JP2003045341A - Plasma discharge display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma discharge display device enabled to discharge at whole surface of a discharge sustain electrode, and to improve brightness and luminous efficiency, which is expected to have a prolonged life. SOLUTION: The plasma discharge display device comprises a first substrate 11, a second substrate 2 arranged so as to form a sealed plasma discharge space 4 between the first substrate 11 and itself, a dielectric layer 14 formed on the plasma discharge space side of the first substrate 11, at least a pair of striped discharge sustain electrodes 12 formed between the first substrate 11 and the dielectric substance layer 14, and a floating electrode 30 located between the discharge sustain electrodes 12, namely, between the first substrate 11 and the dielectric layer 14, which is not electrically connected with the discharge sustain electrodes 12 and external electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma discharge display device, and more particularly to a plasma discharge display device capable of realizing stable discharge and improving emission peak luminance.

[0002]

2. Description of the Related Art Various flat panel display devices have been studied as an image display device to replace a cathode ray tube (CRT) which is currently the mainstream. A liquid crystal display device (LCD), an electroluminescence display device (ELD), and a plasma discharge display device (PDP: plasma display) can be exemplified as such a flat display device. Among them, the plasma discharge display device has advantages such as relatively large screen and wide viewing angle, excellent resistance to environmental factors such as temperature, magnetism, and vibration, and long life. In addition to wall-mounted televisions for home use, it is expected to be applied to large-scale information terminal devices for public use.

In a plasma discharge display device, a voltage is applied to a discharge cell in which a discharge gas composed of a rare gas is sealed in a discharge space, and ultraviolet rays (UV) generated by glow discharge in the discharge gas are generated in the discharge cell. Is a display device that emits light by exciting the phosphor layer. That is, the individual discharge cells are driven by a principle similar to that of a fluorescent lamp, and the discharge cells are usually assembled on the order of hundreds of thousands to form one display screen. Plasma discharge display devices are roughly classified into a DC drive type (DC type) and an AC drive type (AC type) according to a method of applying a voltage to a discharge cell, and each has advantages and disadvantages.

The AC type plasma discharge display device is suitable for high definition because the barrier ribs for partitioning the individual discharge cells in the display screen may be formed in stripes, for example. Moreover, since the surface of the electrode for discharging is covered with the dielectric layer, the electrode has advantages that it is hard to wear and has a long life.

In this AC type plasma discharge display device, there is also known a display device in which a bus electrode is formed along the edge of a pair of transparent discharge sustaining electrodes. The bus electrode is made of a metal film having a lower electric resistance than the discharge sustaining electrode made of a transparent conductive film. This is because the resistance value of the high-resistance discharge sustaining electrode alone becomes too large along the longitudinal direction of the discharge sustaining electrode, which is disadvantageous in manufacturing a large-screen display.

By the way, in such an AC type plasma discharge display device, in the structure of a usual discharge sustaining electrode,
When the filling pressure of the filling gas capable of discharging is increased, the discharge starting voltage increases unless the gap between the sustain electrodes is narrowed. In some cases, discharge cannot be performed.

Therefore, by narrowing the electrode spacing of the sustain electrodes, light emission with a discharge gas having an increased Xe concentration has succeeded, but the discharge starts from the gap of the sustain electrodes and spreads to the metal electrode side which is the bus electrode. This has been confirmed by time-resolved two-dimensional observation. Generally, the discharge starts from the gap between the sustain electrodes and spreads to the metal electrode side which is the bus electrode, but it is difficult to cause the discharge on the entire surface of the electrode.

In order to improve brightness and luminous efficiency, it is desirable to discharge the entire sustain electrode. Each company is making various efforts to improve brightness and luminous efficiency. T
V-shaped electrode (SID'99 DIGEST, pp268-
271), the second sustaining electrode (Japanese Patent No. 3111949),
CSP structure (SID'00 DIGEST, pp102
-105), examination of electrode spacing (SID'00 DIGE
ST, pp106-108).

For example, in the CSP structure, a transparent electrode (ITO) is arranged on a bus electrode (metal electrode) via a dielectric layer to cause capacitive coupling, thereby widening a discharge region to improve brightness and efficiency. I am trying to improve it. However, although this technology has succeeded in improving the brightness and the luminous efficiency, IR (828n
According to the report of the result in m), light emission has not been achieved on the entire surface of the discharge sustaining electrode.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to enable stable discharge to cause light emission on the entire surface of the discharge sustaining electrode and to improve luminance and light emission efficiency. It is an object of the present invention to provide a plasma discharge display device that is capable of achieving a long life.

