Patent Application
20080100537
This application claims the benefit of Korean Patent Application No. 10-2006-0105350 filed on Oct. 27, 2006, which is hereby incorporated by reference.
1. Field of the Disclosure
This document relates to a plasma display apparatus and a method of driving the same.
2. Description of the Background Art
A plasma display apparatus includes a plasma display panel including a plurality of electrodes and a driver supplying driving signals to the electrodes of the plasma display panel.
The plasma display panel includes phosphor layers inside discharge cells partitioned by barrier ribs. The driver supplies the driving signals to the discharge cells through the electrodes.
When the driving signal generates a discharge inside the discharge cells, a discharge gas filled in the discharge cells generates vacuum ultraviolet rays, which thereby cause phosphors formed inside the discharge cells to emit light, thus displaying an image on the screen of the plasma display panel.
This document provides a plasma display apparatus and a method of driving the same capable of reducing the manufacturing cost and improving the driving efficiency.
In one aspect, a plasma display apparatus comprises a plasma display panel including a first electrode, a second electrode and a third electrode intersecting the first electrode and the second electrode, at least one of the first electrode and the second electrode having a singe-layered structure, and a driver that supplies sustain signals to the first electrode and the second electrode during a sustain period of a frame, wherein the sustain signal supplied to the first electrode overlaps the sustain signal supplied to the second electrode.
In another aspect, a method of driving a plasma display apparatus including a plasma display panel including a first electrode, a second electrode and a third electrode intersecting the first electrode and the second electrode, at least one of the first electrode and the second electrode having a singe-layered structure, the method comprises supplying first and second sustain signals to the first electrode and the second electrode, respectively, so that the first sustain signal supplied to the first electrode overlaps the second sustain signal supplied to the second electrode.
In still another aspect, a method of driving a plasma display apparatus including a plasma display panel including a first electrode, a second electrode and a third electrode intersecting the first electrode and the second electrode, at least one of the first electrode and the second electrode having a singe-layered structure, the method comprises successively supplying first and second sustain signals to the first and second electrodes, respectively, successively supplying third and fourth sustain signals to the first and second electrodes, respectively, wherein the first sustain signal overlaps the second sustain signal during a first period, and the third sustain signal overlaps the fourth sustain signal during a second period whose a time width is different from a time width of the first period.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated on and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
Reference will now be made in detail embodiments of the invention examples of which are illustrated in the accompanying drawings.
As illustrated in
The plasma display panel 100 includes first electrodes Y1 to Yn and second electrodes Z1 to Zn positioned parallel to each other and third electrodes X1 to Xm intersecting the first electrodes Y1 to Yn and the second electrodes Z1 to Zn.
The driver 110 supplies sustain signals to the first electrodes Y1 to Yn and the second electrodes Z1 to Zn during a sustain period of a frame. The sustain signal supplied to the first electrodes Y1 to Yn overlaps the sustain signal supplied to the second electrodes Z1 to Zn.
In
For instance, the driver 110 may include a first driver (not shown) for driving the first electrodes Y1 to Yn, a second driver for driving the second electrodes Z1 to Zn and a third driver (not shown) for driving the third electrodes X1 to Xm.
As illustrated in
At least one of the first electrode 202 and the second electrode 203 has a single-layered structure. For instance, at least one of the first electrode 202 and the second electrode 203 may be an electrode with an ITO (indium-tin-oxide)-less structure not including a transparent electrode.
At least one of the first electrode 202 and the second electrode 203 may include an electrically conductive metal material. Examples of the electrically conductive metal material include silver (Ag), copper (Cu), aluminum (Al), and the like. Because at least one of the first electrode 202 and the second electrode 203 includes the electrically conductive metal material, a color of at least one of the first electrode 202 and the second electrode 203 may be darker than a color of an upper dielectric layer 204.
The first electrode 202 and the second electrode 203 receive driving signals for generating a discharge inside discharge cells and maintaining the discharge.
The upper dielectric layer 204 for covering the first electrode 202 and the second electrode 203 is positioned on the front substrate 201 on which the first electrode 202 and the second electrode 203 are positioned. The upper dielectric layer 204 limits discharge currents of the first electrode 202 and the second electrode 203 and provides insulation between the first electrode 202 and the second electrode 203.
A protective layer 205 is positioned on the front substrate 201, on which the upper dielectric layer 204 is positioned, by depositing a material such as magnesium oxide (MgO) on the upper dielectric layer 204.
