JP3499751B2 - Gas discharge panel and gas light emitting device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas discharge tube such as a gas discharge panel and a gas light emitting device, and more particularly to a plasma display panel for high definition.

[0002]

2. Description of the Related Art In recent years, while expectations for high-definition and large-screen televisions such as high-definition television are increasing,
CRT, liquid crystal display (hereinafter referred to as LCD), plasma display panel (Plasma Display P
In the field of each display such as anel (hereinafter referred to as PDP), a display suitable for this is being developed.

The CRT, which has been widely used as a display for television from the past, is excellent in resolution and image quality, but it has a large screen of 40 inches or more because the depth and weight increase with the size of the screen. Is not suitable for. Further, although the LCD has excellent performances of low power consumption and low driving voltage, it is technically difficult to manufacture a large screen and the viewing angle is limited.

On the other hand, the PDP can realize a large screen even with a small depth, and a 50-inch class product has already been developed. PDPs are roughly classified into a direct current type (DC type) and an alternating current type (AC type), but at present, the AC type, which is suitable for a larger size, is the mainstream. In a general AC surface discharge type PDP, a front cover plate and a back plate are arranged in parallel with a partition wall, and a discharge gas is enclosed in a discharge space partitioned by the partition wall. A display electrode is provided on the front cover plate, and the display electrode is covered with a dielectric layer made of lead glass. On the back plate, an address electrode and a partition, and red, green, or blue UV-excited fluorescent light. And a phosphor layer formed of a body.

As the composition of the discharge gas, a mixed gas system of helium [He] and xenon [Xe] or a mixed gas system of neon [Ne] and xenon [Xe] is generally used, and the filling pressure thereof is used. Is usually set in the range of about 100 to 500 Torr in consideration of suppressing the discharge voltage to 250 V or less (for example, M. Nobri).
o, T. Yoshioka, Y .; Sano, K .; Nun
Omura, SID94'Digest 727-73
0 1994).

The light emitting principle of the PDP is basically the same as that of a fluorescent lamp. When a glow discharge is applied to an electrode to generate ultraviolet rays, Xe emits ultraviolet rays to excite the phosphor to emit light. It is difficult to obtain high brightness as in a fluorescent lamp because the conversion efficiency into the fluorescent light and the conversion efficiency into the visible light in the phosphor are low. In this regard, Applied Physics Vol. 51, No. 3 1982 page 344
˜347, in a PDP having a gas composition of He—Xe, Ne—Xe system, only about 2% of electric energy was used for ultraviolet radiation, and finally 0.2% was used for visible light. % (Optical Technology Contact Vol. 34, No. 1 1996 Page 25, FLAT PANEL DISPLAY 9
6'Part 5-3, NHK Technical Research Vol. 31, Vol. 1
No. 1979, page 18).

[0007]

Under such a background, in a discharge panel such as a PDP, a technique of improving luminous efficiency to realize high brightness and suppressing discharge voltage to be low is desired. . Such a demand also exists in the display market. For example, the current 40 ~
In 42-inch TV PDP, NTS
C pixel level (640 × 480 pixels, 0.43 mm × 1.29 mm cell pitch, 0.55 m area per cell)
m ² ), 1.2 lm / w and 400 cd /
A panel efficiency and screen brightness of about m ² are obtained (for example, FLAT-PANEL DISPLAY 1997).
Part5-1 P198).

On the other hand, in the full-spec 42-inch class high-definition television expected in recent years,
The number of pixels is 1920 x 1125, and the cell pitch is 0.15
mm × 0.48 mm. In this case, the area of one cell is 0.072 mm ² , which is less than that of NTSC.
/ 7 to 1/8. Therefore, when a 42-inch high-definition television PDP is made with a conventional cell configuration, the panel efficiency is 0.15 to 0.17 lm / w.
Therefore, it is expected that the screen brightness will be reduced to about 50 to 60 cd / m ² .

Therefore, in a PDP for a 42-inch high-definition television, if the brightness (500 cd / m ² ) comparable to that of the current NTSC CRT is to be obtained, the efficiency is 10
More than double (5 lm / w or more) (for example, “flat panel display 19
97 5-1 Part 200 "). Further, in order to obtain a good image quality in the PDP, it is important to improve not only the brightness but also the color purity to adjust the white balance.

Various studies and inventions have been made to solve the problems of improving luminous efficiency and color purity. For example, as an attempt to devise the composition of the discharge gas, Japanese Patent Publication No. 5-511133 discloses that argon (A
An invention using a mixed gas of three components of r) -neon (Ne) -xenon (Xe) is described.

By introducing argon in this way, the emission of visible light from neon can be reduced and the color purity can be improved, but improvement of the light emission efficiency cannot be expected so much. Also, Japanese Patent 2616538
The publication describes the use of a mixed gas of helium (He) -neon (Ne) -xenon (Xe).

The luminous efficiency obtained by this is improved as compared with the case of the binary gas of helium (He) -xenon (Xe) and neon (Ne) -xenon (Xe), but at the pixel level of NTSC, 1 lm / There is a demand for a technology of about w, which can further improve the luminous efficiency. The present invention has been made under such a background, and
A main object of the present invention is to provide a gas discharge panel such as a DP, which can improve the panel brightness and the conversion efficiency of discharge energy into visible light, and can obtain light emission with good color purity. .

[0013]

In order to achieve the above-mentioned object, the present invention sets the gas medium enclosing pressure in the gas discharge panel to 800 to 4000 Torr, which is higher than the conventional pressure. The main reasons why the light emission efficiency is improved by this configuration are as follows. In a conventional PDP,
The filling pressure of the gas medium is usually less than 500 Torr, and most of the ultraviolet rays generated with discharge have resonance lines (center wavelength 147 nm).

On the other hand, when the filling pressure is high as described above (that is, when the number of atoms filled in the discharge space is large), the molecular beam (center wavelength: 154 nm, 173 n) is used.
The ratio of m) increases. Here, while the resonance line has self-absorption, the molecular beam has almost no self-absorption,
The amount of ultraviolet rays with which the phosphor layer is irradiated is increased, and the brightness and the luminous efficiency are improved.

In addition, the conversion efficiency of ultraviolet rays into visible light in ordinary phosphors tends to be higher on the long wavelength side, which may be another reason why the luminance and luminous efficiency are improved. By the way, in the gas discharge panel, the gas medium generally contains neon (Ne) or xenon (Xe), but when the filling pressure is relatively low, neon (N) is used.
Visible light from e) is likely to cause a problem of deterioration of color purity, whereas visible light from neon (Ne) is mostly absorbed inside the plasma when the pressure of the enclosed gas is high as in the present invention. Therefore, it is difficult to be released to the outside. Therefore, the color purity is improved as compared with the conventional PDP.

In the conventional PDP, the discharge mode is the first.
Shape glow discharge, but 800 to 400 as in the present invention
When set to a high pressure of 0 Torr, it is considered that filament glow discharge or type 2 glow discharge is likely to occur. Therefore, it can be said that the electron density in the positive column of the discharge is increased and energy is concentratedly supplied, so that the emission amount of ultraviolet rays is increased.