[0011]

In order to achieve the above object, the plasma discharge display device according to the present invention forms a sealed plasma discharge space between a first substrate and the first substrate. A second substrate disposed on the first substrate, a dielectric layer formed on the surface of the first substrate on the discharge space side, and at least a pair of stripes formed between the first substrate and the dielectric layer. A discharge sustaining electrode, a floating electrode located between the first substrate and the dielectric layer, between the pair of discharge sustaining electrodes, and not electrically connected to the discharge sustaining electrode and an external electrode; , Are included.

In the present invention, the term "between the first substrate and the dielectric layer" is used to include the inside of the dielectric layer. For example, in the present invention, the discharge sustaining electrode or the floating electrode may be located inside the dielectric layer between the first substrate and the dielectric layer, not necessarily in contact with the first substrate.

Preferably, the floating electrode is formed in a stripe shape substantially in parallel with the discharge sustaining electrode. Also,
The floating electrode may have a discontinuous pattern along the longitudinal direction. Further, the floating electrodes may be formed in a pattern of two or more rows between the pair of discharge sustaining electrodes.

The floating electrode may be formed in the same plane position as the discharge sustaining electrode, or may be located inside the dielectric layer on the discharge space side with respect to the discharge sustaining electrode. .

Usually, the discharge sustaining electrode and the floating electrode are each composed of a transparent electrode. A bus electrode having an electrical resistance lower than the electrical resistance of the discharge sustaining electrodes is electrically connected to the pair of discharge sustaining electrodes along the longitudinal direction of the edge of each discharge sustaining electrode. It is preferably formed so as to be connected to.

[0016]

In the present invention, by arranging the discharge sustaining electrode and the continuous electrode or the island electrode of the floating potential which is not connected to the outside between the discharge sustaining electrodes, the advantage of the short interelectrode discharge, that is, the discharge is possible. It is possible to increase the filling pressure of the discharge gas and to perform stable discharge over the entire surface of the electrode for a short time. As a result, the emission peak brightness of ultraviolet light (UV) can be improved.

The floating electrode having this floating potential is maintained in the same plane position as the discharge sustaining electrode, or even if it is positioned inside the dielectric layer on the discharge space side of the discharge sustaining electrode. If capacitively coupled to the electrodes, it works the same. Even if the floating electrode has a continuous pattern, a discontinuous pattern, or a pattern of two or more rows along the longitudinal direction, it is equivalent as long as it is capacitively coupled to the discharge sustaining electrode. To work.

The discharge sustaining electrode and the floating electrode having a floating potential are capacitively coupled, and have the same function as if the interval between the discharge sustaining electrodes is narrow. Further, because of this capacitive coupling, once discharge occurs, discharge occurs on the entire surface of one of the sustain electrodes. The discharge on the entire surface of the electrode is completed within a short time from the start of discharge.

In the present invention, when the sustaining electrodes and the floating electrodes are transparent, the display light is not blocked, which is more convenient. Moreover, by providing each discharge sustaining electrode with a bus electrode, the resistance value along the longitudinal direction of the discharge sustaining electrode can be reduced, and a large-screen display can be manufactured.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in the drawings. 1 is a cross-sectional view of a main part of a plasma discharge display device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the main part of a first panel shown in FIG. 1, and FIG.
FIG. 4 is a plan view showing the positional relationship between the discharge sustaining electrodes, bus electrodes, and floating electrodes along the line, FIG. 4 is a cross-sectional view of the main part of the first panel in the plasma discharge display device according to another embodiment of the present invention, and FIG. FIG. 6 is a plan view showing a positional relationship among a discharge sustain electrode, a bus electrode and a floating electrode in a plasma discharge display device according to another embodiment of the invention, and FIG. 6 is a discharge sustain electrode in a plasma discharge display device according to another embodiment of the present invention. FIG. 7 is a plan view showing a positional relationship between the bus electrode and the floating electrode, and FIG. 7 is a photograph showing a light emitting state of the plasma discharge display device according to the embodiment of the present invention.

Overall Structure of Plasma Flat Display Device First, the overall structure of an AC-driven (AC) type planar plasma discharge display device (hereinafter, may be simply referred to as a plasma display device) will be described with reference to FIG. The AC type plasma display device 2 shown in FIG. 1 belongs to a so-called three-electrode type, and a discharge is generated between a pair of discharge sustaining (scanning) electrodes 12. This AC type plasma display device 2 is formed by laminating a first panel 10 corresponding to a front panel and a second panel 20 corresponding to a rear panel. Second panel 20
The light emission of the upper phosphor layers 25R, 25G, 25B is observed, for example, through the first panel 10. That is, the first panel 10 is the display surface side.

The first panel 10 includes a transparent first substrate 11
And a plurality of pairs of discharge sustaining electrodes 12 made of a transparent conductive material, which are provided on the first substrate 11 in a stripe shape, and provided to reduce the impedance of the discharge sustaining electrodes 12. The bus electrode 13 made of a material having a low resistivity, the dielectric layer 14 formed on the first substrate 11 including the bus electrode 13 and the discharge sustaining electrode 12, and the protective layer 15 formed thereon. It is configured. The protective layer 15 is not necessarily formed, but is preferably formed.