A lower dielectric layer 215 for covering the third electrode 213 is positioned on the rear substrate 211 on which the third electrode 213 is positioned. The lower dielectric layer 215 provides insulation of the third electrode 213.
Barrier ribs 212 are positioned on the lower dielectric layer 215 to partition discharge spaces (i.e., discharge cells). A red (R) discharge cell, a green (G) discharge cell and a blue (B) discharge cell, and the like, are positioned between the barrier ribs 212. The red (R), green (G) and blue (B) discharge cells may be classified depending on a color of light coming from each discharge cell.
In addition to the red (R), green (G) and blue (B) discharge cells, a white discharge cell or a yellow discharge cell may be further positioned between the barrier ribs 212.
Widths of the red (R), green (G) and blue (B) discharge cells may be substantially equal to one another. Further, a width of at least one of the red (R), green (G) or blue (B) discharge cells may be different from widths of the other discharge cells.
For instance, as illustrated in
The widths of the R, G and B discharge cells determine a width of a phosphor layer 214 positioned inside the R, G and B discharge cells. For instance, in a case of
The plasma display panel may have various forms of barrier rib structures as well as a structure of the barrier rib 212 illustrated in
While the plasma display panel has been illustrated and described to have the red (R), green (G) and blue (B) discharge cells arranged on the same line, it is possible to arrange them in a different pattern. For instance, a delta type arrangement in which the red (R), green (G) and blue (B) discharge cells are arranged in a triangle shape may be applicable. Further, the discharge cells may have a variety of polygonal shapes such as pentagonal and hexagonal shapes as well as a rectangular shape.
The phosphor layer 214 emitting visible light during the generation of a sustain discharge is positioned inside the discharge cell partitioned by the barriers 212.
A thickness of at least one of the phosphor layers 214 inside the red (R), green (G) and blue (B) discharge cells may be different from thicknesses of the other phosphor layers. For instance, as illustrated in
It should be noted that only one example of the plasma display panel applicable to the plasma display apparatus according to the exemplary embodiment has been illustrated and described above, and the exemplary embodiment is not limited to the plasma display panel of the above-described structure. A black layer (not shown) for absorbing external light may be further positioned on the barrier rib 212 to prevent the reflection of the external light caused by the barrier rib 212.
Further, another black layer (not shown) may be further positioned at a specific position of the front substrate 201 corresponding to the barrier rib 212.
The third electrode 213 positioned on the rear substrate 211 may have a substantially constant width or thickness. Further, a width or thickness of the third electrode 213 inside the discharge cell may be different from a width or thickness of the third electrode 213 outside the discharge cell. For instance, a width or thickness of the third electrode 213 inside the discharge cell may be larger than a width or thickness of the third electrode 213 outside the discharge cell.
As illustrated in (a) of
The transparent electrodes 310a and 320a may include an expensive material such as ITO. The expensive material may cause an increase in the manufacturing cost.
On the contrary, as illustrated in (b) of
As illustrated in
As above, when the black layers 400a and 400b are positioned between the front substrate 201 and the second electrode 203 and between the front substrate 201 and the first electrode 202, respectively, the generation of reflection light can be prevented even if the first and second electrodes 202 and 203 are formed of a material with a high reflectivity.
As illustrated in
The line portions 410a, 410b, 440a and 440b each intersect a third electrode 470 inside a discharge cell partitioned by a barrier rib 400.
The line portions 410a, 410b, 440a and 440b are spaced apart from one another with a predetermined distance therebetween. For instance, the first and second line portions 410a and 410b of the first electrode 430 are spaced apart from each other with a distance d1 therebetween. The first and second line portions 1440a and 1440b of the second electrode 1460 are spaced apart from each other with a distance d2 therebetween. The distance d1 may be equal to or different from the distance d2.
The line portions 410a, 410b, 440a and 440b may have a predetermined width. For instance, the first line portion 410a of the first electrode 430 has a width of Wa, and the second line portion 410b of the first electrode 430 has a width of Wb. A shape of the first electrode 430 may be symmetrical or asymmetrical to a shape of the second electrode 460 inside the discharge cell. For instance, while the first electrode 430 may include three line portions, the second electrode 460 may include two line portions.
At least one of the first electrode 430 or the second electrode 460 may include at least one projecting portion. For instance, the first electrode 430 includes two projecting portions 420a and 420b, and the second electrode 460 includes two projecting portions 450a and 450b. The projecting portions 420a and 420b of the first electrode 430 project from the first line portion 410a, and the projecting portions 450a and 450b of the second electrode 460 project from the first line portion 440a. The projecting portions 420a, 420b, 450a and 450b are parallel to the third electrode 470.
