Abstract:
It is disclosed that there is a method and an apparatus for driving a plasma display panel that is adaptive for improving brightness as well as realizing a high resolution. 
     A method and an apparatus for driving a plasma display panel according to the present invention displays discharge cells of the (3i−2) th  and (3i−1) th  rows in use of the first video signal field; and discharge cells of the (3i−1) th  and (3i) th  rows in use of the second video signal field.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a plasma display panel, and more particularly to a method and an apparatus for driving a plasma display panel that is adaptive for improving brightness as well as realizing a high resolution. 
   2. Description of the Related Art 
   Generally, a plasma display panel (PDP) radiates a phosphorus by an ultraviolet generated during a discharge of He+Xe, Ne+Xe or He+Ne+Xe gas to thereby display a picture including characters and graphics. Such a PDP is easy to be made into a thin-film and large-dimension type. Moreover, the PDP provides a very improved picture quality owing to a recent technical development. Particularly, a three-electrode, alternating current (AC) surface-discharge type PDP has advantages of a low-voltage driving and a long life because it can lower a voltage required for a discharge using wall charges accumulated on the surface thereof during the discharge and protect the electrodes from a sputtering caused by the discharge. Further, since the PDP does not need to form an active switching device for each cell like a liquid crystal display LCD, its fabricating process is simple, it is advantageous to be made into a big screen and its response speed is fast. 
   Referring to  FIG. 1 , a discharge cell of a three electrode AC discharge PDP includes a scanning electrode  30 Y and a sustaining electrode  30 Z formed on an upper substrate  10 , and an address electrode  20 X formed on a lower substrate  18 . 
   The scanning electrode  30 Y and the sustaining electrode  30 Z include transparent electrodes  12 Y and  12 Z and metal bus electrodes  13 Y and  13 Z formed on one side edge of the transparent electrode with their line width narrower than that of the transparent electrode  12 Y and  12 Z. The transparent electrodes  12 Y and  12 Z are generally formed from Indium-Tin-Oxide ITO on the upper substrate  10 . Chromium Cr/Copper Cu/Chromium Cr are deposited by a deposition method, and then an Etching process is carried out to form the metal bus electrode, or that is formed by printing photosensitive Silver Ag paste, then patterning it, and then firing it. There are an upper dielectric layer  14  and a passivation film  16  deposited on the upper substrate  10  provided with the scanning electrode  30 Y and the sustaining electrode  30 Z. In the upper dielectric layer  14 , wall charges generated upon a plasma discharge are accumulated. The passivation film  16  protects the upper dielectric layer  14  from a sputtering caused upon the plasma discharge and increase an emission efficiency of secondary electrons. Normally, the passivation film  16  is made from Magnesium Oxide MgO. The address electrode  20 X are formed in a direction of intersecting the scanning electrode  30 Y and the sustaining electrode  30 Z. There are a lower dielectric layer  22  and barrier ribs  24  formed on a lower substrate  18  provided with the address electrode  20 X. There is a phosphorus layer  26  formed on the surface of the barrier ribs and the lower dielectric layer  22 . The barrier ribs are formed in parallel to the address electrode  20 X to divide discharge cells physically and to prevent UV ray and visible ray generated by the discharge from leaking to adjacent discharge cells The phosphorus layer  26  is excited by the UV ray generated upon the plasma discharge and radiates to generate any one visible ray among red, green and blue. There is inactive mixture gas such as He+Xe, Ne+Xe or He+Ne+Xe for the discharge interposed in a discharge space of the discharge cell provided between the upper/lower substrates  10  and  18  and the barrier ribs  24 . 
   The arrangement of the electrodes of the PDP is shown as in  FIG. 2 . As can be seen in  FIG. 2 , the scanning electrode Y 1  to Yn and the sustaining electrode line Z are parallel and form a pair in one discharge cell. The address electrode line X 1  to Xm intersects a pair of sustaining electrode lines Y 1  to Yn, Z. Accordingly, one pair of sustaining electrode lines Y 1  to Yn, Z and one address electrode line X 1  to Xm cross each other in one discharge cell. One pixel  200  is arranged side by side in a horizontal direction and includes three discharge cells  100 , which displays red, green and blue respectively. 