In this embodiment, as shown in FIGS. 2 and 3, the floating electrode 30 is provided between each pair of discharge sustaining electrodes 12.
However, it is formed in a stripe pattern on the same plane as the discharge sustaining electrodes 12 and substantially parallel to the discharge sustaining electrodes 12. The floating electrode 30 is made of the same transparent conductive material as the discharge sustaining electrode 12, and the discharge sustaining electrode 12 is formed on the first substrate 1
It can be formed simultaneously when forming a predetermined pattern on the inner surface of 1. The floating electrode 30 is not electrically connected to the discharge sustaining electrode 12 or any other electrode, and has a floating potential in terms of potential. The positional relationship between the discharge sustaining electrode 12 and the floating electrode 30 will be described later.

On the other hand, the second panel 20 includes a second substrate 21.
A plurality of address electrodes (also referred to as data electrodes) 22 provided in stripes on the second substrate 21, and a dielectric film (not shown) formed on the second substrate 21 including the address electrodes 22. , An insulating partition wall 24 extending in parallel with the address electrode 22 in a region between the adjacent address electrodes 22 on the dielectric film, and fluorescent light provided over the dielectric film and the sidewall surface of the partition wall 24. It is composed of a body layer. The phosphor layers are the red phosphor layer 25R and the green phosphor layer 2
5G, and a blue phosphor layer 25B.

FIG. 1 is a partially exploded perspective view of the display device. Actually, the top of the partition wall 24 on the second panel 20 side is in contact with the protective layer 15 on the first panel 10 side. The region where the pair of discharge sustaining electrodes 12 and the address electrode 22 located between the two barrier ribs 24 overlap corresponds to a single discharge cell. Then, the adjacent partition wall 24 and the phosphor layer 25R,
A discharge gas is enclosed in the discharge space 4 surrounded by 25G and 25B and the protective layer 15. 1st panel 1
The 0 and the second panel 20 are joined at their peripheral portions by using frit glass. The discharge gas sealed in the discharge space 4 is not particularly limited, but may be xenon (Xe) gas, neon (Ne) gas, helium (He) gas, argon (Ar) gas, nitrogen (N ₂ ) gas, or the like. An inert gas or a mixed gas of these inert gases is used. The total pressure of the enclosed discharge gas is not particularly limited, but is 6 × 10 ³ Pa to 8 × 10 ⁴
It is about Pa.

The direction in which the projected image of the discharge sustaining electrodes 12 extends and the direction in which the projected image of the address electrodes 22 extends are substantially orthogonal (although they do not necessarily have to be orthogonal), and the pair of discharge sustaining electrodes 12 and the three primary colors. Emitting phosphor layers 25R, 25
An area where one set of G and 25B overlaps corresponds to one pixel (one pixel). Glow discharge is a pair of discharge sustaining electrodes 12
This type of plasma display device is referred to as a "surface discharge type" because it occurs in between. Immediately before applying a voltage between the pair of discharge sustaining electrodes 12, for example, by applying a panel voltage lower than the discharge starting voltage of the discharge cells to the address electrodes 22, wall charges are accumulated in the discharge cells (display Selection of discharge cells to be performed), the apparent discharge start voltage decreases. Then, the discharge started between the pair of discharge sustaining electrodes 12 may be maintained at a voltage lower than the discharge starting voltage. In the discharge cell, the phosphor layer excited by the irradiation of vacuum ultraviolet rays generated by glow discharge in the discharge gas exhibits a specific emission color according to the type of the phosphor layer material. In addition, vacuum ultraviolet rays having a wavelength corresponding to the type of the enclosed discharge gas are generated.

The plasma display device 2 of the present embodiment is a so-called reflection type plasma display device, and includes a phosphor layer 25R,
Since the light emission of 25G and 25B is observed through the first panel 10, the conductive material forming the address electrode 22 may be transparent or opaque.
2 and the conductive material forming the floating electrode 30 need to be transparent. In addition, the transparency / opacity described here means
It is based on the light transmittance of the conductive material in the emission wavelength (visible light range) peculiar to the phosphor layer material. That is, if it is transparent to the light emitted from the phosphor layer, it can be said that the conductive material forming the discharge sustaining electrodes and the address electrodes is transparent.

