KR100581936B1 - Plasma display panel - Google Patents

Abstract

According to the present invention, an address discharge for selecting a discharge cell for emitting visible light can be stably generated, thereby increasing image quality, increasing discharge amount, inducing luminance increase, and allowing address discharge to occur at a low voltage. It is an object of the present invention to provide a plasma display panel which reduces manufacturing costs by lowering the price of an integrated circuit chip for controlling potential, and in order to achieve the above object, the present invention provides a front substrate and a rear surface facing each other and having edges sealed to each other. A partition wall disposed between the substrate, the front substrate and the rear substrate, and defining a plurality of discharge cells which are spaces for generating a discharge; a phosphor layer disposed in the discharge cell; and the plurality of discharge cells extending adjacent to each other. Extend across and disposed between the phosphor layer and the back substrate, X Electrode pairs having an electrode and a Y electrode, a rear dielectric layer disposed between the phosphor layer and a rear substrate to cover the electrode pairs, intersect the electrode pairs with the discharge cells, and cross the discharge cells; Extending between the front substrate and the phosphor layer, and disposed between the front substrate and the phosphor layer to cover the address electrodes, and at least a part of a surface covering the address electrode is formed inside the discharge cell. It is an object of the present invention to provide a plasma display panel including a front dielectric layer having a front protrusion protruding toward and a discharge gas in the discharge cell.

Description

Plasma display panel {Plasma display panel}

1 is an exploded perspective view showing a plasma display panel of a first embodiment of the present invention;

2 is a cross-sectional view of the plasma display panel according to the first embodiment of the present invention taken along the line II-II;

3 is a cross-sectional view illustrating a change in discharge characteristics when a front protrusion is provided in the front dielectric layer of the first embodiment of the present invention;

4 is an exploded perspective view showing the plasma display panel of the second embodiment of the present invention;

5 is a cross-sectional view of the plasma display panel according to the second embodiment of the present invention taken along the line VV.

<Description of Symbols for Major Parts of Drawings>

100, 200: plasma display panel.

110: front panel 120: rear panel

123: rear dielectric layer 115: front dielectric layer

123a: front projection 123b: rear projection

140: discharge cell 126: electrode pair

130: bulkhead

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to means for inducing stable address discharge to increase image quality, increasing discharge amount to increase luminance, and achieving low voltage address discharge.

BACKGROUND ART In general, a plasma display panel is a display device that implements a predetermined image by exciting phosphors by ultraviolet rays generated by gas discharge. The plasma display panel is configured as a large-screen display of high resolution, and thus has been in the spotlight as a next-generation thin display device.

Conventionally, such plasma display panels are divided into AC type, DC type, and hybrid type according to the structure and driving principle, and AC type and DC type plasma display panel according to the discharge structure. Is divided into a surface discharge type and a counter discharge type, but in recent years, AC type surface discharge plasma display panels have become popular.

The AC type surface discharge plasma display panel is widely used due to its advantages such as its lifespan and stability. However, the driving circuit for driving the plasma display panel at a high voltage has a high discharge voltage during address discharge for selecting a discharge cell to emit light. The available shall apply. In this case, the price of the driving circuit increases as the driving voltage increases, thereby increasing the price of the plasma display panel driven at a high voltage.

In addition, since address discharge is a discharge that selects a discharge cell in which sustain discharge is to be generated, it is important to achieve stable address discharge because a high quality image can be realized only when the address discharge is properly generated in a desired discharge cell. Many other design requirements, such as voltage, are often conflicting and difficult to resolve.

In addition, due to the address discharge, a large amount of wall charges must be accumulated inside the discharge cell to increase the discharge amount, but direct control thereof is difficult.

The present invention solves the above problems, the address discharge to select a discharge cell for emitting visible light can be stably occur to implement high image quality, increase the amount of discharge to induce a brightness increase, the address discharge at a low voltage It is an object of the present invention to provide a plasma display panel in which manufacturing costs are reduced by lowering the price of an integrated circuit chip that controls the potential applied to the address electrode.

