JP2003100241A - Fluorescent character display tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to display precisely and brightly with a fluorescent character display tube capable of preventing leakage of light emission even if it generates potential difference between adjacent anodes. SOLUTION: The fluorescent character display tube contains plural anodes 4 arranged on a glass substrate 1 on which phosphor layer 5 is deposited and filament cathodes 7 opposed to these anodes 4. In the tube which emits light when the electrons emitted from filament cathodes 7 selectively collide with the phosphor layer 5 by the effect of voltage applied to the anodes 4, bank-like projections 10 are created between anodes 4.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fluorescent display tube,
In particular, the present invention relates to a fluorescent display tube in which electrons emitted from a cathode are selectively made to collide with a phosphor layer by a voltage applied to an anode to emit light.

[0002]

2. Description of the Related Art A fluorescent display tube is an electron tube for displaying a desired pattern by causing electrons emitted from a cathode to collide with a phosphor adhered to an anode to emit light in a vacuum container having at least one transparent side. FIG. 6 is a cross-sectional view showing a configuration example of a conventional fluorescent display tube. In the figure, a plurality of anode wirings 2 and an insulating layer 3 covering these anode wirings 2 are formed on a glass substrate 1, and a plurality of anodes 4 are formed on the insulating layer 3. These anodes 4 are connected to the anode wiring 2 via through holes 3 a provided in the insulating layer 3. A phosphor layer 5 is formed on each anode 4 by adhesion. A grid electrode 6 is arranged above the phosphor layer 5 with a predetermined distance therebetween, and a filament cathode 7 is arranged above the grid electrode 6 with a distance therebetween.

A transparent windshield 8 is disposed above the filament cathode 7 so as to face the glass substrate 1, and a frame-shaped spacer glass 9 disposed at the end of the glass substrate 1 provides a predetermined distance from the glass substrate 1. Is held. The glass substrate 1, the windshield 8 and the spacer glass 9 are sealed with a low melting point frit glass (not shown) to form an envelope serving as a vacuum container, and a vacuum of 10 ^-3 to 10 ^-5 Pa is formed. A plurality of leads (not shown) for supplying an electric signal from the outside to the anode wiring 2, the grid electrode 6 and the filament cathode 7 are provided so as to penetrate the contact portion between the glass substrate 1 and the spacer glass 9. Has been.

As shown in FIG. 7, the anodes 4 are arranged in a matrix, and different anode wirings 2 are connected to the adjacent anodes 4. Further, a plurality of grid electrodes 6 are arranged so as to cover the anode groups that are driven simultaneously. In this case, the anode wiring 2 is composed of an aluminum film formed by a vacuum evaporation method or the like, and the insulating layer 3 is an insulating film obtained by firing a glass paste mainly composed of low melting point glass applied by a screen printing method. It is composed of. The anode 4 is formed of a conductive film containing carbon as a main component, which is formed by screen-printing a carbon paste and then firing it. The phosphor layer 5 is composed of a slow electron beam excitation light emitting phosphor such as a ZnO: Zn phosphor.

In the fluorescent display tube having such a structure,
The grid electrode 6 to which a positive voltage is applied is sequentially switched at a predetermined cycle, and a positive (+) or negative (-) voltage indicating display data of the anode 4 corresponding to the grid electrode 6 is applied to the grid electrode 6
By outputting to each anode wiring 2 according to the switching of 1
Display the screen. Here, the grid electrode 6 is applied with a negative voltage when a positive voltage is not applied, thereby preventing unnecessary light emission in areas other than the selected row. As a result, only the phosphor layer 5 facing the grid electrode 6 to which the positive voltage is applied and adhered to the anode 4 to which the positive voltage is applied emits light, so that the pattern corresponding to the display data is displayed.

[0006]

In recent years, there has been a demand for high-definition and high-brightness display even in such a fluorescent display tube. In order to cope with the high-definition display, the interval between the anodes is narrowed and the high-brightness display is made. Increasingly, the anode voltage has been increased in order to cope with this trend. However, in such a fluorescent display tube having a narrow anode spacing, when the anode voltage is increased to cope with higher brightness, a positive voltage (+) is applied to one of the adjacent anodes 4 as shown in FIG. When a negative voltage (−) is applied to the other, as shown in FIG. 8, the anode to which the negative voltage of the pixel of the anode to which the positive voltage is applied is applied regardless of the lit pixel 15 and the unlit pixel 16 There was a problem in that a bright spot 17 was formed on a part of the side facing the.

