JPS608577B2 - Cathode structure of DC gas discharge display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode structure for a direct current gas discharge display panel.

Conventionally, the cathode of a DC gas discharge display panel is
An alloy of iron and nickel or an alloy of iron, nickel, and chromium has been used as a cathode material, but the cathode structure based on these materials is mainly affected by the material, and the applied caloric voltage is approximately 300V, discharge starting voltage is about 20
0V, the discharge sustaining voltage is about 170V, and it is difficult to lower it below that.

The present invention provides a cathode structure in which magnesium or a magnesium alloy is coated on a cathode base metal, and a magnesium oxide layer is further formed on the magnesium or magnesium alloy, or a cathode structure of a DC gas discharge display panel. The main purpose of this is to lower the discharge starting voltage and discharge sustaining voltage by forming a magnesium oxide layer on magnesium or a magnesium alloy.

That is, in the present invention, magnesium can be processed into a plate shape, has a low melting point, and can be easily deposited on the surface of a base metal by means such as hot-dip plating. By means such as the chromic acid method,
This magnesium oxide can be layered with oxides,
Since the work function is low, it is possible to lower the discharge starting voltage and discharge sustaining voltage, which are the main objectives of the present invention, and also to achieve a high melting point (2000
00), which makes it resistant to ion bombardment, and the sputtering rate (wear rate) of magnesium is significantly lower than that of nickel, etc. Considering these characteristics, magnesium is used for direct current gas discharge display panels. This is intended to be applied to the cathode structure of First, to explain the work function of magnesium in detail, in the alloy of iron and nickel mentioned above, the work function is 4. Since the voltage is around $V, the discharge sustaining voltage must be about 170V.

The work function of magnesium itself is about 3.4 steps V, but magnesium oxide has a work function of 1.9 Ve to 2. The discharge sustaining voltage can be set to 70V or lower with a work function near ∊V. Next, regarding the sputtering rate required as a cathode material, even when the surface of magnesium is bombarded with hydrogen ions at an acceleration voltage of 850V, the sputtering rate is only 9 g/Ah. Compared to the sputtering rate of nickel, which has a sputtering rate of 65/9, the wear rate of the cathode is extremely low, making it a highly durable material.

This is caused by the difference in the crystal lattices of magnesium and nickel. That is, nickel is also based on calcium, strontium has a face-centered cubic lattice, barium has a body-centered cubic lattice, whereas magnesium has a close-packed hexagonal lattice. Next, in terms of workability, only magnesium and beryllium exist as metal plates among tokali metals, but beryllium is excluded from the viewpoint of toxicity. Magnesium also has a melting point of 65,000
Because of its relatively low melting point, it is said that it is a material that can be easily hot-dip plated on the surface of the base metal. can be~
Magnesium, manganese, and aluminum alloys have a melting point of 574 oo. These magnesium alloys further improve workability when hot-dip plating the surface of a base metal. The alloy can be deposited on the base metal by a conventional hot-dip plating method, and an oxide layer can be easily formed on the surface by a dichromic acid method (Sutton method).

Figure 1 shows the form of a cathode for a DC gas discharge display panel in which an oxide layer is formed on the surface of magnesium or magnesium alloy coated on a base metal using hot-dip plating or dichromic acid method. As shown in the figure, magnesium or magnesium alloy 2 is added to the base metal 1.
is deposited by means such as hot-dip plating, and a magnesium oxide layer 3 is formed on its surface.The cathode of a DC gas discharge display panel is usually perforated with holes at appropriate intervals. Therefore, this includes magnesium,
When hot-dip plating magnesium alloy, it may get stuck in this hole, but even if it gets stuck, it does not affect the effects of the present invention, and the second
As shown in the figure, a magnesium oxide layer 3 is formed on the upper surface of the cathode 1'.
``Magnesium Alloy 2'' formed by forming a circular thin plate of magnesium ``Magnesium Alloy 2'' may be attached at appropriate intervals by means such as hot-dip plating, or as shown in Fig. A form in which a magnesium-magnesium alloy layer formed by forming the oxide layer 3' is deposited may also be used.

