JPH07110659A - Gas discharging display panel - Google Patents

Abstract

PURPOSE:To reduce degradation of brightness and thereby to prolong the life of a panel without exchange of a cathode material by generation of UV rays by excitation and light emission of gaseous deuterium enclosed in a enclosing vessel. CONSTITUTION:A mixed gas containing gaseous deuterium 17 is enclosed in the panel and fluorescent body 22 are made luminous by UV rays 16 obtained by excitation and light emission of the gaseous deuterium 17. When direct current voltage is applied between a cathode bus-line 13 and a display anode bus-line 14, the mixed gases 18 in respective display cells 20 are selectively excited and are made luminous and then UV rays 16 obtained by the luminous motion of the mixed gas excites and make luminous the fluorescent body 22 arranged in the display cell 20 and visible rays 21 of red, green or blue color are emitted therefrom and the visible rays 21 are emitted from a front plate 11. In this case, the cathode bus-line 13 and the display anode bus-line 14 are composed of gold or platinum to be catalysis and the fluorescent body 22 is covered with a protective film 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas discharge display panel for displaying colored characters, figures, television, etc. by exciting and emitting phosphors by ultraviolet light obtained by gas discharge to generate visible light. Regarding

SUMMARY OF THE INVENTION The present invention relates to a technique for reducing the luminance deterioration caused by sputtering of a cathode material and achieving a long service life of a gas discharge display panel, and for a discharge medium for exciting and emitting a phosphor. By using a single or mixed gas containing deuterium (D ₂ ) as the filling gas, the sputtering rate is reduced by about one digit as compared with the conventional one, and the life is greatly improved.

[0003]

2. Description of the Related Art Conventionally, electrodes have been used as a gas discharge display panel for displaying colored characters, graphics, television, etc. by exciting and emitting phosphors by ultraviolet light obtained by gas discharge to generate visible light. Type exposed to the discharge space and operated by applying a DC voltage (DC type)
And a gas discharge display panel of a type (AC type) which is operated by applying an AC voltage with a structure in which electrodes are covered with a dielectric material have been developed.

FIG. 7 is a partially cut perspective view showing an example of a DC type gas discharge display panel among such gas discharge display panels (Hiroshi Murakami, "Current status and trends of high-definition wall-mounted television"), The Institute of Electronics, Information and Communication Engineers, 75
[9], gas discharge display panel introduced in 968-974 (1992)).

A DC type gas discharge display panel 101 shown in this figure is a front plate 102 composed of a transparent plate.
A plate-shaped rear plate 103 which is arranged at a predetermined distance from the front plate 102, and a cathode bus bar 104 serving as a cathode.
A display anode bus 105 serving as a display anode, an auxiliary anode bus 106 serving as an auxiliary anode, a barrier 109 constituting a plurality of display cells 108 in which a priming gap 107 is formed in a predetermined portion, and each display cell 108. Among them, the red phosphor 110 arranged in the display cell 108 designated as red
And among the display cells 108, green phosphors 111 arranged in the display cells 108 designated as green, and blue phosphors arranged in the display cells 108 designated in blue among the display cells 108. A body 112 and a mixed gas 113 of helium (He) and xenon (Xe) sealed inside the panel are provided.

When a DC voltage is applied between the cathode bus bar 104, the display anode bus line 105 and the auxiliary anode bus line 106, the mixed gas 113 in each display cell 104 is selectively excited and emits light. At the same time, the red phosphor 110, the green phosphor 111, and the blue phosphor 1 arranged in the display cell 108 by the ultraviolet light obtained by this light emitting operation.
12 emits light and color display is performed.

In this case, as the material forming the cathode bus 104, nickel (Ni) or an alloy containing nickel is currently used, and the mixed gas 11 is used.
The vapor of mercury (Hg) is mixed in 3 to reduce the sputtering caused by the collision of the ions of the mixed gas 113 enclosed in the panel.

