JPS62103958A - Discharge type display element - Google Patents

Abstract

PURPOSE:To reduce the size and improve the brightness, while reducing the fluctuation of the discharge characteristic, by employing a multi-layer coaxial electrode as one electrode, while covering a portion of the inside face and the inside bottom face of a display element tubular body with electrically conductive material and employing them as the other discharge electrode. CONSTITUTION:One discharge electrode of multi-layer coaxial structure having the endfaces positioned in and out of an outer tube 1 and the other discharge electrode made of electrically conductive material covering a portion of the inside face and the inside bottom face of the outer tube 1 are arranged in a transparent outer tube 1 encapsulated with discharge gas 2. The electrode of multi-layer coaxial structure comprises a central rod electrode 5 tightly applied with an insulator 6 onto the outer circumference while further provided with a tubular electrode 7 and the other discharge electrode comprises an electrode 9 which is provided so as to cover the inside face near to the bottom face of the inner wall face of the outer tube 1 and an electrode 8 which is provided in line to said electrode 9 so as to cover the inside bottom face of the outer tube 1. Said electrode 8 is connected to the outermost electrode 7 of the multi- layer coaxial electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a discharge type display element, and more particularly to a structure of a gas discharge type display element used in an electronic display device or the like.

[Prior Art] Conventionally, as a discharge type display element, (1) CHD (Colcrdllgh-L
3rightncssDischarge) tube (Ja
panDisplay-83.

11.3) (2) Display discharge lamp with conical cathode (JP-A-59-20
(No. 960) (3) Coaxial cylindrical electrode type display discharge tube (patent pending by the applicant).

Among these, the CHD tube (1) has a green luminance of 11,
500cd/rr? It has sufficient brightness for outdoor display. However, because the dimensions are large with an outer diameter of 34 mm,
For example, the dimensions are generally considered as outdoor display devices such as traffic information display on expressways, destination and time display at airport terminals, large image display at stadiums, etc.
When constructing an electronic display device measuring 6 m long and 8 m wide, the number of display elements in the vertical direction is about 210 and the number of display elements in the horizontal direction is small, about 280, and the resolution is poor for a display device of this size. There was a drawback that the display was difficult to see. CH
The D tube is a discharge type display element that applies the principle of a fluorescent discharge lamp, so if you try to make the tube outer diameter smaller than the current one, part of the energy consumed in the discharge will be due to gas particles colliding with the glass tube. It is difficult to reduce the outer diameter because the energy lost increases and the brightness and efficiency characteristics deteriorate.

Therefore, overall, it can be said that there is little hope for improvement in resolution.

Furthermore, the conical cathode display discharge lamp (2) has a brightness equivalent to that of an incandescent light bulb, and is therefore suitable for outdoor display purposes. However, as shown in FIG. 6, in this display discharge lamp, an anode 3 is placed in a light-transmitting airtight outer tube 1 filled with a discharge gas 2, and penetrates through the center of the bottom opening of a conical cathode 4. Because of the location, changes in the distance between the anode and the conical cathode end in this part have a large effect on the discharge characteristics, and for this reason, especially when manufacturing small-sized indicator lamps, it is important to avoid using lamps with the same discharge characteristics. It is difficult to make many. Also,
In order to utilize the discharge effectively, it is necessary to generate the discharge only inside the conical cathode 4 shown in Fig. 6 and not to generate the discharge outside the conical cathode 4. It is difficult to adjust the positional relationship between the two and the drive voltage.

In addition, the coaxial cylindrical electrode type display discharge tube of (3) above has the seventh
As shown in the figure, a transparent outer tube 1 filled with a discharge gas 2 has a multilayer coaxial structure in which an insulator 6 is wrapped around a rod-shaped center electrode 5, and an electrode 7 is provided on the outer periphery of the insulator 6. By having electrodes, it is possible to realize a compact, high-brightness discharge display tube with uniform discharge characteristics. However, the current brightness is insufficient for outdoor display, and an improvement has been desired.

[Problems to be Solved by the Invention] As described above, conventional discharge type display elements have insufficient brightness and resolution to be used for outdoor display devices, and have difficulty adjusting the positional relationship of electrodes and driving voltage. The disadvantage was that it was difficult to adjust.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and to provide a compact design for high-resolution outdoor display devices.

It is an object of the present invention to provide a novel gas discharge type display element which has high luminance and has less variation in discharge characteristics of each element even when manufactured in large quantities.

