Abstract:
A plasma display panel includes an upper substrate and a lower substrate combined with the upper substrate by a sealant. A black layer is formed on a surface of the upper substrate, outside of a display area of the upper substrate. A film filter, not including a bordering layer, is located on the upper substrate. The film filter includes a ground unit of increased size adjacent its edge, which can electrically engage with a support, thus simplifying an alignment issue during construction of the plasma display and reducing a contact resistance between the ground unit and the support.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a plasma display panel, and more particularly, to a plasma display panel in which a ground area of a film-type front filter can be increased. 
   2. Background of the Related Art 
   A plasma display panel (hereinafter, referred to as a “PDP”) is adapted to display an image, including characters or graphics, by light-emitting phosphors emitting ultraviolet light of 147 nm, generated during the discharge of a gas, such as He+Xe, Ne+Xe or He+Ne+Xe. The PDP can be easily made thin and large, and it can provide greatly increased image quality with the recent development of the relevant technology. Particularly, a three-electrode AC surface discharge type PDP has advantages of lower driving voltage and longer product lifespan, as a voltage necessary for discharging is lowered by wall charges accumulated on a surface upon discharging, and electrodes are protected from sputtering caused by discharging. 
     FIG. 1  is a perspective view illustrating the structure of a discharge cell of a three-electrode AC surface discharge type PDP, in accordance with the background art. Referring now to  FIG. 1 , a discharge cell of a three-electrode AC surface discharge type PDP includes a scan electrode Y and a sustain electrode Z, which are formed on the bottom surface of an upper substrate  10 , and an address electrode X formed on a lower substrate  18 . The scan electrode Y includes a transparent electrode  12 Y, and a metal bus electrode  13 Y, which has a line width smaller than that of the transparent electrode  12 Y and is disposed at one side edge of the transparent electrode  12 Y. Further, the sustain electrode Z includes a transparent electrode  12 Z, and a metal bus electrode  13 Z, which has a line width smaller than that of the transparent electrode  12 Z and is disposed at one side edge of the transparent electrode  12 Z. 
   The transparent electrodes  12 Y and  12 Z, which are generally made of ITO (indium tin oxide), are formed on the bottom surface of the upper substrate  10 . The metal bus electrodes  13 Y and  13 Z are generally formed on the transparent electrodes  12 Y and  12 Z and made of metal such as chromium (Cr), and serve to reduce a voltage drop caused by the transparent electrodes  12 Y and  12 Z having high resistance. On the bottom surface of the upper substrate  10 , in which the scan electrode Y and the sustain electrode Z are placed parallel to each other, is laminated an upper dielectric layer  14  and a protective layer  16 . The upper dielectric layer  14  is accumulated with a wall charge generated during plasma discharging. The protective layer  16  is adapted to prevent damage of the upper dielectric layer  14  due to sputtering caused during plasma discharging, and improve efficiency of secondary electron emission. As the protective layer  16  is generally formed of magnesium oxide (MgO). 
   A lower dielectric layer  22  and barrier ribs  24  are formed on the lower substrate  18 , in which the address electrode X is formed. A phosphor layer  26  is applied to the surfaces of both the lower dielectric layer  22  and the barrier ribs  24 . The address electrode X is formed on the lower substrate  18  in the direction in which the scan electrode Y and the sustain electrode Z intersect with each other. The barrier ribs  24  are formed in a stripe or lattice form to prevent ultraviolet and visible light, generated by discharging, from leaking toward adjacent discharge cells. The phosphor layer  26  is excited with an ultraviolet light generated during the plasma discharging to generate any one visible light of red, green and blue lights. An inert mixed gas is injected into the discharge spaces defined between the upper substrate  10  and the barrier ribs  24 , and between the lower substrate  18  and the barrier ribs  24 . 
