JPH01311540A - Plasma display panel having three electrodes for one picture element - Google Patents

Abstract

PURPOSE: To easily manufacture a display panel, by making a first plate support only a control electrode, a second plate have only the sustaining electrodes of first and second group, and the sustaining electrode equip a projection facing with each other at respective picture element level. CONSTITUTION: This unit is equipped with a first plate 50 for supporting a first control electrode array X (j), to be coated by a dielectric material layer 52. In the case of color display, moreover, a luminous point 56 distributed into three groups is provided. Also, a second plate 60 for supporting an address sustaining electrode (Yae) (i) and a sustaining electrode Ye, and being in parallel with each other and on the same plane is equipped. Since the integer (i) takes on all values from 1 to N, and the integer (i) takes on all values from 1 to P, there are given N.P pieces of pixel panels. The sustaining electrode has no constant width but alternate recesses and projections, and the projections 66 and 68 prescribe the sustaining region for discharge 70, thereby facilitating the manufacture of a plasma display panel.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a plasma display panel with three electrodes per pixel.

The present invention can be applied to display analog, alpha econometric, or other images, for example in color.

BACKGROUND OF THE INVENTION Plasma display panels currently occupy an important position among flat panel display devices. Devices are known that include two insulating plates defining a space in which a gas (generally a neon-based gas mixture) is accommodated. These plates support two intersecting groups of electrodes that define a pixel matrix. Proper excitation of the electrodes causes a discharge in the gas, which emits light.

Although some plasma display panels operate in direct current mode, plasma display panels designed to operate in alternating current are preferred. In this case the electrodes are covered with a layer of dielectric material. The electrodes are therefore no longer in direct contact with either the gas or the electrical discharge.

It is relatively easy to manufacture plasma display panels that operate on alternating current. For this purpose, the following successive steps are carried out: - depositing the electrode array using a suitable method (silk-screen printing, photolithographic etching, etc.); - depositing a layer of dielectric material; - sealing and evacuating, gas filling and sealing.

The structure of AC plasma display panels includes panels with three or four electrodes per pixel. This situation is shown in the attached FIGS. 1 and 2.

The structure of Figure 1 is the same as that of rSID Proceedings, Section 27.
/ Volume 3, 1986, pages 183-187.
) is described in the paper. This structure has electrodes X on the inside.
A first glass plate supporting I sX2 is provided. These electrodes are coated with a layer of dielectric material 12 (for example a layer of borosilicate). This layer is further covered with an oxide layer 14 (for example a layer of MgO). This plate has barriers B3, B211 made of insulating material.
8. It also has: These barriers also function as spacers. These barriers are electrodes x1, X2101
．． is located between.

The structure illustrated here consists of sustain electrodes distributed in pairs,
That is, Y8, Y21. It further includes a second plate 20 that supports *0, Y@. All electrodes Y6 are brought to the same potential. This second group of electrodes is again coated with a layer of dielectric material 22 (for example a layer of borosilicate). This layer further includes an oxide layer 24 (e.g. Mg
layer consisting of O).

In this type of plasma display panel, each pixel is defined by the overlap between a pair of mutually parallel and coplanar electrodes located on the plate 20 and crossed electrodes located on the plate 10. .

Two mutually parallel electrodes are used in the discharge sustaining phase (the so-called Cobraner sustaining phase), and the third electrode is used only for addressing the pixels (for recording or erasing).

It can be seen that in this type of device, the electrodes are all rectangular in shape, with constant width and spacing.

In this case, containment of the discharge must be guaranteed. This corresponds to the barrier B deposited on the first plate,
B, 10. , is the role of These barriers are about a few microns thick and their effect is to prevent the discharge from extending along the sustain electrodes.

Since a means of containing the discharge is thus required,
The manufacturing method for plasma display panels becomes complicated.

Additionally, the presence of the barrier disrupts the flow of charge available to initiate the discharge. As a result of this, new problems arise.