Further, the filling pressure is atmospheric pressure (760 Tor).
Since it exceeds r), there is also an effect that impurities in the atmosphere are prevented from entering the PDP. In addition, within the range of the enclosed pressure of 800 to 4000 Torr, 80
0 Torr or more and less than 1000 Torr, 1000 Torr
r or more and less than 1400 Torr, 1400 Torr or more 2
Less than 000 Torr, more than 2000 Torr and more than 4000T
In each range of orr and below, the features described in the embodiment are observed.

If the gas medium to be filled is replaced with a conventional gas composition such as neon-xenon or helium-xenon, and a quaternary rare gas mixture of helium, neon, xenon and argon is used as the gas medium, Even if the amount of xenon is relatively small, high brightness and high luminous efficiency can be obtained. That is, P having a low discharge voltage and high luminous efficiency
DP can be obtained.

Here, it is preferable that the content of xenon is 5% by volume or less, the content of argon is 0.5% by volume or less, and the content of helium is less than 55% by volume in order to reduce the discharge voltage. . Then, if such a quaternary gas medium is sealed at a high pressure of 800 to 4000 Torr, it is particularly effective for improving the luminance and the luminous efficiency while suppressing the rise of the discharge voltage.

Further, in the case of a panel structure in which the display electrodes and the address electrodes are arranged so as to face each other with a discharge space in between, if the encapsulation pressure is set to a high pressure, the voltage during addressing also tends to increase. If the display electrode and the address electrode are laminated on the surface of either the front cover plate or the back plate via the dielectric layer, the addressing can be performed with a relatively low voltage even when the sealing pressure is high. be able to.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. (First Embodiment) (Overall Configuration and Manufacturing Method of PDP) FIG. 1 is a perspective view showing an outline of an AC surface discharge PDP of the present embodiment.

This PDP includes a front panel 10 having display electrodes (discharge electrodes) 12a and 12b, a dielectric layer 13 and a protective layer 14 arranged on a front glass substrate 11, and an address electrode 22 on a rear glass substrate 21. The rear panel 20 on which the dielectric layer 23 is arranged is arranged in parallel with each other with the display electrodes 12a and 12b and the address electrode 22 facing each other. And front panel 1
0 and the rear panel 20 are separated by a stripe-shaped partition wall 3
A discharge space 30 is formed by partitioning with 0,
A discharge gas is enclosed in the discharge space 40.

In the discharge space 40, a phosphor layer 31 is arranged on the rear panel 20 side. The phosphor layers 31 are repeatedly arranged in the order of red, green and blue. Display electrodes 12a, 12b and address electrode 22
Are both stripe-shaped silver electrodes, and
The addresses a and 12b are arranged in a direction orthogonal to the partition wall 30, and the address electrode 22 is arranged in parallel with the partition wall 30.

A cell structure is formed in which cells for emitting red, green and blue colors are formed at the intersections of the display electrodes 12a and 12b and the address electrodes 22. The dielectric layer 13 includes the display electrodes 12a, 1 of the front glass substrate 11.
It is a layer made of lead glass or the like having a thickness of about 20 μm and arranged so as to cover the entire surface on which 2b is arranged.

The protective layer 14 is made of magnesium oxide (Mg
It is a thin layer of O) and covers the entire surface of the dielectric layer 13. The partition wall 30 is the dielectric layer 2 of the rear panel 20.
3 is projected on the surface. At the time of driving the PDP, a driving circuit is used to apply a pulse voltage between the display electrodes 12a and 12b after applying the voltage between the display electrode 12a and the address electrode 22 of the cell to be lit and performing the address discharge. The ultraviolet light is emitted by sustaining discharge by converting the light into visible light by the phosphor layer 31 to emit light.

The PDP having such a structure is manufactured as follows. Preparation of Front Panel: In the front panel 10, the display electrodes 12a and 12b are formed on the front glass substrate 11, and lead-based glass is applied and fired on the display electrodes 12a and 12b to form the dielectric layer 13.
Is formed, and the protective layer 14 is further formed on the surface of the dielectric layer 13 to form fine irregularities on the surface.

The display electrodes 12a and 12b are formed by a method of screen-printing a silver electrode paste and then firing the paste. The composition of the lead-based dielectric layer 13 is lead oxide [Pb
O] 70% by weight, boron oxide [B ₂ O ₃ ] 15% by weight, and silicon oxide [SiO ₂ ] 15% by weight, which are formed by the screen printing method and firing. Specifically, it is formed by applying a composition obtained by mixing an organic binder [α-terpineol in which 10% of ethyl cellulose is dissolved] by a screen printing method, and then firing at 580 ° for 10 minutes, The film thickness was set to 20 μm.

The protective layer 14 is composed of an oxide of alkaline earth (here, magnesium oxide [MgO]),
It is a film having a fine crystal structure oriented in (0) plane or in (110) plane, and has a structure having fine irregularities on its surface. In the present embodiment, the CVD method (thermal CVD method,
A plasma CVD method is used to form a protective layer made of such MgO having a (100) plane orientation or a (110) plane orientation, and then irregularities are formed on this surface using a plasma etching method. The method of forming the protective layer 14 and the method of forming irregularities on the surface thereof will be described in detail later.

Preparation of back panel: Address electrodes 22 are formed on the back glass substrate 21 by screen-printing a silver electrode paste and then firing, and the screen-printing method is performed on the address electrodes 22, as in the case of the front panel 10. By firing, the dielectric layer 23 made of lead-based glass is formed. Next, the glass partition walls 30 are fixed at a predetermined pitch. Then, in each space sandwiched by the partition walls 30, one of the red phosphor, the green phosphor, and the blue phosphor is applied and baked to form the phosphor layer 31. As the phosphor of each color, a phosphor generally used in PDP can be used, but here, the following phosphors are used.

The red _{phosphor: (Y x Gd 1-x} ) BO 3: Eu 3+ Green phosphor: BaAl ₁₂ O _19: Mn Blue phosphor: BaMgAl ₁₄ O _23: Preparation of PDP by laminating Eu ²⁺ panel: Next, the front panel and the back panel thus produced were bonded together using sealing glass, and the discharge space 30 partitioned by the partition walls 30 was evacuated to a high vacuum (8 × 10 ⁻⁷ Torr). A PDP is manufactured by filling a discharge gas having a predetermined composition with a predetermined pressure.

(Regarding Pressure and Composition of Discharge Gas) The discharge gas filling pressure is in a range higher than the conventional general filling pressure and exceeds 80 at atmospheric pressure (760 Torr).
Set in the range of 0 to 4000 Torr. As a result, the brightness and the luminous efficiency can be improved more than ever before. In addition, in this embodiment, since the discharge gas is sealed at a high pressure, when the panels are bonded together, the sealing glass is applied not only on the outer peripheral portions of the front panel and the rear panel but also on the partition walls 30 and then bonded. Firing is performed (for details, see Japanese Patent Application No. Hei 9-344636). This makes it possible to manufacture a PDP that sufficiently withstands gas encapsulation at a high pressure of about 4000 Torr.