   This PDP is time-driven with one frame being divided into a plurality of sub-fields having a different number of emission in order to implement gray scales of an image. Each of the sub fields is divided into an initialization period for initializing the entire screen, an address period for selecting a scan line and selecting a cell from the selected scan line, and a sustain period for implementing gray scales according to the number of discharging cycles. For example, if it is desired to display an image with 256 gray scales, a frame period (16.67 ms) corresponding to 1/60 seconds is divided into eight sub-fields SF 1  to SF 8 , as shown in  FIG. 2 . Each of the sub-fields SF 1  to SF 8  is subdivided into the initialization period, the address period and the sustain period, as described above. The initialization period and the address period of each of the sub-fields SF 1  to SF 8  are the same every sub-field, whereas the sustain period increases in the ratio of 2 n  (where, n=0, 1, 2, 3, 4, 5, 6, 7) in each sub-field. In the PDP described above, a front filter is disposed on the upper substrate  10  in order to shield electromagnetic interference and also to prevent reflection of external light. 
     FIG. 3  schematically shows one side of a POP, in accordance with the background art Referring to  FIG. 3 , the PDP includes a panel  32  in which an upper substrate  10  and a lower substrate  18  are combined. A front filter  30  is disposed at the front of the panel  32 . A cooling fin  34  is disposed at the rear of the panel  32 . A printed circuit board  36  is attached to the cooling fin  34 . A rear cover  38  is formed to surround the rear of the PDP. A filter support unit  40  connects the front filter  30  and the rear cover  38 , and a support member  42  is disposed between the front filter  30  and the rear cover  38  to surround the filter support unit  40 . 
   The printed circuit board  36  supplies driving signals to electrodes of the panel  32 . The printed circuit board  36  includes various driving units (not shown). The panel  32  displays a given image according to the driving signal supplied from the printed circuit board  36 . The cooling fin  34  dissipates heat generated from the panel  32  and the printed circuit board  36 . The rear cover  38  serves to protect the panel  32  from external shock and also to shield electromagnetic interference (hereinafter, referred to as “EMI”) discharged from the rear side of the panel  32 . 
   The filter support unit  40  electrically connects the front filter  30  to the rear cover  38 . Such a filter support unit  40  grounds the front filter  30  to the rear cover  38 , and also prevents EMI from being discharged laterally. The support member  42  supports the filter support unit  40 , the front filter  30  and the rear cover  38 . 
   The front filter  30  shields EMI and also prevents reflection of external light. For this, the front filter  30  includes an anti-reflection film  50 , an optical characteristic film  52 , a glass  54 , an EMI shield film  56 , and a near infrared (hereinafter, referred to as “NIR”) shield film  58 , as shown in  FIG. 4 . Adhesive layers are formed between the films  50 ,  52 ,  54 ,  56  and  58  of the front filter  30 , respectively, to provide adhesion among the films  50 ,  52 ,  54 ,  56  and  58 . A black layer  60  is further provided at an upper edge of the front filter  30 . 
   The anti-reflection film  50  prevents externally incident light from reflecting toward the outside again, thus improving the contrast of the PDP. This anti-reflection film  50  is formed on the surface of the front filter  30 . The anti-reflection film  50  can be additionally formed on the rear of the front filter  30 . The optical characteristic film  52  serves to lower transmittance of the red (R) and the green (G) light among light incident from the panel  32 , and to improve an optical characteristic of the PDP by increasing transmittance of the blue (B) light. 
   The glass  54  serves to prevent the front filter  30  from being damaged due to external shock. In other words, the glass  54  supports the front filter  30  so as to prevent damage of the front filter  30  from external shock. The EMI shield film  56 , shields EMI to prevent EMI, which is introduced from the panel  32 , from being discharged externally. The NIR shield film  58  shields NIR discharged from the panel  32 , and thus prevents NIR of over a given reference from being discharged externally so that signals transmitted using IR, such as signals from a remote controller, can be transmitted normally without interference. The black layer  60  defines a valid display region A/A of the panel  32 , and also covers unnecessary, unsightly edge portions of the PDP module. 
   The front filter  30  is electrically connected to the rear cover  38  through the filter support unit  40 , as shown in  FIG. 5 . This will be below described in more detail. The filter support unit  40  is connected to the rear of the front filter  30  at one lateral side of the front filter  30 . The filter support unit  40  is electrically connected to at least one of the EMI shield film  56  and NIR shield film  58 . That is, the filter support unit  40  connects the front filter  30  to the rear cover  38 , thus shielding EMI and/or NIR. 
