes at least one second electrode located opposite the first electrode on the surface in contact with the ionized gas. The two electrodes are each coated with a layer of dielectric material. The layer of dielectric material covering the second plate and at least this second electrode is transparent. Further, the conductive material covering at least the first electrode is a colored dielectric.

Various advantageous objects and features of the present invention will become apparent from the following description made with reference to the accompanying drawings. However, this explanation does not limit the present invention in any way.

Embodiment First, a conventionally known plasma display panel will be described with reference to FIGS. 1 and 2.

This plasma display panel is composed of two glass plates 1 and 2 arranged in parallel planes. The glass plate 1 is provided on its inner surface 10 with an electrode network consisting of vertically oriented, mutually parallel electrodes v1, 2, 3, etc.

The glass plate 2 has electrodes ■1, V2, ■ on its inner surface 20.
It is provided with an electrode network consisting of three orthogonal horizontal electrodes H1, H2, H3, etc. Gold or aluminum electrodes are formed by silk screen stamping or photolithography. These bottles are arranged on the inner surface 10 and 20 of each glass plate 1.2. The spacing between these electrodes is several hundred microns. 'Normally, one electrode network contains several hundred electrodes.

Glass+Fi1 and 2 are positioned using a bonding member 3, and sealed with the bonding member 3 in between.

These two glass plates 1 and 2 and the joining member 3 define a space filled with a mixed gas at a predetermined pressure.

The electrode network is separated from the gas mixture 6 by dielectric layers 4 and 5. The thickness of the dielectric layers 4 and 5 varies depending on the properties of the dielectric, but is, for example, 20 to 25 microns.

The dielectrics, Si4 and 5, are coated with a thin film of magnesium oxide or the like. This material has excellent properties as a secondary electron emitter (for sustaining a discharge).

Vertical electrodes on the first glass plate 1, for example
When a sufficient voltage is applied to a horizontal electrode of the glass plate 2, for example H3, the gas is ionized at a point called a cell, which is the intersection of the two electrodes 1 and H3. Therefore, as shown in FIG. 1, a person viewing the glass plate 2 from the direction of the arrow F sees a bright spot due to ionization of the gas through the glass plate 2 and the dielectric layer 5.

As mentioned above, it is necessary to take sufficient care to avoid unnecessary reflections from the glass plate 1 and the electrode (1) in the vertical direction of this glass plate.

In the present invention, for this purpose, the glass plate 1 and the vertical electrodes 1, 2, 3, etc. are covered with a colored dielectric layer 4, as shown in FIG. However, the inner surface 2 of the glass plate 2
The dielectric layer 5 covering the electrodes such as 0 and H3 is transparent.

This is possible, for example, by adding to a normal dielectric a dye that, when fired, colors the dielectric in the desired color.

Such a dielectric material can be manufactured by hand as a commercially available product. Its application method (deposition and firing conditions), physicochemical and electrical properties are similar to conventional transparent enamels and enamels.

Therefore, if the present invention is used, the vertical electrodes such as the electrodes 1 of the glass plate 1 are obscured, and as a result, the amount of ambient light that would have been reflected by those electrodes is reduced, thereby greatly increasing the contrast. It becomes possible to do so.

For example, using a black dielectric can reduce excess light reflection by 50-60%.

The measurement results obtained when using a black dielectric are shown in the table below.

The contrast coefficients in this table are determined by the following formula:

However, L O+1 is the brightness of the point of ignition, and L OFF
is the brightness of the extinguished point.

The luminance measurements were performed here under an illuminance of 1000 lux.

The contrast coefficient in this table is calculated when the ambient illuminance is 1000
Note that measurements were taken in lux and under standard conditions of power supply to the display panel.

The contrast of the fired cells is thus significantly increased.

Furthermore, when using the plasma display panel of the present invention, there is no need to color the inner surface 10 of the glass plate 1, for example, by painting, so that the plasma display panel can be easily manufactured without extra work steps. .

Another advantage of the present invention is that by using colored dielectrics, color contrast can be used to improve readability. At this time, the selection of dye is important. Using green dye can often make it easier to read. When using colored dielectrics, a well-chosen dye can result in a plasma display panel that has the advantage of being ergonomically neat and aesthetically pleasing.

Further, according to the present invention, by using a milky white dielectric in the dielectric layer 4, it is possible to reduce the reflection of light by the vertical electrodes 1, 2, and V3.