The discharge gas to be enclosed is helium (He) or neon (Ne) in place of the conventional gas composition such as helium-xenon system or neon-xenon system in order to improve the luminous efficiency and lower the discharge voltage. ), Xenon (X
It is desirable to use a mixture of e) and a noble gas containing argon (Ar). Here, the content of xenon is 5% by volume.
Hereinafter, the content of argon is preferably 0.5% by volume or less and the content of helium is preferably less than 55% by volume. As a specific example of the gas composition, He (30%)-Ne (67.
A gas composition of 9%)-Xe (2%)-Ar (0.1%) can be mentioned (% in the gas composition formula represents volume%. The same applies hereinafter).

As will be described later in detail, both the setting of the discharge gas composition and the setting of the filling pressure contribute to the luminous efficiency of the PDP and the panel brightness. By combining with the setting of the filling pressure, it is possible to significantly improve the light emission efficiency and the panel brightness while suppressing the rise of the discharge voltage as compared with the conventional case.

Further, the filling pressure is not higher than the atmospheric pressure (500 in the conventional case).
At about Torr or less), visible light is emitted from neon (Ne) to the outside to easily lower the color purity, but when the filling pressure becomes a high pressure of 800 Torr or more,
Even if visible light is generated from neon (Ne), it is almost absorbed inside the plasma and is hardly emitted to the outside. Therefore, the color purity can be improved as compared with the case where the filling pressure is the atmospheric pressure or less (about 500 Torr or less).

When the filling pressure exceeds the atmospheric pressure, impurities in the atmosphere are prevented from entering the discharge space 30. In this embodiment, the cell size of PDP is 40.
The cell pitch is set to 0.2 mm or less so that the display electrodes 12a and 12 can be adapted to the inch class high-definition television.
The distance d between the electrodes of b is set to 0.1 mm or less.

The upper limit of the filling pressure is 4000 Torr
Is set in consideration of suppressing the discharge voltage within a practical range. (Regarding Method of Forming MgO Protective Layer and Method of Forming Irregularities on Its Surface) FIG. 2 is a schematic view of a CVD apparatus used when forming the protective layers 14 and 24. This CVD apparatus can perform both thermal CVD and plasma CVD, and a glass substrate 47 is provided in the apparatus main body 45.
A heater portion 46 for heating (one in which the display electrode and the dielectric layer 13 are formed on the glass substrate 11 in FIG. 1) is provided, and the inside of the device body 45 can be decompressed by the exhaust device 49. There is. Further, a high frequency power source 48 for generating plasma is installed in the apparatus body 45.

The Ar gas cylinders 41a and 41b use a vaporizer (bubbler) for the argon [Ar] gas that is a carrier.
It is supplied to the apparatus main body 45 via 42 and 43. The vaporizer 42 heats and stores a metal chelate, which is a source (source) of MgO, and stores it from the Ar gas cylinder 41a to A
By blowing r gas, this metal chelate can be evaporated and sent to the apparatus main body 45.

The vaporizer 43 heats and stores the cyclopentadienyl compound, which is the source (source) of MgO, and stores it.
By blowing Ar gas from the gas cylinder 41b, the cyclopentadienyl compound can be evaporated and sent to the apparatus main body 45. Specific examples of the sources supplied from the vaporizer 42 and the vaporizer 43 include Magnesium Dipivaloyl Methane [Mg (C
₁₁ H ₁₉ O ₂ ) ₂ ], Magnesium Acetylacetone [Mg (C ₅
H ₇ O ₂ ) ₂ ], Cyclopentadienyl Magnesium [Mg (C ₅
H ₅ ) ₂ ], Magnesium Trifluoroacetylacetone [Mg
(C ₅ H ₅ F ₃ O ₂ ) ₂ ].

The oxygen cylinder 44 supplies oxygen [O 2] which is a reaction gas to the apparatus main body 45. When performing the thermal CVD method: The glass substrate 47 is placed on the heater portion 46 with the dielectric layer facing upward, and the glass substrate 47 is placed at a predetermined temperature (350
Up to 400 ° C.) and the pressure inside the reaction vessel is reduced to a predetermined pressure by the exhaust device 49.

Then, in the vaporizer 42 or the vaporizer 43,
While heating the alkaline earth metal chelate or cyclopentadienyl compound serving as the source to a predetermined temperature (see the column of "vaporizer temperature" in each table below), Ar gas was supplied from the Ar gas cylinder 41a or 41b. Send in. At the same time, oxygen is supplied from the oxygen cylinder 44. As a result, the metal chelate or cyclopentadienyl compound fed into the device body 45 reacts with oxygen, and a MgO protective layer is formed on the surface of the dielectric layer of the glass substrate 47.

When the plasma CVD method is performed, the same procedure as in the above thermal CVD is performed, but the heater portion 4 is used.
The heating temperature of the glass substrate 47 according to No. 6 is 250 to 300 ° C.
Use the exhaust device 49 to set the temperature to about 1
Reduce the pressure to about 0 Torr, drive the high frequency power supply 48,
For example, by applying a high frequency electric field of 13.56 MHz to generate plasma in the device body 45,
A MgO protective layer is formed.

As described above, the thermal CVD method or the plasma CVD method is used.
The MgO protective layer formed by the method has a (100) plane orientation or a (110) plane orientation when the crystal structure is examined by X-ray analysis. On the other hand, the MgO protective layer formed by the conventional vacuum evaporation method (EB method) has a (111) orientation when the crystal structure is examined by X-ray analysis. In addition, M by the CVD method
In forming the gO protective layer, (100) plane orientation and (1)
10) Which of the plane orientations is to be formed can be adjusted by controlling the flow rate of oxygen as a reaction gas.

Next, the formation of irregularities on the protective layer by the plasma etching method will be described. FIG. 3 is a schematic diagram of a plasma etching apparatus for forming fine pyramid-shaped irregularities on the MgO protective layer. In the device main body 52, Mg
There is a substrate 53 on which a protective layer made of O is formed (that is, the display electrodes 12a and 12b, the dielectric layer 13 and the protective layer 14 are formed on the glass substrate 11 in FIG. 1). It is possible to reduce the pressure with the device 56,
Ar gas can be supplied from the Ar gas cylinder 51. A high frequency power source 54 for generating plasma and a bias power source 55 for irradiating the generated ions are installed in the apparatus body 52.

Using this plasma etching apparatus, first, the pressure inside the reaction vessel was reduced by the exhaust device 56 (0.001).
~ 0.1 Torr), Ar gas is sent from the Ar gas cylinder. Drives the high frequency power supply 54 to 13.56 MHz
The argon plasma is generated by applying the high frequency electric field. Then, the bias power supply 55 is driven to apply (−200 V) to the substrate 53 and irradiate with Ar ions for 10 minutes to sputter the surface of the MgO protective layer.

