JPH09120779A - Gas discharge type display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas discharge type display panel which achieves a lowered discharge voltage while the brightness is held to the same level as conventional and which excels in the power efficiency compared with the conventional arrangement. SOLUTION: A gas discharge type display panel concerned has a cathode 3 chiefly consisting of an oxide type electron conductor which contains one or more of lanthanoid and alkali earth elements and one or more elements belonging to Group I, Group II, and Group III transition metals. The distance between the cathode 3 and anode 4 should range from 0.4mm to 2.0mm, while the pressure of the encapsulated gas should be between 10 and 200Torr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas discharge type display panel for displaying characters and figures by utilizing gas discharge.

[0002]

2. Description of the Related Art A gas discharge display panel has features such as a wide viewing angle, a fast response speed, and a relatively large screen size. Therefore, the gas discharge panel for color display is expected as a large-screen wall-mounted television or the like.

There are two types of gas discharge display panels, AC type and D type.
Although roughly classified into C type, DC type is defined by saying that at least one pair of conductive cathode and anode is exposed in the discharge space. In the following, D related to the present invention will be described.
The C type will be described.

In a DC type gas discharge panel for color display, two flat glass plates, which are called a front plate and a back plate, facing each other are stacked at a desired interval, the periphery is hermetically sealed, and He is internally sealed.
200 to 400 torr of -Xe mixed gas is enclosed. Basically, a cathode is arranged on one of the front plate and the back plate, and an anode and a phosphor are arranged on the other plate, and each display cell is divided by a bank called a partition. The distance between the cathode and the anode (distance between the electrodes) is set to 0.1 to 0.25 mm.
With such a configuration, by applying a predetermined voltage between the electrodes, a discharge is generated, and ultraviolet rays emitted along with this are excited to fluoresce the visible light of red, green, and blue. Is converted to and a color image is displayed.

Conventionally, Ni has been used as the cathode of a gas discharge color display panel. However, Ni has a disadvantage that the brightness life of the panel is short because it is weak against sputtering, and Hg is put in the gas space to improve this. Therefore, in addition to the original high sustaining voltage of Ni, a higher sustaining voltage is required due to Hg. In order to solve such a problem, an Al cathode has been studied instead of Ni. Since Al is somewhat superior to Ni in spatter resistance, it is possible to make Hg less, but since it is insufficient, it is compensated by setting a high gas pressure. The standard settings of the current gas discharge type color display panel are cathode Al, mixed gas He-Xe5% ~ He-Xe10% (He95% + Xe5% ~ He90%
+ Xe10%), the gas pressure is 300 to 400 torr, and the distance between the electrodes is 0.1 to 0.25 mm. However, with the current characteristics, the brightness lifetime is still insufficient, and the high discharge sustaining voltage is a major issue. In order to solve such a problem, a cathode of an oxide conductor having a perovskite type crystal structure such as La ₁ -Sr _X CoO ₃ has been developed, and is disclosed in, for example, Japanese Patent Application No. Hei 2 (1996) -87919. . Since the cathode of these oxide conductors has a lower discharge voltage than Ni and is excellent in spatter resistance, the power consumption of the gas discharge type display panel is reduced and the life is improved, and thus Hg less is required. Became possible.

[0006]

In the case of the gas discharge type color display panel, the discharge voltage of the (LaSr) CoO ₃ cathode is reduced to about 1/2 of that of the metal cathode of Ni or the like, and the luminance deterioration life is 10%. It has the excellent property of being about twice as long. However, in the case of a color display panel, (LaS
r) When the CoO ₃ cathode is used, the phosphor emission intensity is N
There is a fatal defect that it is less than half that of a metal cathode made of i, Al or the like.

The present invention solves such a problem and has a low discharge voltage as compared with a conventional Ni cathode.
It is an object of the present invention to provide an excellent gas discharge type display panel having a long luminance life and the same emission luminance.

[0008]

[Means for solving the problem] In order to solve this problem,
The present invention mainly uses an oxide electronic conductor containing at least one element selected from lanthanoid elements and alkaline earth elements and at least one element selected from first, second, and third transition metals as a cathode material. Ingredients and between cathode and anode (between electrodes)
It is characterized in that the distance is 0.4 mm or more and 2.0 mm or less and the pressure of the enclosed gas is 50 torr or more and 200 torr or less.

