KR100612362B1 - Plasma display panel - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a plasma display panel having an electrode structure advantageous for realizing a high density and high luminance display.

A plasma display panel according to the present invention comprises: a first substrate and a second substrate disposed to face each other; Address electrodes formed on the first substrate in parallel with one direction; A plurality of discharge cells are partitioned in a space between the first substrate and the second substrate, the first partition member disposed in a direction parallel to the address electrode and the second partition member disposed in a direction crossing the address electrode; Partition wall to make; A phosphor layer formed in each of the discharge cells; First electrodes between the first substrate and the second substrate, the first electrodes being formed to extend in parallel with the second partition members constituting the discharge cells; And second electrodes disposed between the pair of first electrodes adjacent to each other and passing through the discharge cell inner space across the first partition member.

Plasma, Display, Counter Discharge, Front Panel Bulkhead

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

1 is a graph schematically showing a voltage distribution between a cathode and an anode in a typical glow discharge.

2 is a partially exploded perspective view showing a PDP according to an embodiment of the present invention.

3 is a partial plan view schematically illustrating a structure of an electrode and a discharge cell in a PDP according to an embodiment of the present invention.

4 is a partial cross-sectional view taken along the line A-A by combining the PDP shown in FIG.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a plasma display panel having an electrode structure advantageous for realizing a high density and high luminance display.

In general, a plasma display panel (hereinafter referred to as a 'PDP') is used to implement an image using visible light generated by a vacuum ultraviolet ray (VUV) emitted from a plasma obtained through gas discharge. Display element. Such a PDP can realize an ultra-large screen of 60 inches or more with a thickness of only 10 cm or less, and is a self-luminous display device such as a CRT. In addition, the manufacturing method is simpler than LCD, and thus has advantages in terms of productivity and cost.

The structure of the PDP has been developed for a long time since the 1970s, and the structure generally known is a three-electrode surface discharge type structure. The three-electrode surface discharge type structure consists of one substrate including two electrodes located on the same surface and another substrate including address electrodes vertically spaced apart from each other at a predetermined distance therebetween, with a discharge gas enclosed therebetween. Structure. In general, the presence or absence of the discharge is determined by the discharge of the address electrode facing the scan electrode independently connected to each line, and the sustain discharge indicating the luminance is performed by two electrode groups located on the same plane. .

PDP uses a glow discharge to make visible light visible to humans, which takes several steps to reach the human eye after the glow discharge occurs. That is, when a glow discharge occurs, an excited gas is generated by collision between electrons and gases, and ultraviolet rays are generated from the excited gas. Ultraviolet rays collide with the phosphor in the discharge cell to generate visible light, and the visible light passes through the transparent substrate on the front surface and reaches the human eye. This step results in a significant loss of input power.

Glow discharges are usually obtained by applying a voltage above the discharge start voltage between two electrodes under a low atmospheric pressure (<1 atm). The discharge start voltage is a function of the type of gas, the atmospheric pressure, and the distance between electrodes. In the case of AC discharge, in addition to these three, the discharge start voltage is also affected by the dielectric capacitance (dielectric constant, electrode area, dielectric thickness) and the frequency of the applied voltage.

Although a very high voltage is required to initiate the discharge, the voltage distribution between the cathode and the anode is distorted as shown in FIG. 1 due to the difference in the space charge generated around the cathode and the anode once the discharge occurs. FIG. 1 shows that most of the voltage is being consumed around two electrodes, that is, in areas called cathode sheath and anode sheath, and in the relatively positive column region. It can be seen that the amount of voltage is small. In particular, the glow discharge generated in the PDP is known that the voltage consumed in the cathode sheath is much higher than the voltage of the anode sheath.

The emission of visible light in the phosphor is caused by the collision of the ultraviolet light with the phosphor, and the ultraviolet light is generated when the energy level is changed from the excited state of Xen to the ground state of Xen. . On the other hand, xenon Xe in an excited state is made by collision between Xen in stable state and electrons. Therefore, in order to increase the ratio of generating visible light among the input energy, that is, the luminous efficiency, the electron heating efficiency must be increased.