Although the oxide layer of magnesium oxidized by the dichromic acid method or the like is not shown, the magnesium oxide is in a porous state (porous state with many small pores).

The effects of magnesium oxide in this porous state,
To describe the effects of covering the surface of magnesium with a low melting point with magnesium oxide, which has a melting point of 200,000 and has a high melting point, first of all, as mentioned above, magnesium oxide has a low work function, so it has a low gamma of the cathode in an L discharge tube. -(y) effect (secondary electron emission effect due to ion collision) is high and electrons are easily emitted from the base metal (discharge starting voltage becomes low), but the emitted electrons proceed toward the anode. However, after the electrons are released, the magnesium oxide becomes positively charged. Even if most of the magnesium oxide is positively charged, the cations repel each other and are bent without colliding. In order to eliminate these intestinal ions, since the magnesium layer is a cathode, the electrons released from it must combine with magnesium oxide and have a neutralizing effect. For this purpose, the magnesium oxide layer is made porous and has a structure that can neutralize the cations on the magnesium surface. Furthermore, the reason why the magnesium or magnesium alloy layer is covered with magnesium oxide having a high melting point is that cations (argon, neon, etc.) caused by the gas enclosed in the discharge space migrate toward the negative potential magnesium cathode. The object that these cations collide with is the magnesium oxide layer formed on the surface, and the melting point is as high as 2000q0, so there is no fear that the magnesium oxide layer will evaporate, and the temperature of the electrode surface is also prevented from increasing. If this is configured to collide directly with the magnesium layer, even if the magnesium sputtering rate is low, some parts will evaporate, and the temperature of the electrode surface will increase.From the above effects, In a porous state, magnesium and magnesium alloy are covered with a high melting point magnesium oxide layer.

Furthermore, as shown in FIG. 4, as a cathode structure of a DC gas discharge display panel, as in the above-mentioned invention, "magnesium or a magnesium alloy is attached to a base metal by means such as welding, and magnesium oxide is attached to this by means such as welding." Unlike the structure in which a layer is formed, even if the cathode structure is formed by directly forming a magnesium oxide layer 3 on magnesium or a magnesium alloy 2, the same effects as in the above invention can be achieved. It is something that can be done.

According to the cathode structure of the DC type gas discharge display panel of the present invention described above, in addition to various functions and effects that have a favorable effect on the DC type gas discharge display panel, such as being able to lower the sputtering rate, the present invention also provides a discharge Since the sustaining voltage can be lowered to 70 V or lower, the peripheral circuit components can also be components with a corresponding withstand voltage, and can be manufactured at low cost and further miniaturized. In addition, in current LSI technology, "under the conditions of applied voltage 300V, discharge starting voltage 220V, and discharge sustaining voltage 170V,
After the false 1, it has to be driven indirectly through a drive device such as a transistor, and it is impossible to directly drive it because it is directly connected to the LSI.

Since the LSI can be directly driven at about 40 to 70 V, even if the discharge sustaining voltage according to the cathode structure of the present invention is about 70 to 80 V, it can be divided into an anode and a cathode to reduce the voltage to about 50 V. Since it can be driven by an LSI, it can be directly connected to and driven by an LSI. In addition, the wattage (panel efficiency) increases by the amount that the discharge starting voltage and discharge sustaining voltage are lowered, so it is possible to manufacture large-screen panels with the same efficiency, and the loss of thermal efficiency is also significantly prevented. It has many effects, such as the ability to

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view showing an embodiment of the present invention;
FIG. 3 is an enlarged perspective view showing another embodiment of the present invention, and FIG. 4 is an enlarged sectional view showing another embodiment. 1...Base metal, 1'...Cathode, 2,2'...Ma0
Gnesium or magnesium alloy, 3,3'...
・Magnesium oxide layer. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A cathode structure for a DC gas discharge display panel, characterized in that a magnesium oxide layer is formed on magnesium or a magnesium alloy. 2. A cathode for a DC gas discharge display panel, characterized in that magnesium or a magnesium alloy is adhered to the cathode base metal of the DC gas discharge display panel, and a magnesium oxide layer is formed on the magnesium or magnesium alloy. structure.