By this sputtering, pyramidal irregularities can be formed on the surface of the MgO protective layer. The size of the irregularities formed on the surface can be controlled by adjusting the sputtering time, the applied voltage, and the like. When this unevenness is formed, the surface roughness is 30
It is considered appropriate to form it to have a thickness of about 100 nm to 100 nm.

It can be confirmed with a scanning electron microscope that the unevenness formed on the surface by the sputtering is a pyramid shape. The protective layer which has been subjected to such treatment has the following characteristics and effects. (1) The crystal structure of the MgO protective layer is (100) plane or (1)
10) Emission coefficient (γ value) of secondary electrons due to plane orientation
Is big. Therefore, it contributes to the reduction of the driving voltage of the PDP and the improvement of the panel brightness.

(2) Since the surface of the MgO protective layer has a pyramidal concavo-convex structure, an electric field is concentrated on the top of the protrusion during discharge, and many electrons are emitted from this top. Therefore, linear glow or type 2 glow discharge is likely to occur, and such a form of discharge can be stably generated. When the linear glow discharge or the second-type glow discharge is stably generated, a locally high plasma density may be obtained as compared with the conventional first-type glow discharge. Therefore, it is considered that a large amount of ultraviolet rays (mainly, a wavelength of 173 nm) is generated in the discharge space and a high panel brightness is obtained.

(Description of Form of Glow Discharge) Here, the filament glow discharge and the second type glow discharge will be described. Regarding "Strip Stroke Glow Discharge" and "Type 2 Glow Discharge", Discharge Handbook (The Institute of Electrical Engineers of Japan, June 1, 1991)
It is explained as follows in the daily issue P138).

"Kekez, Barrault, Cra
ggs et al. Phys. D. Appl. Phy
s. , Vol. 13, p. In 1886 (1970), the discharge state changed to flashover, Townsend discharge, first type glow discharge, second type glow discharge, and arc discharge. ] FIG. 4 is a graph showing the current waveforms of transient glow and arc transitions published in this paper.

The first type glow discharge corresponds to a normal glow discharge, and the second type glow discharge corresponds to a time when discharge energy is being intensively supplied to the positive column. In FIG. 4, the first type glow discharge is at a time ta to tc when the current value is slightly low and stable, and the second type glow discharge is td.
It's about te. The linear glow discharge is a time period from tc to td when the first type glow discharge shifts to the second type glow discharge. Then, the second type glow discharge enters the arc discharge.

As described above, the first-type glow discharge is stable, whereas the linear-strand glow discharge and the second-type glow discharge are considered to have a high possibility of transition to arc discharge due to unstable current. However, if arc discharge occurs, the discharge gas is thermally ionized and the discharge gas is thermally ionized, which is not desirable. By the way, the discharge in the PDP has conventionally been performed by the first type glow discharge, but in the present embodiment, the linear glow discharge or the second type glow discharge can be generated relatively stably. Conceivable. As a result, the electron density in the positive column of the discharge is increased and the energy is concentratedly supplied,
It is expected that it is possible to increase the amount of ultraviolet light emitted.

(Regarding relation between filling pressure in discharge gas and luminous efficiency) The filling pressure of discharge gas is higher than that of the conventional one by 800.
The reason why the luminous efficiency is improved by setting the range of up to 4000 Torr will be described. First, it is considered that setting the filling pressure to be high is advantageous for producing the above-mentioned linear glow discharge or second-type glow discharge, and this is the reason for the increase in the amount of ultraviolet light emission. Can be mentioned as one.

Next, as described below, it can be mentioned that the wavelength of ultraviolet rays shifts to the long wavelength side (154 nm and 173 nm). The light emission mechanism of ultraviolet rays of the PDP is roughly classified into two, that is, a resonance line and a molecular beam. Conventionally, since the filling pressure of the discharge gas was less than 500 Torr, the ultraviolet emission from Xe was mainly 147 nm (resonance line of Xe atom), but by setting the filling pressure to 760 Torr or more, long wavelength 173 nm (X
The ratio of the excitation wavelength by the molecular beam of the e molecule) increases. Then, the ratio of the molecular beam having the wavelengths of 154 nm and 173 nm can be made larger than that of the resonance line having the wavelength of 147 nm.

FIG. 5 shows how the relationship between the wavelength of emitted ultraviolet light and the amount of emitted light changes when the pressure of the enclosed gas is changed in a PDP using a He--Xe system discharge gas. It is a characteristic diagram, "O Plus EN
o. 195 P. 1996. 98 ”. In this figure, the wavelength of the graph is 147 nm
(Resonance line) and the peak area at a wavelength of 173 nm (molecular beam) represent the amount of light emission. Therefore, the relative amount of light emission at each wavelength can be known from the peak area of such a graph.

At a pressure of 100 Torr, the wavelength is 147.
Although the luminescence amount of nm (resonance line) occupies most, the proportion of the luminescence amount of wavelength 173 nm (molecular beam) increases as the pressure increases, and at a pressure of 500 Torr, the luminescence amount of wavelength 173 nm is larger. Wavelength 147nm (resonance line)
Is larger than the luminescence amount of. As the wavelength of the ultraviolet rays shifts to the long wavelength side in this way, the effects of (1) increasing the amount of emitted ultraviolet light and (2) improving the conversion efficiency of the phosphor are obtained. Each will be described below. (1) Increasing the amount of emitted ultraviolet light FIG. 6 is a diagram showing the energy order of Xe and various reaction paths.

The resonance line is emitted when an electron in an atom moves from one energy level to another energy level, and in the case of Xe, ultraviolet rays of 147 nm are mainly emitted. However, the resonance line has a phenomenon called stimulated absorption, and a part of the emitted ultraviolet light is absorbed by Xe in the ground state. These phenomena are generally called self-absorption.

On the other hand, in the molecular beam, as shown in FIG. 6, when the excited two atoms approach a certain distance or less, they emit ultraviolet rays and the two atoms return to the ground state. Therefore, almost no absorption is observed. In order to confirm these qualitatively, the following simple theoretical calculation was performed and compared with the experimental results.

First, assuming that the amount of resonance lines generated (V147) is electron density ne and atom density n0, V147 = a.ne.n
It is represented by 0, and the absorption amount (Vabs) is the absorption coefficient b (usually 1
About 0 ^-6), when the plasma length and l, Vabs = exp
It is represented by (-b · n · l).

On the other hand, the molecular beam is generated because the Xe atoms in the excited state are generated in close proximity to each other, so that the generated amount (V173)
Becomes V173 = C · n ⁴ + d · n ^{3 to} C · n ⁴ . The molecular beam has almost no absorption, but V173 = C · n ⁴ −n ^2/3 when geometrical physical scattering is taken into consideration. Therefore, the total amount of ultraviolet rays V is V = a ・ ne ・ n0-c ・ exp (-b
· N · l) + represented by C · n ⁴ -n ^2/3. However, a, b, and c are arbitrary constants here.

