JP2001110324A - Plasma display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide plasma display unit that can prevent brightness from lowering even by making density and precision higher. SOLUTION: AC driving type plasma display unit is equipped with a first panel composed of the first substrate, an electrode group consisting of a plurality of electrodes and a protection layer, and a second panel composed of the second substrate, a fluorescent layer and barrier ribs, the said paired electrodes facing each other comprise (A) the first trunk line 12A, (B) the second trunk line 12B extending in parallel to the said first trunk line 12A, (C) the first branch electrode 13A extending between barrier ribs 25 from the first trunk line 12A toward the second trunk line 12B until before it and (D) the second branch electrode 13B extending in parallel to the first branch electrode 13A between barrier ribs 25 from the second trunk line 12B toward the first trunk line 12A until before it; and cause a discharge between the pair of the first and second branch electrodes 13A and 13B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC drive type plasma display device.

[0002]

2. Description of the Related Art Various types of flat-panel (flat-panel) display devices have been studied as image display devices to replace the current mainstream cathode ray tube (CRT). Examples of such a flat display device include a liquid crystal display device (LCD), an electroluminescence display device (ELD), and a plasma display device (PDP: plasma display). Above all, the plasma display device has advantages such as relatively easy enlargement of the screen and wide viewing angle, excellent resistance to environmental factors such as temperature, magnetism and vibration, and long life. It is expected to be applied not only to home wall-mounted TVs but also to large public information terminals.

In a plasma display device, light is obtained by applying a voltage to a discharge cell containing a rare gas and exciting a phosphor layer in the discharge cell with ultraviolet rays generated based on a glow discharge in the rare gas. A display device. 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 in the order of several hundred thousand to form one display screen. Plasma display devices are roughly classified into a direct current drive type (DC type) and an alternating current 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 display device is suitable for high definition because partition walls which serve to partition individual discharge cells in a display screen may be formed in a stripe shape, for example. In addition, since the surface of the electrode is covered with the dielectric material, the electrode is less likely to be worn and has a long life.

FIG. 6 shows a typical configuration example of a conventional AC plasma display device. This AC type plasma display device belongs to a so-called three-electrode type, and discharge mainly occurs between a pair of discharge sustaining electrodes 113. The AC-type plasma display device shown in FIG. 6 has a front panel 10 and a rear panel 20 bonded together at a peripheral portion. Phosphor layer 24 on rear panel 20
Is observed through the front panel 10.

[0005] A front panel 10 is provided on a transparent first substrate 11 and in a stripe shape on the first substrate 11.
A pair of discharge sustaining electrodes 113 made of a transparent conductive material
A bus electrode 112 made of a material having a lower electrical resistivity than the discharge sustaining electrode 113, provided to reduce the impedance of the sustaining electrode 113;
And a protective layer 14 functioning as a dielectric film formed on the first substrate 11 including the discharge sustaining electrodes 113.

On the other hand, the rear panel 20 includes a second substrate 21
An address electrode (also referred to as a data electrode) 22 provided on the second substrate 21 in a stripe shape; a dielectric film 23 formed on the second substrate 21 including the address electrode 22; An insulating partition wall 25 extending in parallel with the address electrode 22 in a region between the adjacent address electrodes 22 on the film 23, and a fluorescent light provided from the dielectric film 23 to the side wall surface of the partition wall 25. And the body layer 24. The phosphor layer 24 is composed of a red phosphor layer 24R, a green phosphor layer 24G, and a blue phosphor layer 24B.
Are provided in a predetermined order. FIG. 6 is an exploded perspective view. In fact, the top of the partition 25 on the rear panel 20 is in contact with the protective layer 14 on the front panel 10.
A region where the pair of discharge sustaining electrodes 113 and the address electrode 22 located between the two partition walls 25 overlap corresponds to a discharge cell. Then, the adjacent partition wall 25 and phosphor layer 24
A rare gas is sealed in a space surrounded by the protective layer 14 and the protective layer 14.

The direction in which the sustaining electrode 113 extends and the direction in which the address electrode 22 extends form an angle of 90 °. A pair of adjacent sustaining electrodes 113 and the phosphor layers 24R and 24G that emit light of three primary colors are formed. , 24B correspond to one pixel. Since a glow discharge is generated between a pair of adjacent sustain electrodes 113, this type of plasma display device is called a "surface discharge type". In the discharge cell, a phosphor layer excited by irradiation with vacuum ultraviolet light generated based on a glow discharge in a rare gas,
It emits a specific emission color according to the type of the phosphor material. still,
Vacuum ultraviolet rays having a wavelength corresponding to the type of the rare gas enclosed are generated.

In the conventional plasma display device shown in FIG. 6, a discharge sustaining electrode 113, a bus electrode 112 and a partition wall 25 are formed.
7 is schematically shown in FIG. Note that a region surrounded by a dotted line corresponds to one pixel. Also, hatching is used to clarify each area. The outer shape of one pixel is substantially square. One pixel is divided into three sections (cells) by a partition 25, and each of the sections emits one of the three primary colors (R, G, B). When the external dimensions of one pixel was set to L _0, the size of each compartment is a small dimension slightly larger than _{(L 0/3) × (} L 0). Accordingly, the pair of discharge sustaining electrodes 11
In 3, the length of the portion 113A of contributing to the discharge sustain electrodes 113 slightly shorter than (L _0/3).

FIG. 8 schematically shows an example in which the arrangement of the sustain electrode 113, the bus electrode 112, and the partition wall 25 in the conventional plasma display device is modified. This modification is disclosed in JP-A-9-167565. This modification has a structure in which a discharge sustaining electrode 113 extends from each of a pair of bus electrodes 112 toward another bus electrode.