In this case it is possible that the light is scattered. Such a milky-white dielectric material has the advantage of not causing parallax, so it can be used to construct a screen for projecting images such as maps. Projection is done directly onto the plasma display panel. However, there is a difference in that the image is projected on the front side of the display panel by reflection, and the image is projected on the rear side of the display panel by transmission.

Also, depending on the embodiment, the dielectric layer 4 may include several regions, each region covered with a dielectric of a different color. By doing so, a plurality of display areas for visualizing specific information can be formed on one display device.

According to one embodiment of the plasma display panel, the dielectric layers 4 and 5 are deposited with smooth surfaces. In this way, a plasma display panel as shown in the exploded parts arrangement perspective view of FIG. 4 and the sectional view of FIG. 5 is obtained. 4 and 5, a colored dielectric layer 4
and a transparent dielectric layer 5 are shown.

Furthermore, according to another embodiment of the invention, the electrodes H1, H2, H3 on the inner surface 20 of the glass plate 2 and in the horizontal direction
It is possible to color the dielectric layer 5 deposited on etc.

In particular, in some embodiments it may be appropriate to mask a portion of the display panel to a person viewing the glass plate 2 of the display panel along the direction of arrow F. In particular, it is known that ionizing a so-called "conditioning" discharge within the display panel facilitates the ignition of the cell (the intersection between the vertical and horizontal peaks). The conditioning discharge is constantly being continued in areas on the display panel where no useful information is displayed. These areas are preferably provided at the periphery of the plasma display panel. However, if the cells in these adjustment areas are always lit, the information displayed on the display panel becomes difficult to read. Therefore, a mask or frame is typically provided on the outer surface of the display panel between the viewer and the display panel.

However, since there may be parallax due to the thickness of the glass plate 2, the light emitted from the adjustment area may interfere with the reading of the display panel.

According to the invention, as shown in FIG. 6, it is possible to color the region 7 corresponding to the adjustment region using the dielectric layer 5. Region 7 of dielectric layer 5 thus becomes a mask which has the advantage that there are no parallax effects, since the dielectric is in direct contact with the conditioning discharge region. The dye mixed into the dielectric layer 5 is preferably one that colors the dielectric black.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an exploded parts arrangement of an embodiment of a conventional plasma display panel, FIG. 2 is a sectional view of the plasma display panel of FIG. 1, and FIG. 3 is a plasma display panel according to the present invention. 4 is a cross-sectional view of one embodiment of a display panel; FIG. 4 is a perspective view of an exploded parts arrangement of one embodiment of a plasma display panel according to the present invention; and FIG.
FIG. 6 is a cross-sectional view of another embodiment of the plasma display panel according to the present invention. (Main reference numbers) 1.2...Glass plate, 3...Joining means, 4.5...
・Dielectric layer, 10, 20...inner surface,

Claims (10)

[Claims] (1) comprising first and second plates made of an insulating material and arranged in planes parallel to each other; an ionized gas layer is sealed between the first and second plates; has at least one first electrode on a surface in contact with the ionized gas, and the second plate also has at least one first electrode on a surface in contact with the ionized gas opposite the first electrode. a plasma display panel comprising at least one second electrode disposed on the second plate and at least one second electrode, each of the two electrodes being coated with a layer of dielectric material; A plasma display panel characterized in that the layer of dielectric material covering the second electrode is transparent, and the dielectric material covering at least the first electrode is a colored dielectric. (2) The plasma display panel according to claim 1, wherein the colored dielectric covers the first electrode and the surface of the first plate that includes the electrode. (3) The plasma display panel according to claim 1, wherein the colored dielectric material is opaque to visible light. (4) The plasma display panel according to claim 1, wherein the colored dielectric is black. (5) The plasma display panel according to claim 1, wherein the colored dielectric material is green. (6) The plasma display panel according to claim 1, wherein the dielectric material is milky white. (7) The surface of the first plate that comes into contact with the ionized gas comprises a plurality of regions each coated with a dielectric material of a different predetermined color. The plasma display panel described in . (8) The surface of the second plate that comes into contact with the ionized gas comprises a plurality of regions each coated with a dielectric material of a different predetermined color. The plasma display panel described in . (9) The plasma display panel according to claim 8, wherein the plurality of regions are coated with a dielectric material that is opaque to light emitted by the ionized gas. (10) The plasma display panel includes at least one adjustment area, and the surface of the second plate that contacts the ionized gas is located at a position corresponding to the adjustment area.
9. The plasma display panel according to claim 8, further comprising a dielectric layer that is opaque to light emitted by the ionized gas.