That is, the present invention is characterized in that the above-mentioned specific material is used as the cathode, and that the distance between the electrodes is made longer and the pressure of the enclosed gas is made lower than in the conventional case.

The limited range of the distance between the electrodes and the gas pressure is as follows. The effect of the present invention becomes remarkable when the distance between the electrodes is increased to about 0.4 mm. If it is longer than that, the longer the better, but if it is 2.0 mm or more, problems such as delay of discharge occur. Regarding gas pressure, 2
The effect of the present invention appears from about 00 torr or less, and if it is reduced to 50 torr or less, a problem such as erroneous discharge occurs.

[0011]

Therefore, according to the present invention, at least one element selected from lanthanoid elements and alkaline earth elements and at least one element selected from first, second and third transition metals are contained at the same time. Use the oxide electronic conductor as the main component of the cathode material, and make the distance between the cathode and the anode (between the electrodes) 0.4 mm or more 2.0.
mm or less and the pressure of the enclosed gas is 10 torr or more and 200 torr or less, so that the discharge voltage is low, the luminance life is long, and the emission luminance is the same, as compared with the conventional Ni cathode. An excellent gas discharge type color display panel can be provided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

First, the structure of the gas discharge type display panel of this embodiment will be briefly described. FIG. 1 shows a sectional view of the panel. In FIG. 1, 1 is a rear glass substrate, 2 is a base electrode that is a base of the cathode 3, 3 is a cathode, 4 is an anode, and 5 is a partition wall for securing a discharge space 7 between the rear glass 1 and the front glass 6. , 6 is a front glass, 7 is a discharge space for introducing a gas, and 8 is a phosphor laminated on the anode.

The method of manufacturing the gas discharge type display panel of this embodiment will be described below. An Ag paste is screen-printed on the rear glass substrate 1 as a cathode pattern and fired to form a base electrode 2. Next, a LaCoO ₃ paste is laminated on the base electrode 2 as the cathode 3, and this is fired. The rear glass substrate 1 on which the cathode 3 is thus formed, the anode 4 which is a transparent electrode, the phosphor 8 laminated on the anode 4 and the front glass 6 on which the partition wall 5 is provided are Then, the surroundings are baked using a glass frit and hermetically sealed. Then, the discharge space 7 is evacuated to a vacuum,
A rare gas such as He-Xe or Ne-Ar is introduced to make a gas discharge display panel.

In the gas discharge type display panel manufactured as described above, when a negative voltage is applied to the cathode 3 and a positive voltage is applied to the anode 4, plasma discharge occurs in the discharge space 7, and ultraviolet rays generated by the plasma discharge emit light from the phosphor 8. Let Below, La
The characteristics of the gas discharge display panel when CoO ₃ is used as the cathode material will be described using a Ni cathode as a comparative example. As a condition of the gas discharge type display panel, the mixed gas is He
2 and 3 show the luminance characteristics and the discharge sustaining voltage characteristics when the enclosed gas pressure was changed using -Xe5% gas and the electrode spacing as a parameter.

In the case of the conventional Ni cathode, the brightness slightly increases when the pressure of the enclosed gas is increased. On the contrary, with the LaCoO ₃ cathode, the brightness increases when the gas pressure is lowered. The discharge sustaining voltage tends to increase slightly when the gas pressure is lowered for both cathodes.
Regarding the inter-electrode distance, in the Ni cathode, even if the inter-electrode distance is changed, the brightness (fluorescent substance emission intensity) and the discharge sustaining voltage hardly change. On the other hand, in the case of the LaCoO ₃ cathode, the discharge sustaining voltage does not change much when the distance between the electrodes is increased, but the brightness is significantly increased. Assuming that the Ni cathode brightness is 100% at a standard electrode distance of 0.2 mm and a gas pressure of 300 torr, the brightness of LaCoO _{3 under} the same conditions is about 40%, but the electrode distance is 0. The brightness sharply increases from around 4 mm, and becomes saturated at 2.0 mm or more. For example, if the distance between the electrodes is 1 mm and the gas pressure is 100 torr, the brightness increases to about 100%. Saturated state (gas pressure of 200 t when the distance between the electrodes is 2.0 mm or more)
If it is about orr, the same brightness as in the standard state can be obtained. Regarding the sustaining voltage, the Ni cathode under the above standard conditions is 220 V, and the LaCoO ₃ cathode is 130 V,
When the gas pressure is 100 torr and the distance between the electrodes is 1 mm, they are 235V and 140V, respectively. LaCo
In the case of an O ₃ cathode, by setting a low gas pressure and a long distance between electrodes, which cannot be considered by conventional common sense, it is possible to obtain the same brightness as Ni without losing the feature of low voltage.