[0010]

By the way, the plasma table
In display devices, the density of pixels and the resolution
Demands are growing. To address such demands
Is the external dimension L of one pixel ₀I have to make the value of
No. As a result, a discharge occurs at the pair of discharge sustaining electrodes 113.
Length of the portion contributing to electricity [approximately (L₀/ 3)] is short
Discharge area, and the brightness of the plasma display decreases.
Problem arises.

Accordingly, an object of the present invention is to cope with high density and high definition, and even if the size of one pixel is reduced, the length of a portion contributing to discharge in a pair of discharge sustaining electrodes can be sufficiently increased. It is an object of the present invention to provide a plasma display device which can be ensured at a high density, that is, a plasma display device which can prevent a reduction in luminance even with high density and high definition.

[0012]

According to the present invention, there is provided an AC-driven plasma display device which achieves the above object.
A first panel including a first substrate, an electrode group including a plurality of electrodes provided on the first substrate, and a protective layer formed on the first substrate including the electrode group; as well as,
(B) a second substrate, a phosphor layer provided above the second substrate, and a partition wall extending at a predetermined angle to a direction in which the electrodes extend and provided between adjacent phosphor layers. And a pair of electrodes facing each other,
(A) a first main line, (B) a second main line extending in parallel with the first main line, (C) a first main line to a second main line between partition walls. And the first branch electrode extending to the front of the second trunk line, and (D) between the partition walls, from the second trunk line to the first trunk line, and , A second branch electrode extending in front of the first main wiring and facing the first branch electrode, and generates a discharge between the pair of the first branch electrode and the second branch electrode. It is characterized by the following. Note that the plurality of electrodes provided on the first substrate are referred to as a first electrode for convenience, and an electrode group including the plurality of first electrodes is referred to as a first electrode group.

Here, in the AC-driven plasma display device of the present invention, the first panel and the second panel are arranged so as to face each other such that the protective layer and the phosphor layer face each other, and each main wiring is connected to the other. The extending direction and the extending direction of each partition make a predetermined angle (for example, 90 °), and a rare gas is sealed in a space surrounded by the protective layer, the phosphor layer, and the pair of partitions. The layer has a structure that emits light by being irradiated with ultraviolet light generated based on an alternating current glow discharge in a rare gas generated between a pair of opposing branch electrodes. One first electrode (a pair of first and second trunk lines and a pair of first and second trunk lines)
The region where the branch electrode and the second branch electrode are overlapped) and the pair of partition walls correspond to one discharge cell.

In a region sandwiched between a pair of partition walls,
The number of first branch electrodes extending from the first main wiring₁,
The number of second branch electrodes extending from the second main wiring is N_TwoMade
When N ₁= N_Two= 1 or n is an integer of 1 or more
And N₁= 2n-1, N_Two= 2n
Then N₁= N_Two= 2n.

In the plasma display device of the present invention, the first branch electrode and the second branch electrode extend so as to face each other, but the distance between the first branch electrode and the second branch electrode is a predetermined distance. Is more preferable, and furthermore, it is more preferable that the distance is constant. The planar shape of the first branch electrode and the second branch electrode may be substantially rectangular (that is, the first branch electrode and the second branch electrode may be linear shapes), or may be zigzag ( For example, the combination of the character "ku", "S"
Character combination, arc combination, or arbitrary curve combination). In the latter case, in order to prevent the occurrence of abnormal discharge between the first branch electrode and the second branch electrode, there is no corner at the opposing portion of the first branch electrode and the second branch electrode. Is preferred. In the plasma display device of the present invention, the first
The distance between the second branch electrode and the second branch electrode can be essentially any value, but is not more than 1 × 10 ⁻⁴ m, preferably less than 5 × 10 ⁻⁵ m, more preferably It is desirable that it be 4 × 10 ⁻⁵ m or less, and more preferably 2.5 × 10 ⁻⁵ m or less. The minimum value of the distance between the first branch electrode and the second branch electrode may be a distance that does not cause dielectric breakdown between the first branch electrode and the second branch electrode.

In the plasma display device of the present invention, the pressure of the rare gas sealed in the space surrounded by the protective layer, the phosphor layer, and the pair of partition walls is 1 × 10 ² Pa (0.001 atm) to 5 ×. 10 ⁵ Pa (5 atm), preferably 1 × 1
It is desirable that the pressure be in the range of 0 ³ Pa (0.01 atm) to 4 × 10 ⁵ (4 atm). When the distance between the first branch electrode and the second branch electrode is less than 5 × 10 ⁻⁵ m, the pressure of the rare gas in the space is set to 1.0 × 10 ² Pa (0. 00
1 atm) or more and 3.0 × 10 ⁵ Pa (3 atm) or less, preferably 1.0 × 10 ³ Pa (0.01 atm) or more.
× 10 ⁵ Pa (2 atm) or less, more preferably 1.0 ×
It is preferable that the pressure be in the range of 10 ⁴ Pa (0.1 atm) or more and 1.0 × 10 ⁵ Pa (1 atm) or less. The phosphor layer emits light when irradiated with the ultraviolet light,
Within such a pressure range, the higher the pressure, the lower the sputtering rate of the various members constituting the plasma display device, so that the life of the plasma display device can be extended.