An AC type gas discharge display panel is a panel in which electrodes are covered with magnesium oxide (MgO) called a protective layer, and a mixed gas sealed inside the panel is selectively excited and emitted by an AC voltage. At the same time, the red fluorescent material, the green fluorescent material, and the blue fluorescent material arranged in the display cell are caused to emit light by the ultraviolet light obtained by this light emitting operation, thereby performing color display.

However, in this case, since the AC type gas discharge display panel does not need to worry about the occurrence of sputtering more than the DC type gas discharge display panel, mercury vapor or the like is usually mixed in the mixed gas. I haven't.

[0010]

By the way, in each of the conventional gas discharge display panels described above, the display anode bus bar 1 is used.
05 and the cathode bus 104 to cause a gas discharge in the display cell 108 to actively ionize and excite gas molecules, and thereby the excitation level of the xenon gas in the display cell 108. Of the vacuum ultraviolet light from the red phosphor 110, the green phosphor 111, and the blue phosphor 11 which are adjacent to each other.
2 is made to emit light for color display.

In this case, the helium atom (monatomic molecule) plays a role of a buffer (matrix gas) for facilitating discharge, and the xenon atom (monatomic molecule) plays a role of a light emitting atom which emits ultraviolet light. Therefore, the mixed gas 1 enclosed in the gas discharge display panel 101 that performs color display
As the component of 13, these helium gas and xenon gas are essential.

However, such a gas discharge display panel 1
In 01, luminance deterioration occurs due to sputtering of the cathode by the ions of the mixed gas 113 sealed in the panel, and the lifetime of the panel is determined by this luminance deterioration. In order to put the discharge display panel 101 into practical use, it is necessary to develop a technique for reducing sputtering.

Therefore, in order to solve the problem caused by such sputtering, a new cathode having a higher sputtering resistance than the conventionally used material such as nickel (Ni) as the material of the cathode bus 104 and the like. Materials are being searched for, but no definitive material has been found so far.

Further, it is preferable not to use mercury vapor mixed in the mixed gas 113 in order to reduce the sputtering as much as possible from the viewpoint of the panel manufacturing process reduction and the environment resistance.

The present invention has been made in view of the above circumstances, and an object thereof is to significantly reduce luminance deterioration due to sputtering and to extend the life of the panel without changing the cathode material. An object of the present invention is to provide a gas discharge display panel.

[0016]

In order to achieve the above-mentioned object, the present invention provides a gas discharge display panel for generating visible light by receiving ultraviolet light by means of a phosphor arranged in an enclosing container. A deuterium gas (D ₂ ) as a discharge medium gas is enclosed as an enclosed gas, and the deuterium gas is excited and emitted to generate the ultraviolet light.

[0017]

In the above structure, the deuterium gas (D ₂ ) serving as the discharge medium gas is used as the filling gas filled in the filling container in which the phosphor that receives the ultraviolet light and generates the visible light is arranged. By encapsulating and exciting and emitting this deuterium gas to generate the ultraviolet light, the deterioration of brightness caused by sputtering can be significantly reduced and the life of the panel can be prolonged without changing the cathode material. .

[0018]

First, prior to a detailed description of the gas discharge display panel according to the present invention, the enclosed gas used in the present invention will be described.

Considering now the enclosed gas enclosed in the panel, in the case of the helium-xenon mixed gas, the atomic weight of helium is 4, whereas the atomic weight of xenon is 1.
31 is very heavy, so regarding sputtering,
It is thought that xenon is more strongly involved than helium.

In fact, various documents, such as D. Rosen
berg and G.G. K. Weher, “Sputt
ering Yields for Low Ener
gyHe + −, Kr + −, and Xe + −Ion B
mbardment ", J. Appl. Phys.,
33 , [5], 1842-1845 (1962),
It is known that the sputtering rate for various target elements (ratio of the number of sputtering atoms to the number of incident ions) is the value shown in FIG. 3 and that of xenon is the value shown in FIG.