   Such a PDP divides a time period of one field of a video signal into several sub-fields SF 1  to SF 8 , which have their emission frequency different from one another, to display a video. Each sub-field is divided again into a reset period for generating a discharge uniformly, an address period A 1  to A 8  for selecting discharge cells and a sustaining period S 1  to S 8  for realizing gray level in accordance with a discharge frequency. The reset period and the address period of each sub-field are the same every sub-field, whereas a sustaining period and the discharge frequency thereof increase proportional to 2 n  (provided n=0,1,2,3,4,5,6,7) in each sub-field. Like this, since the sustaining periods are different in each sub-field, it is possible to realize a gray level of video. 
   In order to increase a display quality of the PDP, PDP manufacturers have actively been studying on a discharge cell structure and a new driving method for realizing a high resolution and a high speed driving. 
     FIG. 4  briefly illustrates a conventional PDD which is scanned in a interlaced scanning; 
   Referring to  FIG. 4 , in the conventional PDP scanned in the interlaced scanning, the scanning electrode lines Y 1 , Y 2  and Y 3  and the sustaining electrode lines Z 1 , Z 2  and Z 3  are shared by two discharge cells perpendicularly adjacent thereto, and odd horizontal display lines HLodd 1 , HLodd 2  and HLodd 3  are separately displayed from even horizontal display lines HLeven 1 , HLeven 2  and Hleven 3 . 
   Further, the PDP, as in  FIG. 4 , includes the barrier ribs  24  of a stripe shape. Since the PDP has the barrier ribs formed in parallel, it is advantageous that fabrication is easy and space charges freely move between discharge cells. However, since there is no barrier rib between perpendicularly adjacent discharge cells, there is a problem of cross talk being generated between the discharge cells. 
   In order to solve the problem caused in the PDP structure of  FIG. 4 , a PDP proposed in Japanese Laid-open Patent Gazette No. 2001-176396, as in  FIG. 5 , has extended parts and narrow parts repeated perpendicularly and includes barrier ribs  54  formed in a lattice shape. 
   In the PDP as in  FIG. 5 , scanning electrode lines Y 1  to Y 5  and sustaining electrode lines Z 1  to Z 4  are shared by discharge cells adjacent perpendicularly. Also, in the PDP driving method as in  FIG. 5  according to U.S. Pat. No. 6,281,628, one pixel P includes three sub-pixels of red, green and blue together with two scanning electrode lines Y 1  and Y 2 , one sustaining electrode line Z 1  and three address electrode lines X 3 , X 4  and X 5 , and each of sub-pixels of the pixel P is selected by an address discharge and displays a picture by a sustaining discharge. 
   A PDP shown in  FIG. 6  has barrier ribs  64  formed in a lattice shape similarly to that in  FIG. 5 , but there is a difference in the fact that each of discharge cells is separately composed of scanning electrode lines Y 1  to Y 8  and sustaining electrode line Z 1  to z 8  which are adjacent thereto perpendicularly. Accordingly, in the PDP of  FIG. 6 , one pixel P includes three sub-pixels of red, green and blue together with two scanning electrode lines Y 1  and Y 2 , two sustaining electrode lines Z 1  and Z 2  and three address electrode lines X 3 , X 4  and X 5 , and each of sub-pixels of the pixel P is selected by an address discharge and displays a picture by a sustaining discharge. 
   In the PDP of  FIGS. 5 and 6 , the pixel P is formed in a ‘Δ’ (delta) type. The PDP of such a delta type pixel structure, as can be seen in  FIG. 7 , has only four horizontal display lines carry out actual display among eight rows of discharge cells (i−4 to i+3). In other words, the pixels P arranged perpendicularly along the (j−2) th  address electrode line are only four of P(i−3½, j−2), P(i−1½, j−2), P(i+1½, j−2) and P(i+2½, j−2) among eight rows of discharge cells (i−4 to i+3). Also, the pixels P arranged perpendicularly along the (j+1) th  address electrode line are only four of P(i−3½, j+1), P(i−1½, j+1), P(i+1½, j+1) and P(i+2½, and P(i+2½, j+1) among eight rows of discharge cells (i−4 to i+3). 
