Patent Application
20080090482
A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same 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:
Hereinafter, the present invention will be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.
The first substrate 201 is formed of a transparent substrate, for example, soda lime glass. Alternatively, the first substrate 201 may be formed of a semitransparent substrate, a colored substrate, a reflecting substrate, etc. The second substrate 202 can substantially be formed of the same material as the first substrate 201.
Barrier ribs 214 are formed between the first substrate 201 and the second substrate 202 in order to define discharge cells with the first substrate 201 and the second substrate 202. The barrier ribs 214 includes first barrier ribs 215 disposed along an X direction of the plasma display panel 200 and second barrier ribs 216 disposed along an Y direction of the plasma display panel 200. After being assembled, the discharge cells defined by the first substrate 201, the second substrate 202, and the barrier ribs 214 form a lattice structure.
The barrier ribs 214 may be of various types, such as a meander type, a delta type, a waffle type, a honey type, etc. Also, the discharge cells defined by the barrier ribs 214 may have not only a tetragonal cross section as illustrated in the current embodiment, but also other cross sections, such as a polygonal cross section, a circular cross section, an oval cross section, etc.
A pair of sustain discharge electrodes 203 is disposed on an inner surface of the first substrate 201. The pair of sustain discharge electrodes 203 includes X electrodes 204 and Y electrodes 205 extending along the X direction. The X electrodes 204 and the Y electrodes 205 are alternatively disposed along the Y direction of the plasma display panel 200.
The X electrode 204 includes first transparent electrodes 206 formed on the inner surface of the first substrate 201 and a first bus electrode line 207 electrically connected to the first transparent electrodes 206. The Y electrode 205 and the X electrode 204 have substantially the same form. The Y electrode 205 includes second transparent electrodes 208 formed on the inner surface of the first substrate 201 and a second bus electrode line 209 electrically connected to the second transparent electrodes 208.
The first transparent electrodes 206 and the second transparent electrodes 208 are independently disposed in each of the discharge cells and may have tetragonal shapes, but are not limited thereto. Also, the first transparent electrodes 206 and the second transparent substrates 208 are spaced apart from each other at a predetermined interval in order to form discharge gaps therebetween.
The first bus electrode line 207 and the second bus electrode line 209 cross the discharge cells adjacent to each other along the X direction of the plasma display panel 200, and are each disposed on both edges of the discharge cells. The first bus electrode line 207 and the second bus electrode line 209 overlap on the edges of the first transparent electrode 206 and the second transparent electrode 208.
The first transparent electrode 206 and the second transparent electrode 208 are formed of a transparent conductive film, for example, an indium tin oxide film, in order to improve an aperture ratio of the first substrate 201. The first bus electrode line 207 and the second bus electrode line 209 are formed of a conductive metal in a multi-layer form, for example, a silver paste or a chrome-copper-chrome alloy, in order to improve the electric conductivity of the first and second transparent electrodes 206 and 208.
Also, a space between one sustain discharge electrodes 203 disposed above one of the discharge cells and another sustain discharge electrodes 203 disposed above an adjacent discharge cell can correspond to a non-discharge area. In the non-discharge area, a black stripe layer may be formed in order to improve contrast.
The sustain discharge electrodes 203 are covered by a first dielectric layer 210. The first dielectric layer 210 is formed of a high dielectric material, for example, ZnO—B2O3—Bi2O3. The first dielectric layer 210 can be selectively formed on portions where the sustain discharge electrodes 203 are formed, or can be formed on the entire surfaces of the first substrate 201.
A protective layer 211, such as magnesium oxide (MgO), is formed on the surface of the dielectric layer 210 in order to prevent damage of the first dielectric layer 210 and to improve emission of secondary electrons.
Address electrodes 212 are disposed on an inner surface of the second substrate 202. The address electrodes 212 cross the Y electrodes 205. The address electrodes 212 are covered by a second dielectric layer 213. The second dielectric layer 213 is formed of a high dielectric material, for example, PbO—B2O3—SiO2.
Meanwhile, a discharge gas, such as neon-xenon or helium-xenon, is injected in the discharge cells defined by the first substrate 201, the second substrate 202, and the barrier ribs 214.
Phosphor layers 217 for emitting light, when excited by ultraviolet rays generated by the discharge gas, are respectively formed inside the discharge cells. The phosphor layer 217 can be formed on any area of the discharge cell, and in the current embodiment, the phosphor layer 217 is formed on the inner surface of the second substrate 202 and inner sidewall of the barrier ribs 214.