In order to achieve the above object, the present invention provides a plurality of discharge cells which are disposed to face each other and the edge is sealed to each other and the space between the front substrate and the rear substrate, the discharge substrate is a space for generating a discharge A barrier rib defining a partition wall, a phosphor layer disposed in the discharge cell, and a plurality of discharge cells extending adjacent to each other, and disposed between the phosphor layer and the back substrate, wherein the X electrode and the Y electrode Electrode pairs including a rear dielectric layer disposed between the phosphor layer and a rear substrate to cover the electrode pairs, intersect the electrode pairs with the discharge cells, and extend across the discharge cells; Address electrodes disposed between the front substrate and the phosphor layer, and disposed between the front substrate and the phosphor layer to cover the address electrodes. A plasma display panel includes a front dielectric layer having at least a portion of a surface covering the address electrode and having a front protrusion protruding toward the inside of the discharge cell, and a discharge gas in the discharge cell. In this case, in the plasma display panel of the present invention, the rear dielectric layer may further include a rear protrusion in which at least a portion of the rear dielectric layer protrudes toward the inside of the discharge cell. have.

On the other hand, the present invention is disposed between the front substrate and the rear substrate facing each other and the edges are sealed to each other, the partition wall disposed between the front substrate and the rear substrate, the plurality of discharge cells which is a space for generating a discharge, and the discharge A pair of phosphors disposed in the cell, extending across the plurality of discharge cells extending adjacent to each other, disposed between the phosphor layer and the back substrate, and having an X electrode and a Y electrode; A rear dielectric layer disposed between the phosphor layer and the rear substrate so as to cover the electrode pairs, the rear dielectric layer having a rear protruding portion protruding toward the inside of the discharge cell, at least a part of which covers at least one electrode of the electrode pairs; Intersect the electrode pairs with the discharge cells, extend across the discharge cells, and be disposed between the front substrate and the phosphor layer; The present invention may also provide a plasma display panel including address electrodes, a front dielectric layer disposed between the front substrate and the phosphor layer to cover the address electrodes, and a discharge gas in the discharge cell.

In this case, it is preferable that the above-mentioned plasma display panel is disposed in a space defined by the barrier rib and the front dielectric layer so that the phosphor layer covers the address electrode, and the electrode pair is disposed on the front surface of the rear substrate. It is preferably disposed on the rear surface of the front substrate. In addition, the address electrode is preferably formed of a transparent electrode, and in addition, it is preferable to further include a protective film disposed to cover the rear dielectric layer.

Hereinafter, a preferred embodiment of the plasma display panel 100 of the present invention will be described with reference to FIGS. 1 and 2. The plasma display panel 100 includes a front panel 110 and a rear panel 120. In this case, the front panel 110 has a front substrate 111 having a thickness of approximately 2.8 mm made of soda glass and the like, and the rear panel 120 has a rear substrate 121. At this time, the front substrate is preferably formed of a material such as transparent soda glass so that visible light generated in the phosphor layer to be described later, the back substrate is not located on the optical path which is a path for the visible light generated in the phosphor layer. Therefore, it is not necessarily transparent and can be formed of glass or the like, but can also be formed of an opaque material such as metal or plastic. The plasma display panel includes a partition wall 130 disposed between the front substrate and the rear substrate and defining discharge cells 140, which are spaces for generating discharge.