In general, since the electron heating efficiency in the positive column region is higher than the electron heating efficiency in the cathode sheath region, the improvement of the PDP luminous efficiency is possible by increasing the positive column region. Since the sheath region has almost the same thickness under the same pressure, it is necessary to increase the length of the discharge in order to increase the luminous efficiency.

In the case of a PDP having a three-electrode structure, discharge is initiated in the region closest to the two electrodes-at the center of the discharge cell-and the discharge then moves to the edge region of the electrode. The discharge occurs in the center region because the discharge start voltage in this region is low. In general, the discharge start voltage is a function of the product of the pressure and the distance between the electrodes, and the PDP operating region is located to the right of the minimum value of the Paschen curve. Once the discharge is initiated, the discharge is maintained under a voltage much lower than the discharge start voltage due to the formation of space charge, and the voltage between the two electrodes gradually decreases with time. After the start of the discharge, the intensity of the electric field is weakened as ions and electrons accumulate in the central region, and the discharge disappears in this region.

Cathode and anode spots move over time in areas free of surface charge, ie around the electrode edges. At this time, since the voltage applied between the two electrodes decreases with time, strong discharge occurs in the center region of the discharge cell (low light emitting efficiency), and weak discharge occurs near the edge of the discharge cell (high light emitting efficiency). . Based on the same principle, the conventional three-electrode surface discharge structure has a low ratio used for heating electrons among the input energy, resulting in low luminous efficiency.

In order to overcome the weakness of the three-electrode structure, a method of increasing the distance between the display electrodes may be considered, but this causes an increase in the discharge start voltage.

The present invention has been made to solve the above problems, and its object is to place the electrodes involved in the sustain discharge and the address discharge in the discharge cell interior space to induce the sustain discharge and the address discharge to the opposite discharge and discharge start voltage. It is to provide a plasma display panel that can lower the.

Another object of the present invention is to provide a plasma display panel which can secure a longer discharge path by forming electrodes in the partition wall that are involved in sustain discharge.

In order to achieve the above object, a plasma display panel according to the present invention includes: a first substrate and a second substrate facing each other; Address electrodes formed on the first substrate in parallel with one direction; A plurality of discharge cells are partitioned in a space between the first substrate and the second substrate, the first partition member disposed in a direction parallel to the address electrode and the second partition member disposed in a direction crossing the address electrode; Partition wall to make; A phosphor layer formed in each of the discharge cells; First electrodes between the first substrate and the second substrate, the first electrodes being formed to extend in parallel with the second partition members constituting the discharge cells; And second electrodes disposed between the pair of first electrodes adjacent to each other and passing through the discharge cell inner space across the first partition member.

Each of the first electrodes has an outer surface surrounded by a dielectric layer, and each cross section of the first electrodes and the second partition wall member corresponding to the first electrode and the second partition wall member having a plane perpendicular to the longitudinal direction has substantially the same symmetry axis. You can do that.

In addition, it is preferable that the first electrodes have a longer cross section cut in a plane perpendicular to the longitudinal direction in a direction perpendicular to the substrate than a length in a direction parallel to the substrate.

MgO passivation layers are formed on at least side surfaces of the first electrodes facing the inner spaces of the respective discharge cells.

Each of the second electrodes has an outer surface surrounded by a dielectric layer, and a thickness of the dielectric layer formed on the surface of the second electrode facing the first substrate is greater than the thickness of the dielectric layer formed on the surface of the second electrode facing the first electrode. The thickness can be made thicker.

It is preferable that the second electrodes have a longer cross section cut in a plane perpendicular to the longitudinal direction in a direction perpendicular to the substrate than a length in a direction parallel to the substrate.

The second electrodes are formed such that at least an outer surface exposed to the inner space of the discharge cell is surrounded by an MgO protective film. The MgO protective film may have visible light impermeability.

The second electrodes may be formed to penetrate the first partition member.

The first partition member and the second partition member are formed to protrude toward the second substrate surface adjacent to the first substrate, the first partition member adjacent to the second substrate in a shape corresponding to the first partition member. A third partition wall member protruding toward the substrate surface is formed, and a fourth partition wall member protruding toward the first substrate surface is formed adjacent to the second substrate in a shape corresponding to the second partition wall member. do.

