Patent Publication Number: US-2005122045-A1

Title: Plasma display panel

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an AC plasma display panel and in particular to electrodes of an AC plasma display panel.  
      2. Description of the Related Art  
      A plasma display panel (PDP) is a thin type display, and typically has a large viewing area. The luminescent principle of the PDP is the same as that of fluorescent lamps. A vacuum glass trough is filled with inert gas. When a voltage is applied to the glass trough, plasma is generated and radiates ultraviolet (UV) rays. The fluorescent material coated on the wall of the glass trough absorbs the UV rays, hence the fluorescent material radiates visible light including red, green and blue light. A plasma display can be described as a combination of hundreds of thousands of illuminating units, each illuminating unit has three subunits for radiating red, green and blue light, respectively. Images are displayed by mixing these three primary colors.  
      As shown in  FIG. 1 , a conventional PDP  10  has a pair of glass substrates  12 , and  14  arranged parallel and opposite to each other. A discharge space  16  is formed between the glass substrates  12 , and  14  and injected with inert gases, such as Ar, Xe or others. The upper glass substrate  12  has a plurality of transverse electrode groups positioned in parallel. Each group of transverse electrodes has a first and a second sustaining electrode  18  and  20 , each of which includes transparent electrodes  181  and  201  and bus electrodes  182  and  202 . A dielectric layer  24  is further formed covering the transverse electrodes, and a protection layer  26  is formed on the dielectric layer  24 .  
      The lower glass substrate  14  has a plurality of barrier ribs  28  arranged in parallel and spaced apart by a predetermined distance dividing the discharge space  16  into a plurality of groups of sub-discharge spaces. Each group of sub-discharge spaces includes a red discharge space  16 R, a green discharge space  16 G, and a blue discharge space  16 B. Additionally, the lower glass substrate  14  has a plurality of lengthwise electrodes  22  disposed in parallel between two adjacent barrier ribs  28  serving as address electrodes. A red fluorescent layer  29 R, a green fluorescent layer  29 G, and a blue fluorescent layer  29 B are respectively coated on the lower glass substrate  14  and the sidewalls of the barrier ribs  28  within each red discharge space  16 R, each green discharge space  16 G, and each blue discharge space  16 B.  
      When a voltage is applied for driving the electrodes, the inert gases in the discharge space  16  are discharged to produce UV rays. The UV rays further illuminate the fluorescent layers  29 R,  29 G, and  29 B to radiate visible light including red, green and blue light. After the three primary colors are mixed at different ratios, various images are formed and transmitted through the upper glass substrate  12 .  
       FIG. 2  is a local top view of  FIG. 1 . Referring to  FIG. 2 , the ribs  28  are arranged in parallel and spaced apart from each other on the rear substrate. A discharge space  16  is disposed between the first sustain electrode  18  and the second sustain electrode  20 . In the discharge space  16 , the inert gas is ionized to strike the fluorescent layers on the rear substrate and the ribs  28  to generate light. If an address electrode  22  is broken at one point, the function of the address electrode is abnormal. In addition, line defects are generated and yield of the PDP is decreased.  
      U.S. Pat. No. 6,479,932 discloses an AC plasma display panel in which a data electrode having a large width part around the surface discharge gap and a narrow width part. The data electrode may further include a medium width part, however, the electrode of the configuration is prone to breakage.  
     SUMMARY OF THE INVENTION  
      Accordingly, an object of the invention is to provide a PDP comprising fence shaped address electrodes. The fence shaped address electrodes of the invention are capable of remaining coupled even if one line of the fence shaped address electrodes is broken. Furthermore, due to the auxiliary electrode disposed at the discharge area of the cell, the PDP of the invention can provide larger plasma discharge area and better discharge efficiency.  