Alternatively, in the plasma display device of the present invention, a corner portion (corner portion) of the tip of the first branch electrode is provided.
Alternatively, in order to prevent the occurrence of abnormal discharge from the corner (corner) of the tip of the second branch electrode, the tip of the first branch electrode and the tip of the second branch electrode are rounded. Or the corners are preferably rounded. Further, in the plasma display device of the present invention, abnormal discharge between the tip of the first branch electrode and the second trunk wiring is prevented, or the tip of the second branch electrode is connected to the first trunk. In order to prevent abnormal discharge between the first branch electrode and the second branch electrode, the distance between the first branch electrode and the second branch electrode is L ₁ , and the distance between the first main line and the tip of the second branch electrode is L ₁ . It is desirable that L ₁ <L ₂ be satisfied, where L ₂ is the distance between the second main wiring and the tip of the first branch electrode.

The second electrode group composed of a plurality of second electrodes may be provided on the first substrate, or may be provided on the second substrate.
May be provided on the substrate. In the former case, the second electrode is provided on the protective layer via an insulating film, and forms a predetermined angle (for example, 90 °) between the second electrode and the direction in which each trunk wire extends. In the latter case, the second electrode is
And the second electrode and the direction in which each trunk line extends form a predetermined angle (for example, 90 °), and the phosphor layer is provided above the second electrode. .

It is preferable that the conductive material forming the first main wiring and the second main wiring is different from the conductive material forming the first branch electrode and the second branch electrode.
The first main wiring and the second main wiring function as bus electrodes in a conventional plasma display device. The first main wiring and the second main wiring are typically made of a metal material such as Ag, Al, Ni, Cu, Cr, Cr / Cu / Cr.
It can be composed of a laminated film. In the reflective plasma display device, the first main wiring and the second main wiring made of such a metal material reduce the amount of visible light transmitted from the phosphor layer and passing through the first substrate, The first electrode is preferably formed as thin as possible within a range where an electric resistance value required for the first electrode can be obtained, because it may cause a reduction in luminance of a display screen.

The conductive material forming the first branch electrode and the second branch electrode differs depending on whether the plasma display device is a transmission type or a reflection type. In the transmission type plasma display device, since the light emission of the phosphor layer is observed through the second substrate, it does not matter whether the conductive material constituting the first branch electrode and the second branch electrode is transparent or opaque. However, when the second electrode is provided on the second substrate, it is desired that the second electrode be transparent. In a reflection type plasma display device,
Since the light emission of the phosphor layer is observed through the first substrate,
In the case where the second electrode is provided over the second substrate, the conductive material forming the second electrode may be transparent or opaque, but the first branch electrode and the second branch electrode are transparent. It is desired. The transparency / opacity described here is based on the light transmittance of the conductive material at an emission wavelength (visible light region) specific to the phosphor material. That is, if it is transparent to light emitted from the phosphor layer, it can be said that the conductive material forming the first branch electrode and the second branch electrode is transparent. As opaque conductive materials, Ni, Al, Au, Ag, Al,
Pd / Ag, Cr, Ta, Cu, Ba, LaB 6, Ca
Materials such as _0.2 La _0.8 CrO ₃ can be used alone or in appropriate combination. IT as a transparent conductive material
O (indium tin oxide) and SnO ₂ can be mentioned. As a method for forming the first branch electrode and the second branch electrode, an evaporation method, a sputtering method, or a printing method can be appropriately selected depending on a conductive material to be used. That is, the first branch electrode and the second branch electrode having a predetermined pattern may be formed from the beginning using an appropriate mask or screen, or after forming a conductive material layer on the entire surface, The first branch electrode and the second branch electrode may be formed by patterning the material layer.

The protective layer can have a single-layer structure or a laminated structure. Examples of a material constituting the protective layer having a single-layer structure include magnesium oxide (MgO), magnesium fluoride (MgF ₂ ), and aluminum oxide (Al ₂ O ₃ ). Among them, magnesium oxide is a suitable material having characteristics such as being chemically stable, having a low sputtering rate, having a high light transmittance at the emission wavelength of the phosphor layer, and having a low discharge starting voltage. Incidentally, the protective layer may have a laminated structure composed of at least two kinds of materials selected from the group consisting of magnesium oxide, magnesium fluoride and aluminum oxide.

Alternatively, the protective layer may have a two-layer structure. The protective layer having a two-layer structure can be composed of a dielectric layer in contact with the first electrode group and a covering layer provided on the dielectric layer and having higher secondary electron emission efficiency than the dielectric layer. . The dielectric layer is typically comprised of low-melting glass or SiO _2. The coating layer can be typically made of magnesium oxide (MgO), magnesium fluoride (MgF ₂ ), and aluminum oxide (Al ₂ O ₃ ). With such a two-layer structure, when the transparency (light transmittance) of the coating layer in the wavelength region of vacuum ultraviolet rays is not so high, the transparency of the entire protective layer is ensured by the dielectric layer, and the secondary electron emission efficiency is improved. It can be adopted for the purpose of securing the height with the coating layer. Thus, a stable discharge maintaining operation can be performed, and further, a structure in which vacuum ultraviolet rays are hardly absorbed by the protective layer and visible light emitted from the phosphor layer is hardly absorbed by the protective layer can be obtained. .

By forming the protective layer on the first substrate including the first electrode group, direct contact between ions and electrons and the first electrode group can be prevented. Wear of the electrode group can be prevented. The protective layer also has a function of accumulating wall charges generated during the address period, a function of emitting secondary electrons required for discharge, a function as a resistor for limiting an excessive discharge current, and maintaining a discharge state. Memory function.

As a constituent material of the first substrate and the second substrate, soda glass (Na ₂ O.CaO.SiO ₂ ), borosilicate glass (Na ₂ O.B ₂ O ₃ .SiO ₂ ), forsterite ( 2MgO.SiO ₂ ), lead glass (Na ₂ O.Pb)
O.SiO ₂ ). The constituent materials of the first substrate and the second substrate may be the same or different.