As the opaque conductive material, Ni, Al,
Au, Ag, Al, Pd / Ag, Cr, Ta, Cu, B
Materials such as a, LaB ₆ , Ca _0.2 La _0.8 CrO _{3 and the} like can be used alone or in appropriate combination.
Examples of the transparent conductive material include ITO (indium / tin oxide) and SnO ₂ . The discharge sustaining electrode 12, the floating electrode 30, or the address electrode 22 can be formed by a sputtering method, a vapor deposition method, a screen printing method, a sandblast method, a plating method, a lift-off method, or the like. The electrode width W1 of the discharge sustaining electrode 12 is not particularly limited, but is about 40 to 400 μm. Further, the distance (discharge gap) W2 between the electrodes 12 forming the pair
Is not particularly limited, but is preferably 5 to 150 μm,
More preferably, it is about 20 to 100 μm. Also,
The width of the address electrode 22 is, for example, about 40 to 100 μm.

The bus electrode 13 is typically a metallic material,
For example, Ag, Au, Al, Ni, Cu, Mo, Cr
It can be composed of a single layer metal film such as or a laminated film of Cr / Cu / Cr or the like. In the reflection type plasma display device, the bus electrode 13 made of such a metal material reduces the amount of visible light that is emitted from the phosphor layer and passes through the first substrate 11 to reduce the brightness of the display screen. Therefore, it is preferable to form the discharge sustaining electrode as thinly as possible within the range in which the required electric resistance value can be obtained. Specifically, the electrode width W3 of the bus electrode 13 is smaller than the electrode width W1 of the discharge sustaining electrode 12 and is, for example, about 30 to 200 μm. Bus electrode 1
3 can be formed by a sputtering method, a vapor deposition method, a screen printing method, a sandblast method, a plating method, a lift-off method, or the like.

The stripe-shaped floating electrode 30 is formed in the same manner as the discharge sustaining electrode 12, and its electrode width W4 is smaller than the discharge gap W2, preferably 1 μm or more. If the electrode width W4 of the floating electrode 30 is too small,
The effect of the present invention is small. Further, the gap W5 between the floating electrode 30 and the discharge sustaining electrode 12 is preferably 1 to 4
It is 0 μm. If the gap W5 is too small, a short circuit may occur between them, and if the gap W5 is too large, the discharge gap W2 becomes too large, which is not preferable. The gap W5 may be the same or different on both sides of the floating electrode 30.

The dielectric layer 14 formed on the surface of the discharge sustaining electrode 12 is preferably formed by, for example, an electron beam evaporation method, a sputtering method, an evaporation method, a screen printing method or the like. By providing the dielectric layer 12, it is possible to prevent ions and electrons generated in the discharge space 4 from coming into direct contact with the discharge sustaining electrode 12. As a result, wear of the discharge sustaining electrode 12 can be prevented. The dielectric layer 14 has a function of accumulating wall charges generated by discharge, a so-called memory function, and a function as a resistor that limits an excessive discharge current. Dielectric layer 14
Can typically be constructed from low melting glass, but can also be formed using other dielectric materials.

Formed on the surface of the dielectric layer 14 on the discharge space side
A certain protective layer 15 is provided between the ions and electrons and the discharge sustaining electrode.
It has the effect of preventing intimate contact. As a result,
Wear of the pole 12 can be effectively prevented. Also protection
The layer 15 also has a function of emitting secondary electrons necessary for discharging
It As a material for forming the protective layer 15, magnesium oxide is used.
(MgO), magnesium fluoride (MgF)_Two),
Calcium oxide (CaF _Two) Can be illustrated. During ~
But magnesium oxide is chemically stable,
Low tarring rate and light transmission at the emission wavelength of the phosphor layer
Suitable for having features such as high rate and low discharge starting voltage
It is a material. The protective layer 15 is made of these materials.
Composed of at least two materials selected from the group
It may have a laminated film structure.

As a constituent material of the first substrate 11 and the second substrate 21, high strain point glass and soda glass (Na ₂ O.C) are used.
aO ・ SiO ₂ ), borosilicate glass (Na ₂ O ・ B ₂ O ₃
・ SiO ₂ ), forsterite (2MgO ・ Si
O _2), can be exemplified lead glass _{(Na 2 O · PbO · SiO} 2). The constituent materials of the first substrate 11 and the second substrate 21 may be the same or different.

The phosphor layers 25R, 25G, 25B are, for example, phosphors selected from the group consisting of a phosphor layer material that emits red light, a phosphor layer material that emits green light, and a phosphor layer material that emits blue light. It is made of a layer material and is provided above the address electrode 22. When the plasma display device is a color display, specifically, for example, a phosphor layer (red phosphor layer 25R) made of a phosphor layer material that emits red light is provided above the address electrode 22 to display a green color. A phosphor layer (green phosphor layer 25G) composed of a phosphor layer material that emits light is provided above another address electrode 22, and a phosphor layer composed of a phosphor layer material that emits blue light (blue phosphor). Body layer 25B) is further address electrode 2
2 is provided above, and one set of phosphor layers that emit these three primary colors is provided in a predetermined order. Then, as described above, the pair of discharge sustaining electrodes 1
2 and a set of phosphor layers 25 that emit these three primary colors
The area where R, 25G, and 25B overlap corresponds to one pixel (one display cell). The red phosphor layer, the green phosphor layer, and the blue phosphor layer may be formed in a stripe shape or a grid shape.

