JPH0547305A - Plasma display panel - Google Patents

Abstract

PURPOSE:To realize a high-sped and reliable plasma display panel operation by enhancing the panel data writing discharge propability. CONSTITUTION:The electrostatic capacity per unit of area of one or both of an insulation layer and a phosphor layer, each layer coating the data electrodes, from which data writing discharge is caused to occur, is set in the range of from 0.5muF/m<2> to 5muF/m<2>. Further, the dielectric constant of the insulation layer coating the data electrodes is made 10 or less. By reducing the electrostatic capacity of such insulation layer, the writing discharge probability is increased to realize a high-speed and reliable panel operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel used in an information display terminal, a flat-screen television, etc.
In particular, the present invention relates to a structure for realizing high-speed and reliable operation of a color plasma display panel having high definition and large display capacity.

[0002]

2. Description of the Related Art A color plasma display panel is a display which excites and emits a fluorescent substance by ultraviolet rays generated by gas discharge to obtain visible light and performs a display operation. AC
Among the molds, the reflective AC surface discharge type is superior in brightness, luminous efficiency, and life, and is taken as an example. FIG. 2 shows a cross-sectional view of a conventional reflective AC surface discharge plasma display panel. In FIG. 2, the transparent electrode 3 is formed on the front substrate 1 which is the second substrate. The transparent electrode is usually ITO or S
Although it is formed of nO ₂ , the bus electrode 2
Is formed of, for example, an Al thin film or a thick silver film. This is covered with an insulating layer 4 of low melting point lead glass. This surface is a protective layer 5
Cover with. The protective layer is formed of a MgO thin film. On the rear substrate 11 which is the first substrate, the data electrode 10 is formed of, for example, Al.
It is formed of a thin film or a thick silver film and covered with an insulating layer 9. Then, the front substrate 1 and the rear substrate 11 are combined so that the transparent electrode 3 and the data electrode 10 are orthogonal to each other with the partition wall 6 interposed therebetween. At this time, the phosphor 8 is formed on the surfaces of the insulating layer 9 and the partition wall 6. Dischargeable gas inside the panel, eg He and Xe
About 250 torr of the mixed gas is enclosed.

In driving, since every other transparent electrode 3 serves as a scan electrode and a sustain electrode, a sustain pulse is applied between the adjacent transparent electrodes 3, and display data is written by scanning electrodes and data electrodes. It is performed by applying a data pulse during 10 to generate a discharge. An example of the drive waveform is shown in FIG. A scan pulse 20 and a sustain pulse 21 are applied to the scan electrodes. The sustain pulse 22 is applied to the sustain electrodes. The sustaining of the discharge is performed by the sustain pulse 21 and the sustain pulse 22 applied to the scan electrode and the sustain electrode. The data writing is performed by the scan pulse 20 applied to the scan electrode at the same timing as the data pulse 23 applied to the data electrode.
Done by At this time, scan pulse 20, sustain pulse 2
The 1 and sustain pulse 22 are negative voltage pulses, whereas the data pulse 23 applied to the data electrodes is a positive voltage pulse. This is to prevent the ions caused by the discharge for writing data from damaging the phosphor. The written data needs to be erased because the discharge is continued between the sustain pulses 21 and 22. Although not shown, erasing is performed by applying an erasing pulse having a narrow pulse width to the scan electrodes.

Incidentally, the conventional panel has the data electrode 10 shown in FIG.
The insulating layer 9 that covers is usually made of low melting point lead glass. Low melting point lead glass generally used for plasma display panels has a relative dielectric constant of about 11 to 14. Therefore, when an insulating layer with a thickness of about 5 μm is formed,
The capacitance per unit area is about 25 μF / m ² .

[0005]

In the conventional plasma display panel, it is difficult to obtain a good display, especially the data writing operation is incomplete, and it is necessary to increase the data pulse voltage, which causes a driving problem. It was This problem becomes more noticeable in plasma display panels with large areas and large display capacities.

An object of the present invention is to provide a plasma display panel that solves such a problem.

[0007]

According to the present invention, there is provided a first insulating layer or a phosphor layer or a first insulating layer including at least a first insulating layer and a phosphor layer on an electrode group which becomes a data electrode. A first substrate having a functional coating layer formed thereon, and a second substrate
And a second substrate having a surface discharge electrode group for generating a main discharge for display, which is covered with the insulating layer, are opposed to each other with a predetermined discharge gap, hermetically sealed, and discharged inside. in a possible gas plasma display panel formed by sealing a, characterized in that the capacitance per unit area of the first insulating coating layer is 0.5μF / m ² or more 5μF / m ² or less.

Further, the present invention is characterized in that, in the above-mentioned plasma display panel, the first insulating layer has a relative dielectric constant of 10 or less.