As is apparent from FIGS. 3 and 4, the sputtering rate of xenon is larger than that of helium by one digit or more.

However, since xenon gas is a source of ultraviolet light radiation, assuming that this xenon gas is not used, the brightness and the luminous efficiency when the panel is actually operated as the enclosed gas is xenon gas. Finding a gas with an equivalent or higher value is a necessary condition for practical use.

From the above viewpoints, as a result of searching various filled gases having a small sputtering rate and a strong ultraviolet radiation, a deuterium gas (D) used in a deuterium lamp and the like, which has a proven record as an ultraviolet light source for a spectroscope, etc. ₂ ) proved promising.

However, until now, since there is no device for exciting the phosphor for color display by using such deuterium gas, the phosphor for color display is really excited by using deuterium gas. We decided to confirm by experiment whether it could be done.

In this experiment, first, an experimental tube 1 as shown in FIG. 5, that is, an experimental tube 1 which is easy to manufacture and which can directly obtain a simple measurement result, is prepared, and the inner wall of the experimental tube 1 is Manganese-activated zinc silicate (Zn ₂ SiO ₄ : Mn) is applied as the green light-emitting phosphor (G), and europium-activated yttrium vanadate (YVO ₄ :) is applied as the red light-emitting phosphor (R). An experimental device coated with Eu) was prepared.

Then, the helium-xenon (2%) mixed gas which has been conventionally used is enclosed in the experimental tube 1 so that the filling pressure is 20 Torr, and the emission luminance is measured. After degassing the mixed gas, the helium-deuterium (10
%) So that the filling pressure of the mixed gas becomes 20 Torr,
When the light emission luminance was measured by actually enclosing it, the table shown in FIG. 6 could be obtained. In this case, in any case, the sealed pressure of the mixed gas is set to 20 Torr because such a value is adopted from the dimensions of the experimental tube 1, and the actual gas discharge display panel Cell size (1
mm or less), the pressure may be appropriately increased according to Paschen's similarity rule.

As is clear from this table, for the green light-emitting phosphor (G), the mixed gas containing deuterium gas is generally equivalent to the mixed gas containing xenon gas, or It is possible to obtain the above emission brightness,
Even when the discharge current is relatively large, it is possible to obtain a characteristic having no brightness saturation.

Further, for the phosphor (R) for red light emission, which is required to have a higher brightness, the mixed gas containing deuterium gas is more overall than the mixed gas containing xenon gas. Greater brightness improvement can be achieved.

Next, the sputtering rate of deuterium gas will be described.

First, since the molecular weight of deuterium gas is 4, which is the same as the molecule of helium gas (monoatomic molecule), even if a mixed gas containing deuterium gas is used as a sealing gas for the panel, it becomes sufficiently small. It is expected that.

In fact, various documents, for example, Kanehara Yuu, "Sputtering Phenomenon", Tokyo University Press, p. 16 (1987) show that the sputtering rate of hydrogen gas, which is an isotope of deuterium gas, is 0 at the maximum. It is stated that it does not exceed 1. As is clear from this description, when this value is compared with the sputtering rate when the helium gas shown in FIG. 3 is used (the maximum value is approximately 0.22), it is clear that when hydrogen gas is used. The sputtering rate is less than half the sputtering rate when helium gas is used.

Regarding deuterium gas, although no published data can be found, since the molecular weight is 4, which is the same as the molecular weight of helium gas, the sputtering rate is 0.22 or less at the maximum, and FIG. It is estimated that the value of xenon is 1/10 or less of the maximum value of 2.6, which is the maximum value.

Next, the spectrum of ultraviolet light emitted by deuterium gas will be described.

First, the already published documents, for example, edited by Iida et al., "Optical Measurement", 4 by Asakura Shoten (1969).
Pages 9-52 describe in detail the continuous and line spectra emitted by hydrogen.

