Abstract:
A plasma display panel, including: a first substrate; a second substrate; barrier ribs partitioning a space between the first and second substrates to define discharge cells; address electrodes extending along a first direction to correspond to the discharge cells on a surface of the first substrate and covered with a first dielectric layer; first and second electrodes extending along a second direction crossing the first direction on a surface of the second substrate to define a discharge gap at centers of the discharge cells and covered with a second dielectric layer; and a guide portion that corresponds to at least a part of the discharge gap, wherein the second dielectric layer includes, a first dielectric layer section inside a space defined by the guide portion, and a second dielectric layer section on the first dielectric layer section, and wherein a first dielectric constant is smaller than a second dielectric constant.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2008-0115693, filed in the Korean Intellectual Property Office on Nov. 20, 2008, the entire content of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a plasma display panel. More particularly, the present invention relates to a plasma display panel that can reduce reactive power by reducing capacitance between display electrodes that perform surface discharge. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, power consumption of an AC-type plasma display panel (PDP) includes active power consumed when discharge is made and reactive power consumed when the discharge is not made. 
         [0006]    When AC voltage is applied to the PDP, the reactive power is consumed to charge electric charges generated depending on the capacitance. Reactive power consumption is determined depending on capacitance C of the PDP and voltage V applied to the PDP (P=CV 2 ). 
         [0007]    Primary elements constituting the capacitance of the PDP include a gap between the display electrodes that perform the surface discharge, a dielectric layer between the display electrodes and adjacent to an upper part of the display electrode, and a dielectric constant of a glass substrate. Accordingly, the capacitance needs to be reduced on the display electrode in order to reduce the reactive power. 
         [0008]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY OF THE INVENTION 
       [0009]    An aspect of an embodiment of the present invention is directed toward a plasma display panel having a decreased reactive power by reducing capacitance between display electrodes that perform surface discharge. 
         [0010]    An aspect of an embodiment of the present invention is also directed toward a plasma display panel having a reduced capacitance by forming a dielectric layer having a low dielectric constant between display electrodes that perform surface discharge. 
         [0011]    An aspect of an embodiment of the present invention is further directed toward a plasma display panel having an easily and accurately formed dielectric layer having a low dielectric constant between display electrodes that perform surface discharge. 
         [0012]    An exemplary embodiment of the present invention provides a plasma display panel that includes a first substrate; a second substrate facing the first substrate; a plurality of barrier ribs partitioning a space between the first substrate and the second substrate to define a plurality of discharge cells; a plurality of address electrodes on a surface of the first substrate facing the second substrate and is covered with a first dielectric layer, the address electrodes extending in a first direction to correspond to the discharge cells; a first electrode and a second electrode extending in a second direction crossing the first direction on a surface of the second substrate facing the first substrate to define a discharge gap corresponding at the centers of a corresponding one of the discharge cells and covered with a second dielectric layer; and a guide portion corresponding to at least a part of the discharge gap, wherein the second dielectric layer includes a first dielectric layer section within a space defined by the guide portion and a second dielectric layer section on the first dielectric layer section, and wherein the first dielectric layer section has a first dielectric constant and the second dielectric layer section has a second dielectric constant larger than the first dielectric constant. 
         [0013]    Each of the first electrodes and the second electrodes may include a bus electrode and the guide portion may be defined by the bus electrodes at both sides of the discharge gap and facing each other. 
         [0014]    The first electrode and the second electrode may include transparent electrodes between the surface of the second substrate and the bus electrodes, and the guide portion may be further defined by the transparent electrodes at both sides of the discharge gap and facing each other. 
         [0015]    The first dielectric layer section may be between the transparent electrodes defining the discharge gap and between the bus electrodes. 
         [0016]    A thickness of the first dielectric layer section extending toward the first substrate from the surface of the second substrate may be substantially identical to a sum of a thickness of each of the transparent electrodes and a thickness of each of the bus electrodes. 
         [0017]    The first dielectric layer section may extends in the second direction in the discharge gap between the first electrode and the second electrode. 
         [0018]    The second dielectric layer section may be on the first dielectric layer section, the bus electrodes, and the transparent electrodes. 
         [0019]    The bus electrodes may be a plurality of metallic lines. The metallic lines may include inner lines defining the discharge gap and outer lines at sides of the inner lines away from the discharge gap. 
         [0020]    The first dielectric layer section may extends in the second direction between the inner lines. 