For example, the distance between adjacent anodes is 100 μm
In such a case, when the potential difference between these anodes exceeds 100 V, as shown in FIG. 8, the phosphor layer on the anode on the high potential side locally emits light, regardless of whether the pixel is turned on or off ( Hereinafter, it will be referred to as leakage light emission), and the display quality will be deteriorated. Therefore, it is difficult to achieve both high definition and high brightness. An object of the present invention is to enable high-definition and high-luminance display in a fluorescent display tube in which a potential difference occurs between adjacent anodes.

[0008]

In order to solve the above-mentioned problems, the present invention has a plurality of anodes arranged on a substrate and having a phosphor layer deposited thereon, and arranged so as to face these anodes. A fluorescent display tube having a cathode and emitting electrons emitted from the cathode by selectively colliding with a phosphor layer by a voltage applied to the anode to emit light, characterized by having a bank-shaped projection between the anodes. To be One configuration example of the bank-shaped protrusions is made of an insulator provided so as to project from the surface on which the anodes are arranged, and the height from this surface is configured to be higher than 30% and lower than 500% of the height of the anodes. There is.

The reason why leakage light emission can be prevented by providing a bank-shaped projection between the anodes will be described. Although the cause of the leakage light emission is not always clear, the distance between the anodes is narrowed to about 100 μm and the potential difference between the anodes is 10 μm.
Since it occurs when the voltage exceeds 0 V, when a high electric field is applied between the anodes, electrons are emitted from the anode on the low potential side by field emission, and the electrons collide with the phosphor layer on the high potential side. It is thought that this is to cause the phosphor to emit light. In particular, when carbon is used for the anode, field emission occurs at a relatively low potential difference, and it is speculated that leakage emission may become remarkable. In the fluorescent display tube of the present invention, by providing a bank-shaped protrusion between the anodes, electron collision with the phosphor layer from the side direction is prevented, and leakage light emission is prevented.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of the fluorescent display tube according to the first embodiment. In the figure,
A plurality of anode wirings 2 and an insulating layer 3 covering these anode wirings 2 are formed on a glass substrate 1, and a plurality of anodes 4 are formed on the insulating layer 3. These anodes 4 are connected to the anode wiring 2 via through holes 3 a provided in the insulating layer 3. In addition, a phosphor layer 5 is formed on each anode 4.
Has been formed.

Further, a bank-shaped projection 10 is formed between the anodes 4 on the insulating layer 3. This bank-like protrusion 10
Are formed to have a width of 20 μm and the same height as the anode 4, and are arranged in a grid pattern as shown in FIG. FIG. 2 corresponds to FIG.
It is a figure which shows the II line cross section. A grid electrode 6 is arranged above the phosphor layer 5 with a predetermined distance therebetween, and a filament cathode 7 is arranged above the grid electrode 6 with a distance therebetween. Here, the anodes 4 are arranged in a matrix as shown in FIG. 7, and different anode wirings 2 are connected to the adjacent anodes 4. In addition, the grid electrode 6
Are arranged so as to cover the anode groups that are driven simultaneously. A predetermined number of filament cathodes 7 are arranged so as to be orthogonal to the grid electrode 6.

A transparent windshield 8 is arranged above the filament cathode 7 so as to face the glass substrate 1, and a frame-shaped spacer glass 9 arranged at the end of the glass substrate 1 provides a predetermined distance from the glass substrate 1. Is held. The glass substrate 1, the windshield 8 and the spacer glass 9 are sealed with a low melting point frit glass (not shown) to form an envelope serving as a vacuum container, and a vacuum of 10 ^-3 to 10 ^-5 Pa is formed. A plurality of leads (not shown) for supplying electric signals from the outside to the anode wiring 2, the grid electrode 6 and the filament cathode 7 are provided so as to penetrate the contact portion between the glass substrate 1 and the spacer glass 9. Has been.

In the fluorescent display tube of this embodiment, the anode wiring 2 is made of an aluminum film having a thickness of about 1 μm. The anode wiring 2 is formed by forming a film of aluminum on the glass substrate 1 by a vacuum deposition method or the like and then processing it into a predetermined pattern by photoetching or the like. The insulating layer 3 is formed by screen-printing a glass paste containing low melting point glass as a main component on the glass substrate 1 on which the anode wiring 2 is formed, and then firing the paste. In addition, at the time of screen printing,
It goes without saying that printing is performed with the through hole 3a left.