The plasma display device of the present invention is a so-called surface discharge type device. When the second electrode is provided on the second substrate, and when the function of the phosphor layer as a dielectric layer is insufficient, a dielectric layer is provided between the second electrode group and the phosphor layer. A film may be provided. As a constituent material of the dielectric film, low melting point glass or SiO ₂ can be used.

The phosphor layer comprises a phosphor material that emits red light,
It is composed of a phosphor material selected from the group consisting of a phosphor material that emits green light and a phosphor material that emits blue light,
It is provided above the second substrate. Connect the second electrode to the second
Specifically, for example, a phosphor layer (a red phosphor layer) made of a phosphor material that emits red light is provided above the second electrode, and the phosphor that emits green light is provided. A phosphor layer (green phosphor layer) made of a body material is provided above another second electrode, and a phosphor layer (blue phosphor layer) made of a phosphor material emitting blue light is further provided. A set of phosphor layers that emit light of these three primary colors is provided above another second electrode and provided in a predetermined order. On the other hand, when the second electrode is provided on the first substrate, each of the red phosphor layer, the green phosphor layer, and the blue phosphor layer is provided on the second substrate, and these three primary colors are emitted. Phosphor layers are formed as one set and provided in a predetermined order. Then, one first electrode (a combination of a pair of the first main wiring and the second main wiring, and a pair of the first branch electrode and the second branch electrode) and these three primary colors The region where one set of phosphor layers that emit the light of overlaps corresponds to one pixel. The red phosphor layer, the green phosphor layer, and the blue phosphor layer may be formed in a stripe shape or in a lattice shape. Red phosphor layer,
In the case where the green phosphor layer and the blue phosphor layer are formed in a stripe shape, and when the second electrode is provided on the second substrate, one red phosphor layer corresponds to one of the second electrodes. Formed above, one green phosphor layer is formed above one second electrode, and one blue phosphor layer is formed above one second electrode. On the other hand, when the red phosphor layer, the green phosphor layer, and the blue phosphor layer are formed in a lattice, the red phosphor layer,
A green phosphor layer and a blue phosphor layer are formed in a predetermined order.

In the case where the second electrode is provided on the second substrate, the phosphor layer may be formed directly on the second electrode, or may be suspended from the second electrode on the side surface of the partition. May be formed. Alternatively, the phosphor layer may be formed on a dielectric film provided on the second electrode, or may be formed on the dielectric film provided on the second electrode so as to hang on the side surface of the partition wall. It may be formed. Further, the phosphor layer may be formed only on the side surface of the partition. "The phosphor layer is the second
"Is provided above the electrode of". "Is a concept encompassing all of the various forms described above.

As a phosphor material constituting the phosphor layer,
Among the known phosphor materials, high quantum efficiency, vacuum
Select a phosphor material that is less saturated with ultraviolet light
Can be used. Because color display is assumed,
Color purity is close to the three primary colors specified by NTSC.
White balance when mixed, short afterglow time,
Combination of phosphor materials with almost equal afterglow time
Preferably. Emits red light when irradiated with vacuum ultraviolet light
(Y)_TwoO_Three: Eu), (YBO)_Three
Eu), (YVO_Four: Eu), (Y_0.96P_0.60V
_0.40O_Four: Eu_0.04), [(Y, Gd) BO_Three: Eu],
(GdBO_Three: Eu), (ScBO)_Three: Eu), (3.5
MgO ・ 0.5MgF_Two・ GeO_Two: Mn)
Can be. Fireflies that emit green light when irradiated with vacuum ultraviolet light
As the optical material, (ZnSiO_Two: Mn), (BaAl)
₁₂O₁₉: Mn), (BaMg)_TwoAl₁₆O₂₇: Mn),
(MgGa_TwoO_Four: Mn), (YBO)_Three: Tb), (Lu
BO_Three: Tb), (Sr_FourSi_ThreeO₈Cl _Four: Eu)
can do. Emits blue light when irradiated with vacuum ultraviolet light
(Y)_TwoSiO_Five: Ce), (Ca)
WO_Four: Pb), CaWO_Four, YP_0.85V_0.15O_Four, (B
aMgAl₁₄O_{twenty three}: Eu), (Sr_TwoP_TwoO₇: Eu),
(Sr_TwoP_TwoO₇: Sn). fluorescence
As a method of forming a body layer, a thick film printing method,
Laying method, adhesive material in advance on the phosphor layer
Method to attach phosphor particles to the surface, photosensitivity
Fluorescent light by exposure and development using phosphor paste
Method of patterning body layer, forming phosphor layer on the entire surface
To remove unnecessary parts by sandblasting after
Can be mentioned.

The partition may be configured to extend in parallel with the second electrode in a region between the adjacent second electrodes. That is, a structure in which one second electrode extends between a pair of partition walls can be employed. In some cases, the partition includes a first partition extending parallel to the main wiring in a region between adjacent main wirings, and a second partition extending parallel to the second electrode in a region between the adjacent second electrodes. (I.e., a lattice shape). Although such a grid-like partition has been conventionally employed in a DC plasma display device, it can also be applied to an AC plasma display device of the present invention.