As the phosphor layer material forming the phosphor layers 25R, 25G and 25B, a phosphor layer material having a high quantum efficiency and a low saturation with respect to vacuum ultraviolet rays is appropriately selected from conventionally known phosphor layer materials. Can be used. In the case of color display, the color purity is close to the three primary colors specified by NTSC, the white balance is good when the three primary colors are mixed, the afterglow time is short, and the afterglow times of the three primary colors are almost equal. It is preferred to combine the layer materials.

Specific examples of the phosphor layer material are shown below.
For example, as a phosphor layer material that emits red light, (Y_TwoO
_Three: Eu), (YBO_ThreeEu), (YVO_Four: Eu),
(Y _0.96P_0.60V_0.40O_Four: E
u_0.04), [(Y, Gd) BO_Three: Eu], (Gd
BO_Three: Eu), (ScBO_Three: Eu), (3.5Mg
O ・ 0.5MgF_Two・ GeO_Two: Mn), emits green light
As a phosphor layer material for_Two: Mn), (B
aA1₁₂O₁₉: Mn), (BaMg_TwoA1₁₆O
₂₇: Mn), (MgGa_TwoO_Four: Mn), (YB
O_Three: Tb), (LuBO_Three: Tb), (Sr_FourSi_Three
O₈Cl_Four: Eu), as a phosphor layer material that emits blue light
, (Y_TwoSiO₅: Ce), (CaWO_Four: Pb),
CaWO_Four, YP_0.85V_0.15O_Four, (BaMg
A1₁₄O₂₃: Eu), (Sr_TwoP_TwoO₇: Eu),
(Sr_TwoP_TwoO₇: Sn) and the like.

As the method of forming the phosphor layers 25R, 25G, 25B, a thick film printing method, a method of spraying phosphor layer particles, an adhesive substance is attached in advance to the site where the phosphor layer is to be formed, and the phosphor layer is formed. A method of attaching particles, a method of using a photosensitive phosphor layer paste, patterning the phosphor layer by exposure and development, and a method of forming a phosphor layer on the entire surface and then removing unnecessary portions by sandblasting You can

The phosphor layers 25R, 25G, 25B may be directly formed on the address electrode 22, or
It may be formed over the address electrode 22 and the side wall surface of the partition wall 24. Alternatively, the phosphor layer 25R,
25G and 25B may be formed on the dielectric film provided on the address electrode 22 or the address electrode 22.
It may be formed over the dielectric film provided on the sidewall surface of the partition wall 24. Furthermore, the phosphor layer 25R,
25G and 25B may be formed only on the side wall surface of the partition wall 24. Examples of the constituent material of the dielectric film include low melting point glass and SiO ₂ .

As described above, the partition walls 24 (ribs) extending in parallel with the address electrodes 22 are formed on the second substrate 21. The partition wall (rib) 24 may have a meander structure. When the dielectric film is formed on the second substrate 21 and the address electrode 22, the partition wall 24 may be formed on the dielectric film. As a constituent material of the partition wall 24, a conventionally known insulating material can be used. For example, a widely used low-melting glass mixed with a metal oxide such as alumina can be used. The partition wall 24 has a width of, for example, about 50 μm or less, preferably 10 to 35 μm, and a height of 300 μm or less, preferably about 100 to 200 μm. The pitch interval of the partition walls 24 is, for example, about 50 to 400 μm, preferably 150 μm or less. The method of forming the partition wall 24 will be described later.

A pair of partition walls 2 formed on the second substrate 21.
4, the discharge sustaining electrode 12, the address electrode 22, and the phosphor layer 25 occupying the area surrounded by the pair of barrier ribs 24.
One discharge cell is composed of R, 25G, and 25B. And, inside such a discharge cell, more specifically,
A discharge gas composed of a mixed gas is enclosed in the discharge space surrounded by the partition walls, and the phosphor layers 25R, 25
G and 25B emit light by being irradiated with ultraviolet rays generated by the AC glow discharge generated in the discharge gas in the discharge space 4.

Manufacturing Method of Plasma Display Device Next, a manufacturing method of the plasma display device according to the embodiment of the present invention will be described. The first panel 10 can be manufactured by the following method. First, an ITO layer is formed on the entire surface of the first substrate 11 made of high strain point glass or soda glass by, for example, a sputtering method, and the ITO layer is patterned into stripes by a photolithography technique and an etching technique to maintain a pair of discharges. A plurality of electrodes 12 and a plurality of floating electrodes 30 formed between them are formed. Discharge sustaining electrode 12 and floating electrode 30
Extend in a stripe shape in the first direction.