The anode 4 is composed of a conductive film containing carbon as a main component. The anode 4 is formed by screen-printing a carbon paste in a rectangular pattern on a region having the through hole 3a on the insulating layer 3 and then firing it.
The bank-shaped protrusions 10 are formed by screen-printing a glass paste similar to that used for forming the insulating layer 3 on the insulating layer 3 and then firing it. The phosphor layer 5 is, for example, Zn
It is composed of a low-speed electron beam excitation light emitting phosphor such as an O: Zn phosphor. This phosphor layer 5 is formed by screen-printing a phosphor paste on the anode 4 and firing it.

In this fluorescent display tube, the grid electrodes 6 to which a positive voltage is applied are sequentially switched at a predetermined cycle as in the conventional case, and positive (+) or negative (-) indicating the display data of the anode 4 corresponding to the grid electrodes 6 is displayed. ) Is output to each anode wiring 2 in accordance with the switching of the grid electrode 6 to display one screen, and as shown in FIG. 7, a positive voltage (+ ) Is applied and a negative voltage (−) is applied to the other, the phenomenon that the phosphor layer 5 on the anode 4 on the high potential side locally emits light regardless of whether the pixel is turned on or off ( Leakage emission) did not occur. That is, according to this embodiment, it is possible to achieve both high definition and high brightness without causing deterioration in display quality due to leakage light emission.

Next, a second embodiment will be described. FIG. 3 is a cross-sectional view showing the configuration of the fluorescent display tube according to the second embodiment. In the figure, a plurality of anode wirings 2 and an insulating layer 3 covering these anode wirings 2 are formed on a glass substrate 1. A plurality of strip-shaped anodes 14 are formed on the insulating layer 3 in parallel with each other at predetermined intervals, and these strip-shaped anodes 14 are connected to corresponding anode wirings 2 through through holes 3 a provided in the insulating layer 3. Has been done. Further, a phosphor layer 5 is formed on each strip-shaped anode 14 by adhesion.

Further, bank-shaped projections 10 are formed on the insulating layer 3 between the strip-shaped anodes 14. The bank-shaped projections 10 are formed with a width of 20 μm and at the same height as the anodes 4, and are arranged between the strip-shaped anodes 14 with the same length or a long length as the strip-shaped anodes 14 as shown in FIG. . Figure 4
FIG. 4 is a view showing a cross section taken along line II-II of FIG. 3. A plurality of grid electrodes 6 are arranged above the phosphor layer 5 with a predetermined distance therebetween. In this case, the grid electrodes 6 are arranged at predetermined intervals so as to be orthogonal to the strip-shaped anodes 14 as shown in FIG. Above the grid electrode 6, a predetermined number of filament cathodes 7 are arranged so as to be orthogonal to the grid electrode 6 with a predetermined distance therebetween.

A transparent windshield 8 is arranged above the filament cathode 7 so as to face the glass substrate 1, and is held at a predetermined distance from the glass substrate 1 by a frame-shaped spacer glass 9. The glass substrate 1, the windshield 8 and the spacer glass 9 are sealed with a low melting point frit glass (not shown) to form an envelope serving as a vacuum container, and a vacuum of 10 ^-3 to 10 ^-5 Pa is formed. A plurality of leads (not shown) that are held and that supply an electric signal from outside to the anode wiring 2, the grid electrode 6, and the filament cathode 7.
Are provided so as to penetrate the contact portion between the glass substrate 1 and the spacer glass 9.

In the fluorescent display tube of this embodiment, the structure and forming method of the anode wiring 2, the insulating layer 3 and the phosphor layer 5 are the same as those in the first embodiment, and therefore the explanation thereof is omitted. The strip-shaped anode 14 is formed of a conductive film containing carbon as a main component, and a carbon paste is screen-printed so that strip-shaped patterns having a predetermined width are arranged at predetermined intervals in a region including the through holes 3 a on the insulating layer 3. After that, it is formed by firing. The bank-shaped projection 10 is a strip-shaped anode 14 on the insulating layer 3.
A glass paste similar to that used for forming the insulating layer 3 is screen-printed so as to have the same width and height as the band-shaped anode 14 with a predetermined width, and then baked to form.