As a constituent material of the partition, a conventionally known insulating material can be used. For example, a material obtained by mixing a metal oxide such as alumina with a widely used low-melting glass can be used. As a method of forming the partition wall, a screen printing method, a sand blast method, a dry film method,
A photosensitive method can be exemplified. The dry film method refers to a method on a second substrate (when a dielectric film described later is used,
This is a method of laminating a photosensitive film on the dielectric film), removing the photosensitive film at a portion where a partition is to be formed by exposure and development, embedding a material for forming a partition into an opening formed by the removal, and baking. The photosensitive film is burned and removed by baking, and the material for forming the partition embedded in the opening remains, thereby forming a partition. The photosensitive method means on the second substrate (when a dielectric film described later is used, on the dielectric film)
A material layer for forming a partition having photosensitivity is formed, and the material layer is patterned by exposure and development, followed by baking. Note that by making the partition walls black, a so-called black matrix can be formed, and the display screen can have high contrast. Examples of a method of blackening the partition include a method of providing a light absorbing layer such as a photosensitive silver paste layer and a low reflection chromium layer on the top of the partition, and a method of forming the partition using a black colored color resist material. be able to.

The following points are required for the rare gas sealed in the space. It is chemically stable from the viewpoint of extending the life of the plasma display device and the gas pressure can be set high. From the viewpoint of increasing the brightness of the display screen, the emission intensity of vacuum ultraviolet rays is large. Visible from vacuum ultraviolet rays. The wavelength of the emitted vacuum ultraviolet rays is long from the viewpoint of increasing the energy conversion efficiency to light rays. The discharge starting voltage is low from the viewpoint of reducing power consumption.

As the rare gas, He (resonance line wavelength = 5)
8.4 nm), Ne (74.4 nm), Ar (10
7 nm), Kr (124 nm), Xe (147 n)
It is possible to use m) alone or to mix them, but a mixed gas which is expected to lower the firing voltage due to the Penning effect is particularly useful. As such a mixed gas, a Ne—Ar mixed gas, a He—Xe mixed gas, a N
An e-Xe mixed gas can be used. Xe, which has the longest resonance line wavelength among these rare gases, is also a preferred rare gas because it also emits strong vacuum ultraviolet light having a wavelength of 172 nm.

Here, the light emission state of the glow discharge in the discharge cell will be described with reference to FIGS. FIG. 4A schematically shows a light emitting state when DC glow discharge is performed in a discharge tube in which a rare gas is sealed. From the cathode to the anode, an Aston dark part A, a cathode glow B, a cathode dark part (Crooks dark part) C, a negative glow D, a Faraday dark part E, a positive column F, and an anode glow G appear in this order. In the AC glow discharge, since the cathode and the anode repeat inversion at a predetermined frequency, the positive column F is located at the center between the electrodes, and the Faraday dark portion E, the negative glow D, the negative dark portion C, It is considered that the cathode glow B and the aston dark part A appear symmetrically in this order. The state shown in FIG. 4B is seen when the distance between the electrodes is sufficiently long, such as a fluorescent lamp.

As the distance between the electrodes is reduced, the length of the positive column F is reduced. When the distance between the electrodes is further reduced, the positive column F disappears as shown in FIG. 5A, the negative glow D is located at the center between the electrodes, and the cathode dark portions C and the cathodes are disposed on both sides of the negative glow D. It is considered that the glow B and the aston dark part A appear symmetrically in this order. The state shown in FIG. 5A is a state that occurs when the distance between the electrodes is about 1 × 10 ⁻⁴ m. However, in the plasma display device of the present invention, since a pair of the first branch electrode and the second branch electrode for maintaining the discharge are arranged in parallel, the negative glow is the first glow corresponding to the cathode. It is formed in a space region near the surface portion of the protective layer covering the branch electrode or the surface portion of the protective layer covering the second branch electrode.

On the other hand, when the interval between the electrodes is less than 5 × 10 ⁻⁵ m, the cathode glow B is located at the center between the electrodes as schematically shown in FIG. Is considered to appear on both sides of Aston. In some cases, some negative glows may exist. However, in the plasma display device of the present invention, since the pair of first branch electrodes and the second branch electrodes for maintaining the discharge are arranged in parallel, the cathode glow corresponds to the first cathode corresponding to the cathode. It is formed in a space region near the surface portion of the protective layer covering the branch electrode or the surface portion of the protective layer covering the second branch electrode. Thus, the distance between the first branch electrode and the second branch electrode is set to 5
× 10 ⁻⁵ m and the pressure in the space is 1.0 ×
10 ² Pa (0.001 atm) or more and 3.0 × 10 ⁵ Pa
By setting the pressure to (3 atm) or less, it is possible to use the cathode glow as the discharge mode. Therefore, as a result of achieving high AC glow discharge efficiency, high luminous efficiency and luminance can be obtained in the plasma display device.

In the plasma display device of the present invention, the first branch electrode and the second branch electrode extend from the main wiring so as to face each other. The outer shape of one pixel is substantially square, and one pixel is divided into three sections (cells) by partition walls. One of three primary colors (R, G, B) emits light from each section. when the external dimensions of the pixels set to L _0, the pair of branch electrodes, the length of the portion contributing to discharge L ₀
It is a value close to. That is, as compared with the conventional plasma display device, the length of the portion contributing to the discharge can be made about three times, so that the discharge region can be enlarged. Therefore, it is possible to prevent the problem that the luminance of the plasma display device is reduced.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments of the present invention (hereinafter, abbreviated as embodiments).

Embodiment 1 Embodiment 1 relates to an AC-driven plasma display device of the present invention. FIG. 2 is a conceptual exploded perspective view of the plasma display device according to the first embodiment. This plasma display device has a front panel 10 and a rear panel 20. The front panel 10 includes a first substrate 11 made of, for example, glass, a first electrode group including a plurality of first electrodes provided on the first substrate 11, and a first electrode group. And a protective layer 14 formed on the first substrate 11 including the first substrate 11. The protective layer 14 is composed of a dielectric layer made of SiO ₂ or low melting point glass and a coating layer made of magnesium oxide (MgO) formed on the dielectric layer. Expressed in one layer.