   Accordingly, it is difficult to realize a PDP with high resolution and high definition in the PDP of the conventional delta type pixel structure. For example, according to the conventional delta type pixel structure, in order to realize a high resolution PDP with 760 or more horizontal lines, because the number of the discharge cell rows to be needed is twice as many, i.e., 1520, or more, so that it is inevitable that an overall size thereof get big. In order to solve this problem, the area of each discharge cell can be reduced, however if the area of each discharge cell gets small, here comes another problem that its brightness decrease as much. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide a method and an apparatus for driving a plasma display panel that is adaptive for improving brightness as well as realizing a high resolution. 
   In order to achieve these and other objects of the invention, a method of driving a plasma display panel according to an aspect of the present invention includes steps of dividing a video signal into a first video signal field and a second video signal field; displaying discharge cells of the (3i−2) th  and (3i−1) th  rows (provided i is natural number) of the plasma display panel by applying the first video signal field to the plasma display panel; and displaying discharge cells of the (3i−1) th  and (3i) th  rows of the plasma display panel by applying the second video signal field to the plasma display panel. 
   In the method, the rows of the discharge cells are differently selected in accordance with the video signal field. 
   A method of driving a plasma display panel according to another aspect of the present invention includes steps of dividing a video signal into a first video signal field and a second video signal field; displaying discharge cells of the (2i−1) th  and (2i) th  rows (provided i is natural number) of the plasma display panel by applying the first video signal field to the plasma display panel; and displaying discharge cells of the (2i) th  and (2i+1) th  rows of the plasma display panel by applying the second video signal field to the plasma display panel. 
   In the method, the rows of the discharge cells are differently selected in accordance with the video signal field. 
   A method of driving a plasma display panel with a pixel cell that includes sub-pixel cells each displaying red, green and blue according to still another aspect of the present invention includes steps of dividing a video signal into a first video signal field and a second video signal field; displaying a first pixel cell in use of the first video signal field; and displaying a second pixel cell, part of which overlaps with the first pixel cell, in use of the second video signal field. 
   In the method, the first pixel cell have the sub-pixel cells arranged in any one of a ‘Δ’ type and a ‘∇’ type. 
   In the method, the second pixel cell have the sub-pixel cells arranged in any one of a ‘Δ’ type and a ‘∇’ type. 
   In the method, two of the sub-pixel cells of the first pixel cell overlap with two of the sub-pixel cells of the second pixel cell. 
   In the method, the first and second pixel cells overlap with each other in space and are separated in time. 
   A driving apparatus of a plasma display panel with a pixel cell that includes sub-pixel cells each displaying red, green and blue according to still another aspect of the present invention includes a data aligner dividing a video signal into a first video signal field and a second video signal field; a first driver displaying a first pixel cell in use of the first video signal field; and a second driver displaying a second pixel cell, part of which overlaps with the first pixel cell, in use of the second video signal field. 
   The first pixel cell have the sub-pixel cells arranged in any one of a ‘Δ’ type and a ‘∇’ type. 
   The second pixel cell have the sub-pixel cells arranged in any one of a ‘Δ’ type and a ‘∇’ type. 
   Herein, the plasma display panel includes lattice type barrier ribs for dividing the sub-pixel cells; an address electrode alternately arranged in the barrier ribs and the sub-pixel cells in a vertical direction in a cycle of one discharge cell; a scanning electrode intersecting the address electrode; and a sustaining electrode intersecting the address electrode. 
   The scanning electrode and the sustaining electrode are shared by perpendicularly adjacent sub-pixel cells. 
   The scanning electrode and the sustaining electrode are independently arranged in each of perpendicularly adjacent sub-pixel cells. 
   Herein, the first driver includes a data driver for applying data of the first video signal field to the address electrode; and a scanning/sustaining driver for selecting a sub-pixel cell row of the first pixel cell and sustaining a discharge in each of the selected sub-pixel cells. 