The rear panel 120 extends to cross the rear substrate 121 and the plurality of discharge cells 140 extending adjacent to each other, between the phosphor layer 116 and the rear substrate 121 to be described later. In more detail, the electrode pairs 126 including the X electrode 125 and the Y electrode 124 disposed on the front surface 121a of the rear substrate are provided. In this case, the electrode pair does not necessarily need to be disposed on the front surface of the rear substrate, and a layer that performs a separate function, such as a reflective layer that reflects visible light on the front surface of the rear substrate, may be disposed on the front of the layer. Since the electrode pairs may be arranged, there is no limitation on the arrangement position of the electrode pairs, and it is sufficient to be disposed between the phosphor layer 116 and the back substrate 121. On the other hand, the electrode pair is included between the X electrode and the Y electrode, while increasing the distance between the X electrode and the Y electrode, the sustain discharge generated in accordance with the sustain discharge potential applied alternately between the electrode pair at a low potential A floating electrode (not shown) with no potential applied thereto may be further disposed between the X electrode and the Y electrode in order to be able to occur, and an intermediate electrode (not shown) with a potential applied between the X electrode and the Y electrode may be provided. It may be disposed so that the sustain discharge can occur at a low potential while increasing the distance between the X electrode and the Y electrode. Accordingly, the protection range of the plasma display panel 100 of the present invention is not limited to only the electrode pair 126 including the X electrode 125 and the Y electrode 124 as shown in FIG. 1.

On the other hand, since the electrode pairs are disposed on the front surface of the back substrate, the visible light generated by the discharge in the discharge cell 140 is not positioned on the optical path that proceeds forward. Accordingly, the electrode pairs have a wide choice of materials, and thus the electrode pairs may be formed of materials such as aluminum, copper, and chromium having high electrical conductivity and relatively low cost. In addition, the electrode pair has a wide selection of shapes as well as materials, there is an advantage that can be variously modified. On the other hand, the electrode pair may be formed by screen printing or photolithography.

In addition, the rear panel may be disposed between the phosphor layer 116 and the rear substrate 121 to cover the electrode pairs 126, and more particularly, to the front surface 121a of the rear substrate to cover the electrode pairs. The rear dielectric layer 123 is disposed. In this case, the rear dielectric layer may be disposed by applying a dielectric paste which may be formed of PbO, SiO _2, etc., having a thickness of about 30 μm to the entire surface of the back substrate, and then baking. In addition, the rear dielectric layer is not necessarily transparent because it is not located on the optical path of visible light. Rather, the rear dielectric layer is preferably disposed as a white dielectric to increase the reflectance of visible light and increase the ratio of visible light moving forward. On the other hand, the rear dielectric layer 123 is not disposed on the front surface of the rear substrate for the same reason as the position of the electrode pairs, the rear dielectric layer to cover the electrode pair 126 as described above It is sufficient to be disposed between the phosphor layer 116 and the back substrate.

In addition, the rear panel 120 may further include a passivation layer 127 disposed to cover the rear dielectric layer 123. In this case, the passivation layer 127 serves to protect the rear dielectric layer and the electrode pairs covered by the rear dielectric layer, and at the same time, discharges secondary electrons upon collision of charged particles due to discharge to promote discharge. . In this case, MgO or the like is generally used as the material of the protective film, but since the protective film is coated on the rear surface of the rear dielectric layer, light transmittance is not a problem, and thus carbon nanotubes (CNT) having excellent electron emission characteristics may be used.

The front panel 110 crosses the front substrate 111 and the electrode pairs 126 at any discharge cell 140 and extends to cross the discharge cells adjacent to the discharge cell. Address electrodes 112 are disposed between the front substrate 111 and the phosphor layer 116, and more particularly, on the rear surface 111a of the front substrate. In this case, the address electrodes may be disposed on the rear surface of the front substrate by screen printing or photolithography. Meanwhile, the address electrodes 112 are not necessarily disposed on the rear surface of the front substrate, and a near infrared blocking film (not shown) is disposed on the rear surface of the front substrate to block near infrared rays generated during discharge, or an electromagnetic shielding filter layer. (Not shown), since the address electrodes can be disposed on the back of the near infrared blocking film or the electromagnetic wave shielding filter layer, it is sufficient that the address electrodes are disposed between the front substrate and the phosphor layer.

On the other hand, the front panel 120 is disposed between the front substrate 111 and the phosphor layer 116 to cover the address electrode, more specifically, the rear surface of the front substrate, at least of the surface covering the address electrode A portion of the discharge cell 140 includes a front dielectric layer 115 having a front protrusion 115a protruding toward the inside of the discharge cell 140. The function and the reason for the arrangement of the protrusions will be described later in detail.