The calculated values of the resonance line, the molecular beam and the total ultraviolet ray with respect to the change of the discharge gas pressure are shown in the graph of FIG. In FIG. 7, the horizontal axis is an arbitrary axis, but it can be seen that a gas pressure of a certain level or more is necessary to sufficiently bring out the effect of the molecular beam. As a discharge gas, Ne (95%)-Xe (5%), which is usually used in PDPs, was used to examine the ultraviolet output with respect to the gas pressure in a vacuum chamber experiment. The experimental results are shown in FIG. As indicated by the ● mark, the characteristics were close to the above theoretical prediction.

(2) Improvement of conversion efficiency of phosphors FIGS. 8 (a), 8 (b) and 8 (c) are characteristic diagrams showing the relationship between the excitation wavelength and the relative emission efficiency for each color phosphor.
"O Plus E No. 195 P. 1996.
99 ". It can be seen from FIG. 8 that the relative emission efficiency of the long wavelength 173 nm is higher than that of the wavelength 147 nm for the phosphors of any color.

Therefore, the wavelength of ultraviolet rays is 147 nm (Xe
It can be said that the emission efficiency of the phosphor tends to increase as the proportion of the long wavelength increases by shifting from the resonance line) to the long wavelength of 173 nm (molecular beam of Xe atoms). (Regarding Relationship between Filling Pressure, Luminous Efficiency, and Discharge Voltage) The following consideration can be made from the tendency of change of all ultraviolet rays in FIG.

When the gas pressure is in the range of 400 to 1000 Torr, the ultraviolet light output increases as the gas pressure is increased, but it becomes saturated near 1000 Torr, and the ultraviolet light output hardly increases. Then, when the gas pressure is further increased, the ultraviolet ray output increases again from around 1400 Torr, and continues to increase until around 2000 Torr.

When the gas pressure is further increased from this region, there is a region where the increase in the ultraviolet light output becomes slightly gradual, but it is considered that this is because the physical scattering term becomes effective. Although not shown in FIG. 7, as expected from the above theoretical formula, the ultraviolet ray output increases as the gas pressure is further increased beyond this region. Based on the above consideration, the preferable range of the filling pressure of the discharge gas (800
~ 4000 Torr), 800-1000To
rr (region 1), 1000 to 1400 Torr (region 2), 1400 to 2000 Torr (region 3), 200
It was divided into four areas of 0 to 4000 Torr (area 4).

Regarding the numerical value of 800 Torr, in principle, the effect will be obtained if it exceeds 760 Torr, but in consideration of manufacturing conditions such as the temperature at the time of encapsulation being higher than room temperature, this value is set to this numerical value from the industrial viewpoint. Set. The following can be considered with respect to these four areas. Considering only the ultraviolet ray output amount, it is considered that the region 4 of the highest pressure is the best.

On the other hand, in the PDP, the discharge start voltage V
f can be expressed as a function of the product [Pd product] of the filling pressure P and the inter-electrode distance d, and is called Paschen's law (Electronic Display Device, Ohmsha, Showa 59).
Year, see P113-114). Then, as the gas pressure becomes higher, the Pd product tends to increase and the discharge voltage tends to increase.
Here, the Pd product can be suppressed by setting the distance between the electrodes to be small, but as the distance d between the electrodes is reduced, a more advanced dielectric insulating technique is required.

Therefore, it is considered that the technical difficulty increases in the order of the areas 1, 2, 3, and 4. For example, in FIG. 7, the discharge start voltage is 200V in the PDP corresponding to A in the figure, but the discharge start voltage is 450V in the PDP corresponding to B in the figure.

Therefore, the PDP corresponding to the area 1 has a discharge start voltage of about 250 V or less,
Although it is possible to use the dielectric insulation technology and the voltage resistance technology of the driver circuit in the case of PDPs in the regions 3 and 4, advanced technology is required in order to set the interelectrode distance d to a considerably small value, which is costly. Will be higher. (Composition of discharge gas, luminous efficiency, and discharge voltage) As described above, the composition of the discharge gas is changed to helium (He),
Neon (Ne), Xenon (Xe), Argon (Ar)
A mixture of noble gases containing, xenon content of 5% by volume or less, argon content of 0.5% by volume or less, and helium content of less than 55% by volume for high pressure encapsulation. Even in such a case, the device can be driven at a relatively low discharge start voltage (250 V or less, preferably 220 V or less).

That is, by using a gas having such a composition, conventional Ne (95%)-Xe (5%) and He can be used.
The discharge starting voltage can be greatly reduced as compared with the case of using a gas having a composition such as (95%)-Xe (5%). Hereinafter, this point will be described in more detail based on experiments. (Experiment 1: Preliminary Experiment on Discharge Gas Composition) Based on the PDP of the present embodiment, various discharge gas compositions shown in the table of FIG. 9 were set, and Pd products were set to various values. It was produced and the discharge starting voltage was measured.

The Pd product is set by setting the electrode distance d to 20,4.
The gas pressure P is set to 1 while setting to 0, 60 and 120 μm.
It was performed by changing within the range of 00 Torr to 2500 Torr. Here, when setting a small Pd product, a relatively small electrode interval d is mainly used (for example, when the Pd product is 1 to 4, the electrode interval d is 20 μm and the pressure P is
Is set to about 500 to 2000 Torr), and when a relatively large Pd product is set, a relatively large electrode spacing d
By mainly using (60, 120 μm), each P
It was set to the value of the d product.

The graph of FIG. 9 shows the results of this experiment, and shows the relationship between the Pd product and the discharge start voltage. Further, the table in FIG. 9 shows measured values of luminance (around the discharge voltage of 250 V) for PDPs using the respective composition gases and having a Pd product of around 4 (filling pressure is 2000 Torr).

Results and discussion: From the table of FIG. 9, He-Xe
In the system and He-Ne-Xe system, the brightness is higher than that in the Ne-Xe system (in particular, the brightness is higher in the He-Ne-Xe system), and the inclusion of He having the effect of increasing the electron temperature improves the brightness. Considered to be effective. Further, from the graph of FIG. 9, the He-Xe system (marked by ▲) is the Ne-Xe system (◆).
The discharge starting voltage tends to be higher than that of the mark), and it is understood that the discharge starting voltage is not within the practically desirable discharge starting voltage region (220 V or less).

On the other hand, in the graph of FIG. 9, Ne-Xe
The gas in which 0.1% Ar was added to the system (circle) is He-X.
Compared with e-type, Ne-Xe-type, and He-Ne-Xe-type, the discharge start voltage is lower due to the Penning effect, and the graph passes through the desirable use area of 220 V or less and the Pd product of 3 or more. You can see that However, gas containing 0.5% Ar added to the Ne-Xe system (
In (), the discharge starting voltage is not so low. From this, it is understood that it is preferable to add a relatively small amount of Ar (0.5% or less) in order to reduce the discharge start voltage.