As is clear from this description, the wavelength range of ultraviolet light emitted by hydrogen in vacuum is 100 to 17
It has a wide range of 0 nm or more.

The reason for this is that the continuous spectrum is considered to be a spectrum based on hydrogen molecules, and the line spectrum is considered to be a spectrum based on hydrogen atoms formed by dissociation of hydrogen molecules.

On the other hand, although deuterium is not particularly specified in the above-mentioned literature, since deuterium is an isotope of hydrogen and has different atomic nuclei, it can be considered that the electronic states are almost the same. The vacuum ultraviolet light emitted by deuterium is estimated to be at least qualitatively almost the same as the vacuum ultraviolet light emitted by hydrogen.

Then, as is clear from the above description,
It can be seen that during the discharge, deuterium atoms are dissociated and generated in addition to deuterium molecules. It is chemically active,
Since it is clear from experiments that the phosphor will be damaged if it is left as it is, if deuterium gas is used alone or as a mixed gas with helium gas and this gas is used as the enclosed gas for the panel, protection against the phosphor is required. It is necessary to take measures.

Various methods are conceivable as this protective measure.

For example, the first method is to coat the phosphor with the above-mentioned protective film that transmits vacuum ultraviolet light so that the phosphor does not come into contact with active deuterium atoms.

As such a window material, a fluoride of an alkali metal or an alkaline earth metal is used. Specifically, if lithium fluoride (LiF) is used as the window material, the transmission limit wavelength of vacuum ultraviolet light can be set to 105 nm, and if magnesium fluoride (MgF ₂ ) is used as the window material, The transmission limit wavelength of vacuum ultraviolet light is 112n
m, and calcium fluoride (Ca
If F ₂ ) is used as the window material, the transmission limit wavelength of vacuum ultraviolet light can be set to 122 nm, and if strontium fluoride (SrF ₂ ) is used as the window material, the transmission limit wavelength of vacuum ultraviolet light is increased. The wavelength can be 128 nm, and if barium fluoride (BaF ₂ ) is used as the window material, the transmission limit wavelength of vacuum ultraviolet light can be 134 nm.

By using these materials, most or most of the above vacuum ultraviolet light can be covered.

Although the transmission limit wavelength is 141 nm, which is slightly long, sapphire (Al ₂ O ₃ ) may be used as the window material.

As a second method, deuterium atoms produced by dissociation of deuterium molecules are returned to deuterium molecules as quickly as possible.

To this end, the documents already published,
For example, edited by Iida et al., "Optical measurement", Asakura Shoten (196
As is clear from 9), gold (Au) or platinum (P
It is effective to arrange t) etc. in the panel and use them as a catalyst.

Next, an embodiment of the gas discharge display panel according to the present invention, which uses the above-mentioned protective gas for the enclosed gas containing deuterium gas and the phosphor, will be described in detail.

FIG. 1 is a sectional view showing an example of a DC type gas discharge display panel to which the first embodiment of the gas discharge display panel according to the present invention is applied.

The DC type gas discharge display panel 10 shown in this figure includes a front plate 11 made of a transparent plate, and a plate-shaped rear plate 12 spaced apart from the front plate 11 by a predetermined distance. A cathode busbar 13 made of gold or platinum, a display anode busbar 14 made of gold or platinum, a barrier 15 constituting a plurality of display cells 20 having priming gaps formed in predetermined portions, and a panel 15 of this panel. When it is enclosed inside and excited, it emits ultraviolet light 16
A mixed gas 18 containing a deuterium gas 17 which emits light, and a phosphor 2 which is disposed in the display cell 20 and receives the ultraviolet light 16 and emits visible light 21 of red, green or blue.
2 and a protective film 23 that protects the phosphor 22.