In addition, the front panel 120 includes a phosphor layer 116 disposed in the discharge cell 140, more specifically, in a space defined by the front substrate 111 and the partition wall 130. At this time, the arrangement position of the phosphor layer is not limited to the space defined by the front substrate and the partition wall, and the phosphor layer 116 may be applied to the entire surface of the rear dielectric layer 123 in the discharge cell. It is enough if placed in the cell. In this case, the phosphor layer 116 may include red, green, and blue light emitting phosphor layers in order to enable the plasma display panel to implement a color image, and the red, green, and blue light emitting phosphor layers may be provided. May be disposed inside the discharge cell to form a unit pixel. The phosphor layer may include a phosphor paste in which any one of a phosphor, a solvent, and a binder is mixed with a red light emitting phosphor, a green light emitting phosphor, and a blue light emitting phosphor. It is formed by going through a drying and firing process after being applied to a portion of the. Examples of the red light emitting phosphor include (Y, Gd) BO ₃ : Eu ³⁺ , and examples of the green light emitting phosphor include Zn ² Si 04: Mn ^{2 +,} and examples of the blue light emitting phosphor include BaMgAl ₁₀ O ₁₇ : Eu ²⁺ .

On the other hand, since the address electrode 112 is located on an optical path in which visible light generated by the discharge generated in the discharge cell 140 travels forward, the address electrode 112 is formed of a transparent electrode to increase the transmittance of the visible light. It is preferable. In this case, in order to increase the visible light transmittance of the address electrode, in general, the address electrode is formed using indium tin oxide (ITO). Since the ITO has a high light transmittance but high resistance, a potential is applied to the address electrode formed of ITO. In this case, due to the voltage drop due to the high resistance of the ITO material, the size of the electric field formed inside the discharge cells traversing the address electrode is changed, so that address discharge may not be uniformly generated. The front panel may further include a bus electrode (not shown) formed of a metallic conductor material and having three layers of silver or chromium-copper-chromium electrically connected to the address electrode.

On the other hand, the partition wall 130 is disposed between the front substrate and the rear substrate as described above, the discharge cell, the discharge cell that functions as a minimum component of the pixel that is the basic unit for implementing the image of the plasma display panel Define 140. In this case, the partition wall is a glass component containing elements such as Pb, B, Si, Al, and O on the front dielectric layer 115 and, if necessary, fillers such as ZrO 2, TiO 2, and Al 2 O 3 and Cr. It may be formed by applying a barrier material paste composed of a barrier material containing a pigment such as Cu, Co, Fe, TiO2 and firing it. In this case, the partition wall is disposed to cover at least part of the surface of the address electrode 112. The arrangement position of the aforementioned partition wall and the reason thereof will be described later.

On the other hand, the discharge cell is filled with a discharge gas consisting of any one of neon (Ne), helium (He), or argon (Ar) including xenon (Xe) gas, or a mixed gas of two or more thereof. At this time, since the pressure of the discharge gas is in a vacuum state (0.5 atm), the pressure according to the vacuum of the discharge gas acts as a force for pressing the front substrate and the back substrate, which is supported by the partition wall. On the other hand, the front panel and the rear panel is coupled to the edge is sealed by a coupling member such as a frit (flit).

In the plasma display panel according to the first embodiment of the present invention with reference to FIG. 3, at least a portion of a surface of the front dielectric layer covering the address electrode 112 covering the address electrode protrudes toward the discharge cell 115a. It will be described with respect to the reason having a.