In this fluorescent display tube, the grid electrodes 6 to which a positive voltage is applied are sequentially switched at a predetermined cycle, and the positive or negative voltage indicating the display data of the row corresponding to this grid electrode 6 is matched with the switching of the grid electrodes 6. By outputting to each anode wiring 2 by controlling the emission of the phosphor layer 5 on the strip-shaped anode 14 intersecting the grid electrode 6 to display one screen, as shown in FIG. Even when the positive voltage (+) is applied to one of the strip-shaped anodes 14 and the negative voltage (−) is applied to the other, the strip-shaped anode 14 on the high potential side is irrespective of whether the pixel is turned on or off. Phosphor layer 5
No leakage light was emitted. That is, also in this embodiment, it is possible to achieve both high definition and high brightness without causing deterioration of display quality due to leakage light emission.

In each of these embodiments, the width of the bank-shaped protrusion 10 is set to 20 μm, but there is no difference in the effect of preventing leakage light emission depending on the width, and the invention is not limited to this. That is, the width of the bank-shaped protrusion 10 may be narrower or wider than 20 μm. Also, the width may differ between the base and the top. The height of the bank-shaped protrusion 10 is the same as that of the anode 4, but the height is not limited to this.
Any height may be used as long as it is higher than 30% and lower than 500%. This is because when the height of the anode 4 is 30% or less, the effect of preventing leakage light is reduced, and when the height of the anode 4 is 500% or more, the electrons emitted from the filament cathode 7 are bank-like protrusions. 10
This is because light emission is lost due to the interference with the light.
If the height of the bank-shaped protrusion 10 is increased, the process of forming the bank-shaped protrusion 10 becomes complicated.
The height of 0 is preferably the height from the anode 4 to the top of the phosphor layer 5.

Further, in these embodiments, the fluorescent display tube for performing the dot matrix display has been described as an example, but the present invention is not limited to this, and a fluorescent display tube having a structure in which a potential difference is generated between the adjacent anodes. It can be applied to all the cases where leakage light emission occurs. Further, the structure is not limited to the triode structure including the grid electrode, but may be the dipole structure including the cathode and the anode.

[0023]

As described above, in the fluorescent display tube of the present invention, by providing the bank-shaped projection between the anodes, it is possible to prevent the electron collision to the phosphor layer from the side direction, so that the leakage light emission occurs. Can be prevented. As a result, the anode interval can be narrowed and the anode voltage can be increased, so that an effect of enabling high-definition and high-luminance display can be obtained in a fluorescent display tube in which a potential difference occurs between adjacent anodes.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a fluorescent display tube according to a first embodiment.

FIG. 2 is a view showing a cross section taken along line I-I of FIG.

FIG. 3 is a sectional view showing a configuration of a fluorescent display tube according to a second embodiment.

FIG. 4 is a view showing a cross section taken along line II-II of FIG.

FIG. 5 is a diagram illustrating an arrangement and driving example of the strip-shaped anode and the grid electrode of the fluorescent display tube of FIG.

FIG. 6 is a cross-sectional view showing a configuration of a conventional fluorescent display tube.

FIG. 7 is a diagram illustrating an arrangement and driving example of anodes and grid electrodes of the fluorescent display tube of FIGS. 1 and 6;

8 is an explanatory diagram showing a relationship between pixels that are turned on and leakage light emission when the fluorescent display tube of FIG. 5 is driven as shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Anode wiring, 3 ... Insulating layer, 3a ... Through hole, 4 ... Anode, 5 ... Phosphor layer, 6 ... Grid electrode, 7 ... Filament cathode, 8 ... Windshield, 9 ...
Spacer glass, 10 ... Bank-shaped projections, 14 ... Strip anodes, 15 ... Pixels, 16 ... Pixels, 17 ... Bright spots.

Claims (2)

[Claims] 1. A plurality of anodes arranged on a substrate and having a phosphor layer deposited thereon, and a cathode arranged so as to face these anodes, and electrons emitted from the cathode are sent to the anode. A fluorescent display tube which selectively collides with the phosphor layer to emit light by an applied voltage, wherein a bank-shaped projection is provided between the anodes. 2. The bank-shaped projection is made of an insulator provided so as to project from the surface on which the anodes are arranged, and the height from this surface is higher than 30% of the height of the anode and is 500%.
The fluorescent display tube according to claim 1, wherein the fluorescent display tube has a lower structure.