Next, an aluminum film is formed on the entire inner surface of the first substrate 11 by, for example, a vapor deposition method, and the aluminum film is patterned by a photolithography technique and an etching technique.
The bus electrodes 13 are formed along the edges of the. Then, SiO 2 is formed on the entire inner surface of the first substrate 11 on which the bus electrodes 13 are formed.
_A dielectric layer 14 composed of ₂ is formed, and a thickness of 0.6 μm is formed on the dielectric layer 14 by electron beam evaporation or sputtering.
A protective layer 15 made of m magnesium oxide (MgO) is formed. The first panel 10 can be completed through the above steps.

The second panel 20 is manufactured by the following method. First, the second one made of high strain point glass and soda glass
The address electrodes 22 are formed by printing a silver paste in a stripe shape on the substrate 21 by, for example, a screen printing method and baking the same. Address electrode 22
Extend in a second direction orthogonal to the first direction. Next, a low melting point glass paste layer is formed on the entire surface by a screen printing method, and the low melting point glass paste layer is baked to form a dielectric film.

After that, the partition wall 24 having a fine stripe pattern is formed on the dielectric film above the region between the adjacent address electrodes 22. Examples of the method of forming the partition wall 24 include a screen printing method, a sandblast method, a dry film method, and a photosensitive method. The dry film method is a method of laminating a photosensitive film on a substrate, removing the photosensitive film at the planned partition wall formation site by exposure and development, embedding a partition wall forming material in the opening formed by the removal, and baking the material. Is. The photosensitive film is burned and removed by firing, and the partition wall forming material embedded in the openings remains to form partition walls 24. The photosensitive method is a method in which a material layer for forming partition walls having photosensitivity is formed on a substrate, the material layer is patterned by exposure and development, and then baking is performed.

Next, the partition wall 24 formed on the second substrate 21.
In the meantime, three primary color phosphor layer slurries are sequentially printed. Then, the second substrate 21 is baked in a baking furnace to form the partition wall 24.
Phosphor layers 25R, 25G, and 25B are formed on the dielectric film between and on the side wall surface of the partition wall 24. The firing (fluorescent substance firing step) temperature at that time is about 510 ° C.
The firing time is about 10 minutes.

Next, the plasma display device is assembled. That is, first, for example, by screen printing, the second
A sealing layer is formed on the peripheral portion of the panel 20. Next, FIG.
As shown in, the first panel 10 and the second panel 20 are bonded together and fired to cure the seal layer. After that, the space formed between the first panel 10 and the second panel 20 is evacuated, then the discharge gas is filled, and the space is sealed to complete the plasma display device 2.

An example of the AC glow discharge operation of the plasma display device having such a configuration will be described. First, for example,
The discharge start voltage Vbd is applied to all one of the sustaining electrodes 12.
A higher panel voltage is applied for a short time. This causes glow discharge, wall charges are generated on the surface of the dielectric layer 14 near one of the discharge sustaining electrodes due to dielectric polarization, the wall charges are accumulated, and the apparent discharge start voltage is lowered. Thereafter, while applying a voltage to the address electrode 22, a voltage is applied to one of the discharge sustaining electrodes 12 included in the discharge cell which is not displayed, whereby a glow discharge is generated between the address electrode 22 and the one sustaining electrode 12. And the accumulated wall charges are erased. This erase discharge is sequentially executed at each address electrode 22. On the other hand, no voltage is applied to one of the sustain electrodes included in the discharge cell for displaying. This maintains the accumulation of wall charges. afterwards,
By applying a predetermined pulse voltage between all the pair of discharge sustaining electrodes 12, glow discharge starts between the pair of discharge sustaining electrodes 12 in the cell in which the wall charges are accumulated, and in the discharge cell, The phosphor layer excited by the irradiation of the vacuum ultraviolet rays generated by the glow discharge in the discharge gas in the discharge space exhibits a unique emission color according to the type of the phosphor layer material. Note that the phases of the discharge sustaining voltages applied to the one discharge sustaining electrode and the other discharge sustaining electrode are shifted by a half cycle, and the polarities of the electrodes are inverted according to the alternating current frequency.

Plasma discharge display device 2 according to the present embodiment
According to the manufacturing method of (1), the following effects are exhibited. That is, by arranging the discharge sustaining electrode 12 and the floating electrode 30 having a floating potential that is not connected to the outside between the discharge sustaining electrodes 12, the advantage of short-electrode discharge, that is, the dischargeable gas filling pressure capable of discharging is increased. As a result, the entire surface of the electrode can be discharged for a short time. As a result, ultraviolet light (U
The emission peak brightness of V) can be improved.