In FIG. 9, the range of Pd product of 3 or more is set as a desirable use area. Under the present circumstances, it is difficult to set the electrode interval smaller than 10 μm. Therefore, the Pd product of 3 or more is practically used. It is desirable to set the range. From the above, when He is mixed with the Ne-Xe system, the light emission efficiency is improved, but the discharge start voltage tends to be high. By further mixing Ar with this, the discharge voltage is lowered and the light emission efficiency is equal or higher. Could be. Here, it can be inferred that the amount of Ar should be relatively small.

In this experiment, the gas pressure P was 100 To.
The Pd product was set by changing it within the range of rr to 2500 Torr, but the gas pressure P was set to 2500 Torr to 40 Torr.
Even if the range is set to 00 Torr, the same result as the graph of FIG. 9 is obtained. Further, the range of low Xe content (10
%), It is known that the amount of Xe and the luminous efficiency are substantially proportional to each other. However, even in the discharge gas having various compositions described above, the luminous efficiency can be improved by changing the amount of Xe. It has been confirmed experimentally that it also changes accordingly.

(Experiment 2: Comparison of He-Ne-Xe-Ar system gas and Ne-Xe system gas) In the PDP of the above embodiment, He (30%)-Ne (6) was used as the discharge gas.
7.9%)-Xe (2%)-Ar (0.1%) (referred to as "discharge gas A") and Ne (95).
%)-Xe (5%) (referred to as "discharge gas Z") was used, and Pd products were set at various values, and the discharge start voltage was measured.

The Pd product was set by setting the electrode spacing d to 20, 40, 60 and 120 μm and changing the gas pressure P within the range of 100 Torr to 2500 Torr as in Experiment 1. FIG. 10 is a graph showing the results of this experiment and showing the relationship between the Pd product and the discharge start voltage.

From this graph, in the case of the discharge gas Z, Pd
If the product is reduced from 12 to about 4, the discharge start voltage becomes 45
It can be seen that the voltage can be reduced from 0V to 320V by about 130V. On the other hand, in the case of the discharge gas A, even with the same Pd product 12,
It can be seen that the discharge starting voltage can be reduced by about 130 V as compared with the discharge gas Z, and the discharge starting voltage can be further reduced by about 90 V by reducing the Pd product from 12 to 4.

Therefore, when the discharge gas A is used, the discharge voltage can be lowered to a practical level even if the filling pressure is set high, without making the interelectrode distance d too small. In addition, it was confirmed in a separate light emission efficiency comparison experiment that the same brightness can be realized with the discharge gas A even at a considerably lower voltage as compared with the case of using the discharge gas Z. However, when the discharge gas A was used, a luminous efficiency about 1.5 times that when the discharge gas Z was used was obtained.

Such an effect of the discharge gas A is obtained by combining the improvement of the luminous efficiency due to the inclusion of He and the reduction of the discharge voltage due to the addition of a small amount of Ar described in Experiment 1. it is conceivable that. The results of this experiment show that a He-Ne-Xe-Ar mixed gas is used as the discharge gas, and the content of Xe is preferably 5% by volume.
Below, it has been shown that setting the Ar content to 0.5 vol% or less is effective for improving the luminous efficiency and reducing the discharge voltage.

In this experiment, the gas pressure P was 100 To.
The Pd product was set by changing it within the range of rr to 2500 Torr, but the gas pressure P was set to 2500 Torr to 40 Torr.
Even when the range is set to 00 Torr, the same result as the graph of FIG. 10 is obtained. (Experiment 3: He-Ne-Xe system gas and He-Ne-X
Regarding the e-Ar system gas) In the PDP (distance between electrodes d = 40 μm) of the above-described embodiment, H gas was used as the discharge gas.
e (50%)-Ne (48%)-Xe (2%), He
(50%)-Ne (48%)-Xe (2%)-Ar
(0.1%), He (30%)-Ne (68%)-Xe
(2%), He (30%)-Ne (67.9%)-Xe
(2%)-Ar (0.1%) of various composition gases is used, and P
PDPs having various d products were prepared. Then, the brightness and the discharge start voltage of each manufactured PDP were measured.

The table in FIG. 11 shows P using each composition gas.
The measured luminance value (discharge voltage 250 V) is shown for the PDP near d product 4 (filling pressure is 2000 Torr). The measured luminance values shown in the table of FIG. 11 are all He-Xe system, Ne-Xe system, and Ne- shown in the table of FIG.
The value is considerably higher than the measured luminance value of the Xe-Ar system gas. From this, He-Ne-Xe
It is understood that the use of the system gas and the He-Ne-Xe-Ar system gas is effective for improving the brightness.

FIG. 11 shows the measurement results of the discharge starting voltage, and is a graph showing the relationship between the Pd product and the discharge starting voltage for each composition gas. From this graph and table, it can be seen that the discharge gas in which a small amount of Ar is added to the discharge gas of He—Ne—Xe system has a lower discharge start voltage and a slightly improved luminance. .

In particular, He (30%)-Ne (67.9)
%)-Xe (2%)-Ar (0.1%) gas, the brightness is relatively good and the Pd product is 3 to 6
If set within a range of (Torr · cm) (for example,
Distance between electrodes d = 60 μm, fill pressure 1000 Tor
r), it can be seen that the discharge starting voltage can be put in a practically desirable discharge starting voltage region (220 V or less).

Further, in the case of this gas composition, the discharge start voltage shows the minimum value in the vicinity of the Pd product 4, and the Pd product is in the vicinity of 4 (for example, when the filling pressure is 2000 Torr, the electrode distance d = 20 μm). It can also be seen that it is desirable to set. In this experiment, the amount of Xe was set to 2% in each composition gas, but the amount of Xe was set to 10%.
When the following other values are set, the tendency similar to the graph shown in FIG. 11 is obtained, although the absolute value of the discharge start voltage changes.

In this experiment, the He content was 50%.
Although set as follows, such He-Ne-Xe-Ar
It is known from another experiment that the discharge voltage tends to be considerably high when the He content is set to 55% by volume or higher in the system discharge gas. Therefore, in order to keep the discharge voltage low, it can be said that the He content is preferably specified to be less than 55% by volume.

(Experiment 4: Experiment of Ar amount in He-Ne-Xe-Ar system gas) He (30%)-Ne ((6
8-X)%)-Xe (2%)-Ar (X%),
An experiment was conducted to measure the discharge start voltage and the luminous efficiency when X = 0.01, 0.05, 0.1, 0.5, and 1.

The luminous efficiency is measured by measuring the discharge sustaining voltage Vm applied to the panel from the drive circuit and the current I flowing at that time, and then measuring the luminance L with a luminance meter (the measured area of luminance at that time is S And the luminous efficiency η according to the following equation 1.
I asked. η = π · S · L / Vm · I (1) FIG. 12 shows an example of the result and is a graph when the filling pressure is set to 2000 Torr.