Up to this point, it has been explained that when LaCoO ₃ is used as the cathode material, the brightness increases when the gas pressure is low and the distance between the electrodes is long, but this phenomenon occurs only in a specific cathode material. It is a characteristic that it has.

Listed below are cathode materials showing the same effects as LaCoO ₃ . (1) Part or all of La replaced with alkaline earth metal La _1-X A2 _X CoO ₃ (A2 = Ca, Sr, Ba) (2) Part or all of the above 3 types of B sites Substituted with other transition metal La _1-X A2 _X Co _1-Y B2 _Y O ₃ (A2 = Ca, Sr, Ba: B2 = Ti, V, Cr, Mn, Fe, Co, Ni) (3 ) A site substituted with another rare earth element instead of La A1 _1-X Sr _X CoO ₃ (A1 = Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y
b, Lu) (4) Oxide conductor having K2NiF3 type crystal structure (chemical formula: A2BO4) A1 _2−X A2 _X BO ₄ (A1 = rare earth element: A2 = alkaline earth element: B = Cu, Ni) ( 5) YBa ₂ Cu ₃ O ₄ (6) Bi ₂ Ba ₂ CaCu ₂ O ₇ (7) Lu ₂ B ₂ O ₇ (B = Os, Ir, Ru, Rh) (8) ARuO _X (A = Ca, Sr , Ba) (1) to (3) are all conductive oxides having a perovskite type crystal structure. These are characterized in that the A site contains at least a rare earth element or an alkaline earth element, and the B site contains a transition metal element. (4) has a structure similar to that of the perovskite type, but has another crystal structure. (5) to (7) also have a structure different from that of the perovskite type. Therefore, the perovskite type crystal structure is not an important factor. Judging from the above example, any conductive complex oxide containing at least an alkaline earth or rare earth element and the first, second and third transition metal elements as the constituent elements is effective.

[0019]

According to the present invention, it is possible to provide an excellent gas discharge type display panel which has a lower discharge voltage, a longer luminance life and a similar emission luminance as compared with the conventional Ni cathode. It is possible and the effect of the present invention is very large.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gas discharge type display panel according to an embodiment of the present invention.

FIG. 2 is a diagram showing phosphor emission intensity-electrode distance characteristics of the gas discharge type display panel in the example.

FIG. 3 is a diagram showing a discharge sustaining voltage-electrode distance characteristic of the gas discharge type display panel in the example.

[Brief description of reference numerals]

 1 Back Glass Substrate 2 Base Electrode 3 Cathode 4 Anode 5 Partition 6 Front Glass Substrate 7 Discharge Space 8 Phosphor

(72) Inventor Hiroki Kono 3-10-1 Higashisanda, Tama-ku, Kawasaki City, Kanagawa Prefecture Matsushita Giken Co., Ltd. No. Matsushita Giken Co., Ltd. (72) Inventor Isao Sumita 3-10-1 Higashisanda, Tama-ku, Kawasaki-shi, Kanagawa Matsushita Giken Co., Ltd.

Claims (2)

[Claims] 1. A cathode mainly composed of an oxide electronic conductor containing a lanthanoid element or an alkaline earth element and elements of the first, second and third transition metals, and formed at a distance of 0.4 mm or more from the cathode. 200t between the anode and the cathode
A gas discharge type display panel comprising a gas filled at a pressure of orr or less. 2. A cathode mainly comprising an oxide electronic conductor containing a lanthanoid element or an alkaline earth element and elements of the first, second and third transition metals, and a distance of 0.4 mm or more and 2.0 mm or less from the cathode. A gas discharge type display panel comprising an anode formed in advance and a gas sealed between the cathode and the anode at a pressure of 50 torr or more and 200 torr or less.