The floating electrode 30 having this floating potential is capacitively coupled to the discharge sustaining electrodes 12, and functions as if the space between the discharge sustaining electrodes 12 is narrow. Further, due to this capacitive coupling, once discharge occurs, discharge occurs on the entire surface of one sustain electrode 12.
The discharge on the entire surface of the electrode is completed within a short time from the start of discharge. For example, the discharge is generated on the entire surface of the electrode in about 0.1 μsec after the start of discharge, and the discharge of the entire surface of the electrode is finished after 0.2 to 0.7 μsec.

Other Embodiments The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention.

For example, in the present invention, as shown in FIG. 4, the floating electrode 30a may be located inside the dielectric layer 14 on the discharge space side of the discharge sustaining electrode 12. Even in that case, since the floating electrode 30a is capacitively coupled to the discharge sustaining electrode 12, the floating electrode 30a functions similarly to the embodiment shown in FIGS.

Further, as shown in FIG. 5, the floating electrode 30b
May have a discontinuous island pattern along the longitudinal direction. The longitudinal gap W6 of the island pattern is determined such that at least one island-shaped floating electrode 30b is formed for each display cell. Even in that case, since the floating electrode 30b is capacitively coupled to the discharge sustaining electrode 12, the floating electrode 30b has the same function as that of the embodiment shown in FIGS.

Further, as shown in FIG. 6, a floating electrode 30c having a pattern of two or more rows may be used. In this case, the distance W6 between the floating electrodes 30c is equal to
It is preferable that the distance W5 between c and the sustaining electrode 12 is narrower. Even in this case, since the floating electrode 30c is capacitively coupled to the discharge sustaining electrode 12, as shown in FIG.
It functions in the same way as the embodiment shown in FIG.

In the present invention, the specific structure of the plasma display device is not limited to the embodiment shown in FIG.
Other structures may be used. For example, in the plasma display device of the above-described embodiment, the first panel 10 is the display panel side and is a so-called reflection type plasma display device, but the plasma display device of the present invention is a so-called transmission type plasma display device. May be. However, in the transmissive plasma display device, since the light emission of the phosphor layer is observed through the second panel 20, it does not matter whether the conductive material forming the discharge sustaining electrode is transparent or opaque. Since the address electrodes are provided on the second substrate 21, the address electrodes need to be transparent.

[0055]

EXAMPLES The present invention will be described below based on more detailed examples, but the present invention is not limited to these examples.

Example 1 The first panel 10 was manufactured by the following method. First, an ITO layer is formed on the entire surface of the first substrate 11 made of high strain point glass or soda glass by, for example, a sputtering method, and IT is formed by a photolithography technique and an etching technique.
By patterning the O layer in a stripe pattern,
A pair of discharge sustaining electrodes 12 and a plurality of floating electrodes 30 formed between them were formed.

Next, an aluminum film is formed on the entire inner surface of the first substrate 11 by, for example, a vapor deposition method, and the aluminum film is patterned by a photolithography technique and an etching technique.
The bus electrode 13 was formed along the edge of the.

After that, a dielectric layer 14 made of a silicon oxide (SiO ₂ ) layer was formed on the entire inner surface of the first substrate 11 on which the bus electrodes 13 were formed. Next, a protective layer 15 made of magnesium oxide (MgO) having a thickness of 0.6 μm was formed on the dielectric layer 14 made of the silicon oxide layer by an electron beam evaporation method. The first panel 10 was completed through the above steps.

The second panel 20 was manufactured by the following method. First, the second one made of high strain point glass and soda glass
The address electrode 22 was formed on the substrate 21 by printing a silver paste in a stripe shape by, for example, a screen printing method and baking it. Address electrode 22
Extend in a second direction orthogonal to the first direction. Next, a low melting point glass paste layer is formed on the entire surface by a screen printing method, and this low melting point glass paste layer is formed,
A dielectric film was formed by firing this low melting point glass paste layer.

Then, a low melting point glass paste was printed on the dielectric film above the region between the adjacent address electrodes 22 by, for example, a screen printing method. Then, the second substrate 21 was fired in a firing furnace to form the partition wall 24. The firing (partition wall firing step) at this time is performed in air,
The firing temperature was about 560 ° C, and the firing time was about 2 hours.

Next, the partition wall 24 formed on the second substrate 21.
In the meantime, three primary color phosphor layer slurries were sequentially printed. Then, the second substrate 21 is baked in a baking furnace to form the partition wall 24.
The phosphor layers 25R, 25G, and 25B were formed on the dielectric film between them and on the side wall surfaces of the partition walls 24, and baked at 510 ° C. for 10 minutes to complete the second panel 20.

Next, the plasma display device was assembled. That is, first, by screen printing, the second panel 2
A seal layer was formed on the peripheral portion of 0. Next, the first panel 1
0 and the second panel 20 were attached and fired to cure the seal layer. Then, the first panel 10 and the second panel 2
After evacuating the space formed between the plasma display device 2 and the plasma display device 2, a discharge gas composed of Ne-Xe gas (Ne: 96% by volume / Xe: 4% by volume) is sealed at a gas pressure of 66.6 kPa. Was completed.