The first electrode is positioned between the second partition member and the fourth partition member, and the second electrode is positioned between the first partition member and the third partition member.

A phosphor layer may be formed in an area of the second substrate partitioned by the third and fourth partition members.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

2 is a partially exploded perspective view showing a PDP according to an embodiment of the present invention, Figure 3 is a partial plan view schematically showing the structure of the electrode and the discharge cell. 4 is a partial cross-sectional view taken along the line A-A by combining the PDP shown in FIG.

As shown, the PDP according to the present embodiment basically has a predetermined interval between the first substrate 10 (hereinafter referred to as the 'back substrate') and the second substrate 20 (hereinafter referred to as the 'front substrate'). They are disposed to face each other, and a plurality of discharge cells 18 are partitioned by the partitions 16 and 26 in the space between the substrates 10 and 20. In the discharge cell 18, phosphor layers 19 and 29, which absorb ultraviolet rays and emit visible light, are formed along the partition walls and the bottom surface, and discharge gas (for example, xenon (Xe), Mixed gas containing neon or the like) is filled.

Address electrodes 12 are formed along one direction (y-axis direction of the drawing) on the opposite surface of the front substrate 20 of the rear substrate 10, and cover the entire address surfaces of the rear substrate 10 while covering the address electrodes 12. A dielectric layer 14 is formed in the. The address electrodes 12 are formed in parallel with each other while maintaining a predetermined distance from neighboring ones.

The partition wall includes a rear plate partition wall 16 formed to protrude toward the front substrate 20 adjacent to the rear substrate 10, and a front plate protruded toward the rear substrate 10 adjacent to the front substrate 20. The partition 26 is made.

The back plate partition 16 is formed over the dielectric layer 14 formed on the back substrate 10. In the present embodiment, the back plate partition 16 is arranged in a direction parallel to the address electrode 12. And a second partition member 16b formed to intersect the first partition member 16a and partitioning each discharge cell 18 into an independent discharge space. The front plate partition wall 26 may include a third partition member 26a having a shape corresponding to the first partition member 16a and a fourth partition member having a shape corresponding to the second partition member 16b. 26b). Accordingly, the third partition wall member 26a and the fourth partition wall member 26b are formed in the direction crossing each other to form a region 28 corresponding to each discharge cell 18 on the front substrate 20.

Meanwhile, between the rear substrate 10 and the front substrate 20, corresponding to the second partition members 16b constituting each discharge cell 18 along the parallel direction (x-axis direction in the drawing). The first electrode 31 is formed to be long. In the present exemplary embodiment, since the first electrodes 31 correspond to each of the second partition members 16b one by one, the first electrodes 31 are disposed to pass over the second partition members 16b, so that the first electrodes 31 are parallel to the address electrodes 12. It can be a reference to distinguish the adjacent discharge cells 18 in the y-axis direction.

In addition, second electrodes 32 are disposed between the pair of first electrodes 31 adjacent to each other. The second electrodes 32 are formed to pass through the discharge cell 18 across the first partition member 16a.

At this time, the second electrode 32 plays a role of selecting the discharge cells 18 to be turned on by participating in the discharge of the address section together with the address electrode 12, and the first electrode 31 is the second electrode ( 32) and plays a role in displaying the screen by participating in the discharge of the maintenance section. However, since the electrodes may have different roles depending on the signal voltage applied thereto, the present invention does not need to be limited to the above.

Referring to FIG. 3, each of the discharge cells 18 is divided into two regions 18a and 18b by the second electrode 32, and the first and second discharge cells 18 are disposed in each of the regions 18a and 18b. A sustain discharge occurs between the electrode 31 and the second electrode 32. That is, since the discharge is generated between the second electrode 32 crossing the discharge cell 18 and the pair of first electrodes 31 disposed on both sides, the electrodes involved in the discharge maintenance are respectively formed at the edge of the discharge cell. The discharge gap between the two electrodes causing the discharge is reduced by almost half than that of the adjacent case, so that it can be driven even with a low discharge start voltage.