The phosphor layer 217 may be a red, green, or blue phosphor layer, but is not limited thereto. The red phosphor layer 217 may be formed of (Y,Gd)BO3;Eu+3, the green phosphor layer 217 may be formed of Zn2SiO4:Mn2+, and the blue phosphor layer 217 may be formed of BaMgAl10O17:Eu2+.
The red, green, and blue phosphor layers 217 can be formed in the discharge cells by simultaneously applying raw materials for red, green, or blue phosphor layers, using an application means, such as a dispenser.
Hereinafter, processes of applying raw materials for phosphor layers according to embodiments of the present invention will be described with reference to
Barrier ribs 403 are formed on the display area 401 and the non-display areas 402a and 402b in a lattice type structure. The barrier ribs 403 include main barrier ribs 403a formed on the display area 403 and dummy barrier ribs 403b formed on the non-display areas 402a and 402b. The dummy barrier ribs 403b extend from the main barrier ribs 403a as integration.
The dummy barrier ribs 403b extend from the main barrier ribs 403a in order to prevent the main barrier ribs 403a from contracting and deforming when the barrier ribs 403 are calcinated. Also, the dummy barrier ribs 403b are formed in order to reduce noise generated when a plasma display panel is operating.
Red, green, and blue phosphor layers are respectively formed inside discharge cells defined by the main barrier ribs 403a. Also, the red, green, and blue phosphor layers are respectively formed in discharge cells defined by the dummy barrier ribs 403b.
The phosphor layers are formed in the discharge cells defined by the dummy barrier ribs 403b in order to preferentially discharge the raw materials for the phosphor layers on the non-display areas 402a and 402b so that the phosphor layers in the display area 401 have uniform thicknesses.
The process of applying the raw materials for the phosphor layers on the substrate 400 is described as follows.
First, the substrate 400, divided into the display area 401 and the non-display areas 402a and 402b around the edges of the display area 401, is prepared. Then, the main barrier ribs 403a are formed on the display area 401 and the dummy barrier ribs 403b, which extend from the main barrier ribs 403a, are formed on the non-display area 403b of the substrate 400. At the same time, discharge electrodes (not shown) are formed in the discharge cells defined by the barrier ribs 403. The discharge electrodes extend from the display area 401 to the non-display areas 402a and 402b.
Next, raw materials for the phosphor layers for emitting lights of various colors are applied in the discharge cells. The raw materials for the phosphor layers are continuously and simultaneously applied using a dispenser that moves from one discharge cell to another discharge cell and also moves from one direction to another direction on the substrate 400 after finishing application of the raw material to a column of the discharge cells. As defined above, an applying path is defined as a path along which the dispenser moves while applying the raw material for the phosphor layer to the substrate, and a moving path is defined as a path along which the dispenser moves regardless of the application of the raw material. Therefore, in this case, the moving path and the applying path are the same (or identical). That is, the dispenser moves from the top right side 404 to the bottom left side 407 along a determined paths while applying the raw materials for forming the red, green, and blue phosphor layers in discharge cells defined by the barrier ribs 403.
At this time, the starting position for discharging the raw materials is the non-display area 402a, which includes the top right side 404 of the substrate 400. After reaching the bottom right side 405 of the substrate, which is the non-display area 402b, the dispenser moves horizontally in order to apply the raw materials in other columns of adjacent discharge cells. Accordingly, the dispenser moves from bottom to top above the substrate 400 while applying the raw materials for the phosphor layers. The area where the dispenser moves horizontally corresponds to the non-display area 405. Meanwhile, the raw materials for the phosphor layers are applied on the top surface of the barrier ribs 403.
Through the above processes, the dispenser moves from the top right side 404 to the bottom right side 405, to the center region of the substrate 400, to the top left side 406, and to the bottom left side 407 of the substrate 400, and thus it can continuously simultaneously apply the raw materials for the red, green, and blue phosphor layers in the discharge cells.
According to the current embodiment, the moving path of the dispenser and the applying path of the raw materials are the same, and thus the raw materials can be applied by moving the dispenser along the path without stopping application of the raw material. Also, the starting point and the ending point of the operation of applying the raw materials are both in the non-display areas, and the beginning and stopping of the dispensing process for the red, green, and blue phosphor ends on the same line.