On the other hand, the rear panel 20 includes a second substrate 21 made of, for example, glass and a plurality of second electrodes (also referred to as address electrodes or data electrodes) 22 provided in stripes on the second substrate 21. Composed second
, A phosphor layer 24 provided above the second electrode 22, and a partition wall 25 provided between the adjacent second electrodes 22. Note that a dielectric film 23 is formed on the second substrate 21 including the second electrode 22. The partition wall 25 made of an insulating material is formed in a region between the adjacent second electrodes 22 on the dielectric film 23, and extends in parallel with the second electrode 22. The phosphor layer 24 is provided over the dielectric film 23 and on the side wall surface of the partition 25. The phosphor layer 24 includes a red phosphor layer 24R, a green phosphor layer 24G, and a blue phosphor layer 24B, and the phosphor layers 24R, 24G, and 24B of these colors are provided in a predetermined order. ing.

FIG. 2 is an exploded perspective view. In practice, the top of the partition 25 on the rear panel 20 is in contact with the protective layer 14 on the front panel 10. Also, the front panel 10
The rear panel 20 and the rear panel 20 are disposed so as to face each other such that the protective layer 14 and the phosphor layer 24 face each other, and are bonded to each other at a peripheral portion thereof via a seal layer (not shown). A pair of first trunk wires 12A, 12B, and these trunk wires 12A, 12B;
A region where the pair of branch electrodes 13A and 13B extending from the second electrode 22 and the second electrode 22 located between the two partition walls 25 overlap corresponds to a discharge cell. Also, a pair of first trunk wires 1
2A, the second main wiring 12B, the first branch electrode 13A and the second branch electrode 13B, and the phosphor layers 24R, 24 of the three primary colors.
An area where one set of G and 24B overlaps corresponds to one pixel. In the space formed by the front panel 10 and the rear panel 20, for example, a Ne—Xe mixed gas (for example, a Ne50% -Xe50% mixed gas) has a pressure of 8 × 10.
It is sealed at ⁴ Pa (0.8 atm). That is, a rare gas is sealed in a space surrounded by the adjacent partition wall 25, the phosphor layer 24, and the protective layer 14.

FIG. 1 schematically shows a positional relationship between a pair of opposing first electrodes and the partition wall 25. In addition, in order to clarify each area, the area is hatched. The pair of first electrodes facing each other include (A) the first main wiring 12A and (B) the first main wiring 1
Second trunk wiring 12B extending in parallel with 2A, (C) partition wall 2
5, a first branch electrode 13A extending from the first main wiring 12A toward the second main wiring 12B and shortly before the second main wiring 12B, and (D). Between the partition walls 25, from the second main wiring 13B toward the first main wiring 13A, and between the first main wiring 12A and the second main wiring 13B.
The second branch electrode 13B extends to face the first branch electrode 13A up to the position A. The first electrode group includes a first main wiring 12A, a second main wiring 12B,
Of the first branch electrode 13A and the second branch electrode 13B. In the first embodiment, the planar shape of the first branch electrode 13A and the second branch electrode 13B is substantially rectangular,
13A and the second branch electrode 13B extend in parallel. Also, the first trunk wiring 12A and the second trunk wiring 12B
Extend in parallel with the main wirings 12A and 12B.
Is, for example, 90 °.

As shown in FIG. 1, the distance between the first branch electrode 13A and the second branch electrode 13B is L ₁ , and the distance between the first trunk line 12A and the tip of the second branch electrode 13B is L ₁ . when the distance between, or the distance between the tip portion of the second main wiring 12B and the first branch electrodes 13A and the L _2, which satisfies the L ₁ <L _2. In the first embodiment, specifically, L ₁ = 5
× 10 ⁻⁵ m (50 μm), L ₂ = 8 × 10 ⁻⁵ m (80 μm)
m).

In FIG. 1, a region surrounded by a dotted line corresponds to one pixel. The outer shape of one pixel is generally square,
The pixel is divided into three sections (cells) by a partition 25, and each section emits one of the three primary colors (R, G, B). When the external dimensions of one pixel was set to L _0, the size of each compartment is a small dimension slightly larger than _{(L 0/3) × (} L 0). Therefore, in the pair of branch electrodes 13A and 13B, portions 13 of the branch electrodes 13A and 13B contributing to the discharge.
The lengths of A ′ and 13B ′ are values close to (L ₀ ).

Each of the branch electrodes 13A and 13B is connected to the first substrate 1
1 and is formed of a transparent conductive material such as ITO. On the other hand, as a conductive material forming the first main wiring 12A and the second main wiring 12B, IT
A material having a lower electric resistivity than O, for example, a chromium / copper / chromium laminated film is used. First and second trunk wires 12A, 1
The line width of 2B is made as narrow as possible (for example, 50 μm width) so as not to impair the luminance of the display screen (here, the upper surface of the first substrate 11 in the drawing).

The second electrode group is an aggregate of second electrodes 22 formed in a stripe on the second substrate 21.
Each second electrode 22 is made of, for example, silver or aluminum, and contributes to the start of discharge together with the first and second branch electrodes 13A and 13B, and emits light generated from the phosphor layer 24 to the display screen side. Reflection also contributes to improving the brightness of the display screen. The phosphor layer 24 includes the red phosphor layer 2
4R, a green phosphor layer 24G and a blue phosphor layer 24B, and a phosphor layer 2 that emits these three primary colors.
4R, 24G, and 24B form a set, and are provided on the second electrode 22 in a predetermined order.