      To achieve the above objects, the present invention provides a PDP structure comprising the following elements. A first substrate is opposite a second substrate. A plurality of ribs are interposed between the first substrate and the second substrate, defining a plurality of discharge cells. A plurality of fence shaped address electrodes are disposed on the second substrate, wherein each discharge cell is passed through a corresponding fence shaped address electrode. Each fence shaped address electrode comprises a plurality of main electrodes and at least one auxiliary electrode, and the auxiliary electrode connects two adjacent main electrodes in each cell.  
      The plasma display panel of the invention additionally comprises a plurality a sub pixels, each comprising two row electrodes extending in a first direction and isolated from each other, and one fence shaped address electrode under and spaced apart from the row electrodes, extending substantially in a second direction. The fence shaped address electrode comprises a plurality of main electrodes and at least one auxiliary electrode connecting two adjacent main electrodes.  
      A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
       FIG. 1  shows the structure of the conventional PDP;  
       FIG. 2  is a plane view of the conventional PDP with closed discharge spaces;  
       FIG. 3A  is a top view of a PDP of the first embodiment;  
       FIG. 3B  is a top view of a PDP of another electrode structure of the first embodiment;  
       FIG. 3C  is a top view of a PDP of yet another electrode structure of the first embodiment;  
       FIG. 4  is a top view of a PDP of the second embodiment;  
       FIG. 5  is a top view of a PDP of the third embodiment;  
       FIG. 6  is a top view of a PDP of an electrode structure of the fourth embodiment;  
       FIG. 7  is a top view of a PDP of an electrode structure of the fifth embodiment;  
       FIG. 8  is a top view of a PDP of an electrode structure of the sixth embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The present invention provides a fence shaped address electrode passing through each discharge cell of a PDP, each comprising a plurality of main electrodes extending along direction Y and auxiliary electrodes connecting the main electrodes. Furthermore, a fence shaped address electrode in a cell and the one in another cell adjacent thereto along direction X are connected outside the display region of the PDP to form a common address electrode, and each common address electrode is not connected. The fence shaped address electrode of the invention is applicable in any rib and row electrode configuration. Structures of the ribs, row electrodes and fence shaped address electrodes are disclosed in detail in each of the followed embodiment.  
     First Embodiment  
       FIGS. 3A and 3B  are top views of the PDP of the first embodiment. A PDP comprises a front substrate and a rear substrate. Referring to  FIG. 3A , a plurality of ribs  302  are formed on the rear substrate, defining a plurality of closed rectangular discharge cells  304 . The front and rear substrates are preferably glass.  
      A plurality of row electrodes  306  are formed on the front substrate, extending in the direction X along the horizontal side of the rectangular ribs  302 . A plurality of fence shaped address electrodes are formed on the rear substrate, and each closed rectangular cell  304  passes trough a fence shaped address electrode, each of which comprises a plurality of main electrodes and at least one auxiliary electrode in each cell. In  FIG. 3A , the main electrodes are referred to as a first main electrode  308  and a second main electrode  310 . At least one auxiliary electrode  312  is interposed between the first main electrode  308  and the second main electrode  310 , providing electrical connection therebetween. The auxiliary electrode  312  can be any shape and can electrically connect the main electrodes in any way. As shown in  FIG. 3A , for example, the auxiliary electrodes  312  extend in the direction X, connecting the first and the second main electrodes  308  and  310 .  FIG. 3B  shows another example, wherein the auxiliary electrodes  312  are tiled. In yet another example, as shown in  FIG. 3C , the auxiliary electrode  312  has a predetermined width, preferably larger than 20 μm. Due to the auxiliary electrode  312  being disposed at the discharge area of the cell  304 , the PDP of the invention can provide larger plasma discharge area and better discharge efficiency. In the preferred embodiment of the invention, each auxiliary electrode  312  is separated from the ribs  302  by a distance of 20 μm˜50 μm.  
     Second Embodiment  
       FIG. 4  is top view of the PDP of a second embodiment of the invention. A PDP comprises a front substrate and a rear substrate. Referring to  FIG. 4 , a plurality of ribs  402  are formed on the rear substrate, defining a plurality of closed hexagonal discharge cells  404 . The front and rear substrates are preferably glass.  