         [0021]    A thickness of the first dielectric layer section extending toward the first substrate from the surface of the second substrate may be substantially identical to a thickness of each of the inner lines. 
         [0022]    The second dielectric layer section may be integrally formed on the surface of the second substrate between the inner lines and the outer lines, the first dielectric layer section, the inner lines, and the outer lines. 
         [0023]    The first electrode and the second electrode may include transparent electrodes on the surface of the second substrate and bus electrodes on the transparent electrodes, the second substrate has a groove corresponding to the discharge gap on the surface of the second substrate facing the first substrate, and the guide portion may be defined by the groove. 
         [0024]    The guide portion may be further defined by the transparent electrodes at both sides of the discharge gap and facing each other. 
         [0025]    The first dielectric layer section may be between the groove and the transparent electrodes. 
         [0026]    A thickness of the first dielectric layer section extending toward the first substrate from a surface of the groove of the second substrate may be substantially identical to a sum of a depth of the groove and a thickness of each of the transparent electrodes. 
         [0027]    The second dielectric layer section may be integrally formed on the first dielectric layer section, the transparent electrodes, and the bus electrodes. 
         [0028]    A thickness of the first dielectric layer section extending toward the first substrate in the groove of the second substrate may be substantially identical to a sum of a depth of the groove, a thickness of each of the transparent electrodes, and a thickness of a protruding portion that protrudes further than the thickness of each of the transparent electrodes. 
         [0029]    The thickness of the protruding portion may be substantially identical to a thickness of each of the bus electrodes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present invention, and, together with the description, serve to explain the principles of the present invention. 
           [0031]      FIG. 1  is an exploded perspective schematic view of a plasma display panel according to a first exemplary embodiment of the present invention. 
           [0032]      FIG. 2  is a cross-sectional schematic view taken along line II-II of  FIG. 1 . 
           [0033]      FIG. 3  is plan schematic view of a disposition relationship of a display electrode, a first dielectric layer section, and a discharge cell. 
           [0034]      FIG. 4  is a cross-sectional schematic view of a plasma display panel (PDP) according to a second exemplary embodiment of the present invention. 
           [0035]      FIG. 5  is a cross-sectional schematic view of a plasma display panel (PDP) according to a third exemplary embodiment of the present invention. 
           [0036]      FIG. 6  is a cross-sectional schematic view of a plasma display panel (PDP) according to a fourth exemplary embodiment of the present invention. 
       
    
    
     DESCRIPTION OF REFERENCE NUMERALS INDICATING CERTAIN ELEMENTS IN THE DRAWINGS 
       [0000]    
       
         
           
               100 ,  200 : Plasma display panel 
               10 : First substrate (Rear substrate) 
               20 : Second substrate (Front substrate) 
               11 : Address electrode 
               13 : First dielectric layer 
               16 : Barrier rib 
               16   a ,  16   b : First and second barrier rib members 
               17 : Discharge cell 
               19 : Phosphor layer 
               31 ,  41 ,  51 : First electrode (Sustain electrode) 
               32 ,  42 ,  52 : Second electrode (Scan electrode) 
               31   a ,  41   a ,  51   a    32   a ,  42   a ,  52   a : Transparent electrode 
               31   b ,  41   b ,  51   b ,  32   b ,  42   b ,  52   b : Bus electrode 
               21 ,  51 ,  61 ,  71 : Second dielectric layer 
               211 ,  511 ,  611 ,  711 : First dielectric layer section 
               711   a : Protruding portion 
               212 ,  512 ,  612 ,  712 : Second dielectric layer section 
               23 : Protective layer 
               41   a ,  42   a : Inner line 
               41   b ,  42   b : Outer line 
             G: Groove 
             Tg: Depth 
             T, T 2 , T 3 , T 4 , Ta, Tb: Thickness 
           
         
       
     
       DETAILED DESCRIPTION 
       [0060]    The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
         [0061]      FIG. 1  is an exploded perspective schematic view of a plasma display panel according to a first exemplary embodiment of the present invention.  FIG. 2  is a cross-sectional schematic view taken along line II-II of  FIG. 1 . 
         [0062]    Referring to  FIGS. 1 and 2 , the plasma display panel  100  according to the first exemplary embodiment includes a first substrate (hereinafter, “rear substrate”)  10  and a second substrate (hereinafter, “front substrate”)  20  that are attached to face each other with a space therebetween, and a barrier rib  16  disposed between the front and rear substrates  10  and  20 . 