In the present embodiment, the moving speeds of dispensers respectively discharging the raw materials for the red, green, and blue phosphor layers are different. That is, the moving speed of the dispenser discharging the raw material for the red phosphor layer is the highest, the moving speed of the dispenser discharging the raw material for the green phosphor layer is intermediate, and the moving speed of the dispenser discharging the raw material for the blue phosphor layer is the lowest.
Due to the differences in the moving speeds, the dispensers reach different locations in the non-display area 502b corresponding to the bottom right side 505 of the substrate 500. That is, due to the differences in the moving speeds, the locations of the discharge cells, where the raw materials for the red, green, and blue phosphor layers are applied in the non-display area 502b, differ by one cell. Accordingly, when the raw materials for the red, green, and blue phosphor layers are applied from the top right side 504 to the bottom right side 505 of the substrate 500, the dispenser discharging the raw material for the red phosphor layer and having the fastest speed moves the farthest, and the dispenser discharging the raw material for the blue phosphor layer and having the slowest speed moves the least.
After reaching the bottom right side 505 of the substrate 500, the dispensers move horizontally in the non-display area 502b. Thus, since the moving speeds of the dispensers are different while moving from the top right side 504 to the bottom right side 505, each dispenser moves to a different location in the non-display area 502b.
Through the above processes, the dispenser moves from the top right side 504 to the bottom right side 505, to the center region, to the top left side 506, and to the bottom left side 507 of the substrate 500, and thus the raw materials for red, green, and blue phosphor layer are continuously simultaneously applied in the discharge cells.
As described above, in the current embodiment of the present invention, the starting points of the operation of applying the raw materials are the same (i.e., the top right side 504), but since the moving speeds of the dispensers are different, the locations of the dispensers in the non-display areas 502a and 502b are different. Accordingly, the phosphor layers do not overlap.
Accordingly, when the dispensers move with the same speed, the dispenser discharging the raw material for the red phosphor layer in the non-display area 602b, which corresponds to the bottom right side 605 of the substrate 600, is located at the farthest distance from a display area 601, the raw material for the green phosphor layer is located at an intermediate distance from the display area 601, and the raw material for the blue phosphor layer is located at the nearest distance from the display area 601.
Next, the dispensers move horizontally to the center region of the substrate 600, and continuously move to the top left side 606 and the bottom left side 607 of the substrate 600 while applying the raw materials for respectively the red, green, and blue phosphor layers in the discharge cells. The dispensers for discharging red, green, and blue phosphors moves at the same speed while moving horizontally in the non-display area (near area 605).
As described above, the moving speeds of the dispensers discharging the raw materials for the red, green, and blue phosphor layers are the same, but the starting points of applying the raw materials are different. Accordingly, the dispensers are located at different positions in the non-display areas 602a and 602b, and thus the raw materials do not overlap.
In the present embodiment, unlike in the above embodiments in which the discharge electrodes are patterned on the substrate and the dielectric layers are formed both on the display area and the non-display area, the dielectric layers are selectively formed only on a display area 701. Accordingly, thicknesses of the display area 701 and non-display areas 702a and 702b are different by the thickness of the dielectric layers. Thus, the raw materials for forming the phosphor layers are applied to the non-display areas 702a and 702b in the areas where the dielectric layers are not formed. Consequently, when the dispensers move horizontally, the height of the raw materials for forming the phosphor layers is as much as the height of the dielectric layers.
Here, an interval d1 between portions 808a of the discharge electrodes 808 disposed on the display area 801 and an interval d2 between portions 808b of the discharge electrodes 808 disposed on the non-display area 802 are different. That is, the interval d1 is relatively smaller than the interval d2. Accordingly, when the dielectric layers are formed on the display area 801 and the non-display area 802, thicknesses of the dielectric layers can be reduced since the interval d2 between the portions 808b on the non-display area 802 is relatively larger.
Accordingly, when the dispensers apply the raw materials for forming the red, green, and blue phosphor layers, the thicknesses of the raw materials for the red, green, and blue phosphor layers are reduced as much as the thicknesses of the dielectric layers.
The method of manufacturing the plasma display panel according to the present invention has the following advantages. First, the raw materials for forming the phosphor layers for emitting light of various colors can be simultaneously and continuously applied using the dispensers. Accordingly, the processes of applying the raw materials can be simplified. Second, the dispensers are located at different positions in the non-display area, and thus the overlapping height of the raw materials can be reduced. Third, a mis-discharge is prevented since the overlapping amount of the raw materials for forming the phosphor layers is reduced.
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 changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1020060099364 | Oct 2006 | KR | national |
