This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. § 119 from an application for PLASMA DISPLAY PANEL earlier filed in the Korean Intellectual Property Office on 9 Aug. 2005 and there duly assigned Serial No. 10-2005-0072964.
1. Field of the Invention
The present invention relates to a Plasma Display Panel (PDP) having a new structure.
2. Description of the Related Art
Plasma Display Panels (PDPs) have recently replaced conventional Cathode Ray Tube (CRT) displays. In a PDP, a discharge gas is sealed between two substrates on which a plurality of discharge electrodes are formed, a discharge voltage is applied, phosphors formed in a predetermined pattern are excited by ultraviolet rays generated by the discharge voltage to obtain a desired image.
A conventional Plasma Display Panel (PDP) having a similar structure to a PDP referred to in Japanese Laid-open Patent Publication No. 1998-172442 includes a first substrate, a plurality of pairs of sustain electrodes disposed on the first substrate, a first dielectric layer that covers the pairs of sustain electrodes, a protective layer that covers the first dielectric layer, a second substrate that is opposite to the first substrate, a plurality of address electrodes disposed on the second substrate to be parallel to one another, a second dielectric layer that covers the address electrodes, barrier ribs formed on the second dielectric layer, and phosphor layers formed on a top surface of the second dielectric layer and on both sides of the barrier ribs.
However, in the conventional PDP, a considerable portion (about 40%) of visible light rays emitted from the phosphor layer is absorbed by the pairs of sustain electrodes, the first dielectric layer, and the protective layer. In addition, when the conventional three-electrode surface discharge-type PDP displays the same image for a long time, the phosphor layers are ion-sputtered by charged particles of the discharge gas whereby permanent image sticking is formed.
To solve the problem, Korean Laid-open Patent Publication No. 2005-40635 refers to a PDP in which discharge electrodes are disposed at the sides of barrier ribs to cause a discharge, thereby improving brightness and luminous efficiency. In the case of the PDP having the above structure, since the discharge electrodes are disposed at the sides of the barrier ribs, a method of manufacturing the PDP is complicated.
The present invention provides a Plasma Display Panel (PDP) that can be simply manufactured.
The present invention also provides a PDP that reduces damages caused by thermal expansion.
According to an aspect of the present invention, a PDP is provided, the PDP including: a first substrate and a second substrate arranged opposite to and spaced apart from each other; an electrode sheet arranged between the first substrate and the second substrate and having barrier ribs partitioning discharge cells and pairs of discharge electrodes adapted to cause a discharge in the discharge cells; and fixing members arranged on sides of the electrode sheet and adapted to fix the electrode sheet between the first substrate and the second substrate.
The fixing members are preferably symmetrical with the electrode sheet. The fixing members preferably surround the electrode sheet. The electrode sheet preferably has a rectangular flat panel shape, and the fixing members are preferably arranged to correspond to at least two opposite vertices of the electrode sheet. The fixing members are alternatively preferably arranged to correspond to each of four vertices of the electrode sheet.
The electrode sheet preferably has a rectangular flat panel shape, and the fixing members are preferably arranged to correspond to at least two edges of the electrode sheet. The fixing members are alternatively preferably arranged to correspond to each of four edges of the electrode sheet.
The fixing members are preferably fixed on at least one of the first substrate and the second substrate.
The PDP preferably further includes a sealing member surrounding the electrode sheet and the fixing members and adapted to bond the first substrate to the second substrate. The sealing member preferably includes frit glass.
The discharge electrodes are preferably arranged within the barrier ribs. Each of the discharge electrodes preferably extends to surround the discharge cells disposed in one direction. Each of the pairs of discharge electrodes preferably includes a first discharge electrode and a second discharge electrode, the first discharge electrode and the second discharge electrode extending to cross each other. Each of the pairs of discharge electrodes alternatively preferably includes a first discharge electrode and a second discharge electrode, the first discharge electrode and the second discharge electrode extending to be parallel each other.
The PDP preferably further includes address electrodes extending to cross the pairs of discharge electrodes. The address electrodes are preferably arranged within the barrier ribs and extend to surround the discharge cells disposed in one direction.
The PDP preferably further includes grooves arranged on at least one of the first substrate and the second substrate, the grooves corresponding to the discharge cells.
The PDP preferably further includes phosphor layers arranged within the grooves.
The barrier ribs preferably include a dielectric substance.