         [0063]    The barrier rib  30  partitions a space provided between the rear substrate  10  and the front substrate  20  to form a plurality of discharge cells  17 . Phosphor layers  19  are formed in the discharge cells  17  and are filled with discharge gas (i.e., mixed gas containing neon (Ne), xenon (Xe), etc.). 
         [0064]    The discharge gas generates vacuum ultraviolet rays by gas discharge. Here, the phosphor layers  19  are excited by the vacuum ultraviolet rays, and then stabilized to emit visible light of red (R), green (G), and/or blue (B). To cause the gas discharge, address electrodes  11  and display electrodes are disposed in the discharge cells  17 . 
         [0065]    In one example, the address electrodes  11  extend along the surface of the rear substrate  10  facing the front substrate  20  in a first direction (hereinafter, referred to as “y-axis direction”) and correspond to the discharge cells  17  adjacent in the y-axis direction. The plural address electrodes  11  are disposed parallel to the discharge cells  17  adjacent in a second direction (hereinafter, referred to as “x-axis direction”) crossing the y-axis direction. 
         [0066]    A first dielectric layer  13  covers the surface of the rear substrate  10  and the address electrodes  11 . The first dielectric layer  13  protects the address electrodes  11  from the gas discharge by blocking (or preventing) positive ions or electrons from colliding directly with the address electrodes  11  in discharge. Further, the first dielectric layer  13  provides forming and accumulation spaces of wall charges to enable address discharge by low voltage. 
         [0067]    The address electrodes  11  are disposed on the rear substrate  10  so as not to interrupt penetration of the visible light through the front substrate  20 . Therefore, the address electrodes  11  may be formed of an opaque electrode, that is, a metal electrode such as silver (Ag) having high electrical conductivity. 
         [0068]    The barrier rib  16  is disposed on the first dielectric layer  13  and partition a space between the first dielectric layer  13  and the front substrate  20 . For example, the barrier rib  16  includes first barrier rib members  16   a  that extend along the y-axis direction and second barrier rib members  16   b  that are disposed to be spaced apart from each other between the first barrier rib members  16   a  in the y-axis direction and extend in the x-axis direction. 
         [0069]    That is, the first barrier rib members  16   a  partition the discharge cells  17  adjacent in the x-axis direction and the second barrier rib members  16   b  partition the discharge cells  17  adjacent in the y-axis direction. Therefore, in a quadrangular barrier rib structure, the discharge cells  17  are arranged in a matrix. 
         [0070]    The phosphor layers  19  may be formed by applying a phosphor paste onto side surfaces of the first barrier rib members  16   a  and the second barrier rib members  16   b  and the surface of the first dielectric layer  13  defined (or surrounded) by the first barrier rib members  16   a  and the second barrier rib members  16   b , and drying and sintering the applied phosphor paste. 
         [0071]    The phosphor layers  19  are formed of phosphors that generate visible light of the same color in the discharge cells  17  in the y-axis direction. The phosphor layers  19  are formed of phosphors that generate visible light of red (R), green (G), and blue (B) in the discharge cells  17  in the x-axis direction. That is, the phosphor layers  19  that are formed of the phosphors generating the visible light of red (R), the phosphors generating the visible light of green (G), and the phosphors generating the visible light of blue (B) are repetitively and respectively disposed in the x-axis direction. 
         [0072]    The display electrodes include a first electrode (hereinafter, referred to as “sustain electrode”)  31  and a second electrode (hereinafter, referred to as “scan electrode”)  32  formed on the surface of the front substrate  20  facing the rear substrate  10 , which correspond to the discharge cells  17 . The sustain electrode  31  and the scan electrode  32  form a surface discharge structure in correspondence with each of the discharge cells  17 . 
         [0073]    The sustain electrode  31  and the scan electrode  32  extend in the x-axis direction crossing the address electrode  11  and are parallel to each other. A discharge gap DG is formed between the sustain electrode  31  and the scan electrode  32 . The discharge gap DG corresponds to the center of the discharge cell  17 . 
         [0074]    For example, the sustain electrode  31  and the scan electrode  32  include the discharge gap DG, transparent electrodes  31   a  and  32   a  that form a surface discharge region, and bus electrodes  31   b  and  32   b  that apply voltage signals to the transparent electrodes  31   a  and  32   a.    