Then, the cathode busbar 13 and the display anode busbar 1
4 when a DC voltage is applied between each of the display cells 20
The mixed gas 18 therein is selectively excited and made to emit light, and the ultraviolet light 16 obtained by this light emitting operation excites and makes the phosphor 22 arranged in the display cell 20 emit red, green, and blue light. Visible light 21 is emitted,
This is emitted from the front plate 11.

As described above, in the first embodiment, the mixed gas 18 containing the deuterium gas 17 is enclosed in the panel,
Since the phosphor 22 is made to emit light by the ultraviolet light 16 obtained by exciting and emitting this deuterium gas 17, it is possible to significantly reduce the luminance deterioration due to sputtering without changing the cathode material. It is possible to extend the life of the panel.

Further, in this embodiment, the cathode busbar 13 and the display anode busbar 14 are made of gold or platinum serving as a catalyst, and the phosphor 22 is covered by the protective film 23. It is possible to prevent the phosphor 22 from being damaged by hydrogen atoms.

Further, in the first embodiment, the cathode busbar 13 and the anode busbar 14 are formed of gold or platinum so that the cathode busbar 13 and the anode busbar 14 are directly used as catalysts. Even if only one of the cathode busbar 13 and the anode busbar 14 is formed of gold or platinum, the basic portion of the cathode busbar 13 or the anode busbar 14 is made of another material, and the surface of this basic portion is formed. Gold or platinum may be attached.

Further, the cathode bus bar 13 and the anode bus bar 14 are formed of the same material as the conventional one, and gold or platinum as a catalyst is arranged in the display cell 20 as a bulk metal piece.
It may be attached in the form of a thin film or a thick film.

FIG. 2 is a perspective view showing an example of an AC type gas discharge display panel to which the second embodiment of the gas discharge display panel according to the present invention is applied.

The AC type gas discharge display panel 30 shown in this figure includes a front plate 31 formed of a transparent plate, and a plate-shaped rear plate 32 which is arranged at a predetermined distance from the front plate 31. , Two electrodes 33 to which an AC voltage is applied
And a mixed gas 36 containing deuterium gas 35 that emits ultraviolet light 34 when it is enclosed in this panel and excited, and is placed in the display cell 37 to emit the ultraviolet light 34.
Received visible light of red, green, or blue
It comprises a phosphor 39 that emits light, a protective film 40 that protects the phosphor 39, and a catalyst 41 that is made of gold, platinum, or the like and that is arranged at a predetermined portion in the display cell 37.

Then, one electrode 33 and the other electrode 33
When an AC voltage is applied between the display cell 37 and each of the display cells 37, the mixed gas 36 in each display cell 37 is selectively excited and made to emit light, and the ultraviolet light 34 obtained by this light emitting operation is arranged in the display cell 37. The fluorescent substance 39 is excited to emit red, green, or blue visible light 38, which is emitted from the front plate 31.

As described above, in the second embodiment, as in the first embodiment described above, the deuterium gas 35 is contained in the panel.
A mixed gas 36 containing a gas is enclosed, and the deuterium gas 35 is excited to emit light.
Since it is designed to emit light, it is possible to significantly reduce the luminance deterioration due to sputtering and to extend the life of the panel without changing the cathode material.

Furthermore, in the second embodiment, the catalyst 41 made of gold or platinum is arranged in the display cell 37, and the phosphor 3 is formed by the protective film 40.
Since 9 is covered, it is possible to prevent the phosphor 39 from being damaged by deuterium atoms.

Further, in the second embodiment, the catalyst 41 is arranged at a position slightly apart from the intersection of the electrodes 33, but when the cell barrier exists,
The catalyst 41 may be attached to the side wall of the cell barrier.

In the first and second embodiments described above, deuterium gas 17, 35 is added to helium gas at a partial pressure ratio of 1.
The mixed gases 18 and 36 mixed with 0% are used, but if the partial pressure ratio is in the range of 2 to 20%, almost the same luminance characteristics can be secured. Even if the deuterium gases 17 and 35 are used alone, good results can be obtained.