FIG. 2 is a diagram of another type of conventional plasma display panel using three or four electrodes per pixel. This device is based on European Patent Application No. 135
．． It is described in No. 382. The device comprises a first glass plate 30 without electrodes and a second glass plate supporting a pair of sustain electrodes (y+)+, (Y2)I covered with a layer of dielectric material 42.
A plate 40 is provided. Also deposited in the layer of dielectric material 42 is a control electrode X, orthogonal to the counter electrodes (Y, )i, (Y2)I.

This unit is covered with an oxide layer 44 (for example a layer of MgO). If necessary, a separation electrode S is added to the already provided electrodes (thereby bringing the number of electrodes per pixel to 4).

Therefore, in this alternative example, the electrodes are all supported on the same plate. Further, the electrodes i(y+)i and (Y2)i are provided with protrusions 46, 48 facing each other. It is between these protrusions that the sustaining discharge is located. This alternative example thus avoids using a barrier unlike the first approach.

It is therefore easier in this respect.

This alternative example has other advantages. If a color display is desired, a phosphor 32 sensitive to the ultraviolet radiation emitted by the discharge is deposited on the top plate 30.

The light emitters are arranged in triplets and emit light of three primary colors.

By the way, in the above structure, the light emitter does not come into contact with the discharge in the gas. This is because the gas is confined to the vicinity of the bottom electrode that initiates or sustains the discharge. Therefore, the life of the light emitter is extended.

However, this type of structure is not without drawbacks. For example, it is difficult to manufacture. The need to provide two levels of electrodes on the same substrate causes serious problems such as undesirable capacitance and dielectric breakdown. Problems also arise regarding differences in the thickness of the dielectric layer covering each group of electrodes. That is, structurally, the upper layer is coated with a thinner layer than the lower layer. This structure is therefore weaker.

Problems to be Solved by the Invention The purpose of the present invention is to solve precisely these problems. To achieve this objective, the invention aims to combine some of these previously known arrangements to avoid the difficulties inherent in the prior art described above.

More specifically, the present invention provides an insulating first plate, an insulating second plate, and a control circuit intersecting a first group and a second group of sustain electrodes. The plasma display panel is intended for plasma display panels in which the electrodes are provided in a known manner, all of which are covered with a layer of dielectric material, and a pixel is defined at each intersection point. According to the invention, this plasma display panel comprises: - the first plate supports only the control electrodes; - the second plate supports only the first group as well as the second group of sustain electrodes; The electrode is characterized in that it comprises, on at least one side, protrusions arranged opposite each other at the level of each pixel.

It can be seen that returning to separating the working electrode into two plates of the panel is contrary to the teachings of the prior art in the case of color displays. This is because it is believed that the light emitters of the first plate will rapidly deteriorate in contact with the discharge.

In fact, the inventors of the present invention realized that in this case, since the recording discharge occurs from one plate to another, there is a risk that only this discharge will affect the quality of the illuminant; It has been found that the sustain discharge occurs near the second plate where the sustain electrode is provided, and therefore does not affect the light emitter.

In this case, there are the following major advantages regarding the manufacture of panels:

- No crossing of electrodes, thus limiting problems with capacitance and breakdown.

- There is no plasma containment barrier, thus simplifying the manufacture of the top plate. Moreover, the removal of such a barrier facilitates the initiation of electrical discharge (due to conditioning effects).

- Finally, the relative positions of the two electrode arrays are no longer constrained as in the case of the conventional panel shown in Figure 2;
Crossings can therefore be provided perpendicularly to the protrusions or laterally to the protrusions. The problems regarding charge transfer involved in the recording phase are thus simplified.

All these advantages obtained by the present invention can be particularly utilized for manufacturing large size display panels.

In any case, the features and advantages of the invention will become clear through the following description. The description is given by way of example only and with reference to the accompanying drawings, in which: FIG.

Embodiment FIG. 3 is a diagram of a plasma display panel of the present invention. This panel is made of glass, for example, and comprises a first plate 50 supporting a first control electrode array X'. This unit is coated with a layer 52 of dielectric material, for example made of borosilicate. However, it is possible to locally remove this layer of dielectric material, leaving the electrode coated.