Next, an example of the AC glow discharge operation of the plasma display device having the above configuration will be described. First, for example, a pulse voltage higher than the discharge start voltage V _bd is applied to all the first main wires 12A for a short time. As a result, a discharge occurs, and wall charges are generated on the surface of the protective layer 14 near one of the branch electrodes due to dielectric polarization, the wall charges are accumulated, and the apparent discharge start voltage is reduced. Thereafter, while a voltage is applied to the second electrode (address electrode) 22 and a voltage is applied to one of the trunk lines included in the cells not to be displayed, a voltage is applied between the second electrode 22 and one of the branch electrodes. , Causing the accumulated wall charges to be erased. This erasing discharge is sequentially performed on each second electrode 22. On the other hand, no voltage is applied to one of the trunk lines included in the cell to be displayed. This maintains the accumulation of wall charges. Thereafter, by applying a predetermined pulse voltage again between all the pair of trunk wires 12A and 12B, discharge is started between the pair of branch electrodes 13A and 13B in the cell in which the wall charge has been accumulated, In the discharge cell, the phosphor layer excited by the irradiation of the vacuum ultraviolet ray generated based on the glow discharge in the rare gas emits a specific emission color according to the type of the phosphor material. Note that the phases of the sustaining voltage applied to one main wiring and the other main wiring are shifted by a half cycle, and the polarities of the electrodes are inverted according to the AC frequency.

Alternatively, another example of the AC glow discharge operation of the plasma display device having such a configuration will be described. First, an erasing discharge is performed on all the pixels to initialize all the pixels, and then a discharging operation is performed. The discharge operation is performed by dividing into an address period in which wall charges are generated on the surface of the protective layer 14 by the initial discharge and a discharge sustaining period in which the discharge is maintained. In the address period, a pulse voltage lower than the discharge start voltage V _bd is applied for a short time to one of the selected main wires and the selected second electrode 22. A region where one of the trunk lines to which the pulse voltage is applied and the second electrode 22 overlaps is selected as a display pixel, and in this overlap region, the protection layer 14
A wall charge is generated on the surface of the substrate due to the dielectric polarization, and the wall charge is accumulated. In the subsequent discharge sustaining period, the pair of trunk wires 12
A discharge sustaining voltage V _sus lower than V _bd is applied to A and 12B. Wall voltage V _w induced by wall charges and sustain voltage V _sus
Is greater than the _firing voltage V _bd (ie,
_{V w + V sus> V bd} ), discharge is started. The phases of the sustaining voltage V _sus applied to one main wiring and the other main wiring are shifted by a half cycle, and the polarity of the electrodes is inverted according to the AC frequency.

In the pixel in which the AC glow discharge is maintained, the phosphor layer 24 is excited by irradiating vacuum ultraviolet rays radiated based on the excitation of the rare gas generated in the space, and the phosphor layer 24 has a characteristic corresponding to the kind of the phosphor material. Light emission of the following colors is obtained.

In the plasma display device of the present invention, the length of the electrode contributing to the discharge (ie, the length of the portion of the pair of branch electrodes 13A and 13B facing each other) is longer than that of the conventional plasma display device. Therefore, the area of the discharge region is shown in FIG.
8 can be greatly increased as compared with the conventional three-electrode type AC plasma display device shown in FIG. 8, so that the brightness of the display screen can be increased.

The outline of the method of manufacturing the plasma display device according to the first embodiment will be described below. In the following description, at any stage of the manufacturing method, the first substrate 11 and all structures formed thereon, or the second substrate 21 and all structures formed thereon are referred to as It may be referred to as “substrate”.

The front panel 10 can be manufactured as follows. First, an ITO layer is formed on the entire surface of the first substrate 11 by, for example, a sputtering method, and the ITO layer is patterned in a stripe shape by a photolithography technique and an etching technique.
And the second branch electrodes 13A and 13B can be formed. Next, a chromium / copper / chromium laminated film is formed on the entire surface of the base by, for example, a sputtering method, and the chromium / copper / chromium laminated film is patterned by a photolithography technique and an etching technique, thereby forming the first and second main wirings. 12A and 12B can be formed. Note that one end of the first branch electrode 13A and the first main line 12A overlap, and one end of the second branch electrode 13B and the second main line 12B overlap. After that, the protective layer 14 is formed on the entire surface of the base. The protective layer 14 has a two-layer structure of a dielectric layer having a thickness of about 10 μm and a covering layer having a thickness of about 0.6 μm. For example, a single layer made of magnesium oxide (MgO) having a thickness of about 10 μm is used. It may be a layer. The dielectric layer can be formed, for example, by forming a low-melting glass paste layer on the entire surface of the substrate by a screen printing method, and firing the low-melting glass paste layer.
Further, the protective layer 14 composed of a coating layer or a single layer is
For example, it can be obtained by forming a magnesium oxide layer by an electron beam evaporation method on the entire surface of the dielectric layer or on the first substrate including the first electrode group. Through the above steps, the front panel 10 can be completed.

The rear panel 20 can be manufactured as follows. First, a silver paste is printed in a stripe shape on the second substrate 21 by, for example, a screen printing method, and the second electrode 22 can be formed through firing. Next, a low melting point glass paste layer is formed on the entire surface of the substrate by a screen printing method, and the dielectric film 23 is formed by firing the low melting point glass paste layer. Thereafter, a low-melting glass paste is printed on the dielectric film 23 above the region between the adjacent second electrodes 22 by, for example, a screen printing method, and the partition 25 is formed through firing. The height of the partition 25 is, for example, 1 × 10 ⁻⁴ m (100 μm).
m) to 2 × 10 ⁻⁴ m (200 μm). Next, phosphor slurries of three primary colors are sequentially printed, and baked to form phosphor layers 24R, 24G, and 24B. Through the above steps, the rear panel 20 can be completed.