   The front filter  30 , in accordance with the background art, uses a glass  54  having a size greater than the upper substrate of the panel  32 , so as to prevent the front filter  30  from being broken due to external shock. However, if the glass  54  is included in the layers of the front filter  30 , there is a disadvantage in that a thickness of the front filter  30  is enlarged. Further, if the glass  54  is included in the front filter  30 , there are problems in that a weight is increased and the manufacture cost is also increased. 
   In view of these disadvantages, a film-type front filter  70  from which the glass  54  is removed has been proposed.  FIG. 6  shows such a film-type front filter  70 , in accordance with the background art. The film-type front filter  70  has the same size as the upper substrate of the panel, and includes an anti-reflection film  80 , an optical characteristic film  82 , an EMI shield film  86  and a NIR shield film  88 . Adhesive films are formed between the films  80 ,  82 ,  86  and  88  of the film-type front filter  70 , respectively, to provide adhesion among the films  80 ,  82 ,  86  and  88 . The film-type front filter  70  further includes a ground face  72  formed at an edge region of the anti-reflection film  80 , and a black layer  90  formed in a region, which is spaced apart from the ground face  72  by a given distance. 
   The anti-reflection film  80  is formed on a surface of the film-type front filter  70 , and serves to prevent externally incident light from being reflecting externally again. This anti-reflection film  80  can be additionally formed at the rear of the film-type front filter  70 . The optical characteristic film  82  lowers transmittance of the red (R) light and the green (G) light among light incident from the panel, and also improves an optical characteristic of the PDP by increasing transmittance of the blue (B) light. 
   The EMI shield film  86  shields EMI to prevent EMI incident from the panel from being discharged externally. The NIR shield film  88  serves to shield NIR incident from the panel. Such a NIR shield film  88  prevents NIR of over a given reference from being discharged externally, so that signals transmitted from a remote controller to the panel can be transmitted normally without interference. The ground face  72  is electrically connected to the rear cover  38 , as shown in  FIG. 3 , through a filter support unit (not shown). The black layer  90  defines a valid display region A/A of the panel, and also covers unnecessary, unsightly edge portions of a the PDP module. 
   In the PDP having the above-described film-type front filter  70 , the film-type front filter  70  is fabricated to have the same size as the upper substrate of the panel. Thus, the ground face  72  and the black layer  90  are formed at the same time. Due to this, there are disadvantages in that the area of the ground face  72  is reduced in size. The reduced size makes it difficult to achieve alignment between the film type front filter  70  and the upper substrate of the panel because spaces for forming the ground face  72  and the black layer  90  are insufficient. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to address one or more of the drawbacks associated with the background art. 
   It is an object of the present invention to provide a plasma display panel in which a ground area of a film-type front filter can be increased in size. 
   It is an object of the present invention to provide a front film-type filter which does not include a black layer. 
   These and other objects are accomplished by a plasma display panel, comprising: an upper substrate; a lower substrate, arranged below said upper substrate; and a display area bordering layer disposed on a surface of said upper substrate. 
   Moreover, these and other objects are accomplished by a film filter for a plasma display panel having a display area bordering layer disposed on a surface of an upper substrate of the plasma display panel, said film filter comprising: a plurality of layers, not including a display area bordering layer, wherein said plurality of layers includes at least two of the following films; an anti-reflection film; an optical characteristic film; an electromagnetic interference (EMI) shielding film; and a near infrared (NIR) shielding film. 