[Means and effects for solving the problems] A discharge type display element according to the present invention uses the above multilayer coaxial electrode as one electrode in a discharge type display element having an electrode of a multilayer coaxial structure, and also uses the multilayer coaxial electrode as one electrode. A part of the inner surface of the body and the inner bottom surface are covered with an electrically conductive material, and these are used as the other discharge electrode.

[Example] The present invention will be explained below with reference to illustrated embodiments.

FIGS. 1A and 1B are a vertical cross-sectional view and a cross-sectional view taken along line B-B of a gas discharge type display element according to a first embodiment of the present invention, in which a discharge gas 2 is sealed. Inside the transparent outer tube 1, there is one discharge electrode of a multilayer coaxial structure with end faces located on both the inside and outside of the outer tube 1, and a discharge electrode that covers a part of the inner surface and the inner bottom surface of the outer tube 1. and the other discharge electrode made of an electrically conductive material.

The electrode with the multilayer coaxial structure has an insulator 6 covered around the outer periphery of the central rod-shaped electrode 5, and a cylindrical electrode 7 is provided on top of the insulator 6, and the other discharge electrode is formed of an outer tube. It consists of an electrode 9 provided so as to cover the inner surface of the inner wall surface of the outer tube 1 near the bottom surface, and an electrode 8 connected to this electrode 9 and provided so as to cover the inner bottom surface of the outer tube 1. . This electrode 8 is connected to the outermost layer electrode 7 of the multilayer coaxial electrode. Therefore, electrode 7 is electrically connected to electrodes 8 and 9. In this case, the height of the electrode 9 from the inner bottom surface of the outer tube 1 may be the same as the height of the electrode 7 inside the tube, or may have a different height.

The discharge type display element of the first embodiment configured in this way is as follows:
The center electrode 5 is used as an anode, and the electrodes 8 and 9 electrically connected to the electrode 7 are used as cathodes.

FIG. 2 shows a gas discharge type display element showing a second embodiment of the present invention. In this display element, the outermost layer of the electrode of the multilayer coaxial structure was formed of the electrode 7 made of an electrically conductive material in the display element of the first embodiment, whereas the outermost layer of the electrode of the multilayer coaxial structure was formed of the insulator 6. This is the case. That is, the insulator 6 is closely covered with the outer periphery of the center electrode 5, and the electrode 5 and the insulator 6 form a coaxial cylindrical structure, with end surfaces located both inside and outside the outer tube 1, respectively. ing.

Further, the electrode 8 provided on the inner bottom surface of the outer tube 1 is formed in the shape of a donut plate and is provided apart from the insulator 6. This electrode 8 is electrically connected to an electrode 9 provided on the inner surface of the outer tube 1, and the electrode 8 is connected to the outer electrode 1.
It is electrically connected to 3. A discharge voltage is applied to the external electrode 13 from an electric circuit (not shown) separately from the electrode 5.

Furthermore, in the first and second embodiments described above, discharge voltages are applied to two sets of electrodes inside the display tube from two sets of electric circuits outside the display tube, but the When three or more sets of electrodes are provided and a discharge voltage is applied to each electrode from three or more sets of electric circuits outside the display tube, a multilayer coaxial electrode is configured, for example, as in the third embodiment described below. do it.

FIG. 3 shows a third embodiment of the invention having three sets of electrodes. In this example, an electrode with a multilayer coaxial structure is
Three conductor electrodes 5 insulated with insulators 6 and 10, respectively
．． 7.11, and the outermost layer is an electrically conductive material. This outermost layer electrode 11 is electrically connected to an electrode 8 on the inner bottom surface of the outer tube, and the electrode 8 is electrically connected to an electrode 9 on the inner surface of the outer tube 1.

In the discharge type display element of the third embodiment configured as described above, the electrodes 8.9 are used as cathodes, and the center electrode 5 is used as an anode.
By using the intermediate electrode 7 as an auxiliary discharge electrode, an auxiliary discharge is induced between the electrodes 7 and 9, and by utilizing this, effects such as lowering the driving voltage are exhibited.

Next, FIGS. 4 and 5 respectively show modified examples of the discharge type display element according to the present invention.

That is, as shown in FIG. 4, a phosphor 12 is coated on the inside front surface of the outer bulb 1, thereby making it possible to display an arbitrary color. In this case, the application range of the phosphor is not limited to the inner front surface of the outer tube 1. If the electrode 9 does not cover the entire inner surface of the outer tube 1, as shown in FIG. Also, by applying the phosphor 12, the brightness can be improved.

[Effects of the Invention] According to the present invention, the electrode area of the outermost layer of the multilayer coaxial structure electrode can be increased without changing the dimensions of the display element, so the following remarkable effects can be obtained. .