[0061]

As described above, according to the first to third aspects of the present invention, without changing the cathode material, the deterioration of brightness caused by sputtering can be greatly reduced and the panel life can be extended. be able to.

Further, according to the invention described in claims 4 to 8, it is possible to prevent the phosphor from being damaged by the deuterium gas.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a DC type gas discharge display panel to which a first embodiment of a gas discharge display panel according to the present invention is applied.

FIG. 2 is a perspective view showing an example of an AC type gas discharge display panel to which a second embodiment of the gas discharge display panel according to the present invention is applied.

FIG. 3 is a table showing an example of a sputtering rate of helium for various target elements used in a general gas discharge display panel.

FIG. 4 is a table showing an example of a sputtering rate of xenon for various target elements used in a general gas discharge display panel.

FIG. 5 is a front view showing an example of an experimental tube used for confirming the basic characteristics of the gas discharge display panel according to the present invention.

6 is a discharge current-luminance characteristic diagram obtained by an experiment using the experimental tube shown in FIG.

FIG. 7 is a partially cut perspective view showing an example of a conventionally known DC type gas discharge display panel.

[Explanation of symbols]

 10 DC type gas discharge display panel 11, 31 Front plate (encapsulation container) 12, 32 Back plate (encapsulation container) 13 Cathode bus bar 14 Display anode bus bar 15 Barrier 16, 34 Ultraviolet light 17, 35 Deuterium gas 18, 36 Mixed Gas 20, 37 Display cell 21, 38 Visible light 22, 39 Phosphor 23, 40 Protective film 30 AC type gas discharge display panel 33 Electrode 41 Catalyst

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01J 61/16 N

Claims (8)

[Claims] 1. A gas discharge display panel for generating visible light by receiving ultraviolet light from a phosphor arranged in an enclosure, wherein the enclosure gas in the enclosure is deuterium gas (D) serving as a discharge medium gas. _2. A gas discharge display panel, characterized in that the deuterium gas is excited to emit light by using ₂ ) to generate the ultraviolet light. 2. A gas discharge display panel which emits visible light by receiving ultraviolet light from a phosphor disposed in an enclosure, wherein the enclosure gas is helium (He) as a base gas and the discharge medium is a discharge medium. Deuterium gas as a gas (D ₂ )
A gas discharge display panel, wherein a mixed gas having a partial pressure ratio of 2% or more and 20% or less is used. 3. The enclosure comprises a plurality of DC type discharge elements in which electrodes are exposed in a discharge space and formed in a matrix, or a plurality of AC type in which electrodes covered with a dielectric material in a discharge space are formed in a matrix. The gas discharge display panel according to claim 1, further comprising a discharge element. 4. A chemically active deuterium atom generated by dissociating the deuterium gas in the enclosed gas by covering the phosphor disposed in the enclosed container with a protective film that transmits ultraviolet light. The gas discharge display panel according to claim 1, 2 or 3, which prevents the phosphor from being damaged by D). 5. A material of the protective film is lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), calcium fluoride (CaF ₂ ), strontium fluoride (S).
The gas discharge display panel according to claim 4, wherein rF ₂ ), barium fluoride (BaF ₂ ) or sapphire (Al ₂ O ₃ ) is used. 6. A metal serving as a catalyst is placed in the sealed container, and the deuterium gas (D) generated by dissociation of the deuterium gas in the sealed gas by the metal is converted into a deuterium molecule (D). gas discharge display panel according to any one of claims 1, 2, 3, 4 or 5 back to D _2). 7. The metal serving as the catalyst is gold (Au)
Alternatively, the gas discharge display panel according to claim 6, which uses platinum (Pt). 8. The gas discharge display panel according to claim 6, wherein the metal serving as the catalyst is used by adhering to the electrode itself arranged in the discharge space of the enclosure or this electrode.