An interval g1 between the first and second electrodes 430 and 460 at the projecting portions 420a, 420b, 450a and 450b is shorter than an interval g2 between the first and second electrodes 430 and 460 in the discharge cell. Accordingly, a firing voltage of a discharge generated between the first electrode 430 and the second electrode 460 can be lowered.
At least one of the projecting portions 420a, 420b, 450a and 450b may overlap the third electrode 470 inside the discharge cell. Therefore, a firing voltage between the first electrode 430 and the third electrode 470 and a firing voltage between the second electrode 460 and the third electrode 470 can be lowered. Further, the driving efficiency and an address jitter characteristic can be improved.
A discharge generated between the projecting portions 420a and 420b of the first electrode 430 and the projecting portions 450a and 450b of the second electrode 460 can be diffused into the first and second line portions 410a and 410b of the first electrode 430 and the first and second line portions 440a and 440b of the second electrode 460. While the first electrode 430 and the second electrode 460 each include two projecting portions in
As illustrated in
As illustrated in
Accordingly, a discharge can be easily diffused inside a discharge cell partitioned by a barrier rib 500 due to the connecting portions 520c and 550c.
As illustrated in
Referring to
The projecting portions 620a, 620b, 620d, 650a, 650b and 650d projecting toward the first and second directions can more widely diffuse a discharge inside the discharge cell.
While the first and second electrodes 630 and 660 each include only one second projecting portion projecting toward the second direction in
As illustrated in
For instance, a width W10 of the first projecting portions 720a, 720b, 750a and 750b may be larger than a width W20 of the second projecting portions 720d and 750d.
When the width W10 of the first projecting portions 720a, 720b, 750a and 750b is larger than the width W20 of the second projecting portions 720d and 750d, a firing voltage between a first electrode 730 and a second electrode 760 can be lowered. Further, since an area of the opposing electrodes increases, the intensity of a discharge can increase.
As illustrated in
When the width W10 of the second projecting portions 720d and 750d is larger than the width W20 of the first projecting portions 720a, 720b, 750a and 750b, a discharge generated inside a discharge cell can be efficiently diffused into the rear of the discharge cell.
As illustrated in
As illustrated in
As illustrated in
As illustrated in
Each subfield is subdivided into a reset period for initializing all the cells, an address period for selecting cells to be discharged, and a sustain period for representing gray level in accordance with the number of discharges.
For instance, one frame, as illustrated in
The plasma display apparatus according to the exemplary embodiment uses a plurality of frames to display an image for 1 second. For instance, 60 frames are used to display an image 1 second. In this case, a time width T of one frame may be 1/60 seconds, i.e., 16.67 ms.
In
As illustrated in
The pre-sustain signal is substantially maintained at a pre-sustain voltage Vpz. The pre-sustain voltage Vpz is substantially equal to a voltage (i.e., a sustain voltage Vs) of a sustain signal (SUS) which will be supplied during a sustain period.
As above, during the pre-reset period, the first falling signal is supplied to the first electrode and the pre-sustain signal is supplied to the second electrode. Hence, wall charges of a predetermined polarity are accumulated on the first electrode, and wall charges of a polarity opposite the polarity of the wall charges accumulated on the first electrode are accumulated on the second electrode. As a result, the initialization of all the discharge cells can be performed stably so that a setup discharge with the sufficient intensity occurs during the reset period.
A subfield, which is first arranged in time order in a plurality of subfields of one frame, may include a pre-reset period prior to a reset period. Further, two or three subfields may include a pre-reset period prior to a reset period. All the subfields may not include the pre-reset period.
The reset period is further divided into a setup period and a set-down period. During the setup period, a rising signal of a polarity direction opposite a polarity direction of the first falling signal is supplied to the first electrode.
The rising signal includes a first rising signal and a second rising signal. The first rising signal gradually rises from a second voltage V2 to a third voltage V3 with a first slope, and the second rising signal gradually rises from the third voltage V3 to a fourth voltage V4 with a second slope.
The rising signal generates a weak dark discharge (i.e., a setup discharge) inside the discharge cell during the setup period, thereby accumulating a proper amount of wall charges inside the discharge cell.
The second slope of the second rising signal is gentler than the first slope of the first rising signal. When the second slope is gentler than the first slope, the quantity of light generated by the setup discharge is reduced. Accordingly, a contrast characteristic can be improved.