From this figure, the luminous efficiency is almost constant in the range of 0.1% or less of Ar, but 0.1%.
It can be seen that in the range of 0.5% to 0.5%, the luminous efficiency gradually decreases as the Ar amount increases, and when it exceeds 0.5%, it rapidly decreases as the Ar amount increases. On the other hand, with respect to the discharge start voltage, it has a minimum value when the Ar amount is 0.1%, and in the range of 0.1% to 0.5%, the luminous efficiency gradually increases as the Ar amount increases, It can be seen that when the content exceeds 0.5%, the value increases sharply with the increase in the amount of Ar.

Therefore, it is understood that the added amount of Ar is preferably 0.5% or less. In addition, He amount and Xe
When the amount is changed, although not shown, although the light emission efficiency and the absolute value of the discharge start voltage are changed, the same result as the graph of FIG. 12 is obtained. Also, when the filling pressure is set to near normal pressure, the same result as the graph of FIG. 12 is obtained.

(Second Embodiment) FIG. 13 is a schematic sectional view of an AC surface discharge type PDP according to the present embodiment. This PDP is similar to the PDP of the first embodiment, but in the first embodiment, the display electrodes are provided on the front panel side and the address electrodes are provided on the rear panel side. The difference is that the address electrode 61 and the display electrodes 63a and 63b are provided on the front panel side via the first dielectric layer 62.

Although the pair of display electrodes 63a and 63b are shown in cross section in FIG. 13 for the sake of convenience, in reality, the pair of display electrodes 63a and 63b are the same as in FIG. It is provided in the direction that intersects with. In this PDP, the front panel 10 is manufactured as follows. In manufacturing the front panel 10, the address electrode 61 is formed on the front glass substrate 11, and the first dielectric layer 62 is formed thereon by using lead-based glass. And
The display electrodes 63a and 63b are formed on the surface of the first dielectric layer 62, and the second dielectric layer 64 is formed thereon using lead-based glass. Then, it can be manufactured by forming a protective layer 65 made of MgO on the surface of the second dielectric layer 64.

Address electrodes 61, display electrodes 63a, 63
The materials and forming methods of b, the dielectric layers 62 and 64, and the protective layer 65 are the same as those described in the first embodiment. Also in this embodiment, the surface of the protective layer 65 is uneven by the plasma etching method. Is preferably formed. Also in this embodiment, the composition of the discharge gas and the filling pressure are the same as those in the first embodiment.
By setting in the same manner as above, the same effect as described in the first embodiment can be obtained.

Further, in the present embodiment, the address electrode 61
Since the display electrodes 63a and 63b are provided on the front panel side via the first dielectric layer 62, addressing can be performed with a low address voltage even when the discharge gas sealing pressure is high. That is, when the discharge space is interposed between the address electrode and the display electrode as in the first embodiment, Paschen's law is applied to the address discharge. Here, if the distance between the address electrode and the display electrode is narrowed, it is considered that stable address discharge can be performed even at a low address voltage, but in reality, it cannot be so narrowed. The higher the filling pressure of the discharge gas, the higher the address voltage must be.

On the other hand, in the case of the PDP of this embodiment, since there is no discharge space between the address electrode 61 and the display electrodes 63a and 63b, even if the discharge gas filling pressure is set high. Stable addressing can be performed at a low address voltage. FIG. 14 is a schematic sectional view of another AC surface discharge type PDP according to the present embodiment.

In the PDP of FIG. 13 described above, the address electrode 61 and the display electrodes 63a and 63b were provided on the front panel 10 side via the first dielectric layer 62, but in the PDP of FIG. The address electrode 71 and the display electrodes 73a and 73b are provided on the rear panel 20 side via the first dielectric layer 72. The back panel 20 is manufactured by forming the address electrodes 71 on the back glass substrate 21 and then using lead-based glass on the address electrodes 71.
Form 2. Then, the display electrodes 73a and 73b are formed on the surface of the first dielectric layer 72, and the second dielectric layer 74 is formed thereon using lead-based glass. Then, it can be manufactured by forming a protective layer 75 made of MgO on the surface of the second dielectric layer 74.

Also in this PDP, the PD shown in FIG. 13 is used.
It has the same effect as P. Further, in this PDP, since the address electrode 71 and the display electrodes 73a and 73b are provided on the rear panel side, visible light generated in the discharge space is
It is taken out to the front without being disturbed by the electrodes. In this respect, it is advantageous to improve the brightness as compared with the PDP of FIG.

(Experiment 5)

[0099]

[Table 1] No. of Table 1 The PDPs 1 to 6 are examples produced based on the first and second embodiments, and are the material No. The PDPs 1 to 4 were manufactured based on FIG. The PDP of No. 5 was manufactured based on FIG. The PDP 6 is manufactured based on the first embodiment.

The cell size of the PDP is such that the partition wall height is 0.08 mm and the partition wall interval (cell pitch) is 0.1 according to the 42-inch high-definition television display.
The distance between the display electrodes was set to 5 mm, and the distance d between the display electrodes was set to 0.05 mm. The dielectric layer is composed of 70% by weight of lead oxide [PbO], 15% by weight of boron oxide [B ₂ O ₃ ] and 1% of silicon oxide [SiO ₂ ] 1.
5% by weight was mixed with an organic binder [α-terpineol in which 10% of ethyl cellulose was dissolved], and the composition was applied by a screen printing method, and then 580
It was formed by firing at 10 ° for 10 minutes, and its film thickness was set to 20 μm.

For the method of forming the protective layer, refer to Plasma C
It was formed by the VD method. As a result of X-ray analysis of the crystal plane of the formed MgO protective layer, the (100) plane or (110) plane was obtained.
It was a plane orientation. The composition of the discharge gas to be filled is He (3
0%)-Ne (67.9%)-Xe (2%)-Ar
(0.1%), and as shown in the column of filling pressure in Table 1,
Encapsulation was performed at a pressure within the range of 500 to 200 Torr.

No. 1-6 PDP
For, the panel brightness and the stable address voltage were measured. For the stable address voltage, the state of the image was observed while changing the address voltage, the lowest address voltage required to obtain a stable image was measured, and this was taken as the stable address voltage.

Table 1 shows the measurement results of the panel brightness and the stable address voltage. Results and discussion: No. Comparing the luminances of 1 to 4 shows that the luminance increases as the enclosed voltage increases to 100 Torr and 2000 Torr as compared with the case where the enclosed pressure is equal to or lower than the normal pressure.

No. Comparing the stable address voltage between 1 to 4 shows that it increases slightly as the filling pressure increases. The stable address voltages of 1 to 5 are as follows. 6
It can be seen that the value is considerably lower than the stable address voltage of. This is because the configuration of the PDP of the second embodiment is
It is shown that it is effective to keep the address voltage low even when the filling pressure is high.