Next, the plasma display device is assembled. First, the rear panel 2 is screen-printed, for example.
A seal layer (not shown) is formed on the periphery of the zero. next,
Attach the front panel 10 and the rear panel 20,
Baking to cure the seal layer. Next, after exhausting the space formed between the front panel 10 and the rear panel 20, a Ne-Xe mixed gas (for example, Ne50% -Xe
50% mixed gas) at a pressure of 8 × 10 ⁴ Pa (0.8 atm)
To complete the plasma display device. The front panel 10 and the rear panel 20 were bonded together at a pressure of 8 × 10 ⁴ Pa (0.8 atm) by Ne-
If the process is performed in a chamber filled with the Xe mixed gas, it is possible to omit the exhaust step and the sealing step of the Ne—Xe mixed gas.

(Embodiment 2) Embodiment 2 is a modification of Embodiment 1. Embodiment 2 is different from Embodiment 1 in that a pair of opposing first electrodes and partition walls 2 are shown in FIG.
As shown schematically in FIG. 5, the first branch electrode 13
The tip of A and the tip of the second branch electrode 13B have rounded corners. The planar shapes of the first branch electrode 13A and the second branch electrode 13B are macroscopically substantially rectangular. Except for this point, the plasma display device according to the second embodiment can have the same structure and configuration as the plasma display device according to the first embodiment, and thus detailed description is omitted.

As described above, the present invention has been described based on the embodiments. However, the plasma display device of the present invention is not limited to these embodiments. The details of the configuration, constituent materials, and manufacturing method of the plasma display device are appropriately changed,
Selection and combination are possible. A second electrode group including a plurality of second electrodes may be provided on the first substrate. That is, the second electrode is provided on the protective layer 14 with the insulating film interposed therebetween, and the second electrode and the direction in which each trunk line extends has a predetermined angle (for example, 90 °). You can also.

[0056]

According to the plasma display device of the present invention,
Since the first branch electrode and the second branch electrode extend from the main wiring so as to face each other, the length of the portion of the electrode contributing to the discharge can be made sufficiently long. Therefore, since the discharge region can be enlarged, it is possible to prevent the problem that the brightness of the plasma display device is reduced despite the simple configuration.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an arrangement relationship between a pair of opposed first electrodes and a partition in the plasma display device according to the first embodiment of the present invention.

FIG. 2 is a conceptual exploded perspective view of the plasma display device according to the first embodiment of the present invention.

FIG. 3 is a diagram schematically showing an arrangement relationship between a pair of opposing first electrodes and partition walls in a plasma display device according to a second embodiment of the present invention.

FIG. 4 is a diagram schematically showing a light emitting state of a glow discharge in a discharge cell.

FIG. 5 is a diagram schematically showing a light emitting state of a glow discharge in a discharge cell.

FIG. 6 is a conceptual exploded perspective view of a conventional plasma display device.

FIG. 7 is a diagram schematically showing an arrangement relationship between a pair of opposing first electrodes and partition walls in a conventional plasma display device.

FIG. 8 is a diagram schematically showing a modification of the arrangement relationship between a pair of opposing first electrodes and partition walls in a conventional plasma display device.

[Explanation of symbols]

10 front panel, 11 first substrate, 1
2A, 12B: trunk wiring, 13A, 13B: branch electrode, 14: protective layer, 20: rear panel, 21.
..Second substrate, 22... Second electrode (address electrode), 23... Dielectric film, 24, 24R, 24G, 2
4B: phosphor layer, 25: partition

Claims (8)

[Claims] 1. A first substrate, an electrode group including a plurality of electrodes provided on the first substrate, and a protective layer formed on the first substrate including the electrode group And (b) a second substrate, a phosphor layer provided above the second substrate, extending at a predetermined angle to a direction in which the electrodes extend, and being adjacent to each other. An AC-driven plasma display device comprising: a second panel comprising a partition provided between phosphor layers, wherein the pair of electrodes facing each other include: (A) a first main wiring; ) A second trunk line extending in parallel with the first trunk line; and (C) a second trunk line between the partition walls from the first trunk line toward the second trunk line. (D) between the partition walls, from the second trunk wiring toward the first trunk wiring, and Until the front of the trunk line, the first
A second branch electrode extending in opposition to the first branch electrode and generating a discharge between the pair of first and second branch electrodes. 2. The plasma display device according to claim 1, wherein a planar shape of the first branch electrode and the second branch electrode is substantially rectangular. 3. The plasma display according to claim 1, wherein the tip of the first branch electrode and the tip of the second branch electrode are rounded or rounded. apparatus. 4. The distance between the first branch electrode and the second branch electrode is L ₁ , the distance between the first trunk wiring and the tip of the second branch electrode, or the second trunk electrode. _2. The plasma display device according to claim ₁ , wherein L ₁ <L ₂ is satisfied, where L ₂ is a distance between the wiring and the tip of the first branch electrode. 3. 5. The plasma display device according to claim 1, wherein a distance between the first branch electrode and the second branch electrode is less than 5 × 10 ⁻⁵ m. 6. The conductive material forming the first main wiring and the second main wiring is different from the conductive material forming the first branch electrode and the second branch electrode. Item 2. The plasma display device according to item 1. 7. The plasma according to claim 6, wherein the conductive material forming the first branch electrode and the second branch electrode is transparent to light emitted from the phosphor layer. Display device. 8. A second electrode group comprising a plurality of second electrodes is provided on a second substrate, and the phosphor layer is formed of a second electrode.
2. The plasma display device according to claim 1, wherein said plasma display device is provided above said electrode.