[ Equation 1 ]

Q = C * V

[ Equation 2 ]

C = ε * A / d

First, suppose that an electrode is covered by a dielectric and a predetermined potential is applied to the electrode. When the dielectric is a polar dielectric due to the potential applied to the electrode, the dipole moment acts on the molecules and is aligned in a certain direction. In the case of a nonpolar dielectric, the molecules are polarized and aligned in the predetermined direction, and formed by the potential applied to the electrode. As the electric field passes through the dielectric and acts on the space, wall charges, which are charges that accumulate on the outer surface of the dielectric by applying electric force to the charged particles in the space, are accumulated on the outer surface of the dielectric. At this time, when the same potential is continuously applied and the potential difference between the electrode and the outer surface of the dielectric is kept constant, the greater the dielectric constant of the dielectric, the greater the amount of wall charges accumulated on the outer surface of the dielectric. This means that the larger the relative dielectric constant ε in Equation 2, the higher the capacitance C, and when the potential difference V is kept constant in Equation 1, when the capacitance C increases, the total amount Q of charges accumulated in the capacitor increases accordingly. Can be easily predicted from

This theoretical consideration will be applied to the situation where address discharge occurs. In general, an address discharge is applied with a positive potential (approximately 60 V) to an address electrode, and a negative potential (approximately -50 V) is applied to a Y electrode that intersects the address electrode in a discharge cell in which sustain discharge is to occur. A predetermined potential difference occurs between the Y electrodes. In this case, as shown in FIG. 2, the address electrode 112 and the Y electrode 124 are flat plates to which a potential is applied, and the front dielectric layer 115, the rear dielectric layer 127, and the discharge gas are interposed between the flat plates. The electric field formed in the discharge cell may be modeled as a flat plate capacitor when a potential is applied between the address electrode and the Y electrode when the address is discharged. In this case, when the potential applied between the address electrode and the Y electrode is fixed as described above, the larger the dielectric constant of the dielectric inserted between the address electrode and the Y electrode, the greater the amount of charge accumulated in the address electrode and the Y electrode. And the size of the electric field formed inside the discharge cell by the address electrode and the Y electrode is increased. In this case, when the size of the electric field formed in the discharge cell is increased, it means that the average kinetic energy of the charged particles colliding with the discharge gas in the discharge cell can be further increased, thereby colliding with the discharge gas. By exciting the discharge gas, the number of charged particles having kinetic energy sufficient to generate a discharge can be increased. This means that the amount of discharge increases as the dielectric constant of the dielectric inserted between the address electrode and the Y electrode increases.

Therefore, it is necessary to increase the relative dielectric constant of the dielectric inserted between the address electrode and the Y electrode. In this case, the relative dielectric constant of the discharge gas is close to 1, and since the relative dielectric constant of the front dielectric layer 115 is relatively high, it is preferable to increase the proportion of the front dielectric layer in the dielectric between the address electrode and the Y electrode. Do. Therefore, based on these considerations, when at least a portion of the front dielectric layer covering the address electrode protrudes, the dielectric constant of the dielectric between the address electrode 112 and the Y electrode 124 increases, and thus the amount of discharge during the address discharge. Is increased. As a result, the increase in the discharge amount increases the amount of charged particles in the discharge cell and the amount of accumulated wall charge in the discharge cell after the end of the address discharge so that the discharge amount during the sustain discharge can be increased, thereby increasing the luminance of the plasma display panel. Will be. In addition, due to an increase in the dielectric constant of the dielectric between the address electrode and the Y electrode, address discharge occurs more stably under a predetermined voltage, and it becomes easier to control the discharge in a desired discharge cell.

In addition, an integrated circuit chip that controls the potential applied to the address electrode under a predetermined address discharge condition can be switched to be driven at a low voltage because the address discharge can occur even at a low voltage, and thus the plasma The manufacturing cost of the display panel is reduced.