   The PDP may include the film filter disposed on the upper substrate, and a ground unit formed at the edge of the film filter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: 
       FIG. 1  is a perspective view illustrating the construction of a discharge cell of a three-electrode AC surface discharge type PDP, in accordance with the background art; 
       FIG. 2  shows a frame for representing 256 gray scales in accordance with a PDP of the background art; 
       FIG. 3  schematically shows one side of a PDP, in accordance with the background art; 
       FIG. 4  is a cross-sectional view schematically showing a front filter shown in  FIG. 3 ; 
       FIG. 5  shows a detailed grounding process of the front filter and the filter support unit shown in  FIG. 3 ; 
       FIG. 6  is a schematic perspective view of a film type front filter, in accordance with the background art; 
       FIG. 7  is a plan view of a PDP according to a first embodiment of the present invention; 
       FIG. 8  is a cross-sectional view of the PDP taken along line I-I′ in  FIG. 7 ; 
       FIG. 9  is a plan view of a PDP according to a second embodiment of the present invention; 
       FIG. 10  is a cross-sectional view of the PDP taken along line II-II′ in  FIG. 9 ; 
       FIG. 11  is a plan view of a PDP according to a third embodiment of the present invention; 
       FIG. 12  is a plan view of a PDP according to a fourth embodiment of the present invention; 
       FIG. 13  is a plan view of a PDP according to a fifth embodiment of the present invention; and 
       FIG. 14  is a plan view of a PDP according to a sixth embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will be described in a more detailed manner with reference to  FIGS. 7 to 14 . Referring to  FIGS. 7 and 8 , a plasma display panel (PDP) according to a first embodiment of the present invention includes a plurality of discharge cells formed on a valid display region A/A of a panel  100 , a sealant  140  formed at the edges of an upper substrate  110  and a lower substrate  118 , for combining the upper substrate  110  and the lower substrate  118 , and a black layer  160  formed between the end of the valid display region A/A and the sealant  140 . 
   Each of the plurality of the discharge cells includes a scan electrode and a sustain electrode (not shown), both of which are formed on the upper substrate  110 , and an address electrode (not shown) formed on the lower substrate  118 . Each of the scan electrode and the sustain electrode includes a transparent electrode, and a metal bus electrode, which has a line width smaller than that of the transparent electrode and is formed at the end of one side of the transparent electrode. 
   The transparent electrode is mainly made of indium-tin-oxide (ITO), and is formed on the upper substrate  110 . The metal bus electrode is mainly made of a metal, such as chrome (Cr), and is formed on the transparent electrode. The metal bus electrode serves to reduce a voltage drop due to the transparent electrode having high resistance. An upper dielectric layer and a protection film are laminated on the upper substrate  110 , in which the scan electrode and the sustain electrode are formed parallel to each other. Wall charges generated upon plasma discharging are accumulated on the upper dielectric layer. The protective layer is adapted to prevent damage of the upper dielectric layer due to sputtering caused during plasma discharging, and improve an efficiency of secondary electron emission. As the protective layer, magnesium oxide (MgO) is generally used. 
   A lower dielectric layer and barrier ribs are formed on the lower substrate  118 , in which the address electrode is formed. The address electrode is formed in the direction in which the scan electrode and the sustain electrode intersect with each other. The barrier ribs are formed in a stripe or lattice form to prevent ultraviolet light and visible light generated by discharging from leaking toward adjacent discharge cells. The phosphor layer is excited with ultraviolet light generated during the plasma discharging to generate any one visible light of red, green and blue. 
   The upper substrate  110  and the lower substrate  118  are combined together by the sealant  140  applied around a perimeter edge region of the upper and lower substrates  110  and  118 . An inert mixed gas is injected into discharge spaces defined between the upper substrate  110  and the barrier ribs, and between the lower substrate  118  and the barrier ribs. The sealant  140  is initially applied at the perimeter edges of one of the upper substrate  110  and the lower substrate  118 , and combines the upper substrate  110  and the lower substrate  118  together. 
   The black layer  160  is formed at the rear of the upper substrate  110  using a non-conductive paste. More specifically, the black layer  160  is formed between the end of the valid display region A/A and the sealant  140  (from the valid display region A/A to the portion where the sealant  140  is coated). The black layer  160  defines the valid display region A/A of the panel, and also covers unnecessary and/or unsightly portions of the edge portions of the PDP module. 
