JPS5927062B2 - Surface discharge plasma display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the electrode structure of a single-side discharge type plasma display panel, and in particular, the dielectric layer near the electrode boundary and This invention relates to a new electrode structure that prevents the protective layer from causing dielectric breakdown.

In a conventional surface discharge type plasma display panel, paired discharge electrodes are placed on the same substrate with a fixed discharge gap (usually 1
The electrode pairs are covered with a dielectric layer and a protective layer, and a gas is filled in the gap between the protective layer and the cover glass so that the dielectric layer and the protective layer are formed between adjacent electrodes. It is common to generate a discharge through the layers.

However, in such conventional panels, a particularly strong electric field is concentrated between the adjacent end faces of a pair of adjacent electrodes, and a large discharge current due to this is concentrated at the end faces, and the dielectric layer and protective layer near the electrode boundary are concentrated. In addition to causing dielectric breakdown, it also caused uneven brightness in the display discharge light, making it impossible to obtain a good panel.

In order to solve the above-mentioned drawbacks, the present invention provides a novel surface discharge in which a protective electrode is newly provided to prevent dielectric breakdown phenomenon and brightness unevenness of the dielectric layer and protective layer covering the boundary between the discharge electrode pair. type plasma display panel.

The drawings will be explained in detail below.

FIG. 1 is a sectional view of a main part of a conventional surface discharge type plasma display panel, in which an electrode 3 supported on a substrate 1 is covered with a dielectric layer 4 made of low melting point glass and a protective layer 5 made of MgO or the like. The electrodes are covered with a very narrow gap (usually 100μ~) to lower the discharge starting voltage.
200μ).

This causes a strong concentration of electric field between the adjacent end faces of the electrode pair,
The strong discharge current caused by this is concentrated at the edges, causing dielectric breakdown in the dielectric layer and protective layer covering the electrode boundary, and uneven brightness where the electric field concentration area becomes abnormally high brightness. , as mentioned above, significantly deteriorates the characteristics of the panel.

In the present invention, a protective electrode is newly installed in order to prevent the above-mentioned drawbacks, and an embodiment thereof is shown in FIG.

That is, FIG. 2a shows the electrode arrangement according to this embodiment in plan view, and this figure shows a cross-sectional view taken along the line A-A in the previous figure. The same symbols are given.

As is clear from these figures, in this example, the electrode pair 3
a.

A protective electrode 7 is provided in the dielectric layer 4 at the upper part of the electrode installation surface corresponding to the boundary between the electrodes 3b, that is, between the electrodes, and overlaps with the proximal end surface of the electrode pair.

By applying a ground potential or an appropriate bias voltage (a positive and negative potential of about half or less of the discharge voltage) to the protective electrode 7, the electric field between the electrode pair and the discharge current are concentrated on the proximal end surface of the electrodes. This allows the electrode to be evenly distributed over the entire surface of the electrode.

An example of the mitigation effect of discharge current concentration on the protective electrode 7 is the case where the protective electrode is kept at ground potential and a voltage of +150V and a zero voltage are alternately applied between the electrode pair 3a and 3b. This will be explained in detail.

First, when a voltage of +150 V is applied to the electrode 3a and a zero voltage to the electrode 3b, a discharge current flows between the pair of electrodes 3a and 3b, and a discharge is generated in the display discharge section constituted by them.

At the same time, an electric field is applied between the one electrode 3a and the protective electrode T, so that a discharge similarly occurs.

This discharge generates electrons and ions in the gas space, and the ions are deposited on the surface of the protective layer 5 corresponding to the electrode 3b and the protective electrode 7, and the electrons are deposited on the surface of the protective layer corresponding to the electrode 3a: This accumulates and forms wall charges (wall voltage).

As is well known, the wall voltage corresponding to the electrode pair 3a, 3b is +1
As a result of being applied to the display discharge section in relation to the voltage of 50 cm, a sustaining discharge that takes over the discharge is generated in this discharge section.

Along with this discharge, wall charges having a polarity opposite to that of the previous discharge are accumulated on the surface of the protective layer corresponding to the electrode pair 3a, 3b.

At this time, between the protective electrode 1 and the discharge electrode 3b, the positive wall charge accumulated on the surface of the protective layer corresponding to the protective electrode cancels out a part of the voltage applied from the discharge electrode 3b. Therefore, discharge at the corresponding part of the protective electrode is suppressed,
As a result, concentration of discharge current at the proximate end face portion of the discharge electrode pair 3as3b is alleviated.

Incidentally, since the protective electrode 7 is always at the ground potential, the wall charge of the protective electrode corresponding portion remains in the same state and acts in the same way thereafter to inhibit discharge and alleviate discharge current concentration.

Therefore, it is possible to prevent local dielectric breakdown of the dielectric layer and protective layer covering the electrode boundaries as in the conventional case, and
Luminance unevenness can be prevented by reducing the luminance at the electrode boundary.

Therefore, according to the present invention, it is possible to provide a surface discharge type plasma display panel with high quality and long life.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main part of a conventional surface discharge type plasma display panel, and FIG. 2 shows an embodiment of the surface discharge type plasma display panel according to the present invention. b is a cross-sectional view taken along line A-A of the previous one. 1...Substrate, 2...Cover glass, 3
a and 3b...discharge electrode, 4...dielectric layer, 5...protective layer, 6...gas space, 7... Protective electrode.

Claims (1)

[Claims] 1. In a surface discharge plasma display panel in which pairs of electrodes are arranged in parallel on the same substrate at a constant distance and covered with a dielectric layer and a protective layer, the electrodes corresponding to each other between the pairs of electrodes are covered with a dielectric layer and a protective layer. In the dielectric layer above the electrode installation surface, the electrode has a shape that overlaps the adjacent end surface of the pair of electrodes, and is held at a positive (or negative) potential of less than half of the earth potential or the discharge voltage. A surface discharge plasma display panel characterized in that a protective electrode is provided to prevent local concentration of discharge current.