      The hexagonal discharge cells  404  are arranged in delta configurations. A plurality of row electrodes  406  are formed on the front substrate, extending substantially in the direction X along the bevel side of the hexagonal ribs  402 . A plurality of fence shaped address electrodes are formed on the rear substrate, and each closed hexagonal cell  404  pass trough a fence shaped address electrode, wherein each of which comprises a plurality of main electrodes and at least one auxiliary electrode. In  FIG. 4 , the main electrodes are referred to as a first main electrode  408  and a second main electrode  410 , in which the first and second main electrodes are zigzag shaped and extend substantially in the direction Y.  
      At least one auxiliary electrode  412  is interposed between the first and the second main electrodes  408  and  410  in each cell, electrically connecting thereboth. The auxiliary electrode  412  can be any shape and can electrically connect the main electrodes in any way. Due to the auxiliary electrode  412  being disposed at the discharge area of the cell, the PDP of the invention can provide larger plasma discharge area and better discharge efficiency. In the preferred embodiment of the invention, each auxiliary electrode  412  is separated from the ribs  402  by a distance of 20 μm˜50 μm.  
     Third Embodiment  
       FIG. 5  is top view of the PDP of the third embodiment of the invention. A PDP comprises a front substrate and a rear substrate. Referring to  FIG. 5 , a plurality of line shaped ribs  502  are formed on the rear substrate, extending in the direction Y. The front and rear substrates are preferably glass.  
      A plurality of row electrodes  506  are formed on the front substrate, extending in the direction X. The line shaped ribs  502  and the row electrodes  506  define a plurality of discharge cells  504 . A plurality of fence shaped address electrodes are formed on the rear substrate, and each rectangular cell passes trough a fence shaped address electrode, each of which comprises a plurality of main electrodes and at least one auxiliary electrodes. In  FIG. 5 , the main electrodes are referred to as a first main electrode  508  and a second main electrode  510 . At least one auxiliary electrode  512  is interposed between the first and the second main electrode  508  and  510 , providing electrical connection therebetween. The auxiliary electrode  512  can be any shape and electrically connects the main electrodes  508  and  510  in any way. Due to the auxiliary electrode  512  disposed at the discharge area of the cell, the PDP of the invention can provide larger plasma discharge area and better discharge efficiency. In the preferred embodiment of the invention, each auxiliary electrode  512  is separated from the ribs  502  by a distance of 20 μm˜50 μm.  
     Fourth Embodiment  
       FIG. 6  is a top view of the PDP of a fourth embodiment of the invention. A PDP comprises a front substrate and a rear substrate. Referring to  FIG. 6 , a plurality of zigzag shaped ribs  602  are formed on the rear substrate, extending in the direction Y, defining a plurality of hexagonal discharge cells  604 . A dark region  606  is interposed between each two adjacent discharge cells  616  and  618  along direction Y, connecting the two discharge cells. The front and rear substrates are preferably glass.  
      A plurality of row electrodes  608  are formed on the front substrate, extending substantially in the direction X along the bevel side of the hexagonal ribs  602 . A plurality of fence shaped address electrodes are formed on the rear substrate, and each closed hexagonal cell passes trough a fence shaped address electrode, each of which comprises a plurality of main electrodes and at least one auxiliary electrode. In  FIG. 6 , the main electrodes are referred to as a first main electrode  610  and a second main electrode  612 , in which the first and second main electrodes are zigzag shaped and extend substantially in the direction Y.  
      At least one auxiliary electrode  614  is interposed between the first main electrode  610  and the second main electrode  612  in each cell, providing electrical connection therebetween. The auxiliary electrode  614  can be any shape and electrically connects the main electrodes  610  and  612  in any way. Due to the auxiliary electrode  614  disposed at the discharge area of the cell the PDP of the invention can provide larger plasma discharge area and better discharge efficiency. In the preferred embodiment of the invention, each auxiliary electrode  614  is separated from the ribs  602  by a distance of 20 μm˜50 μm.  