   Herein, the second driver includes a data driver for applying data of the second video signal field to the address electrode; and a scanning/sustaining driver for selecting a sub-pixel cell row of the second pixel cell and sustaining a discharge in each of the selected sub-pixel cells. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects of the invention will be apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings, in which: 
       FIG. 1  illustrates a perspective view of a conventional three-electrode AC surface discharge PDP; 
       FIG. 2  illustrates a plane view of an electrode arrangement of a PDP shown in  FIG. 1 ; 
       FIG. 3  illustrates a view of a general field arrangement; 
       FIG. 4  illustrates a plane view of an electrode arrangement of a conventional PDP; 
       FIG. 5  illustrates a plane view of a PDP with a conventional delta type pixel arrangement; 
       FIG. 6  illustrates a plane view of a PDP with another conventional delta type pixel arrangement; 
       FIG. 7  illustrates a plane view of horizontal display lines in a PDP with a conventional delta type pixel arrangement; 
       FIG. 8  illustrates a plane view of a PDP according to the present invention and a driving apparatus for the PDP; 
       FIG. 9  is a view representing a field arrangement of a video signal of a PDP according to the first embodiment of the present invention; 
       FIG. 10  illustrates a plane view of horizontal display lines and a pixel arrangement when the video signal of  FIG. 9  is applied to the PDP of  FIG. 8 ; 
       FIG. 11  is a view representing a field arrangement of a video signal of a PDP according to the second embodiment of the present invention; and 
       FIG. 12  illustrates a plane view of horizontal display lines and a pixel arrangement when the video signal of  FIG. 11  is applied to the PDP of  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
   Referring to  FIG. 8 , a driving apparatus of a PDP according to an embodiment of the present invention includes a PDP  80 ; a data aligner  82  dividing data RGB into a first video signal field and a second video signal field; an X driver  83  applying the data from the data aligner  82  to address electrode lines (X(j−4) to X(j+4)) of the PDP  80 ; a Y driver  84  driving scanning electrode lines (Y(i−5) to Y (i+3)) of the PDP  80 ; a Z driver  85  driving sustaining electrodes (Z(i−4) to Y(i+2)) of the PDP  80 ; a timing controller  81  controlling each of the electrode drivers  81  to  83 ; and a power supply circuit  86  generating driving voltages Vx, Yy and Zz. 
   In the PDP  80 , there are barrier ribs  54  formed in a lattice type. Herein, an extended part is repeated in a vertical direction and a,narrow part in a horizontal direction. Also, the PDP  80  has a ‘Δ’ delta type pixel P 1  displaying the first video signal field overlap with an ‘∇’ inverted delta type pixel P 2  displaying the second video signal field. The PDP  80  can be replaced with a PDP as in  FIG. 6  that has discharge cells arranged in a ‘ ’ delta type and scanning electrodes and sustaining electrodes arranged in each of perpendicularly adjacent discharge cells with a separate structure. 
   The data aligner  82  does reverse gamma correction and error diffusion by a reverse gamma corrector and an error diffuser etc. (not shown), and then divides data mapped by sub-fields by a sub-field mapping circuit (not shown) into the first video signal field and the second video signal field under the control of the timing controller  81  and realigns them. The more detailed explanation in respect of the first video signal field and the second video signal field is described below in conjunction with  FIGS. 9 to 12 . 
   The X driver  83  simultaneously applies the data from the data aligner  82  to the address electrode lines (X(j−4) to X(j+4)) by one horizontal line portion under the control of the timing controller  81 . 
   The Y driver  84  applies a reset signal initializing a full screen, a scanning pulse selecting discharge cell rows (i−4 to i+3) and a sustaining pulse sustaining a discharge of the selected discharge cells to the scanning electrode lines (Y(i−5) to Y(i+3)) under the control of the timing controller  81 . 
   The Z driver  85  applies the sustaining pulse to the sustaining electrode lines (Z(i−4) to Z(i+2)) under the control of the timing controller  81  while operated in turn with the Y driver  84 . 
   The timing controller  81  receives a vertical/horizontal synchronization signal to generate a timing control signal necessary for each of the electrode drivers  81  to  83 . 
   The power supply circuit  86  generates voltages, i.e., a reset signal voltage, a data voltage, a scanning voltage and a sustaining voltage etc., necessary for an electrode driving of the PDP  80 . 