   A front filter  130  is formed as a film-type filter on the upper substrate  110  of the PDP. The front filter  130  shields electromagnetic interference (EMI) and also prevents reflection of external light, as shown in  FIG. 8 . The film-type front filter  130  has the same size as the upper substrate  110  of the panel  100 , and includes an anti-reflection film, an optical characteristic film, an EMI shield film and a NIR shield film. Adhesive films are formed between the respective films of the film-type front filter  130 , respectively, to provide adhesion among the films. The film type front filter  130  further includes a ground unit  172  formed at an edge region of the anti-reflection film. 
   The anti-reflection film is formed on a surface of the film-type front filter  130  to prevent externally incident light from reflecting externally again. The anti-reflection film can be additionally formed at the rear of the film type front filter  130 . An optical characteristic film serves to lower transmittance of red (R) light and green (G) light among light incident from the panel, and to improve an optical characteristic of the PDP by increasing transmittance of blue (B) light. An EMI shield film shields EMI to prevent EMI, which is incident from the panel, from being discharged externally. A NIR shield film shields NIR incident from the panel. The NIR shield film prevents NIR, over a given reference level, from leaving the panel  100  and being discharged toward the outside so that signals, which are transmitted from a remote controller, etc. to the panel, can be transmitted without interference. The optical characteristic film and the NIR shield film can be formed as a single layer or multiple layers. 
   The ground unit  172  is electrically connected to a rear cover (not shown) of the panel through a filter support unit (not shown). In the PDP constructed above according to a first embodiment of the present invention, the black layer (formed on the film-type filter in the background art) is now formed in the upper substrate  110  of the panel  100 . Thus, only the ground unit  172  is formed in the film-type front filter  130 . Accordingly, in the PDP according to the first embodiment of the present invention, the area of the ground unit  172  formed in the edge region of the film-type front filter  130  is larger, as compared to the background art, and a contact resistance between the filter support unit and the ground unit  172  is thereby reduced. Moreover, in the PDP according to a first embodiment of the present invention, a space for forming the ground unit  172  on the film-type front filter is increased, as compared to the background art. Therefore, the assembly process is simplified and the process time to assembly the PDP is shortened, since it is easier to align the filter support unit with the ground unit  172 . 
   Referring to  FIGS. 9 and 10 , a PDP, according to a second embodiment of the present invention, will be described. A plasma display panel (POP), according to the second embodiment of the present invention, includes a plurality of discharge cells formed on a valid display region A/A of a panel  200 , a sealant  240  formed at the perimeter edges of an upper substrate  210  and a lower substrate  218 , for combining the upper substrate  210  and the lower substrate  218 , and a black layer  260  formed between the end of the valid display region A/A and the end of the upper substrate  210 . 
   Each of the plurality of the discharge cells includes a scan electrode and a sustain electrode (not shown), both of which are formed on the upper substrate  210 , and an address electrode (not shown) formed on the lower substrate  218 . Each of the scan electrode and the sustain electrode includes a transparent electrode, and a metal bus electrode, which has a line width smaller than that of the transparent electrode and is formed at the end of one side of the transparent electrode. 
   The transparent electrode is mainly made of indium-tin-oxide (ITO), and is formed on the upper substrate  210 . The metal bus electrode is mainly made of a metal, such as chrome (Cr), and is formed on the transparent electrode. The metal bus electrode serves to reduce a voltage drop due to the transparent electrode having a high resistance. An upper dielectric layer and a protection film are laminated on the upper substrate  210 , in which the scan electrode and the sustain electrode are formed parallel to each other. Wall charges generated upon plasma discharging are accumulated on the upper dielectric layer. The protective layer is adapted to prevent damage of the upper dielectric layer due to sputtering caused during plasma discharging, and improve an efficiency of secondary electron emission. Magnesium oxide (MgO) is generally used as the protective layer. 
   A lower dielectric layer and barrier ribs are formed on the lower substrate  218  in which the address electrode is formed. The address electrode is formed in the direction in which the scan electrode and the sustain electrode intersect with each other. The barrier ribs are formed in the stripe or lattice form to prevent ultraviolet and visible light generated by discharging from leaking toward adjacent discharge cells. The phosphor layer is excited with ultraviolet light generated during the plasma discharging to generate any one visible light of red, green and blue. 