     Fifth Embodiment  
       FIG. 7  is top view of the PDP of a fifth embodiment of the invention. A PDP comprises a front substrate and a rear substrate. Referring to  FIG. 7 , a plurality of line shaped ribs  706  are formed on the rear substrate, extending in the direction Y. The front and rear substrates are preferably glass.  
      A plurality of row electrodes  706  are formed on the front substrate, extending in the direction X. The line shaped ribs  702  and the row electrodes  706  define a plurality of discharge cells  704 . A plurality of fence shaped address electrodes are formed on the rear substrate, and each rectangular cell passes trough a fence shaped address electrode, each of which comprises a plurality of main electrodes and at least one auxiliary electrode. In  FIG. 7 , the main electrodes are referred to as a first main electrode  708  and a second main electrode  710 . At least one auxiliary electrode  712  is interposed between the first main electrode  708  and the second main electrode  710 , providing electrical connection therebetween. The auxiliary electrode  712  can be any shape and electrically connect the main electrodes  708  and  710  in any way. Due to the auxiliary electrode  712  disposed at the discharge area of the cell, the PDP of the invention can provide larger plasma discharge area and better discharge efficiency. In the preferred embodiment of the invention, each auxiliary electrode  712  is separated from the ribs  702  by a distance of 20 μm˜50 μm.  
      A fence shaped address electrode  714  in a cell and the one  716  in another cell  718  adjacent thereto along direction X are connected outside the PDP&#39;s display region to form a common address electrode  720 , and each common address electrode  720  is not connected.  
     Sixth Embodiment  
       FIG. 8  is a top view of the PDP of the sixth embodiment. A PDP comprises a front substrate and a rear substrate. Referring to  FIG. 8 , a plurality of zigzag shaped ribs  802  are formed on the rear substrate, extending in the direction Y, defining a plurality of hexagonal discharge cells  804 . A dark region  806  is interposed between each two adjacent discharge cells along direction Y, connecting the two discharge cells. The front and rear substrates are preferably glass.  
      A plurality of row electrodes  808  are formed on the front substrate, extending substantially in the direction X along the bevel side of the hexagonal ribs. A plurality of fence shaped address electrodes are formed on the rear substrate, and each closed hexagonal cell passes trough a fence shaped address electrode, each of which comprises a plurality of main electrodes and at least one auxiliary electrodes. In  FIG. 8 , the main electrodes are referred to as a first main electrode  810  and a second main electrode  812 , in which the first and second main electrodes are zigzag shaped extending substantially in the direction Y.  
      At least one auxiliary electrode  814  is interposed between the first and the second main electrodes  810  and  812  in each cell, providing electrical connection therebetween. The auxiliary electrode  814  can be any shape and electrically connects the main electrodes in any way. Due to the auxiliary electrode  814  being disposed at the discharge area of the cell, the PDP of the invention can provide larger plasma discharge area and better discharge efficiency. In the preferred embodiment of the invention, each auxiliary electrode  814  is separated from the ribs by a distance of 20 μm˜50 μm.  
      A fence shaped address electrode  816  and the neighboring one  818  along direction X are connected outside the display region of the PDP to form a common address electrode  820 , and each common address electrode  820  is not connected.  
      The above described common address electrode is applied in the rib and electrode structures of the fifth and the sixth embodiments. The described common address electrodes can be further applied in the rib structures and row address structures disclosed in the first, second, third and fourth embodiment.  
      The fence shaped address electrodes of the invention can remain coupled even if one electrode of the fence shaped address electrodes is broken. Furthermore, Due to the auxiliary electrode being disposed at the discharge area of the cell, the PDP of the invention can provide larger plasma discharge area and better discharge efficiency.  
      While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of thee appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.