During the set-down period, a second falling signal of a polarity direction opposite a polarity direction of the rising signal is supplied to the first electrode. The second falling signal gradually falls from a fifth voltage V5 to a sixth voltage V6.
The second falling signal generates a weak erase discharge (i.e., a set-down discharge) inside the discharge cell. Further, the remaining wall charges are uniform inside the discharge cells to the extent that an address discharge can be stably performed.
As illustrated in
As illustrated in
Referring again to
A width of the scan signal may vary from one subfield to the next subfield. For instance, a width of a scan signal in a subfield may be larger than the width of a scan signal in the next subfield in time order.
As above, when the scan signal (Scan) is supplied to the first electrode, a data signal (data) corresponding to the scan signal (Scan) is supplied to the third electrode. The data signal (data) rises from a ground level voltage GND by a data voltage magnitude ΔVd.
As the voltage difference between the scan signal (Scan) and the data signal (data) is added to the wall voltage generated during the reset period, the address discharge occurs inside the discharge cell to which the data signal (data) is supplied.
A sustain bias signal is supplied to the second electrode during the address period so as to prevent the generation of the unstable address discharge caused by interference of the second electrode.
The sustain bias signal is substantially maintained at a sustain bias voltage Vz. The sustain bias voltage Vz is lower than the voltage Vs of the sustain signal and is higher than the ground level voltage GND.
During the sustain period, a sustain signal (SUS) is alternately supplied to the first electrode and the second electrode. As the wall voltage within the discharge cell selected by performing the address discharge is added to the sustain voltage Vs, every time the sustain signal (SUS) is supplied, a sustain discharge occurs between the first electrode and the second electrode. Accordingly, a predetermined image is displayed on the plasma display panel.
As above, when the sustain signal supplied to the first electrode overlaps the sustain signal supplied to the second electrode, wall charges produced by the sustain signal supplied to the first electrode can contribute to a sustain discharge generated when the sustain signal is supplied to the second electrode. Hence, the driving efficiency can be improved.
A panel structure in which at least one of the first electrode or the second electrode has a single-layered structure has a higher firing voltage than a panel structure including a transparent electrode. Accordingly, it is advantageous that a sustain signal supplied to the first electrode overlaps a sustain signal supplied to the second electrode in consideration of the driving efficiency.
As illustrated in (b) of
The driving efficiency can be improved and the generation of image sticking can be further prevented by using three or more types of sustain signals.
While two sustain signals overlap each other during a period d in (a) of
As illustrated in
In
Time widths of the overlapping periods d1 and d2 may be substantially equal to or different from each other. The period T1 or T2 may range from 4 μs to 6 μs.
The generation of image sticking can be further prevented by overlapping the sustain signal supplied to the first electrode with the sustain signal supplied to the second electrode and adjusting the pulse width or the period of the sustain signal.
As illustrated in (a) of
As illustrated in (b) of
A time width of the overlapping period d1 may be substantially equal to or different from a time width of the overlapping period d2. Further, the voltage rising period in (a) or (b) of
The generation of image sticking can be further prevented by overlapping the sustain signal supplied to the first electrode with the sustain signal supplied to the second electrode and adjusting at least one of the voltage rising period, the voltage maintenance period and the voltage falling period of the sustain signal.
A last sustain signal SUS6 supplied to the first electrode overlaps a last sustain signal SUS7 supplied to the second electrode during a period d of a predetermined subfield. In other words, an overlapping state of the last sustain signal SUS6 and the last sustain signal SUS7 is maintained until the predetermined subfield ends.
As a time width of the overlapping period d of the last sustain signals supplied to the first and second electrodes becomes longer during a sustain period of the predetermined subfield, the initialization of discharge cells can be easily performed during a reset period of a next subfield following the predetermined subfield using wall charges produced during the sustain period of the predetermined subfield. Hence, the driving efficiency can be improved.
The reliability of a first generated sustain discharge can be improved by setting pulse widths of a first sustain signal SUS1 and a second sustain signal SUS2 to be longer than a pulse width of the other sustain signals.
As above, the plasma display panel according to the exemplary embodiment can be manufactured using a simple manufacturing process at the low manufacturing cost by forming at least one of the first electrode or the second electrode in a single-layered structure.
Further, the driving efficiency can be improved and the generation of image sticking can be prevented by overlapping the sustain signal supplied to the first electrode with the sustain signal supplied to the second electrode.
Embodiments of the invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0105350 | Oct 2006 | KR | national |