   The upper substrate  210  and the lower substrate  218  are combined together by the sealant  240  formed in the edge region. An inert mixed gas is injected into discharge spaces defined between the upper substrate  210  and the barrier ribs, and between the lower substrate  218  and the barrier ribs. The sealant  240  is initially applied to the perimeter edges of one of the upper substrate  210  and the lower substrate  218 , and combines the upper substrate  210  and the lower substrate  218  together. 
   The black layer  260  is formed at the rear surface of the upper substrate  210  using nonconductive paste. More specifically, the black layer  260  is formed from the end of the valid display region A/A and the end of the upper substrate  210  (from the valid display region A/A to the portion where the sealant  240  is coated), thus covering the sealant  240 . The black layer  260  defines the valid display region A/A of the panel, and also covers unnecessary, unsightly edge portions of the PDP module. 
   A front filter  230 , being a film-type filter, is formed on the upper substrate  210  of the PDP. The front filter  230  shields electromagnetic interference (EMI) and also prevents reflection of external light, as shown in  FIG. 10 . The film-type front filter  230  has the same size as the upper substrate  210  of the panel  200 , and includes an anti-reflection film, an optical characteristic film, an EMI shield film and a NIR shield film. For a description of the anti-reflection film, the optical characteristic film, the EMI shield film and NIR shield film, which constitute the film type front filter  230 , reference can be made to the description of the PDP according to the first embodiment of the present invention. 
   A ground unit  272  is formed at the edge on the anti-reflection film of the film-type front filter  230 . The ground unit  272  is electrically connected to a rear cover (not shown) of the PDP through a filter support unit (not shown). 
   In the PDP, constructed according to the second embodiment of the present invention, the black layer (which is formed on the film-type filter in the background art) is now formed on the upper substrate  110  of the panel  200 . Thus, only the ground unit  272  is formed on the film-type front filter  230 . Accordingly, in the PDP according to the second embodiment of the present invention, the area of the ground unit  272  formed in the edge region of the film-type front filter  230  is larger, as compared to the background art, and a contact resistance between the filter support unit and the ground unit  272  is reduced. Moreover, in the PDP according to the second embodiment of the present invention, a space for forming the ground unit  272  is increased, as compared to the background art. Therefore, the assembly process is simplified and the assembly process time is shortened. 
   Referring to  FIG. 11 , a PDP, according to a third embodiment of the present invention, is illustrated. All components, except for black layers  360 , are the same as those of the PDP according to the first embodiment of the present invention shown in  FIGS. 7 and 8 . Therefore, in the PDP according to the third embodiment of the present invention, reference can be made to the description of the PDP according to the first embodiment of the present invention for a description of the components other than the black layers  360 . 
   The black layers  360  are formed parallel to each other at upper and lower edges (e.g. top and bottom edges) of the rear surface of the upper substrate using a non-conductive paste. More specifically, the black layers  360  are formed between the top and bottom of the valid display region A/A and the sealant  340  (between the ends of the valid display region A/A on the upper side and portions where the sealants  340  are coated). The black layers  360  define the valid display region A/A of the panel  300 , and also cover unnecessary, unsightly edge portions of the PDP module. 
   In the PDP constructed according to the third embodiment of the present invention, the area of the ground unit formed in the edge region of the film-type front filter is large, as compared to the background art, and a contact resistance between the filter support and the ground area is thus reduced. Furthermore, in the PDP according to the third embodiment of the present invention, a space for forming the ground unit is increased, as compared to the background art. Therefore, the assembly process is simplified and the assembly process time is shortened. 
   Referring to  FIG. 12 , a PDP, according to a fourth embodiment of the present invention, is illustrated. All components, except for black layers  460  are the same as those of the PDP according to the second embodiment of the present invention shown in  FIGS. 9 and 10 . Therefore, in the PDP according to the fourth embodiment of the present invention, reference can be made to the description of the PDP according to the second embodiment of the present invention for a description of the components, other than the black layers  460 . 