         [0075]    The transparent electrodes  31   a  and  32   a  are made of a transparent material (i.e., indium tin oxide (ITO)) to secure an aperture ratio of the discharge cell  17 . Further, the bus electrodes  31   b  and  32   b  are made of a metallic material having high electrical conductivity on the transparent electrodes  31   a  and  32   a  so as to apply the voltage signals to the transparent electrodes  31   a  and  32   a.    
         [0076]    The bus electrodes  31   b  and  32   b  are formed at both sides of the discharge gap DG on the transparent electrodes  31   a  and  32   a  and form the discharge gap DG together with the transparent electrodes  31   a  and  32   a . That is, the discharge gap DG is defined (or established) by the transparent electrodes  31   a  and  32   a  on the surface of the front substrate  20  and by the bus electrodes  31   b  and  32   b  on the transparent electrodes  31   a  and  32   a , in a z-axis direction. 
         [0077]    That is, the metallic bus electrodes  31   b  and  32   b  are disposed at about the center of the discharge cell  17  to thereby effectively reduce or prevent voltage drop around the discharge gap DG where a strong electric field is formed at the time of applying the voltage. 
         [0078]    A second dielectric layer  21  covers the surface of the front substrate  20 , the sustain electrode  31 , and the scan electrode  32 . The second dielectric layer  21  protects the sustain electrode  31  and the scan electrode  32  from the gas discharge by protecting (or preventing) the positive ions or electrons from colliding directly with the sustain electrode  31  and the scan electrode  32  in discharge. Further, the second dielectric layer  21  provides the forming and accumulation spaces of the wall charges to enable the sustain discharge by the low voltage. 
         [0079]    The second dielectric layer  21  includes a first dielectric layer section  211  that is formed between the bus electrodes  31   b  and  32   b  and a second dielectric layer section  212  that is formed at both sides of the first dielectric layer section  211  and on the first dielectric layer section  211 . In the case in which the sustain electrode  31  and the scan electrode  32  include the transparent electrodes  31   a  and  32   a , the first dielectric layer section  211  may be formed between the transparent electrodes  31   a  and  32   a . That is, the first dielectric layer  211  is formed in the discharge gap DG of the sustain electrode  31  and the scan electrode  32 . 
         [0080]    The first dielectric layer section  211  has a first dielectric constant and the second dielectric layer section  212  has a second dielectric constant. The first dielectric constant is smaller than the second dielectric constant. Therefore, the first dielectric layer section  211  has a dielectric constant in the discharge gap DG lower than a dielectric constant in parts other than the discharge gap DG. 
         [0081]    That is, the first dielectric layer section  211  reduces capacitance between the sustain electrode  31  and the scan electrode  32  by lowering the dielectric constant around the discharge gap DG where the electric field is concentrated at the time of applying the voltage in which the discharge does not occur while driving the plasma display panel  100 . As the capacitance is reduced, the reactive power may be reduced. 
         [0082]    The bus electrodes  31   b  and  32   b  are disposed at both sides of the discharge gap DG. Therefore, when the first dielectric layer section  211  is formed inside of the discharge gap DG, the bus electrodes  31   b  and  32   b  guide application and injection of the dielectric paste. That is, the bus electrodes  31   b  and  32   b  reduce or prevent the dielectric paste from being applied and injected outside of the discharge gap DG. Accordingly, the bus electrodes  31   b  and  32   b  facilitate formation of the first dielectric layer section  211  having a low dielectric constant therebetween and enable precise formation of the first dielectric layer section  211 . 
         [0083]    That is, since the bus electrodes  31   b  and  32   b  are disposed in correspondence with the discharge gap DG, the bus electrodes  31   b  and  32   b  form a guide portion for forming the first dielectric layer section  211  at both sides of the discharge gap DG. Further, the transparent electrodes  31   a  and  32   a  corresponding to both sides of the discharge gap DG also form the guide portion for forming the first dielectric layer section  211 . 
         [0084]    Referring to  FIG. 2 , a thickness T of the first dielectric layer section  211  is established (or extending) toward the rear substrate  10  from the surface of the front substrate  20  and is about (or equal to) a thickness T=Ta+Tb acquired by adding a thickness Ta of the transparent electrodes  31   a  and  32   a  and a thickness Tb of the bus electrodes  31   b  and  32   b  that are established in the same direction as the thickness T. 
         [0085]      FIG. 3  is plan schematic view of a disposition relationship of a display electrode, a first dielectric layer section, and a discharge cell. Referring to  FIG. 3 , the first dielectric layer section  211  extends in the x-axis direction in the discharge gap DG between a sustain electrode  31  and a scan electrode  32 . 