[0009]

[Operation] As a result of detailed examination of the data write operation,
Between the capacitance of the insulating coating layer on the data electrode and the writing discharge probability, the writing discharge probability can be increased by reducing the capacitance of the insulating coating layer as shown in FIG. I knew I could do it. Conventionally, in order to increase the voltage applied to the discharge space, the insulating coating layer should be made as thin as possible or a material with a high relative dielectric constant should be used to increase the capacitance of the insulating coating layer within the range of withstand voltage. It was considered better to make it larger. The reason for the opposite results can be explained as follows. When the drive waveform as shown in FIG. 3 is used, the potential difference between the scan electrode and the data electrode where the writing discharge occurs is always positive on the data electrode side or zero, and does not become negative on the data electrode side.
Therefore, the writing discharge is always a unipolar discharge in which the data electrode side is the anode and the scanning electrode side is the cathode. This is to prevent the ions generated by the write discharge from damaging the phosphor on the data electrode. As a result, the wall charges generated by the write discharge are always negative on the data electrode side and positive on the scan electrode side. The wall electric field due to the wall charges is in the opposite direction to the sum of the data pulse and the scanning pulse and serves to cancel it. Since the probability of the write discharge is substantially proportional to the voltage applied between the electrodes, when the same data pulse voltage and scan pulse voltage are applied, the weaker the wall electric field, the higher the probability of the write discharge. Since the amount of wall charges is proportional to the current of the writing discharge, it increases as the capacitance of the insulating coating layer on the data electrodes increases.

The discharge probability described here is an average probability per unit time when discharge is always generated with a constant probability.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. Here, the reflective AC surface discharge plasma display panel described in the conventional example will be described as an example. However, in addition to this, the structure in which the data electrode is covered with the insulating coating layer and the electrode for generating the main discharge is separately provided The same effect can be obtained with the AC plasma display panel. In the plasma display panel described in the conventional example, the capacitance of the insulating coating layer on the data electrode is very large, for example, about 25 μF / m ² . This is because the insulating coating layer on the data electrode is made of low melting point lead glass having a relative dielectric constant of about 11 to 14 and the film thickness is usually about 5 μm. As shown in FIG. 1, if the capacitance of the insulating coating layer that covers the data electrode is set to 5 μF / m ² or less at which the probability of writing discharge starts to increase greatly, a fast and reliable writing operation can be performed. The film thickness of 5 μF / m ² is about 24 μm when the insulating coating layer is formed of, for example, low melting point lead glass having a relative dielectric constant of 13.5. When this is formed by screen printing, it is necessary to use a screen thickly coated with dairy material or to perform multiple printing. Moreover, the thicker the insulating layer is, the more practically it is up to about 50 μm, and it is difficult to manufacture the insulating layer more than this. When the film thickness is 50 μm, the capacitance per unit area is about 2.4 μF / m ² .

If the insulating layer of the insulating coating layer is formed of only the low melting point lead glass as in the conventional case, a very thick film thickness is required as described above, which makes manufacturing difficult. Therefore, when an insulating layer is mixed with a low melting point lead glass and a substance having a relative dielectric constant lower than that of the low melting point lead glass, an insulating layer having a smaller film thickness and a smaller capacitance can be formed. For example, MgO (relative permittivity ~ 3), S
iO ₂ (dielectric constant ~4), Al ₂ O ₃ (dielectric constant 8)
Etc. By forming an insulating layer in which at least one of these is mixed with low melting point lead glass, an insulating layer having a small capacitance can be formed without extremely increasing the film thickness. For example, low melting point lead glass and MgO are 2: 8
When the insulating layer is formed by mixing at a ratio of, the relative dielectric constant becomes about 4, and when the film thickness is 50 μm, the capacitance is about 0.7 μm.
It becomes F / m ² . Further, in order to obtain a capacitance of 5 μF / m ^2, the film thickness is about 7 μm, which is very easy to manufacture by screen printing. When low melting point lead glass and Al ₂ O ₃ are mixed at a ratio of 2: 8 to form an insulating layer, the relative dielectric constant is about 10 and a film thickness of about 18 μm is required to obtain a capacitance of 5 μF / m ^2. Good. This is almost the upper limit of the film thickness that does not require multiple printing when the insulating layer is formed by screen printing.

[0013]

As described above, according to the plasma display panel of the present invention, a plasma display panel capable of high speed and reliable data writing operation can be manufactured.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between an insulating layer capacitance on a data electrode and a write discharge probability.

FIG. 2 is a cross-sectional view of an AC surface discharge type color plasma display panel.

FIG. 3 is a driving waveform of an AC surface discharge type to a plasma display panel.

[Explanation of symbols]

 1 Front Substrate 2 Bus Electrode 3 Transparent Electrode 4 Insulating Layer 5 Protective Layer 10 Partition 11 Discharge Gas 12 Phosphor 13 Insulating Layer 14 Data Electrode 15 Rear Substrate 20 Scanning Pulse 21, 22 Sustaining Pulse 23 Data Pulse

Claims (2)

[Claims] 1. A first insulating coating layer including at least a first insulating layer, a phosphor layer, or both a first insulating layer and a phosphor layer is formed on an electrode group serving as a data electrode. A first substrate and a second substrate covered with a second insulating layer, on which a surface discharge electrode group for generating a main discharge for display is formed, facing each other with a predetermined discharge gap; In a plasma display panel which is hermetically sealed and a dischargeable gas is sealed inside, the capacitance per unit area of the first insulating coating layer is 0.5 μF / m ^2.
A plasma display panel characterized by being 5 μF / m ² or less. 2. The plasma display panel according to claim 1, wherein the first insulating layer has a relative dielectric constant of 10 or less.