     FIG. 9  is a view representing a video signal of a PDP according to the first embodiment of the present invention. 
   Referring to  FIG. 9 , a driving apparatus of a PDP according to an embodiment of the present invention divide a video signal of one field portion into a plurality of sub-fields SF 1  to SF 8 . And in the driving apparatus, the PDP is driven with the first video signal field displaying discharge cells of the (3i−2) th  (i is natural number) and (3i−1) th  rows, and the second video signal field displaying discharge cells of the (3i−1) th  (i is natural number) and (3i) th  rows. The first video signal field and the second video signal field each include a plurality of sub-fields SF 1  to SF 8  and are alternately arranged. 
   When displaying the first video signal field, the Y driver  84  selects the discharge cells of the (3i−2) th  (i is natural number) and (3i−1) th  rows (i−4, i−3, i−1, i, i+2, i+3). By the selected discharge rows (i−4, i−3, i−1, i, i+2, i+3), the first video signal field is displayed in the ‘Δ’ delta or ‘∇’ inverted delta type pixels, shown in solid line in  FIG. 10 . 
   When displaying the second video signal field, the Y driver  84  selects the discharge cells of the (3i−1) th  (i is natural number) and (3i) th  rows (i−3, i−2, i, i+1, i+3, i+4). By the selected discharge rows (i−3, i−2, i, i+1, i+3, i+4), the second video signal field is displayed in the ‘Δ’ delta or ‘∇’ inverted delta type pixels, shown in dotted line in  FIG. 10 . 
   Accordingly, the PDP according to the first embodiment of the present invention, assuming that the size and the discharge cell size of this PDP are the same as those of the PDP with the conventional delta type pixel structure, has the horizontal display lines increased 1.5 times as many as or more than the PDP with a conventional delta type pixel structure. Herein, the horizontal display lines is where actual display is carried out. 
     FIG. 11  is a view representing a video signal of a PDP according to the second embodiment of the present invention. 
   Referring to  FIG. 11 , a driving apparatus of a PDP according to an embodiment of the present invention is driven with the first video signal field displaying discharge cells of the (2i−1) th  and (2i) th  rows, and the second video signal field displaying discharge cells of the (2i) th  and (2i+1) th  rows. The first video signal field and the second video signal field each include a plurality of sub-fields SF 1  to SF 8  and are alternately arranged. 
   When displaying the first video signal field, as in  FIG. 12 , the Y driver  84  selects the (2i−1) th  and (2i) th  discharge cell rows (i−4, i−3, i−2, i−1, i, i+1, i+2, i+3). By the selected discharge rows (i−4, i−3, i−2, i−1, i, i+1, i+2, i+3), the first video signal field is displayed in the ‘Δ’ delta or ‘∇’ inverted delta type pixels, shown in solid line in  FIG. 12 . 
   When displaying the second video signal field, as in  FIG. 12 , the Y driver  84  selects the discharge cells of the (2i) th  and (2i+1) th  rows (i−3, i−2, i−1, i, i+1, i+2, i+3, i+4). By the selected discharge rows (i−3, i−2, i−1, i, i+1, i+2, i+3, i+4), the second video signal field is displayed in the ‘Δ’ delta or ‘∇’ inverted delta type pixels, shown in dotted line in  FIG. 12 . 
   Accordingly, the PDP according to the second embodiment of the present invention, assuming that the size and the discharge cell size of this PDP are the same as those of the PDP with the conventional delta type pixel structure, has the horizontal display lines increased 2 times as many as or more than the PDP with a conventional delta type pixel structure. Herein, the horizontal display lines is where actual display is carried out. 
   On the other hand, the driving method of the PDP according to the embodiment of the present invention selects discharge cells in accordance with the first video signal and/or the second video signal while moving upward or downward by one low at a time, so that it is possible to ease a phenomenon that discharges are concentrated a specific discharge cell. 
   As described above, in the method and the apparatus for the PDP according to the present invention, it is possible to realize a high resolution and increase the resolution without reducing the size of the discharge cell since the horizontal display lines are increased in the same condition as the PDP with the conventional delta type pixel structure, so that a picture can be displayed with high brightness. 
   Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the invention is not limited to the embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.