   The black layers  460  are formed parallel to each other at upper and lower edges (e.g. top and bottom edges) of the rear surface of the upper substrate using a non-conductive paste. More specifically, the black layers  460  are formed from the ends of the valid display region A/A to the ends of an upper substrate (from the valid display region A/A to portions where sealants  440  are coated), thereby covering the sealant  440 . The black layers  460  define the valid display region A/A of the panel  400 , and also cover unnecessary, unsightly edge and sealant portions of the PDP module. 
   In the PDP constructed according to the fourth embodiment of the present invention, the area of the ground unit formed in the edge region of the film-type front filter is large, as compared to the background art, and a contact resistance between the filter support and the ground unit is thus reduced. Furthermore, in the PDP according to the fourth embodiment of the present invention, a space for forming the ground unit on the film-type front filter is increased, as compared to the background art. Therefore, the assembly process is simplified and the assembly process time is shortened. 
   Referring to  FIG. 13 , a PDP, according to a fifth embodiment of the present invention, is illustrated. All components, except for black layers  560 , are the same as those of the PDP according to the first embodiment of the present invention shown in  FIGS. 7 and 8 . Therefore, in the PDP according to the fifth embodiment of the present invention, reference can be made to the description of the PDP according to the first embodiment of the present invention for a description of the components, other than the black layers  560 . 
   The black layers  560  are formed parallel to each other at right and left edges of the rear surface of the upper substrate using a non-conductive paste More specifically, the black layers  560  are formed between the right and left ends of the valid display region A/A and the sealant  640  (between the ends of the valid display region A/A on the on the right and left sides and portions where the sealants  540  are coated). The black layers  560  define the valid display region A/A of the panel  500 , and also cover unnecessary, unsightly edge portions of the PDP module. 
   In the PDP constructed according to the fifth embodiment of the present invention, the area of the ground unit formed in the edge region of the film-type front filter is large, as compared to the background art, and a contact resistance between the filter support and the ground unit is thus reduced. Furthermore, in the PDP according to the fifth embodiment of the present invention, a space for forming the ground unit on the film-type front filter is increased, as compared to the background art. Therefore, the assembly process is simplified and the assembly process time is shortened. 
   Referring to FIG- 14 , a PDP, according to a sixth embodiment of the present invention, is illustrated. All components, except for black layers  660 , are the same as those of the PDP according to the second embodiment of the present invention shown in  FIGS. 9 and 10 . Therefore, in the PDP according to the sixth embodiment of the present invention, reference can be made to the description of the PDP according to the second embodiment of the present invention for a description of the components, other than the black layers  660 . 
   The black layers  660  are formed parallel to each other at right and left edges of the rear surface of the upper substrate using a nonconductive paste. More specifically, the black layers  660  are formed from the ends of the valid display region A/A to the right and left ends of the upper substrate (from the valid display region A/A to portions where sealants  640  are coated), thereby covering the sealant  640 . The black layers  660  define the valid display region A/A of the panel  600 , and also cover unnecessary, unsightly edge portions of the PDP module. 
   In the PDP constructed according to the sixth embodiment of the present invention, the area of the ground unit formed in the edge region of the film-type front filter is large, as compared to the background art, and a contact resistance between the filter support and the ground unit is thus reduced. Furthermore, in the PDP according to the sixth embodiment of the present invention, a space for forming the ground unit on the film-type front filter is increased, as compared to the background art. Therefore, the assembly process is simplified and the assembly process time is shortened. 
   As described above, a PDP in accordance with an embodiment of the present invention includes a black layer formed on an upper substrate, for defining a valid display region of the panel and covering unnecessary edge portions of a POP module. The black layer has been illustrated as being formed on a rear surface of the upper substrate, facing to the lower substrate. However, the black layer could alternatively, or additionally, be formed on an upper surface of the upper substrate, facing to the front film-type filter. By the present invention, the area of a ground unit formed on an edge region of a film-type front filter can be increased in size, as compared to the background art, and a space for forming the ground unit on the film-type front filter can be increased, as compared to the background art. Accordingly, the present invention is advantageous in that the assembly process is simplified and the assembly process time is reduced. 
   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 spirit and 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.