         [0086]    As the transparent electrodes  31   a  and  32   a  and the bus electrodes  31   b  and  32   b  extend in the x-axis direction and the first dielectric layer section  211  extend in the discharge gap DG, the dielectric paste can be continuously applied by a dispenser, for example. Further, the capacitance is evenly reduced within an entire x-axis direction range of the corresponding discharge cell  17 . The first dielectric layer section  211  may be formed by methods such as screen printing, offset printing, inkjet printing, a dispenser, etc. 
         [0087]    The transparent electrode may be formed by a protruding electrode that protrudes toward the bus electrode to correspond to each discharge cell. In this case, the first dielectric layer section may extend in the x-axis direction or may be formed at the center of the discharge cell independently corresponding to each of the discharge cells. 
         [0088]    Referring back to  FIG. 2 , the second dielectric layer section  212  covers the surfaces of the first dielectric layer section  211 , the sustain electrode  31 , the scan electrode  32 , and the front substrate  20  to form a flat plane throughout. That is, the second dielectric layer section  212  covers the transparent electrodes  31   a  and  32   a  and the bus electrodes  31   b  and  32   b.    
         [0089]    A protective layer  23  covers the second dielectric layer section  212 . For example, the protective layer  23  is made of transparent MgO that protects the second dielectric layer section  212  in gas discharge and increases a secondary electron emission coefficient. 
         [0090]    Reset discharge occurs by a reset pulse applied to the scan electrode  32  during a reset period while driving the plasma display panel  100 . Address discharge occurs by a scan pulse applied to the scan electrode  32  and an address pulse applied to the address electrode  11  during an addressing period subsequent to the reset period. Thereafter, sustain discharge occurs by a sustain pulse applied to the sustain electrode  31  and the scan electrode  32  during a sustain period. 
         [0091]    The sustain electrode  31  and the scan electrode  32  serve as electrodes that apply the sustain pulse required for the sustain discharge, the scan electrode  32  serves as an electrode that applies the reset pulse and the scan pulse, and the address electrode  11  serves as an electrode that applies the address pulse. The sustain electrode  31 , the scan electrode  32 , and the address electrode  11  may play different roles depending on a waveform of voltage applied to the electrodes. Therefore, the electrodes may play roles different from the above roles. 
         [0092]    The plasma display panel  100  selects a discharge cell  17  to be turned on by the address discharge that occurs by an interaction between the address electrode  11  and the scan electrode  32 , and drives the selected discharge cell  17  by the sustain discharge that occurs by an interaction between the sustain electrode  31  and the scan electrode  32  to create or realize an image. 
         [0093]      FIG. 4  is a cross-sectional schematic view of a plasma display panel (PDP) according to a second exemplary embodiment of the present invention. Referring to  FIG. 4 , in the plasma display panel  200  of the second exemplary embodiment, the sustain electrode  41  and the scan electrode  42  may be formed of a metallic bus electrode without the transparent electrodes  31   a  and  32   a , as compared to the first exemplary embodiment. 
         [0094]    The bus electrode may be formed of a plurality of metallic lines to have a front aperture ratio of the discharge cell  17  so as to transmit the visible light generated from the discharge cell  17  to the front. For example, the bus electrode, that is, the metallic lines, include inner lines  41   a  and  42   a  that establish the discharge gap DG and outer lines  41   b  and  42   b  that are formed at sides of the inner lines  41   a  and  42   a  away from the discharge gap DG. 
         [0095]    A first dielectric layer section  511  has a first dielectric constant and is formed in the discharge gap DG, that is, between the inner lines  41   a  and  42   a . While the inner lines  41   a  and  42   a  face each other and form the discharge gap DG, the inner lines  41   a  and  42   a  guide the application and injection of the dielectric paste at the time of forming the first dielectric layer section  511 . 
         [0096]    In the first exemplary embodiment, the transparent electrodes  31   a  and  32   a  and the bus electrodes  31   b  and  32   b  form a guide portion, while in the second exemplary embodiment, the inner lines  41   a  and  42   a  constituting the bus electrode form the guide portion. 
         [0097]    A second dielectric layer section  512  has a second dielectric constant higher than the first dielectric constant. The second dielectric layer section  512  is formed on each of the surface of the front substrate  20  between the inner lines  41   a  and  42   a  and the outer lines  41   b  and  42   b , the first dielectric layer section  511 , the inner lines  41   a  and  42   a , and the outer lines  41   b  and  42   b.    