A thermal expansion coefficient of the electrode sheet is preferably less than thermal expansion coefficients of the first substrate and the second substrate.
A more complete appreciation of the present invention and many of the attendant advantages thereof, will be readily apparent as the present invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
However, in the conventional PDP 100, a considerable portion (about 40%) of visible light rays emitted from the phosphor layer 110 is absorbed by the pairs of sustain electrodes 106 and 107, the first dielectric layer 109, and the protective layer 111. In addition, when the conventional three-electrode surface discharge-type PDP 100 displays the same image for a long time, the phosphor layers 110 are ion-sputtered by charged particles of the discharge gas whereby permanent image sticking is formed.
To solve the problem, Korean Laid-open Patent Publication No. 2005-40635 refers to a PDP in which discharge electrodes are disposed at the sides of barrier ribs to cause a discharge, thereby improving brightness and luminous efficiency. In the case of the PDP having the above structure, since the discharge electrodes are disposed at the sides of the barrier ribs, a method of manufacturing the PDP is complicated.
A Plasma Display Panel (PDP) 200 according to an embodiment of the present invention is illustrated in
The PDP 200 includes a first substrate 210, a second substrate 220, an electrode sheet 280, first phosphor layers 225, second phosphor layers 226, fixing members 240, and a sealing member 299. The electrode sheet 280 has a substantially rectangular flat panel shape.
The first substrate 210 is manufactured of a material that can be mainly formed of glass and has excellent light transmission. The first substrate 210 can be colored so as to reduce reflection brightness to improve contrast in a bright room. In addition, the second substrate 220 is separated from the first substrate 210 by a predetermined distance and opposes the first substrate 210. The second substrate 220 defines a plurality of discharge cells 230 together with the first substrate 210 and the electrode sheet 280. The second substrate 220 is manufactured of a material having excellent light transmission, such as glass. The second substrate 220 can also be colored as in the first substrate 210. In addition, the first substrate 210 and the second substrate 220 can be formed of the same material. A thermal expansion coefficient of the first substrate 210 is the same as that of the second substrate 220.
Visible light rays emitted by the discharge cells 230 can be emitted through the first substrate 210 and/or the second substrate 220. Since the sustain electrodes 106 and 107, the first dielectric layer 109, and the protective layer 111 that have existed on the first substrate 101 of the PDP 100 of
Referring to
The electrode sheet 280 includes first discharge electrodes 260 and second discharge electrodes 270. Referring to
Each of the second discharge electrodes 270 extends to surround the discharge cells 230 disposed along a second direction (Y-direction) that crosses the first direction (X-direction) in which the first discharge electrodes 260 extend. Each of the second discharge electrodes 270 is disposed to be more adjacent to the first substrate 210 than the first discharge electrodes 260. However, the present invention is not limited to this. Each of the second discharge electrodes 270 includes second loop portions 270a that surround the discharge cells 230, and second loop connecting portions 270b that connect the second loop portions 270a. Each of the second loop portions 270a has a circular loop shape. However, each of the second loop portions 270a is not limited to this and the second loop portions 270a can have various shapes such as rectangular loop shapes. The second loop portions 270a can have the same shapes as the cross-sections of the discharge cells 230.
The PDP 200 forms a two-electrode structure. That is, one of the first discharge electrode 260 and the second discharge electrode 270 serves as a scan and sustain electrode, and the other thereof serves an addressing and sustain electrode. However, the present invention is not limited to the two-electrode structure and can have a three-electrode structure.
In the above-described embodiments, the PDP 200 has a two-electrode or three-electrode surface discharge structure. However, the present invention is not limited to the above-described surface discharge structure and can have an opposed discharge structure in which the first discharge electrodes and the second discharge electrodes oppose toward a middle direction of the discharge cells 330 in the barrier ribs 214. The address electrodes in which the first discharge electrodes cross the second discharge electrodes can be further disposed.
Referring to
The first discharge electrodes 260 and the second discharge electrodes 270 are arranged in the barrier ribs 214. The barrier ribs 214 prevents electrical shorts between the adjacent first discharge electrodes 260 and the second discharge electrodes 270 during a discharge, prevents positive ions or electrons from colliding with the first discharge electrodes 260 and the second discharge electrodes 270 and prevents the first discharge electrodes 260 and the second discharge electrodes 270 from being damaged. The barrier ribs 214 can be formed of a dielectric substance that induces wall charges to accumulate.
The electrode sheet 280 includes protective layers 215 applied on adjacent portions of sides of the barrier ribs 214 to the first discharge electrodes 260 and the second discharge electrodes 270. The protective layers 215 prevent the barrier ribs 214 formed of the dielectric substance and the first and second discharge electrodes 260 and 270 from being damaged by the sputtering of plasma particles, and reduce a discharge voltage by emitting secondary electrons. Magnesium oxide (MgO) is applied on the sides of the barrier ribs 214 to a predetermined thickness to form the protective layers 215.
The fixing members 240 are closely adhered to the electrode sheet 280. The fixing members 240 have cross-sections substantially bent at 90 degrees, for example, “L”-shaped cross-sections, and correspond to each of four vertices 280a of the electrode sheet 280. The electrode sheet 280 is fixed between the first substrate 210 and the second substrate 220 so as not to move therebetween, using the fixing members 240. According to the current embodiment of the present invention, the fixing members 240 have similar shapes. For example, the fixing members 240 are symmetrical with the electrode sheet 280. However, the present invention is not limited to this and the fixing members 240 have only to fix the electrode sheet 280. In order to increase a fixing force generated by the fixing members 240, the fixing members 240 can be disposed at opposite sides of the electrode sheet 280. The fixing members 240 can be formed of various materials. In addition, the fixing members 240 are fixed on the first substrate 210 and/or the second substrate 220 using frit glass.
The PDP 200 further includes the first phosphor layers 225 and the second phosphor layers 226. More specifically, first grooves 210a are formed on the first substrate 210 that opposes the discharge cells 230. The first grooves 210a are discontinuously formed in each of the discharge cells 230, and the first phosphor layers 225 are disposed in the first grooves 210a. Similarly, second grooves 220a are discontinuously formed on the second substrate 220 that opposes the discharge cells 230. The second phosphor layers 226 are disposed in the second grooves 220a. The positions of the first phosphor layers 225 and the second phosphor layers 226 are not limited to those described above and the layers can be disposed in various positions. For example, the first phosphor layers 225 or the second phosphor layers 226 can be disposed on the sides of the barrier ribs 214 in which the protective layers 215 are not formed. The first and second phosphor layers 225 and 226 have components for generating visible light rays in response to ultraviolet light rays. The phosphor layers 225 and 226 formed in red discharge cells include phosphors such as Y(V,P)O4:Eu, the phosphor layers 125 and 126 formed in green discharge cells include phosphors such as Zn2SiO4:Mn, and the phosphor layers 125 and 126 formed in blue discharge cells include phosphors such as BAM:Eu.
A sealing member 299 is interposed between the first substrate 210 and the second substrate 220. The sealing member 299 surrounds the electrode sheet 280 and the fixing members 240 while not contacting the electrode sheet 280 and the fixing members 240. The sealing member 299 bonds boundaries of the first substrate 210 and the second substrate 220 to each other. The discharge cells 230 are sealed using the sealing member 299. The sealing member 299 can be formed of various materials, for example, a material including frit glass.
The size of the electrode sheet 280 and an area in which the sealing member 299 is disposed can be selected in various ways. For example, the barrier ribs 214 of the electrode sheet 280 do not include additional dummy barrier ribs and define only the discharge cells 230. In this case, the electrode sheet 280 can correspond to a display area D. The sealing member 299 can be disposed between the display area D and an outline C in which the first substrate 210 and the second substrate 220 overlap. In this structure, since the sealing member 299 and the electrode sheet 280 do not directly contact each other, the electrode sheet 280 is prevented from being contaminated by the sealing member 299 during a sealing process. In addition, since the barrier ribs 214 of the electrode sheet 280 do not include additional dummy barrier ribs, the amount of materials needed to form the barrier ribs 214 is reduced such that costs are reduced.
A method of manufacturing the PDP 200 having the above structure is described below. First, the first substrate 210, the second substrate 220, and the electrode sheet 280 are prepared. Next, the first substrate 210 and the second substrate 220 are etched or sand-blasted, thereby forming the first grooves 210a and the second grooves 220a. After that, pastes for the first phosphor layers 225 and the second phosphor layers 226, respectively, are applied, dried and fired. The fixing members 240 for fixing the electrode sheet 280 are fixed on the first substrate 210 or the second substrate 220 using a material such as frit glass. The electrode sheet 280 can be manufactured using various methods, for example, using the following method. Referring to
In general, there is the possibility of damages caused by a thermal expansion coefficient difference between components. However, in the case of the PDP 200 of
A change of temperature in a sealing furnace according to time during the sealing process is shown in
After the first substrate 210 and the second substrate 220 are sealed, a gas inside the first and second substrates 210 and 220 is exhausted and then, a discharge gas such as Ne or Xe, or a mixed gas thereof is sealed between the first and second substrates 210 and 220. A discharge surface increases and a discharge area increases so that the amount of plasma increases and low voltage driving can be performed. Thus, even though a high-concentration Xe gas is used as a discharge gas, low voltage driving can be performed whereby luminous efficiency can be remarkably improved.
A method of driving the PDP 200 having the above structure is described below.
First, an address discharge occurs between the first discharge electrodes 260 and the second discharge electrodes 270, and the discharge cells 230 in which a sustain discharge will occur as a result of the address discharge are selected. After that, if an AC sustain voltage is supplied between the first discharge electrodes 260 and the second discharge electrodes 270 of the selected discharge cells 230, a sustain discharge occurs between the first discharge electrodes 260 and the second discharge electrodes 270. The energy level of the excited discharge gas during the sustain discharge is reduced and UV light rays are emitted. The UV light rays excite the first and second phosphor layers 225 and 226 in the discharge cells 230. The energy level of the excited phosphor layers 225 and 226 is reduced, visible light is emitted, and the emitted visible light constitutes an image.
In the conventional PDP 100, a sustain discharge between the sustain electrodes 106 and 107 occurs in a horizontal direction, and a discharge area is relatively small. However, in the PDP 200 according to the current embodiment of the present invention, a sustain discharge occurs in all sides that define the discharge cells 230, and the discharge area is relatively large.
In addition, the sustain discharge according to the current embodiment of the present invention occurs in a looped curve along sides of the discharge cells 230 and gradually diffuses toward middle portions of the discharge cells 230. As a result, the volume of a region in which the sustain discharge occurs increases, and space charges in the discharge cells 230 that have not well been used in prior art also contribute to emission. Accordingly, luminous efficiency of the PDP 200 is improved. In particular, since cross-sections of the discharge cells 230 are circular shapes, the sustain discharge occurs uniformly on all sides of the discharge cells 230.
In addition, since the sustain discharge occurs only in central portions of the discharge cells 230, ion sputtering of phosphor layers caused by charged particles in the conventional PDP 100 is prevented. Thus, even when the same image is displayed for a long time, permanent image sticking is not formed.
The PDP according to the present invention has the following effects.
First, the number of processes is remarkably reduced and the processes are simplified such that the PDP can be very easily manufactured. Second, even in various thermal environment such as a high temperature process, the possibility of damages caused by thermal expansion is greatly reduced. Third, the sealing member is applied once to seal the first substrate and the second substrate such that a sealing process is simplified. Fourth, the first substrate, the second substrate, and the electrode sheet can be easily aligned using the fixing members such that manufacturing defects are reduced. Fifth, since a surface discharge can occur on all sides in which a discharge space is formed, a discharge surface can be greatly enlarged.
Sixth, since a discharge occurs on sides in which the discharge cells are formed and spreads toward middle portions of the discharge cells, a discharge area is remarkably improved compared to prior art such that the entire discharge cells are effectively used. Thus, driving can be performed at a lower voltage such that luminous efficiency is remarkably improved.
Seventh, even when a high-concentration Xe gas is used as a discharge gas, a low driving voltage can be used such that luminous efficiency is improved.
Eighth, discharge response speed is fast and a low driving voltage can be used. Since the discharge electrodes are not disposed on the first and second substrates which visible light rays transmit but are disposed at sides of the discharge space, electrodes having a low resistance, for example, metal electrodes, can be used as the discharge electrodes without the need of using transparent electrodes having a high resistance as the discharge electrodes such that discharge response speed is fast and a low driving voltage can be used without the distortion of waveforms.
Ninth, permanent image sticking can be prevented. Since an electric field caused by voltages supplied to the discharge electrodes formed on the sides of the discharge space allows the plasma to be concentrated on middle portions of the discharge space, ions generated by the discharge are prevented from colliding with phosphors by the electric field such that permanent image sticking is prevented from being formed due to ion sputtering. In particular, when a high-concentration Xe gas is used as a discharge gas, formation of permanent image sticking can be prevented.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various modifications in form and detail can be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
Number | Date | Country | Kind |
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10-2005-0072964 | Aug 2005 | KR | national |