No. 3 and No. Comparing the luminances with No. 5 and No. It can be seen that 5 has a slightly higher luminance. (Other Matters) The present invention is based on the P of the above embodiment.
The present invention is not limited to DP and can be applied to general PDPs and gas discharge panels.

For example, the protective layer is not limited to the CVD method as described above, but may be formed by the vacuum deposition method. Further, the glass substrate, the dielectric layer, the phosphor material, and the method for forming the protective layer are not limited to those described above. The material of the protective layer is not limited to MgO alone, but may be Ba or S in MgO.
You may use what added r, hydrocarbon (CH), etc.

Further, in the above embodiment, an example in which the phosphor layer is provided only on the back panel side has been shown, but by providing it on the front panel side as well, the brightness can be further improved. Further, when the phosphor material forming the phosphor layer is coated with a protective layer made of MgO with a thickness of several tens of nm, further improvement in brightness and improvement in luminous efficiency can be expected.

In the above embodiment, an example in which a pair of display electrodes are arranged in parallel on either surface of the front glass substrate or the rear glass substrate is shown. The same can be applied to a PDP in which display electrodes are arranged on the rear glass substrate so as to face each other. Further, in the above-described embodiment, the example in which the partition wall 30 is fixed to the rear glass substrate 21 to form the rear panel is shown, but the invention can be widely applied to a case where the partition wall is attached to the front panel side. .

Regarding the composition of the discharge gas, the Ne-Xe system, the He-Ne-Xe system, and the He-Ne-X system described above are also used.
The discharge gas is not limited to e-Ar type, but is a krypton-xenon type discharge gas (for example, Kr (90%)-Xe (10
%)), Or using a krypton-neon-xenon-based discharge gas and setting the filling pressure to 800 to 4000 Torr, high brightness and high luminous efficiency can be expected.

Furthermore, the present invention is not limited to a gas discharge panel, but an electrode and a phosphor layer are arranged in a container, and a discharge space in which a gas medium is enclosed is formed, so that ultraviolet rays are emitted along with the discharge. It can also be applied to a gas discharge device that emits light and emits light by converting it into visible light in the phosphor layer. For example, for a fluorescent lamp in which a discharge gas is enclosed in a cylindrical glass container having a phosphor layer formed on the inner surface,
INDUSTRIAL APPLICABILITY The present invention is applicable, and by using the discharge gas having the composition described in the above embodiment, it is possible to obtain one having high brightness, high luminous efficiency, and low discharge voltage.
By encapsulating at an encapsulating pressure within the range of up to 4000 Torr, excellent effects can be expected.

[0111]

As described above, in the gas discharge panel of the present invention, the filling pressure of the gas medium is higher than the conventional pressure.
By setting within the range of 0 to 4000 Torr (each range of the above areas 1 to 4), it becomes possible to improve the luminous efficiency and the panel brightness as compared with the conventional case.

Further, the gas medium to be enclosed is a mixture of rare gases containing helium, neon, xenon and argon, in place of the conventional gas composition, and the content of Xe is preferably 5% by volume or less and the content of Ar is 0. When the content of He is less than 0.5% by volume and the content of He is less than 55% by volume, the luminous efficiency can be improved and the discharge voltage can be lowered. In addition, display electrodes and address electrodes on the surface of either the front cover plate or the back plate,
With the structure in which the dielectric layers are stacked, the addressing can be performed at a relatively low voltage even when the sealing pressure is high.

The present invention as described above is effective for power saving of the gas discharge panel, and is particularly effective for improving the brightness and labor of the PDP for high definition. Further, not only the gas discharge panel but also a gas light emitting device such as a fluorescent lamp is effective for improving the brightness and saving the labor of a general gas discharge tube.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a facing AC discharge type PDP according to a first embodiment.

FIG. 2 is a CV used when forming a protective layer of the PDP.
It is a schematic diagram of D device.

FIG. 3 is a schematic view of a plasma etching apparatus that forms pyramid-shaped fine irregularities on a MgO protective layer.

FIG. 4 is a graph showing current waveforms of transient glow and arc transfer.

FIG. 5 is a characteristic diagram showing the relationship between the wavelength of ultraviolet light and the amount of emitted light when the enclosed gas pressure is changed.

FIG. 6 is a diagram showing the energy order of Xe and various reaction paths.

FIG. 7 is a characteristic diagram showing the relationship between discharge gas pressure and resonance lines, molecular beams, and total ultraviolet rays.

FIG. 8 is a characteristic diagram showing the relationship between the excitation wavelength and the relative emission efficiency for each color phosphor.

9 is a graph and chart showing the results of Experiment 1. FIG.

FIG. 10 is a graph showing the results of experiment 2.

11 is a graph and chart showing the results of Experiment 3. FIG.

FIG. 12 is a graph showing the results of Experiment 4.

FIG. 13 is a schematic sectional view of an AC surface discharge type PDP according to a second embodiment.

FIG. 14 is a schematic cross-sectional view of an AC surface discharge type PDP according to a second embodiment.

[Explanation of symbols]

10 Front panel 11 Front glass substrate 12a, 12b display electrodes 13,23 Dielectric layer 14,24 Protective layer 20 back panel 21 Rear glass substrate 22 Address electrode 30 bulkheads 31 phosphor layer 40 discharge space 61 Address electrode 62,64 Dielectric layer 63a, 63b display electrodes 65 Protective layer 71 address electrode 72,74 Dielectric layer 73a, 73b Display electrodes 75 Protective layer

Front Page Continuation (72) Inventor Yoshiki Sasaki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masaki Aoki, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72 ) Inventor Shinto Kudo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroyuki Kado 1006 Kadoma, Kadoma City, Osaka Prefecture (72) Inventor Takada Yusuke 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References Japanese Patent Laid-Open No. 9-320474 (JP, A) Special Table 8-507645 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) H01J 17/20 H01J 11/00 H01J 11/02

Claims (3)

(57) [Claims] 1. Between a pair of plates arranged to face each other
, A discharge space in which the gas medium is enclosed is formed, and
At least one of the facing surfaces of the pair of plates is electrically charged.
A pole and a phosphor layer are provided, and emit ultraviolet rays when discharged.
The phosphor layer emits light by converting to visible light.
A gas discharge panel, wherein the gas medium is a noble gas containing helium, neon, xenon, and argon.
A mixture of 5% by volume or less xenon and 0.5% by volume or less argon.
Under helium is contained less than 55% by volume, characteristics and be Ruga scan discharge panel that the gas pressure is less than 4000Torr than 800 Torr. 2. The electrode has at least a part thereof covered with a dielectric layer, and the dielectric layer is formed by a thermal chemical vapor deposition method or a plasma chemical vapor deposition method, and has a (100) plane or a (110) plane. The gas discharge panel according to claim 1, wherein the gas discharge panel has a crystal structure oriented in a plane and is covered with a magnesium oxide film having pyramid-shaped irregularities on its surface. 3. The gas discharge panel according to claim 1 or 2.
And a drive circuit that drives the discharge panel by applying a voltage to the electrodes.