The pattern of the floating electrode is shown in FIG.
The floating electrode 30b having an island pattern as shown in FIG.
The electrode width W4 of the floating electrode 30b is 30 μm, the discharge gap W2 is 70 μm, and the distance W5 between the floating electrode 30b and the discharge sustaining electrode 12 is 20 μm.
Met.

A driving test was conducted on this plasma display device 2 under the conditions of an applied voltage of 244 V and a cycle of 8 μsec.
The luminescence phenomenon was photographed and observed. FIG. 7 shows an emission state at 828 nm (0.9 μsec after the start of discharge) which is said to be equivalent to ultraviolet emission at 147 nm. It was confirmed that the light emission spreads over the entire surface of the sustain (scan) electrode within 0.1 μsec. It was also confirmed that the discharge on the entire surface of the electrode was completed 0.2 to 0.7 μs after the start of discharge.

This is the effect of the island-shaped floating electrode. From this, it was confirmed that the display device can be expected to have improved brightness.

[0066]

As described above, according to the present invention, since discharge light emission occurs on the entire surface of the discharge sustaining electrode, a dramatic improvement in brightness can be expected. Similarly, improvement in luminous efficiency can be expected.

Further, in the present invention, since light emission occurs on the entire surface of the electrode in a short time, the pulse sustaining time for expanding the discharge region is shortened, and the sustain frequency can be raised.
Further improvement in brightness can be expected. Further, since the brightness can be dramatically improved, the display time period can be shortened if the brightness is the same, and the number of display subfields can be expected to increase. Further, according to the present invention, since the discharge region of the discharge sustaining electrode is expanded, the breakdown of the protective film and / or the dielectric layer due to discharge sputtering is reduced, and the life of the display device can be expected to be extended.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a plasma discharge display device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an essential part of the first panel shown in FIG.

FIG. 3 is a plan view showing the positional relationship between the discharge sustaining electrodes, the bus electrodes and the floating electrodes along the line III-III shown in FIG.

FIG. 4 is a cross-sectional view of an essential part of a first panel in a plasma discharge display device according to another embodiment of the present invention.

FIG. 5 is a plan view showing a positional relationship among discharge sustain electrodes, bus electrodes and floating electrodes in a plasma discharge display device according to another embodiment of the present invention.

FIG. 6 is a plan view showing a positional relationship among discharge sustain electrodes, bus electrodes and floating electrodes in a plasma discharge display device according to another embodiment of the present invention.

FIG. 7 is a photograph showing a light emitting state of a plasma discharge display device according to an embodiment of the present invention.

[Explanation of symbols]

2 ... Plasma display device 4 ... Discharge space 10 ... First panel 11 ... First substrate 12 ... Discharge sustaining electrode 13 ... Bus electrode 14 ... Dielectric layer 15 ... Protective layer 20 ... Second panel 21 ... Second substrate 22 ... Address electrode 24 ... Partition wall 25R, 25G, 25B ... Phosphor layer 30, 30a, 30b, 30c ... Floating electrodes

Claims (8)

[Claims] 1. A first substrate, a second substrate disposed so as to form a sealed plasma discharge space between the first substrate, and a surface of the first substrate on the discharge space side. A dielectric layer formed between the first substrate and the dielectric layer, at least a pair of discharge sustaining electrodes formed in stripes between the first substrate and the dielectric layer, and between the first substrate and the dielectric layer, And a floating electrode that is located between the discharge sustaining electrodes and is not electrically connected to the discharge sustaining electrodes and external electrodes. 2. The plasma discharge display device according to claim 1, wherein the floating electrode is formed in a stripe shape substantially in parallel with the discharge sustaining electrode. 3. The plasma discharge display device according to claim 1, wherein the floating electrode has a discontinuous pattern along the longitudinal direction. 4. The floating electrodes are formed in a pattern of two or more rows between the pair of discharge sustaining electrodes.
4. The plasma discharge display device according to any one of 3 to 3. 5. The plasma discharge display device according to claim 1, wherein the floating electrode is formed at a substantially same plane position as the discharge sustaining electrode. 6. The plasma discharge display device according to claim 1, wherein the floating electrode is located inside the dielectric layer on the discharge space side with respect to the discharge sustaining electrode. 7. The plasma discharge display device according to claim 1, wherein the discharge sustaining electrode and the floating electrode are each formed of a transparent electrode. 8. A bus electrode having an electric resistance lower than the electric resistance of the discharge sustaining electrodes is provided in the pair of discharge sustaining electrodes along a longitudinal direction of an edge portion of each of the discharge sustaining electrodes. The plasma discharge display device according to claim 7, wherein the plasma discharge display device is formed so as to be electrically connected to.