4 to 5, the plasma display panel 200 according to the second embodiment of the present invention will be described with reference to the differences from the first embodiment of the present invention. The plasma display panel 200 of the second embodiment of the present invention differs from that of the first embodiment of the present invention in that the rear dielectric layer 223 disposed to cover the electrode pair 126 is formed of at least one of the electrode pairs. At least a part of the surface covering the electrode further includes a rear protrusion 223a protruding toward the inside of the discharge cell. In this case, the protruding portion may be formed on at least a portion of the electrode pair that covers the address electrode 112 and the electrode causing the address discharge. In the embodiment of the present invention, the electrode is the Y electrode 124. It is preferable. On the other hand, due to the presence of the rear dielectric layer 223, in the plasma display panel of the second embodiment of the present invention, the dielectric constant of the dielectric between the address electrode and the Y electrode is increased so that the discharge amount of the address discharge is further increased. The characteristics according to the address discharge mentioned in the first embodiment of the invention are further improved.

On the other hand, the rear projection portion of the rear dielectric layer applied in the plasma display panel of the second embodiment of the present invention is not necessarily applied simultaneously with the front projection portion of the front dielectric layer disposed to cover the address electrode, which is why the protrusions are formed. It can naturally be derived from the description of the first embodiment of the present invention to increase the dielectric constant of the dielectric between the electrode and the Y electrode. Accordingly, the present invention can achieve the intended features of the invention only if the front dielectric layer does not have a front protrusion and the rear dielectric layer has a rear protrusion.

The present invention can solve the above problems, it is possible to achieve a high image quality by allowing the address discharge to select a discharge cell for emitting visible light stably.                     

In addition, the present invention can improve the quality of the plasma display panel by increasing the discharge amount during the address discharge to induce a rise in the brightness of the plasma display panel.

In addition, the present invention improves the price competitiveness of the plasma display panel by reducing the cost of the integrated circuit chip to control the potential applied to the address electrode by allowing the address discharge to occur at a low voltage.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (7)

A front substrate and a rear substrate which are disposed to face each other and whose edges are sealed to each other; A partition wall disposed between the front substrate and the rear substrate and defining a plurality of discharge cells which are spaces for generating a discharge; A phosphor layer disposed in the discharge cell; Electrode pairs extending across the plurality of discharge cells extending adjacent to each other, disposed between the phosphor layer and the rear substrate, and having an X electrode and a Y electrode; A rear dielectric layer disposed between the phosphor layer and the rear substrate to cover the electrode pairs; Address electrodes intersecting the electrode pairs with the discharge cells, extending to cross the discharge cells, and disposed between the front substrate and the phosphor layer; A front dielectric layer disposed between the front substrate and the phosphor layer to cover the address electrodes, and a front dielectric layer having at least a portion of a surface covering the address electrode protruding toward the inside of the discharge cell; And a discharge gas in the discharge cell. The method of claim 1, And the rear dielectric layer includes a rear protrusion which protrudes toward at least a portion of a surface of at least one of the electrode pairs toward the inside of the discharge cell. A front substrate and a rear substrate which are disposed to face each other and whose edges are sealed to each other; A partition wall disposed between the front substrate and the rear substrate and defining a plurality of discharge cells which are spaces for generating a discharge; A phosphor layer disposed in the discharge cell; Electrode pairs extending across the plurality of discharge cells extending adjacent to each other and disposed between the phosphor layer and the rear substrate, the electrode pairs including an X electrode and a Y electrode; A rear dielectric layer disposed between the phosphor layer and the rear substrate to cover the electrode pairs, the rear dielectric layer having a rear protrusion part at least part of a surface of which covers at least one electrode of the electrode pairs toward the inside of the discharge cell; Address electrodes intersecting the electrode pairs with the discharge cells, extending to cross the discharge cells, and disposed between the front substrate and the phosphor layer; A front dielectric layer disposed between the front substrate and the phosphor layer to cover the address electrodes; And a discharge gas in the discharge cell. The method according to claim 1 or 3, And the phosphor layer is disposed in a space defined by the barrier rib and the front dielectric layer so as to cover the address electrode. The method according to claim 1 or 3, And the electrode pair is disposed on the front surface of the rear substrate, and the address electrode is disposed on the rear surface of the front substrate. The method according to claim 1 or 3, And the address electrode is formed of a transparent electrode. The method according to claim 1 or 3, And a passivation layer disposed to cover the rear dielectric layer.

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