In the case of a color display, the plate 50 is further provided with luminous dots 56 distributed in triplicates according to known techniques for color displays.

The illustrated panel also includes a second plate 60 that supports a second electrode array formed by two groups of electrodes that are parallel and coplanar with each other. One group (Y,.)i is called address-sustain electrodes, and the other group Y0 is called sustain electrodes. Since the integer j takes on all values from 1 to N, and the integer i takes on all values from 1 to P, a panel of NP pixels is given.

The symbol Y1 indicating the sustain electrode has no subscript.

This is because, generally, the same sustaining AC voltage is applied to all of these sustaining electrodes. Electrode
Yas) i only receives a voltage depending on the state displayed on the pixel PiJ. However, it is of course also possible to consider other examples in which the electrodes Y are arranged in groups that can be controlled separately.

The width of the sustain electrodes is not constant, and depressions and protrusions alternate. The protrusions 66,68 define a discharge sustaining region.

FIG. 4 shows the relative positions of two electrode arrays in a particular embodiment. It can be seen that the control electrode X passes through the center of the protrusion 66,68. In this case, the electrical discharge in the gas extends along a space whose contour is indicated by the dotted line 70.

FIG. 4 further shows possible sizes of the different electrodes. The sizes shown here are merely illustrative examples and are not intended to limit the scope of the invention.

FIG. 5 shows another embodiment in which the protrusion of Y6, which is the sustain electrode of the second group, is shorter than the protrusion 66 of the address-sustain electrode (Yak) i of the first group. This is a diagram. Therefore, the control electrode xj is connected to the protrusion 6
6 and the shortened portion of the protrusion 68. The result of this is that the discharge 70 is maintained in the space located to the side of the electrode xj and no longer below this space as in the case of FIG. Therefore, the discharge is no longer hidden by the control electrode. This makes it extremely easy to manufacture control electrodes from opaque materials.

The above description relates to rectangular electrodes. Of course, this is merely for illustration and the invention also covers the case of electrodes of any shape, for example serpentine shapes.

The protrusion does not necessarily have to be rectangular either, but can be of any shape (such as a trapezoid or a protrusion with rounded edges).

[Brief explanation of the drawing]

FIG. 1 is a diagram of a conventional plasma display panel with a containment barrier. FIG. 2 is a diagram of a conventional plasma display panel in which all electrodes are on the same plate. FIG. 3 is a diagram of a plasma panel display of the present invention. FIG. 4 is a detailed view of this panel. FIG. 5 is a diagram showing another embodiment of the panel of the present invention. (Main reference numbers) 10.20.30.40.50.60...Glass plate, 12.22.42.52...Dielectric material layer, 14.2
4.44...Oxide layer, 32.56...Light emitter, 46.48.66.68...Protrusion, 70...Discharge, Bl, B2...Barrier, S
...Separation electrode, X7, X2, XJ...Control electrode, y,, Y2, Yl,...Sustain electrode, (Yo)i...Address-sustain electrode

Claims (5)

[Claims] (1) comprising an insulating first plate, an insulating second plate, and a control electrode intersecting with the first group and the second group of sustain electrodes, all of these electrodes being made of a dielectric material layer; A plasma display panel in which a pixel is defined at each intersection point, the first plate supporting only the control electrodes, and the second plate supporting the first group as well as the second group. 1. A plasma display panel supporting only electrodes, the sustaining electrodes comprising, on at least one side, protrusions arranged facing each other at the level of each pixel. (2) The plasma display panel according to claim 1, wherein the control electrode intersects with the sustain electrode above the protrusion thereof. (3) The plasma display panel according to claim 1, wherein the control electrode intersects with the sustain electrode above the side of the protrusion. (4) The projections of the sustain electrodes of the first group are longer than the sustain electrodes of the second group, and the control electrodes are
2. The plasma display panel according to claim 1, wherein the plasma display panel passes over the edges of the protrusions of the sustain electrodes of the first group without overlapping the protrusions of the sustain electrodes of the second group. (5) The plasma display panel according to any one of claims 1 to 4, wherein the first plate has one or more light emitters.