         [0098]    Referring to  FIG. 4 , a thickness T 2  of the first dielectric layer section  511  is established (or extending) toward the rear substrate  10  from the surface of the front substrate  20  and is about (or equal to) a thickness Tb of the inner lines  41   a  and  42   a , which is established in the same direction as the thickness T 2  (T 2 =Tb). 
         [0099]    The first dielectric layer section  511  reduces capacitance between the sustain electrode  41  and the scan electrode  42 , that is, between the inner lines  41   a  and  42   a , by lowering the dielectric constant around the discharge gap DG where the electric field is concentrated at the time of applying the voltage in which the discharge does not occur while driving the plasma display panel  200 . As the capacitance is reduced, the reactive power may be reduced. 
         [0100]      FIG. 5  is a cross-sectional schematic view of a plasma display panel (PDP) according to a third exemplary embodiment of the present invention. Referring to  FIG. 5 , in the plasma display panel  300  of the third exemplary embodiment, the guide portion is formed, as a groove G, on the surface of the front substrate  20  facing the rear substrate  10  to correspond to the discharge gap DG. 
         [0101]    In a sustain electrode  51  and a scan electrode  52 , transparent electrodes  51   a  and  52   a  form the discharge gap DG of the surface discharge and bus electrodes  51   b  and  52   b  are formed on the transparent electrodes  51   a  and  52   a  at a position away from the discharge gap DG. 
         [0102]    Therefore, the guide portion is further formed of the transparent electrodes  51   a  and  52   a  that form both sides of the discharge gap DG in addition to the groove G. That is, the guide portion is established by a space of the groove G and a space between the transparent electrodes  51   a  and  52   a.    
         [0103]    In a second dielectric layer  61 , a first dielectric layer section  611  is formed between the groove G and the transparent electrodes  51   a  and  52   a ; and a second dielectric layer section  612  is integrally formed on the first dielectric layer section  611 , the transparent electrodes  51   a  and  52   a , and the bus electrodes  51   b  and  52   b.    
         [0104]    A thickness T 3  of the first dielectric layer section  611  is established (or extending) toward the rear substrate  10  from a surface of the groove G of the front substrate  20  and is about (or equal to) a sum of a depth Tg of the groove G and a thickness Ta of the transparent electrodes  51   a  and  52   a  that are established in the same direction as the thickness T 3  (T 3 =Tg+Ta). 
         [0105]      FIG. 6  is a cross-sectional view of a plasma display panel (PDP) according to a fourth exemplary embodiment of the present invention. Referring to  FIG. 6 , in the plasma display panel  400  of the fourth exemplary embodiment, a thickness T 4  of a first dielectric layer section  711  is larger than a thickness T 3  of the first dielectric layer section  611  in the third exemplary embodiment. 
         [0106]    A thickness T 4  of the first dielectric layer section  711  is established toward the rear substrate  10  from a surface of the groove G of the front substrate  20  and is about (or equal to) a sum of a depth Tg of the groove G, a thickness Ta of the transparent electrodes  51   a  and  52   a , and a thickness Tp of a protruding portion  711   a  that protrudes further than the thickness Ta of the transparent electrodes  51   a  and  52   a  that are established in the same direction as the thickness T 4  (T 4 =Tg+Ta+Tp). Further, the thickness Tp of the protruding portion  711   a  may be about (or equal to) a thickness Tb of the bus electrodes  51   b  and  52   b  (Tp=Tb). 
         [0107]    The second to fourth exemplary embodiments exemplify various constituent members that have the similar or same effect as the first exemplar embodiment. 
         [0108]    According to an exemplary embodiment of the present invention, a dielectric layer of a front substrate is formed by a first dielectric layer section having a comparatively low dielectric constant and a second dielectric layer section having a comparatively high dielectric constant, and the first dielectric layer section having the low dielectric constant is formed in a space of a guide portion (i.e., bus electrodes, transparent electrodes, and/or a groove) that corresponds to a discharge gap, thereby reducing capacitance. Since the capacitance is reduced in the discharge gap or the guide portion, reactive power is reduced. 
         [0109]    The guide portion, that is, the bus electrodes and/or the transparent electrodes that are formed at both sides of the discharge gap, and the groove serve as a guide for an applied dielectric paste at the time of forming the first dielectric layer section, such that the first dielectric layer section can be formed accurately and easily. 
         [0110]    While this invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof.