This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. ยง119 from an application for PLASMA DISPLAYPANEL earlier filled in the Korean Intellectual Property Office on 4 Nov. 2004 and there duly assigned Serial No. 10-2004-0089228.
1. Field of the Invention
The present invention relates to a Plasma Display Panel (PDP) displaying images using a gas discharge phenomenon.
2. Description of the Related Art
Plasma Display Panels (PDPs) are flat panel displays that are considered to be next generation flat panel displays due to their wide screens, and excellent display characteristics such as high image quality, ultra-thin thickness, and light weight. In addition, it is easy to fabricate a PDP and to enlarge the panel.
PDPs can be classified into Direct Current (DC) PDPs, Alternating Current (AC) PDPs, and hybrid PDPs according to their driving method. In addition, PDPs can be classified into opposing discharge PDPs and surface discharge PDPs according to their discharge structure. Most PDPs produced recently have been three-electrode surface discharge PDPs.
A three-electrode surface discharge PDP includes an upper substrate and a lower substrate facing the upper substrate. Sustain electrode pairs are disposed on a lower surface of the upper substrate, and an upper dielectric layer embedding the sustain electrode pairs and a protective layer covering the upper dielectric layer are formed sequentially thereon. Each of the sustain electrode pairs includes a scan electrode and a common electrode. In addition, the scan electrode and the common electrode respectively include transparent electrodes and bus electrodes.
Address electrodes extending perpendicularly to the sustain electrode pairs and a lower dielectric layer embedding the address electrodes are formed on an upper surface of the lower substrate. Barrier ribs are formed on the lower dielectric layer to define a plurality of discharge cells. The barrier ribs extend in two directions crossing each other in a matrix pattern. A phosphor layer is formed on the barrier ribs and on the lower dielectric layer, and a discharge gas is contained within the discharge cells.
In the PDP having the above structure, a plasma is formed by a discharge caused by the sustain electrode pairs, and the phosphor layer is excited by vacuum ultraviolet rays emitted from the plasma. Then, visible light is emitted by the phosphor layer to display image.
However, in such a three-electrode surface discharge PDP, about 40% of the emitted visible light is absorbed by the sustain electrode pairs, the upper dielectric layer, and the protective layer formed under the upper substrate while the remaining visible light pass through those layers. Therefore, the light emission efficiency is low. In addition, if the same image is displayed for a long time, charged particles of the discharge gas may collide with the phosphor layer, thus causing a permanent residual image.
When forming the PDP, the upper portion of the PDP including the upper substrate and the lower portion of the PDP including the lower substrate are sealed, and an air exhausting process for discharging impure gas in the PDP and a filling process for filling a discharge gas in the discharge cells are performed. In the air exhausting process, a vacuum pump exhausts the gas from the PDP through an air exhaustion hole disposed in the lower substrate while the PDP is heated. If the exhaustion of the PDP is not performed sufficiently, the discharge gas to be filled in the panel later and the impure gas remaining in the panel mix, and the composition of the discharge gas is changed, and accordingly, a display operation becomes unstable. Since the discharge cells are sealed by the barrier ribs, sufficient air ventilation is interrupted, and thus, it takes a long time to exhaust the impure gas and fill the discharge gas. In addition, the impurities remain in the discharge cells that are located far from the ventilation hole. Especially in PDPs with super-fine and high resolutions, the inner structure of the panel is fine, and thus, difficulties with the exhaustion of the impure gas must be solved.
The present invention provides a PDP having good light emission efficiency and driving efficiency, and little phosphor material degradation.
The present invention also provides a PDP having an improved structure, in which flow resistance is reduced so that exhaustion of an impure gas and filling of a discharge gas can be performed rapidly.
According to an aspect of the present invention, a Plasma Display Panel (PDP) is provided comprising: an upper substrate: a lower substrate facing the upper substrate; upper barrier ribs arranged between the upper and lower substrates to define a plurality of discharge cells together with the upper substrate; discharge electrodes adapted to generate a discharge in the plurality of discharge cells; lower barrier ribs arranged between the upper barrier ribs and lower substrate along a row of the plurality of discharge cells to define a plurality of flow paths adapted to enable the plurality of discharge cells to communicate with each other; a phosphor layer arranged at a same level as the lower barrier ribs; and a discharge gas contained within the plurality of discharge cells.
The upper barrier ribs preferably extend in two directions crossing each other in a matrix pattern, and the lower barrier ribs are preferably arranged in a striped pattern extending along one of the two directions.
The upper barrier ribs preferably embed upper discharge electrodes and lower discharge electrodes separated from each other in a vertical direction and surrounding the plurality of discharge cells.
The upper and lower discharge electrodes preferably extend parallel to each other, each of the upper and lower discharge electrodes preferably surrounds a row of the plurality of discharge cells, and address electrodes preferably extend along the plurality of discharge cells and are arranged perpendicular to the upper and lower discharge electrodes.
The address electrodes are preferably arranged between the lower substrate and the phosphor layer, and a dielectric layer is preferably arranged between the phosphor layer and the address electrodes.
The lower barrier ribs preferably extend along a direction in which the address electrodes extend.
The lower barrier ribs preferably alternatively extend in a direction perpendicular to a direction in which the address electrodes extend.
The PDP preferably further comprises a protective layer adapted to cover side surfaces of the upper barrier ribs.
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:
Address electrodes 22 extending perpendicularly to the sustain electrode pairs 16 and a lower dielectric layer 23 embedding the address electrodes 22 are formed on an upper surface of the lower substrate 21. Barrier ribs 24 are formed on the lower dielectric layer 23 to define a plurality of discharge cells 30. The barrier ribs 24 extend in two directions crossing each other in a matrix pattern. A phosphor layer 25 is formed on the barrier ribs 24 and on the lower dielectric layer 23, and a discharge gas is contained within the discharge cells 30.
In the PDP having the above structure, a plasma is formed by a discharge caused by the sustain electrode pairs 16, and the phosphor layer 25 is excited by vacuum ultraviolet rays emitted from the plasma. Then, visible light is emitted by the phosphor layer 25 to display image.
However, in such a three-electrode surface discharge PDP, about 40% of the emitted visible light is absorbed by the sustain electrode pairs 16, the upper dielectric layer 14, and the protective layer formed under the upper substrate 11 while the remaining visible light pass through those layers. Therefore, the light emission efficiency is low. In addition, if the same image is displayed for a long time, charged particles of the discharge gas may collide with the phosphor layer 25, thus causing a permanent residual image.
When forming the PDP, the upper portion of the PDP including the upper substrate 11 and the lower portion of the PDP including the lower substrate 21 are sealed, and an air exhausting process for discharging impure gas in the PDP and a filling process for filling a discharge gas in the discharge cells are performed. In the air exhausting process, a vacuum pump exhausts the gas from the PDP through an air exhaustion hole (not shown) disposed in the lower substrate while the PDP is heated. If the exhaustion of the PDP is not performed sufficiently, the discharge gas to be filled in the panel later and the impure gas remaining in the panel mix, and the composition of the discharge gas is changed, and accordingly, a display operation becomes unstable. Referring to
Referring to
Upper barrier ribs 114 are formed under the upper substrate 111, and the upper barrier ribs 114 define discharge cells 130 with the upper substrate 111 to prevent cross talk from occurring between the discharge cells 130. Each of the discharge cells 130 is a Red sub-pixel, Green sub-pixel, or Blue sub-pixel of a pixel.
The upper barrier ribs 114 can be formed in a matrix pattern by extending in the x and y directions. The arrangement of the upper barrier ribs 1114 is not limited to the matrix pattern and can have a waffle or delta structure. The upper barrier ribs 114 are formed of a dielectric material to prevent upper discharge electrodes 112 and lower discharge electrodes 113 from electrically contacting each other, and induce wall charges to accumulate. The dielectric material forming the upper barrier ribs 114 can be PbO, B2O3, or SiO2.
It is desirable that a protective layer 115 covers side surfaces of the upper barrier ribs 1114 to prevent charged particles from colliding with and causing damage to the upper barrier ribs 114, and to emit a large number of secondary electrons. The protective layer 115 can be composed of MgO.
The upper discharge electrodes 112 and the lower discharge electrodes 113 are embedded in the upper barrier ribs 114. The upper and lower discharge electrodes 112 and 113 are separated in the z-direction. The discharge electrodes 112 and 113 effect a sustain discharge to display the image. Referring to
The upper and lower discharge electrodes 112 and 113 are formed of a metal having a high electrical conductivity, for example, Ag, Cu, or Al. Therefore, the voltage drop caused by the resistance of the upper and lower discharge electrodes themselves can be minimized, and thus, driving efficiency and response speed can be improved, and a uniform voltage can be supplied to the discharge cells disposed far from the point where the voltage is supplied.
In addition, referring to
The address electrodes 122 are embedded in a dielectric layer 123. The dielectric layer 123 prevents the charged particles of the discharge gas from directly colliding with and damaging the address electrodes 122, and induces the wall charges. The dielectric layer 123 is formed of a dielectric material, for example, PbO, B2O3, or SiO2.
Lower barrier ribs 124 with an open structure are formed on the dielectric layer 123. The lower barrier ribs 124 are formed in a striped pattern extending in one of the x and y directions, and in
In addition, after performing the air exhaustion process, the discharge gas, in which Ne and Xe are mixed, is injected into the panel using a gas injection device (not shown), and the discharge gas injected through the ventilation hole flows into the discharge cells 130 through the flow paths 140 formed along rows of the discharge cells 130. Therefore, the air exhaustion process or the filling process does not take an extended period of time, and accordingly, the fabrication costs of the PDP can be reduced.
In addition, if the lower barrier ribs 124 extend in the direction of the address electrodes 122 as shown in
The phosphor material 125 is applied at the same level as the lower barrier ribs 124, that is, the phosphor material is disposed at the same height as the lower barrier ribs 124. In more detail, the phosphor material 125 is applied on the dielectric layer 123 and the sides of the lower barrier ribs 124, and referring to
Referring to
On the upper substrate 1111in the PDP according to the present embodiment, the discharge sustain electrode pairs 16 and the dielectric layer 14 covering the discharge sustain electrode pairs 16 that are disposed on the upper substrate 111of a conventional PDP of do not exist. Therefore, the visible light emitted from the phosphor material 125 is not blocked, and the upward transmittance of the visible light is greatly improved. In addition, the PDP can be driven with a lower voltage than a conventional PDP, and thus, the light emission efficiency is improved.
In addition, in the PDP of the present embodiment, since the sustain discharge S occurs only in the region defined by the upper barrier ribs 114, ion sputtering of the phosphor material caused by the charged particles is prevented, and accordingly, a permanent residual image is not generated even when the same image is displayed on the screen for a long time.
The discharge electrodes including the upper and lower discharge electrodes 1112 and 113, a protective layer 215, a phosphor material 225, a dielectric layer 223, and the address electrodes are the same as those of the previous embodiment.
In the drawing figures of the present invention, the upper and lower discharge electrodes surround the discharge cells arranged along a row extending in the direction in which upper and lower discharge electrodes extend. However, another structure of the discharge electrodes can be applied to the present invention; for example, the upper and lower discharge electrodes can extend in a striped pattern while crossing side portions of the discharge cells arranged in a row. If the upper and lower discharge electrodes are extended while crossing the side portions of the discharge cells that are arranged in two directions perpendicular to each other, additional address electrodes are not required.
According to the present invention, the flow paths of the PDP are formed for communication between the discharge cells arranged in a row, and the facilitation of the exhaustion of the impure gas and the filling of the discharge gas. Accordingly, the manufacturing time can be reduced and productivity yield can be improved.
In addition, the impure gas can be exhausted to the outside through the flow paths, and thus, a change in the composition of the discharge gas due to the remaining impure gas can be prevented, and the image display can be performed stably.
Furthermore, the brightness level and the light emission efficiency are higher than those of a conventional three-electrode surface discharge PDP, and a degrading of the phosphor material can be avoided.
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 |
---|---|---|---|
10-2004-0089228 | Nov 2004 | KR | national |