Referring to FIG. 4, in the present embodiment, each cross section of the first electrodes 31 and the second partition wall member 16b corresponding to each of them is cut in a plane perpendicular to the longitudinal direction (the x-axis direction in the drawing). It has substantially the same axis of symmetry L. In this way, the first electrodes 31 can be engaged with both of the pair of discharge cells 18 adjacent to each other in the direction parallel to the address electrode 12.

In addition, in the present embodiment, the first electrodes 31 may have a cross section cut in a plane perpendicular to the longitudinal direction and may be perpendicular to the substrate 10 and 20 planes rather than the length w1 in a direction parallel to the substrate 10 and 20 planes. The length h1 in the direction may be longer, and the second electrode 32 is also perpendicular to the substrate surface than the length w2 in the direction parallel to the substrate surface whose cross section is cut in a plane perpendicular to the longitudinal direction. The length h2 in one direction may be longer. Therefore, the opposite discharge can be induced more easily between the electrodes 31 and 32, thereby obtaining a high luminous efficiency.

Meanwhile, each of the first electrodes 31 and the second electrodes 32 is surrounded by dielectric layers 34 and 35 on its outer surface. These first and second electrodes 31 and 32 may be manufactured by a thick film ceramic sheet (TFCS) method. That is, the electrode unit including the first electrode 31 and the second electrode 32 may be separately manufactured, and then coupled to the rear substrate 10 having the partition wall 16 formed thereon. At this time, the electrode is coated with a ceramic (ceramic).

The MgO passivation layer 36 may be formed on the surfaces of the dielectric layers 34 and 35 covering the first electrode 31 and the second electrode 32. In particular, the MgO passivation layer 36 may be formed in a portion exposed to the plasma discharge occurring in the discharge space inside the discharge cell 18. In the present embodiment, since the first electrode 31 and the second electrode 32 are not formed on the front substrate, the MgO protective layer 36 applied to the dielectric layers 34 and 35 covering these electrodes is not visible light impermeable. MgO having the characteristic of can be used. Visible light-transmissive MgO has a much higher secondary electron emission coefficient value than visible light-transmissive MgO, thus further lowering the discharge start voltage.

In this embodiment, the thickness of the dielectric layer formed on the surface of the second electrode 32 facing the rear substrate 10 is greater than the thickness δl of the dielectric layer formed on the surface of the second electrode 32 facing the first electrode 31. (δh) is formed thicker. In this way, address discharge is prevented from occurring at the bottom surfaces of the address electrode 12 and the second electrode 32 so as to occur at the side of the address electrode 12 and the second electrode 32.

As such, the first electrode 31 having the dielectric layer 34 and the MgO protective film 36 is parallel with the partition members 16b and 26b between the second partition member 16b and the fourth partition member 26b. To be located. However, the second electrode 32 having the dielectric layer 35 and the MgO protective film 36 is positioned to intersect these partition members 16a and 26a between the first partition member 16a and the third partition member 26a. do.

In particular, a groove may be formed in a portion of the first partition member to form the second electrode 32, and the second electrode 32 coated with the dielectric layer 35 and the MgO protective layer 36 may be inserted into the groove. have. In this case, the second electrode 32 and the first electrode 31 may be formed to have the same distance measured from the back substrate 10, and the dielectric layer 35 surrounding the second electrode 32. An upper end surface of the first barrier rib member 16a may be formed to substantially coincide with an upper end surface of the first partition member 16a. The second electrode 32 may be formed to penetrate the first partition member 16a.

The first electrode 31 and the second electrode 32 is preferably made of a metal electrode.

The phosphor layer 29 may be formed in the region 28 of the front substrate 20 partitioned by the third and fourth partition members 26a and 26b formed adjacent to the front substrate 20. Can be. The phosphor layer 29 may apply a dielectric layer on the front substrate 20, form a front plate partition 26, and then apply a phosphor layer on the dielectric layer, and selectively apply the dielectric layer to the front substrate 20. Instead, the front plate partition wall 26 may be formed on the front substrate 20 to apply a phosphor layer. Furthermore, the front substrate 20 may be etched to match the shape of the discharge cell 18 and then a phosphor layer may be coated thereon. At this time, the front plate partition 26 is made of the same material as the front substrate 20.