That is, when using visible light or ultraviolet rays generated by DC glow discharge for display, increasing the cathode area will cause
Cathode glow located in front of the cathode.

The cathode dark area and the area where the negative glow spreads can be enlarged. Therefore, visible light is emitted from the cathode glow and negative glow, and ultraviolet rays are emitted from the dark part of the cathode, so increasing the cathode area can increase display brightness regardless of whether visible light or ultraviolet rays are used for display. can. If a display element is driven by using the outermost electrode of the multilayer coaxial structure electrode of the present invention as a cathode, the cathode area is larger than that of the conventional "coaxial cylindrical electrode display discharge tube".
It is possible to display images with higher brightness than conventional ones.

Another way to increase the cathode area is to increase the length of the multilayer coaxial electrode to increase the area of the outermost layer electrode used as a cathode, but visible light or ultraviolet light generated near the cathode can be Considering that the cathode is used on the front surface, it is clear that the shorter the distance between the cathode and the front surface of the display element, the higher the utilization efficiency.From this point of view, the electrode structure of the present invention is better because the multilayer coaxial electrode The average distance between the cathode and the front surface of the display element can be made shorter than when the cathode area is increased by increasing the length, and the electrode structure of the present invention is superior in this respect.

Considering FIG. 1 as an example of an embodiment of the present invention, if the length of the electrode 9 covering the inner side surface of the outer tube from the inner bottom surface of the outer tube is longer than the length from the bottom surface of the center electrode 5, The discharge phenomenon is almost the same as when using the hollow cathode effect, but since the electrode shape of the present invention was invented for the purpose of manufacturing a display element in a small size, its shape is different from the conventional "conical" shape. Display discharge lamp with shaped cathode (Japanese Patent Application Laid-open No.
9-20960), and is also different from the above-mentioned conventional display discharge lamp in that the electrodes are provided in close contact with the outer bulb 1.

As mentioned above, in this "display discharge lamp", it is difficult to accurately set the positional relationship between the bottom opening of the conical cathode and the anode that passes through it, and it is difficult to suppress variations in the discharge characteristics of a large number of display elements. Although it was difficult, according to the present invention, the electrodes have a multilayer coaxial structure with an insulator sandwiched between them, so the positional relationship can be set accurately! − is advantageous.

Even in the present invention, it is difficult to accurately set the positional relationship between the electrodes provided on the inner surface of the outer tube and the electrodes of the multilayer coaxial structure, but when manufacturing display elements with the same dimensions, the set value of the distance between these electrodes is clearly larger than the set value of the distance between the bottom opening of the conical cathode and its anode in the above-mentioned "display discharge lamp", so the required dimensional setting accuracy is lower than that of the above-mentioned "display discharge lamp". good. Therefore, there is no problem even if the setting accuracy of the positional relationship at this point is somewhat low.

[Brief explanation of drawings]

FIGS. 1(A) and 3(B) are longitudinal and horizontal sectional views of a discharge type display element showing a first embodiment of the present invention, and FIGS. 4.5 is a sectional view showing a modification of the discharge type display element to which the present invention is applied, and FIGS. 6 and 7 are sectional views of a conventional discharge type display element. FIG. 3 is a cross-sectional view showing each display element. 1・・・・・・・・・・・・・・・・・・・・・Outer tube (
Display element tube) 2・・・・・・・・・・・・・・・・
...Discharge gas 5.7.11 ...Multilayer coaxial structure electrode 8.9 ...... Electric conductor material (electrode) 6.10 ...... Electrical insulation material patent applicant Hitachi Cable Co., Ltd. No. 40, No. 5

Claims (3)

[Claims] (1) In a discharge type display element having electrodes of a multilayer coaxial structure made by alternately arranging electrically conductive materials and electrically insulating materials, at least a part of the inner side surface and the inner bottom surface of the display element tube are electrically conductive. A discharge type display element characterized in that it is covered with a material and electrically connected to these electrically conductive materials. (2) The outermost layer of the electrode of the multilayer coaxial structure is formed of an electrically conductive material, and this electrically conductive material covers the inner bottom surface of the display element tube and the electrically conductive material that covers the inner side surface. The discharge type display element according to claim 1, wherein the discharge type display element is electrically connected to at least one side. (3) The outermost layer of the electrode of the multilayer coaxial structure is formed of an electrically insulating material, and at least one of the electrically conductive material that covered the inner bottom surface of the display element tube and the electrically conductive material that covered the inner side surface is the display element. The discharge type display element according to claim 1, wherein the discharge type display element is electrically connected to an external electrically conductive material.