In the above case, the phosphor layer 29 formed on the front substrate is used to generate visible light by absorbing vacuum ultraviolet rays (VUV) directed toward the front substrate 20 after discharge is generated in the discharge cell 18. The phosphor layer 29 needs to be able to transmit visible light. For this purpose, the phosphor layer 29 may be formed on the front substrate 20 to have a thickness thinner than that of the phosphor layer 19 formed on the rear substrate 10. have.

In this way, the luminous efficiency can be improved by minimizing the loss of vacuum ultraviolet rays.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications or changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. In addition, it is natural that it belongs to the scope of the present invention.

As described above, according to the plasma display panel according to the present invention, two electrodes causing a discharge are caused by allowing electrodes commonly associated with an address discharge and a sustain discharge to penetrate the inner space of the discharge cell, and disposing the electrodes involved in the sustain discharge together. The discharge gap between the electrodes is reduced, and thus driving can be performed even at a low discharge start voltage.

In addition, since the dielectric layer and the transparent electrode do not need to be formed on the front substrate, the manufacturing cost of the PDP can be reduced and the visible light transmittance can be increased.

In addition, by using a visible light impermeable MgO having a much higher secondary electron emission coefficient as a protective film than a visible light transmissive MgO, the discharge initiation voltage can be further lowered, and a fluorescent material is formed on the front substrate to minimize the loss of vacuum ultraviolet rays and thus the luminous efficiency. Can increase.

Claims (17)

A first substrate and a second substrate disposed to face each other; Address electrodes formed on the first substrate in parallel with one direction; A plurality of discharge cells are partitioned in a space between the first substrate and the second substrate, the first partition member disposed in a direction parallel to the address electrode and the second partition member disposed in a direction crossing the address electrode; Partition wall; Phosphor layers formed in the discharge cells; First electrodes formed between the first substrate and the second substrate to extend over the second partition members to correspond to the second partition members that partition each discharge cell; Second electrodes disposed between the pair of first electrodes adjacent to each other and formed to pass through the discharge cell inner space across the first partition member. Plasma display panel comprising a. The method of claim 1, Each of the first electrodes has an outer surface surrounded by a dielectric layer. The method of claim 1, And cross-sections of the first electrodes and the second partition wall members corresponding to the first electrodes and the second partition wall members, respectively, having substantially the same symmetry axis. The method of claim 1, And wherein the first electrodes have a longer cross section cut in a plane perpendicular to the longitudinal direction in a direction perpendicular to the substrate than a length in a direction parallel to the substrate. The method of claim 1, And a MgO passivation layer formed on a side surface of the first electrodes facing at least an inner space of each discharge cell. The method of claim 1, Each of the second electrodes has an outer surface surrounded by a dielectric layer. The method of claim 6, And a thickness of the dielectric layer formed on the surface of the second electrode facing the first substrate is thicker than the thickness of the dielectric layer formed on the surface of the second electrode facing the first electrode. The method of claim 1, And the second electrodes have a longer cross section cut in a plane perpendicular to a longitudinal direction in a direction perpendicular to the substrate than a length in a direction parallel to the substrate. The method of claim 1, And at least an outer surface of the second electrodes exposed to an inner space of the discharge cell is surrounded by an MgO protective film. The method according to claim 6 or 9, The MgO passivation layer has a visible light impermeability. The method of claim 1, And the second electrodes are formed to penetrate the first partition members. The method of claim 1, And the first barrier member and the second barrier member protrude toward the surface of the second substrate adjacent to the first substrate. The method of claim 12, And a third partition wall member protruding toward the first substrate surface adjacent to the second substrate in a shape corresponding to the first partition wall member. The method of claim 12, And a fourth partition wall member protruding toward the first substrate surface adjacent to the second substrate in a shape corresponding to the second partition wall member. The method of claim 12, And the first electrode is positioned between the second partition member and the fourth partition member. The method of claim 12, And the second electrode is positioned between the first partition member and the third partition member. The method of claim 12, A third partition member protruding toward the first substrate surface adjacent to the second substrate in a shape corresponding to the first partition member; A fourth partition member protruding toward the first substrate surface adjacent to the second substrate in a shape corresponding to the second partition member; Including, And a phosphor layer formed in an area of the second substrate partitioned by the third and fourth partition members.

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